当前位置：文档库 › Bioremediation of diesel-contaminated soil by heated and humidified biopile system in cold climates

Bioremediation of diesel-contaminated soil by heated and humidified biopile system in cold climates

Bioremediation of diesel-contaminated soil by heated and humidi ?ed biopile system in cold climates

David Sanscartier ?,Barbara Zeeb,Iris Koch,Ken Reimer 1

Environmental Sciences Group,Royal Military College of Canada,Canada

a b s t r a c t

a r t i c l e i n f o Article history:

Received 4September 2007Accepted 24July 2008Keywords:

Bioremediation Hydrocarbons

Arctic environments Aeration Heating

Humidi ?cation

Bioremediation is a proven and widely accepted technology for the remediation of soil contaminated with various mixtures of petroleum hydrocarbons (PHC)in temperate climates but its application in cold climates has received far less attention.Low ambient temperature is one of the main factors limiting microbial degradation of the organic contaminants in such locations.Heating the soil should therefore enhance bioremediation as laboratory studies have shown increased biodegradation rates in Arctic soils with increasing soil temperature.

A biopile is one of the many bioremediation techniques to treat hydrocarbon-contaminated soil where the soil is piled over an air distribution system and aerated.The air distribution system can also be used to provide heat to the soil in order to optimize soil temperature when conditions are limiting.However,heating the soil by forced air may cause excessive drying of the soil which may inhibit microbial activity and promote volatilization of the contaminants rather than their biodegradation.During treatment of hydrocarbon contaminated soils in a biopile system,biodegradation is preferred over volatilization and should be optimized.Few ?eld-scale studies have tested the use of heated biopile systems in cold climates.This paper examines the effect of humidifying the air for the treatment of PHC-contaminated soil by an aerated/heated biopile system.Three biopiles were constructed with soil freshly contaminated with diesel fuel (initial total petroleum hydrocarbon concentration,[TPH],~11,000mg/kg dry weight)and operated for 10months in Kingston,ON,Canada.One biopile was heated with an aerating/heating system previously tested in the Arctic.A second biopile was also aerated and heated but received water by humidifying the air prior to entering the soil pile.A third biopile was passively aerated by pipes protruding from the soil pile.TPH,available nutrients content,and pH were monitored by periodic collection and analysis of soil samples.Volatilization of hydrocarbon compounds was measured by trapping them on activated charcoal.Temperature and moisture were monitored continuously with a datalogger.Hydrocarbon concentrations in soil and charcoal samples were measured by solvent extraction followed by gas chromatography ?ame ionization detection (GC/FID)analysis.

Signi ?cant TPH reduction was observed in all systems.TPH reduction followed ?rst-order kinetics for the ?rst two-third of the treatment.The humidi ?ed system maintained optimal soil moisture content and produced signi ?cantly lower ?nal TPH than the other two treatments (~300mg/kg dry weight).Findings suggest that humidifying the air enhanced biodegradation and minimized volatilization.The removal of hydrocarbons of different carbon chain lengths was investigated by GC/FID analysis.Three hydrocarbon fractions were de ?ned (b nC11,nC11?nC15,N nC15)based on equivalent straight-chain alkane ranges.Results from this analysis showed that all fractions were removed during treatment,but the overall data suggest that biodegradation was dominant for the highest molecular weight fraction.

1.Introduction

Fuel spills result in hydrocarbon contamination on a global scale.In Canada,approximately 60%of contaminated sites involve petroleum hydrocarbon (PHC)contamination,including sites in cold climates and

the Arctic,which may impair the quality and uses of land and water (CCME 2000).Despite improved handling practices,spills are still frequent in the Arctic where re ?ned hydrocarbons,mainly diesel,are widely used for transportation,power generation and heating.In addition,numerous historic spills still remain to be addressed in these areas.Therefore cost effective and environmentally-sound soil remediation technologies are required.

Bioremediation is now a widely accepted solution for the treatment of PHC-contaminated soils in temperate climates (Dobson et al.,2004)and is increasingly viewed as an appropriate clean-up

Cold Regions Science and Technology 55(2009)167–

173

?Corresponding author.Fax:+16135416596.

E-mail addresses:david.sanscartier@rmc.ca (D.Sanscartier),reimer-k@rmc.ca (K.Reimer).1

Fax:+16135416596.

10.1016/j.coldregions.2008.07.004

Contents lists available at ScienceDirect

Cold Regions Science and Technology

j o u r n a l h o m e p a g e :w ww.e l s ev i e r.c o m /l o c a t e /c o l d re g i o n s

option for this type of contamination in cold climates(Aislabie et al., 2006).Its practical application in cold regions has received far less attention than in temperate https://www.wendangku.net/doc/4917796715.html,boratory and?eld-scale studies have shown the potential of this technology for the treatment of PHC-contaminated soil in cold temperature(Filler et al.,2001;Reimer et al., 2003;Aislabie et al.,2006;Schiewer and Niemeyer,2006).Soil nutrient content and low temperature are two of the main factors limiting the rate and the extent of hydrocarbon biodegradation.

Biodegradation is thought to be the main PHC removal process during bioremediation but volatilization can also play an important role(Margesin et al.,2000;Riffaldi et al.,2006).The release of volatile organic compounds(VOCs)to the atmosphere can contribute to reduced air quality(vanLoon and Duffy,2000);thus it should be minimized during soil remediation.Consequently some treatment systems include?lters to control air emissions(EC1993).

Landfarms and biopiles are two approaches that can be used to treat PHC-contaminated soil on-site.In landfarming,soil is spread over large areas,and can be amended with water,fertilizers,and surfactants.The soil is then tilled periodically to promote volatiliza-tion and biodegradation of the contaminants.It is currently used at numerous sites in the Arctic.For example,McCarthy et al.(2004) remediated3,600m3of PHC-contaminated soil from~1,400to ~430mg/kg in55days in Alaska with this technique.

In a biopile system,soil is amended and piled over a piping system through which air is delivered to the soil.Biopiles require less area than landfarms for treating the same volume of soil but require greater engineering and are relatively more expensive to build and operate than landfarms.Aeration can be forced or passive.Air pumps generally provide a better distribution of the air in the pile but require power,not always available in remote locations.A wind-powered biopile system was used to treat~15,000m3of PHC-contaminated soil at Savitok Point,North West Territories,Canada(ESG,2001). Concentrations were reduced from~7000to800mg/kg over a two-year period.Northern sites experience warm temperature for short period during the summer.A heating system can be incorporated into a biopile design to increase soil temperature and extend treatment season,thereby shortening remediation time.Increased temperature enhances microbial activity and contaminants availability(Aislabie et al.,2006).These characteristics can be important advantages of biopiles over landfarms at Arctic sites when time,space,property boundaries,and rough terrain can be constraints.At some Arctic remote military stations,where PHC contamination is often present, electricity may be produced in excess of usage and thus be available for heating the soil in a biopile system to speed up remediation (Cameron,2007).

Few studies have tested the use of heated biopiles to treat PHC-contaminated soil in the Arctic(Filler et al.,2001;Reimer et al.,2003). Reimer et al.(2003)tested a heated biopile system in the Canadian Arctic.In this system,the air was heated prior to being injected in the soil.The soil temperature was maintained at~15°C despite daily temperature as low as?42°C.Soil PHC concentrations were reduced by up to~60%from initial concentrations of~5000mg/kg. Alternatives to this system include heating cables and blankets(Filler et al.,2001).A major advantage of heating the injected air is that it delivers air and heat to the soil in one step,thereby simplifying design. However the aerated/heated system caused excessive drying of the soil that may have inhibited microbial activity and promoted volatilization of the contaminants(Reimer et al.,2003).

In the present study,we investigated the effect of humidifying the air on the treatment of PHC-contaminated soil by the aerated/heated biopile system.Field-scale biopiles were constructed with soil freshly contaminated with diesel fuel and operated at different aeration/heating regimes for10months in Kingston,ON,Canada.The test was conducted partly during the winter to test the equipment in cold conditions (average temperature in the winter of?6°C).The contribution of volatilization on the removal of PHCs was also investigated.2.Materials and methods

2.1.Biopile design

Three4m3biopiles were built at Canadian Forces Base(CFB) Kingston,Kingston,ON.Two piles were mechanically aerated and heated.For one of the two heated biopiles,air was humidi?ed prior to entering the soil.The third biopile was not heated but was passively aerated by slotted pipes protruding from the soil pile.These pipes were laid out in the direction of prevailing wind.Throughout the paper,the three biopiles will be referred to as heated biopile/system for the actively aerated and heated biopile;humidi?ed biopile/system for the actively aerated,heated and humidi?ed biopile;and passive biopile/system for the passively aerated biopile.Treatment was initiated on Nov22,04,and terminated on Sept14,05.

Nine cubic meters of clayey soil contaminated with heating oil was excavated from CFB Kingston.Individual biopiles were constructed by spreading~3m3of the soil on a tarpaulin.Bulking agents(~0.4m3of vermiculite,~0.4m3of sand,and~0.4m3of3/4″clean gravel)were mixed-in to improve soil porosity.The initial characteristics of the resulting soil mixture are presented in Table1.The following amend-ments were spread on the soil mixture:i)an anionic biodegradable synthetic surfactant(BioSolve?,Westford Chemical Corporation, Westford,ME)solution(20L of1.5%solution);ii)agricultural fertilizers (urea—(NH2)2CO and diammonium phosphate—(NH4)2HPO4)to obtain a C:N:P of100:7.5:0.5;iii)75L of commercial diesel fuel;and iv) water to adjust soil moisture to60%water holding capacity.The soil was then thoroughly homogenized with a rototiller.Biosolve?is manufac-tured as a bioremediation-enhancing agent and has shown to stimulate bioremediation in Arctic soil(Reimer et al.,2003).Fertilizers were added as the application of nutrients has shown to enhance bioremediation (Aislabie et al.,2006;Schiewer and Niemeyer,2006).The effects of amendments on bioremediation were not investigated in this study.The soil mixture was piled over aeration pipes and a thin layer(5cm)of clean ?ne sand in a containment area,consisting of a lined and bermed?at area.An exhaust was installed on top of the pile.The pile was then covered by an insulating blanket(Polyair?,Toronto,ON)that was sealed to a similar blanket laid underneath the clean sand to provide an enclosed system and reduce heat losses.Fig.1presents a simpli?ed diagram of a system.All biopiles were constructed in the same manner; each in separate containment area.

Five thermocouples(105T,Campbell Scienti?c,Edmonton,AB)and three gypsum soil-moisture blocks(223,Campbell Scienti?c)were inserted in each biopile to measure soil temperature and soil water potential.Hourly average measurements were recorded by the datalogger(CR23X,Campbell Scienti?c).Outdoor air temperatures were obtained from Environment Canada climate archive(EC,2005). Soil–gas oxygen levels were measured periodically with a gas portable analyzer(TMX-410,Industrial Scienti?c,Oakdale,PA)from three sampling probes.Sensors and probes locations are shown in Fig.1.

Table1

Characteristics of the soil mixture prior to the application of surfactant,fertilizers and diesel

Parameter(unit)Value

Particle size distribution(%)

Gravel(N2mm) 4.6 Coarse sand(2–0.5mm)47.6 Medium sand(0.5–0.25mm)16.3 Fine sand(0.25–0.075mm)16.6 Silt and clay(b0.075mm)14.9 TPH(mg/kg dw)1000 Total organic carbon(%) 1.1 Ammonia(mg/kg dw)ND a Nitrite+nitrate(mg/kg dw)ND a Orthophosphates(mg/kg dw)0.6

a ND=below detection limit(2mg/kg dw).

168 D.Sanscartier et al./Cold Regions Science and Technology55(2009)167–173

Aeration was provided by a regenerative blower (EG&G Rotron,Kent,OH).Heating was carried out with a 2kW heating element (Watlow,St.Louis,MO)connected to the outlet of the blower.The air was delivered to the soil in 2″ABS piping and 4″slotted ?exible plastic piping covered by a membrane.Air ?ow to the heated and the humidi ?ed biopiles was controlled by valves installed after the heater and adjusted manually periodically.Air ?ow was initially set to ~70L/min,increased to ~700L/min during the winter and decreased to ~210L/min the following spring.

Humidi ?cation was carried out by injecting a water mist in the air stream after the heater.The mist was produced by a fuel injection nozzle connected to tap water.Before injection,the water was ?ltered with a 30μm ?lter and heated to ~50°C.The humidifying system was installed in a temperature-controlled box.Relative humidity of the air stream was measured periodically with a handheld thermo-hygro-meter (Fisher Scienti ?c,Ottawa,ON).2.2.Sampling,analysis and monitoring

2.2.1.Soil

Soil sampling of the biopiles was conducted six times (Nov.22,04;Dec.21,04;Jan.21,05;Mar.15,05;May 05,05;and Sept.14,05).At each sampling event,10samples (?ve at surface [0–10cm]and ?ve at depth [60–80cm])were collected from each biopile.Samples could not be collected from the passive pile in Jan and Mar because it was frozen.At the end of the experiment,three samples were collected in the clean sand layers and from outside the containment areas to assess leaching.Surface soil samples were collected with reusable stainless steel scoop and depth samples with an auger.Samples were placed in:i)125mL amber jars with Te ?on lined lids and stored at ?20°C (for PHC and pH analysis);and ii)into Whirl-Paks ?stored at 7°C (for nutrients analysis).

Soil PHC concentrations were determined as Total Petroleum Hydrocarbons (TPH)with data analysis allowing for the identi ?cation of PHC fractions equivalent to a carbon scan (C-Scan)standard.Hexane extraction (U.S.EPA,1996)of an aliquot of soil was followed by analysis of the extract by gas chromatography /?ame ionization detection (GC/FID)(U.S.EPA,2000).A TPH standard was prepared with commercial diesel fuel.A C-Scan standard was prepared with straight-chain alkanes (nC10,nC12,…,nC28)(Sigma-Aldrich Canada Ltd,Oakville,ON).For data analysis and reporting,three C-Scan fractions were de ?ned as follows:C-Scan fraction 1(CF1):b nC11,C-Scan fraction 2(CF2):nC11–nC15,and C-Scan fraction 3(CF3):N nC15.The fraction data provide more information than TPH alone,and are of great use to assess the mechanisms involved in the removal of PHC mixtures such as diesel from soil and to properly evaluate risks associated with residual PHCs in the remediated soil.Soil moisture content was measured gravimetrically by weighing ~10g of wet soil,drying overnight at 105°C and weighing it again.Data were reported as TPH and by C-Scan fractions in mg/kg of soil (dry weight —dw).

Soil pH was carried out with ~10g of wet soil mixed with 30ml of distilled water.The slurry was left undisturbed for 2h to allow settling of soil and pH of the solution was taken.

In this study the expression “available nutrients ”refers to the concentration of available nitrogen (N)(i.e.ammonia (NH 3),and

nitrate and nitrite (NO 3?+NO 2?)),and orthophosphates (PO 43?

).NH 3and

NO 3?+NO 2?

(reported as N)were determined by extracting an aliquot of soil sample with 2M solution of potassium chloride (KCl)and mixing for 30min.The slurry was then ?ltered.The ?ltrate was analyzed using colorimetric methods 4500-NH 3G and 4500-NO 3H (APHA et al.,

2005).PO 43?

was extracted from soil with a 0.5M solution of sodium hydrogen carbonate (NaHCO 3)by mixing for 30min.The slurry was then ?ltered.The ?ltrate was analyzed using colorimetric method 4500-P (APHA et al.,2005).Data were reported in mg/kg dw.

Total Organic Carbon (TOC)was determined based on U.S EPA,(1996).Sieved,dried samples were exposed to hydrochloric acid (HCl)fumes to decompose carbonates.Samples were then analyzed with a combustion/infrared analyzer (CS-244LECO?).

2.2.2.Diesel volatilization

Two different methods were utilized to measure the volatilization of diesel from the heated and the humidi ?ed biopiles.Volatilization from the passive system was not measured because it did not provide an enclosed system.The ?rst method consisted of passing the air ef ?uent from the biopiles through ?lters of granular activated carbon (GAC)(AC Carbon Canada,St-Jean-sur-Richelieu,QC).Moisture captured on the GAC froze and made the ?lters inoperable after b two months of operation.Starting on Feb 15,05,air samples were collected by pumping (0.2L/min for 98min)through charcoal tubes.VOC concentrations on GAC samples and charcoal tubes were determined by extraction with carbon disul ?de (CS 2)followed by analysis of the extract by GC/FID (method adapted from NIOSH,2003)with C-Scan data analysis.

2.2.

3.Statistical analysis

PHC data (TPH and fractions)were transformed to the logarithm base 10in order to allow the use of parametric statistics.Analysis of Variance (ANOVA)was used.No transformation was suitable for the pH data so a non-parametric statistical analysis (Kruskal –Wallis test)was conducted.Signi ?cance was accepted at α=0.05(95%con ?dence level)for all statistical analysis.3.Results and discussion 3.1.Temperature

The mean soil temperatures of the heated system and the humidi ?ed system were maintained above the freezing point during winter while outdoor air temperatures reached as low as ?20°C (Fig.2).Average temperatures in the heated and the humidi ?ed systems ?uctuated for the ?rst two months before proper adjustment of the heating and aerating system was achieved.For this period of time,average temperatures were 5.8and 11.7°C in the heated and the humidi ?ed systems respectively.These temperature ranges were shown to promote biodegradation of PHCs (Coulon et al.,2005;Schiewer and Niemeyer,2006).In cold regions,maintaining soil temperature of 5–10°C would enhance biodegradation and bioavail-ability of the contaminants without being detrimental to native cold-tolerant soil micro-organisms (Coulon et al.,2005).Temperature in the passive biopile (not heated)followed the air temperature trend.This pile was frozen from Dec 26,04to Apr 5,05.3.2.Moisture

Initial mean water potential (WP)was ~?25kPa in all three piles (Fig.3),equivalent to ~60%of the soil water holding capacity.

Fig.1.Diagram representing the general features of the biopile design,dimensions and locations of sensors (T:thermocouples,G:soil –gas probes,and M:soil-moisture blocks).

169

D.Sanscartier et al./Cold Regions Science and Technology 55(2009)167–173

decrease in WP signi ?es a decrease of soil moisture content.The humidifying system provided 5±1kg of water/d which resulted in a slight WP increase and maintained soil moisture within the optimum range for bioremediation (Aislabie et al.,2006).In contrast,the heated (not humidi ?ed)system and the passive system both experienced drying starting in Apr 05.Drying was likely due to the combination of the dry heated air (heated pile only),increasing outdoor air temperature and solar heat gain.Sensors froze during the winter in the passive system;WP data thus were not available during this period.Sensors started functioning properly upon thawing.3.3.pH

Initial and ?nal mean soil pH values are presented in Table 2.The soil in all biopiles was slightly alkaline throughout the experiment which should not have limited bioremediation.The humidi ?ed biopile was the only system to experience a signi ?cant drop in https://www.wendangku.net/doc/4917796715.html,anic acids may accumulate during biodegradation (Aislabie et al.,2006),a drop in pH thus may indicate greater microbial activity in the humidi ?ed system.Lower ?nal soil pH in this system may also be explained by the pH of the tap water (pH=6.9±0.1)that was injected into the soil.3.4.Oxygen

An average of 20.4±0.5%vol.was measured in the soil pores of all biopiles with a low of 17.6±0.1%vol.in the heated and the humidi ?ed

biopiles and a low of 13.8±0.1%vol.in the passive biopile.Biode-gradation should not have been limited by availability of O 2in the heated and the humidi ?ed systems but may have been slowed by the lower O 2content in the passive system.3.5.Diesel removal

Initially,there were no signi ?cant differences in TPH between treatments (Table 2).Signi ?cant reduction was observed in all treatments over time.The humidi ?ed biopile produced signi ?cantly lower ?nal TPH than the other two biopiles.Fig.4presents TPH over time (log-linear scale).In Jan and Mar 05,the humidi ?ed system had signi ?cantly lower TPH than the heated system (data is not available for passive system because it was frozen at those sampling events).Faster reduction in the humidi ?ed pile was likely due to the higher temperatures of the soil in this system up to Jan 28,05(Fig.2).The 6°C difference in average temperatures between those two piles for the ?rst two months of treatment does not seem to have affected the extent of bioremediation.By May 05,TPH levels were equivalent in

the

Fig.3.Average soil water potential (WP).WP was not measured in the passive system during the winter due to freezing of the sensors.

Table 2

Initial and ?nal mean Total Petroleum Hydrocarbon (TPH)values,C-Scan fraction values (C-Scan F1—CF1;C-Scan F2—CF2;C-Scan F3—CF3),percent contribution of C-Scan F3on TPH (%CF3),TPH reduction rates (k-values),soil pH,and results of statistical analysis Parameters

Biopiles

Heated

Humidi ?ed Passive TPH (mg/kg dw)

a,b

Initial 11,000±5000A 9600±4400A 13,000±9000A Final 500±400B 290±480C 1000±1300B CF1(mg/kg dw)a,b Initial 1400±800A 700±230A 1200±1100A Final ND c

B ND c

B 70±130B CF2(mg/kg dw)a,b Initial 4400±1900A 3500±1700A 4700±3600A Final 120±70B

C 100±160C 410±560B CF3(mg/kg dw)a,b Initial 5300±2400A 5400±2500A 6900±4600A Final 420±380B 190±310C 540±630B %CF3

a,b

Initial 48±2A 56±2A 56±5A Final 72±9B 66±12B 60±9A k -values (d ?1)0.0170.0190.013Soil pH a,d

Initial 8.6±0.4A 8.5±0.1A 8.5±0.4A Final

8.1±0.5

7.7±0.1

7.9±0.5

Values with different letters indicate signi ?cant difference (α=0.05)between treatments and sampling time within each chemical analysis (i.e.TPH,CF1,CF2,CF3,%CF3,and pH).b

Uncertainties are one standard deviation from the mean (n =10).c

ND=below detection limit (40mg/kg dry soil).d

Uncertainties are one standard deviation from the mean (n =

4).

Fig.4.Mean Total Petroleum Hydrocarbons (TPH)reduction in the heated (5)the humidi ?ed (D )and passive (o )biopiles (log-linear scale).Samples were not collected from the passive system in Jan and Mar because frozen.Error bars are one standard deviation from the mean (n =10);only one side is presented for

clarity.

Fig.2.Average outdoor air temperature and soil temperatures.

170 D.Sanscartier et al./Cold Regions Science and Technology 55(2009)167–173

heated and the humidi ?ed biopiles.This observation suggests that heating the soil to ~5°C is suf ?cient to promote signi ?cant bioremediation.Despite being frozen for more than three months during the winter,a signi ?cant TPH decrease was measured in the passive system between Dec 04and May 05.However,TPH in this pile was still signi ?cantly higher than that of the other two piles at that point.In May 05,the heated pile reached a TPH residual plateau as no signi ?cant reduction was observed subsequently (despite slight measured volatilization [Fig.5]);a possible consequence of the rapid drying of this pile after Apr 05(Fig.3).This residual plateau was not observed in the humidi ?ed and the passive systems;signi ?cant TPH reduction was measured in those piles after May 05.The moister soils likely maintained microbial activity.The higher ?nal TPH level in the passive biopile suggests limiting conditions (i.e.O 2availability and lower temperature)and slower volatilization rates in this pile.

Hydrocarbon loss during bioremediation is typically modeled by ?rst-order kinetic (Zytner et al.,2001;Namkoong et al.,2002).First-order TPH reduction rates (k-values —Table 2)were obtained by linear regression of the Ln-transformed average TPH values of the Nov 04to May 05period.TPH reduction stalled or followed a linear trend afterwards;the Sept 05data thus were left out of the regression.K-values decreased in the following order:humidi ?ed pile N heated pile N passive pile,consistent with the TPH measurements.TPH reduction rates are consistent with that reported in the literature.In bench-scale studies,a range of k-values from 0.028to 0.21d ?1has been observed for diesel-contaminated soils (Zytner et al.,2001;Namkoong et al.,2002).Slower rates than that in the laboratory can be expected in ?eld-scale experiments (Davis et al.,2003).

Initially,there were no signi ?cant differences in individual fractions levels between treatments (Table 2).Levels of the three PHC fractions were signi ?cantly reduced in all biopiles over time (Table 2).Treatments were equally ef ?cient in reducing CF1concentrations.The ?nal CF2level in the humidi ?ed pile was signi ?cantly lower than that of the passive pile but was equivalent to the heated biopile level.The humidi ?ed biopile produced signi ?cantly lower concentration of the higher molecular weight,less volatile and more recalcitrant CF3fraction.With time,the proportion of CF3(%CF3—Table 2)increased in the humidi ?ed and the heated systems indicating that this fraction was removed at a slower rate than CF1and CF2.Preferential removal of the more volatile and easily degraded compounds (fractions CF1and CF2)was also observed by Zytner et al.(2001),and Namkoong et al.(2002).Residual contamination by CF3is of less concern than that of CF1and CF2as compounds from CF3are generally less toxic and less mobile than the

lighter compounds (CCME,2000).Furthermore,although little is known about the toxicity of residual PHC unresolved complex mixture (UCM)(Scarlett et al.,2007),bioremediation generally decreases toxicity of PHC-contaminated soils (Molina-Barahona et al.,2005).3.6.Diesel volatilization

For the ?rst two months,volatilization was measured by trapping VOCs on GAC ?lters.Total masses of PHCs trapped were estimated by multiplying the average TPH of three GAC samples collected in each ?lter by the total mass of GAC in the ?lter.The heated and the humidi ?ed systems experienced a similar extent of volatilization:90±64and 98±38g of diesel,respectively.Similar WP (Fig.3)but different temperatures (Fig.2)were measured in the two biopiles during those two months.By the end of this period (Jan 05),the humidi ?ed biopile had lower TPH than the heated system (Fig.4).These combined ?ndings suggest that a difference of ~6°C in the average temperature between the two piles during this period did not affect volatilization greatly but promoted faster biodegradation in the humidi ?ed pile.

Starting on Feb 15,05,volatilization rates were estimated with VOC concentrations data (air sampling)and air injection rates in the heated and the humidi ?ed systems only (Fig.5).The humidi ?ed system produced lower volatilization rates than the heated system until the end of the experiment.The signi ?cantly lower TPH in the humidi ?ed pile in Jan and Mar 05may explain these results.Humidifying the air also may have reduced volatilization by promoting biodegradation due to moister soil and increased bioavailability of adsorbed organic compounds displaced from soil particles by the water (Batterman et al.,1995).The added moisture may have reduced the soil-pore space available for diffusion of the contaminants,thereby reducing volatilization (Dragun,1998).Displacing adsorbed compounds may also have enhanced their volatilization.C-Scan analysis of charcoal tubes showed that the CF1and CF2accounted for ~90%of the total PHCs volatilized (Fig.5).These ?ndings show that volatilization accounted for little of the total loss of CF3fractions,an indication that biodegradation was the main removal mechanism for this fraction.

Total diesel removed by volatilization could not be estimated but ?ndings indicate that this process played an important role in TPH reduction.The literature presents con ?icting data on this topic.Studies have reported that abiotic processes (e.g.volatilization,leaching)made a negligible contribution to the removal of diesel during bioremediation (Quinn and Reinhart,1997;Namkoong et al.,2002);while others reported that they were important,contributing between 35%and 60%of total removal (Margesin et al.,2000;Chatham 2003;Riffaldi et al.,2006).Fresh vs aged contamination,air injection rates,and soil organic matter content (Namkoong et al.,2002)certainly in ?uence the extent of volatilization during treatment.3.7.Nutrients

Numerous biotic and abiotic processes affect the fate of available nutrients in soil.Analysis of their concentrations over time provides

Table 3

Initial (after application of fertilizers)and ?nal mean concentrations of ammonia (NH 3),

nitrite+nitrate (NO 2?+NO 3?),and orthophosphate (PO 43?

)in biopiles

Parameters

Biopile NH 3(mg/kg dw)NO 2?+NO 3?

(mg/kg dw)

PO 43?

(mg/kg dw)

Final

Initial

920±140ND a

160±30Heated 310±310310±300 2.4±3.6Humidi ?ed 0.6±0.3340±900.3±0.2Passive

380±550

460±90

2.4±

3.3

Uncertainties are one standard deviation from the mean (n =3).a

ND=below detection limit (2

mg/kg).

Fig.5.Hydrocarbon compounds volatilization rates and relative contribution of the C-Scan fractions 1and 2to total hydrocarbons volatilized (%CF1+%CF2)in the heated (5)and the humidi ?ed (D )biopiles.Arrows point to the corresponding Y -axis.

171

D.Sanscartier et al./Cold Regions Science and Technology 55(2009)167–173

insight into microbial activity.NH3may be used by microbes as a source of N,undergo nitri?cation,and volatilize.NO3?+NO2?may be used by microbes as a source of N,undergo denitri?cation,and leach from soil(Blankenau et al.,2000;Delgado2002).PO43?is readily utilized by microbes and adsorbs quickly to soil(McLaughlin et al., 1988;Frossard et al.,2000).The soil mixture used for the construction of the piles was poor in available nutrients prior to amending with fertilizers(Table1).The fertilizers applied to the soil provided N in the form of NH3and P in the form of PO43?.In all three biopiles,the reduction of NH3and PO43?levels and the increase of NO2?+NO3?levels are indications of microbial activity in soil(Table3).The lowest?nal levels of NH3and PO43?were measured in the humidi?ed biopile suggesting the greatest microbial activity in this pile.The increase of NO2?+NO3?,consistent with Deni and Penninckx,(2004),con?rms that diesel contamination and bioremediation do not completely inhibit nitri?cation,an important microbially-mediated process in soil.

3.8.Leaching

Samples collected from the clean sand underneath each biopile (Fig.1)and from outside the containment area,were analysed for TPH and available nutrients to assess leaching during treatment.The sand had initially non-detectable TPH and nutrient concentrations.Analy-tical results and mass of sand were used to estimate the extent of leaching of diesel and nutrients from the contaminated soil(Table4). Migration outside the containment areas was not observed.Humidi-fying the air did not result in greater leaching of diesel and PO43?.More available N(NH3+NO2?+NO3?)leached from the humidi?ed biopile than from the heated biopile,mainly in the form of the easily leachable ions NO2?+NO3?(Delgado,2002),possibly resulting from the moister conditions in this pile.The passive biopile experienced the greatest leaching of diesel and available N;an indication that this system did not provide optimal conditions for bioremediation. Leaching of PO43?was low and equivalent in all three systems,as expected.

Irrigation water often creates leachate that needs to be collected and recycled in the system or treated before release(EC,1993). Findings show that the humidifying system tested here could be an interesting alternative to other irrigation systems.It simpli?es design, construction and operation by removing the requirement for irriga-tion pipes and a leachate collection system.In cold climates it has the advantage of preventing possible failure of the irrigation system by pipes freezing up.

4.Conclusions and recommendations

This study investigated the bioremediation of soil freshly con-taminated by diesel fuel.Findings may not be directly applicable to aged contamination that tends to be less bioavailable,thus more recalcitrant to bioremediation(Strokes et al.,2006),and that may have already lost lighter compounds to the atmosphere.The three biopiles tested treated highly contaminated soil to low concentrations.The heated pile reached a residual plateau after two-third of the treatment,probably due to the dryness of the soil;while further TPH reduction was observed in the other two piles.The humidi?ed biopile produced signi?cantly lower?nal TPH than the other systems. The humidifying system maintained optimal soil moisture content without promoting excessive leaching.Findings suggest that humidi-fying the air enhanced biodegradation of the least degradable compounds(CF3fraction)and minimized volatilization.

For large-scale projects,optimization of soil temperature should balance shortened remediation time with energy consumption and cost.In this study heating the soil to only5°C promoted bioremedia-tion.This temperature could be a valid starting point for site-speci?c optimization.Although the passive biopile was the least ef?cient system in regards to?nal TPH and leaching of PHCs,it was the least energy and resource intensive treatment.It may be a cost-effective and environment-friendly solution if remediation time is not a constraint,often the case at unmanned northern sites.

The heating/humidifying system should now be tested in Arctic conditions in parallel with the passive biopile to compare both systems and gain further knowledge on treatment time required for bioreme-diation with these systems in the North.A detailed environmental life cycle assessment comparing the two systems,operating in cold and temperate climates,would provide insights on their true environ-mental bene?ts.Biodegradation and volatilization play important roles in removing PHCs from soil.Their relative contributions need to be properly quanti?ed,and parameters affecting them studied,in future experimentation in order to further optimize biopile systems.

Acknowledgment

We thank the Director General Environment of the Canadian Department of National Defence for?nancial support and the Canadian Forces Base Kingston for providing funding and logistical support during the study.We also thank the Analytical Services Group, Royal Military College of Canada,Kingston,ON,and the Analytical Services Unit,Queen's University,Kingston,ON,for help and guidance for data analysis.

References

Aislabie,J.,Saul,D.J.,Foght,J.M.,2006.Bioremediation of hydrocarbon-contaminated polar soils.Extremophiles10,171–179.

American Public Health Association(APHA)American Water Works Association (AWWA)Water Environment Federation(WEF),2005.Standard Methods for the Examination of Water&Wastewater—21st Edition.Port City Press,Baltimore,MD. Batterman,S.,Kulshrestha,A.,Cheng,H.Y.,1995.Hydrocarbon vapor transport in low moisture soils.Environ.Sci.Technol.29,171–180.

Blankenau,K.,Olfs,H.W.,Kuhlmann,H.,2000.Effect of microbial nitrogen immobiliza-tion during the growth period on the availability of nitrogen fertilizer for winter cereals.Biol.Fertil.Soils32,157–165.

Cameron A.2007.North Warning System Of?ce,National Defence.Personal communication.

Canadian Council of Ministers of the Environment(CCMe),2000.Canada-Wide Standards for Petroleum Hydrocarbons(PHCs)in Soil:Scienti?c Rationale Supportinsg Technical Document.Winnipeg,MB,Canada.

Chatham,J.R.,https://www.wendangku.net/doc/4917796715.html,ndfarming on the Alaskan North Slope-Historical Development and Recent Applications.In Proceedings of the10th International Petroleum Environmental Conference.https://www.wendangku.net/doc/4917796715.html,/Conf2003/Papers/chatham_35.

pdf.

Coulon,F.,Pelletier,E.,Gourhant,L.,Delille,D.,2005.Effect of nutrient and temperature on degradation of petroleum hydrocarbons in contaminated sub-Antarctic soil.

Chemosphere58,1439–1448.

Davis, C.,Cort,T.,Dai, D.,Illangasekare,T.H.,Munakata-Marr,J.,2003.Effects of heterogeneity and experimental scale on the biodegradation of diesel.Biodegrada-tion14,373–384.

Delgado,J.A.,2002.Quantifying the loss mechanisms of nitrogen.J.Soil Water Conserv.

57(6),389–398.

Deni,J.,Penninckx,M.J.,2004.In?uence of long-term diesel fuel pollution on nitrite-oxidising activity and population size of nitrobacter spp.in soil.Microbiol.Res.159, 323–329.

Dobson,R.,Schroth,M.H.,Schuermann,A.,Zeyer,J.,2004.Methods to assess the amenability of petroleum hydrocarbons to bioremediation.Environ.Toxicol.Chem.

23(4),929–937.

Dragun,J.,1998.The Soil Chemistry of Hazardous Materials,Second Edition.Amherst Scienti?c Publisher,Amherst,MA.

Table4

Average mass of diesel(D),available nitrogen(N=NH3+NO2?+NO3?),and orthophosphate

(PO43?),and percentage of each amendment initially applied(in parenthesis)found in the

clean sand(underneath the contaminated soil)after the experiment

Biopiles Parameters

D(kg)(%)N(g)(%)PO43?(g)(%)

Heated2±2(3±3)34±5(0.8±0.1)10±2(1.2±0.2)

Humidi?ed2±1(3±2)105±17(2.6±0.4)9±2(1.1±0.2)

Passive7±2(11±3)139±20(3.4±0.5)8±2(1.0±0.3)

Uncertainties are one standard deviation from the mean(n=3).

172 D.Sanscartier et al./Cold Regions Science and Technology55(2009)167–173

Environment Canada(EC),1993.Guidelines on the ex-situ bioremediation of petroleum hydrocarbon contaminated soils on federal crown land.Ottawa,ON,Canada. Environment Canada(EC),2005.National Climate Data and Information Archive.

Ottawa,ON,Canada.http://www.climat.meteo.ec.gc.ca/.

Environment Science Group(ESG),2001.Savitok Point Hydrocarbon Bioremediation of the Former Tank Farm Pad QA/QC Report.Technical report.Kingston,ON,Canada. Filler,D.M.,Lindstrom,J.E.,Braddock,J.F.,Johnson,R.A.,Nickalaski,R.,2001.Integral biopile components for successful bioremediation in the Arctic,Cold Reg.Sci.

Technol.32,143–156.

Frossard,E.,Condron,L.M.,Oberson,A.,Sinaj,S.,Fardeau,J.C.,2000.Processes governing phosphorus availability in temperate soils.J.Environ.Qual.29,15–23. Margesin,R.,Zimmerhauer,A.,Schinner,R.,2000.Monitoring of bioremediation by soil biological activities.Chemosphere40,339–346.

McCarthy,K.,Walker,L.,Vigoren,L.,Bartel,J.,2004.Remediation of spilled petroleum hydrocarbons by in situ landfarming at an Arctic site.Cold Reg.Sci.Technol.40, 31–39.

McLaughlin,M.J.,Alston,A.M.,Martin,J.K.,1988.Phosphorus cycling in wheat-pasture rotations.II.?Role of the microbial biomass in phosphorus cycling.Aust.J.Soil Sci.

26,333–342.

Molina-Barahona,L.,Vega-Loyo,L.,Guerrero,M.,Ramirez,S.,Romero,I.,Vega-Jarquin,

C.,Albores,A.,2005.Ecotoxicological evaluation of diesel-contaminated soil before

and after a bioremediation process.Environ.Toxicol.20,100–109.

Namkoong,W.,Hwang, E.Y.,Park,J.S.,Choi,J.Y.,2002.Bioremediation of diesel-contaminated soil with composting.Environ.Pollut.119,23–31.

National Institute for Occupational Safety and Health(NIOSH),2003.Hydrocarbons,BP 36–216°C:Method1500,Issue3.Atlanta,GA.Quinn,J.W.,Reinhart,D.R.,1997.Bioremediation of diesel contaminated soil using biopiles.Pract.Period.Hazard.,Toxic,Radioact.Waste Manag.18–25Jan. Reimer,K.J.,Colden,M.,Francis,P.,Mauchan,J.,Mohn,W.W.,Poland,J.S.,2003.In:Nahir, M.,Biggar,K.,Cotta,G.(Eds.),Cold Climate Bioremediation—A Comparison of Various Approaches.Conference proceedings,Assessment and Remediation of Contaminated Sites in Arctic and Cold Climates.Edmonton,Canada,pp.290–298. Riffaldi,R.,Levi-Minzi,R.,Cardelli,R.,Palumbo,S.,Saviozzi,A.,2006.Soil biological activities in monitoring the bioremediation of diesel oil-contaminated soil.Water, Air,Soil Pollut.170,3–15.

Scarlett,A.,Galloway,T.S.,Rowland,S.J.,2007.Chronic toxicity of unresolved complex mixtures(UCM)of hydrocarbons in marine sediments.J.Soils Sediments7(4), 200–206.

Schiewer,S.,Niemeyer,T.,2006.Soil heating and optimized nutrient addition for accelerating bioremediation in cold climates.Polar Rec.42(220),23–31. Strokes,J.D.,Paton,G.I.,Semple,K.T.,2006.Behaviour and assessment of bioavailability of organic contaminants in soil:relevance for risk assessment and remediation.Soil Use Manage.21,475–486.

U.S.EPA,1996.Method3550B—Ultrasonic Extraction,https://www.wendangku.net/doc/4917796715.html, Environmental Protection Agency,Of?ce of Solid Waste,Washington,DC.

U.S.EPA,2000.Method8015C—Nonhalogenated Organics Using GC/FID,https://www.wendangku.net/doc/4917796715.html, Environmental Protection Agency,Of?ce of Solid Waste,Washington,DC. vanLoon,G.W.,Duffy,S.J.,2000.Environmental chemistry—a global perspective.

Oxford University Press,New York,NW.

Zytner,R.G.,Salb,A.,Brook,T.R.,Leunissen,M.,Stiver,W.H.,2001.Bioremediation of diesel fuel contaminated soil.Can.J.Civil Eng.28(Suppl.1),131–140.

173

D.Sanscartier et al./Cold Regions Science and Technology55(2009)167–173

如何写先进个人事迹

如何写先进个人事迹篇一：如何写先进事迹材料如何写先进事迹材料一般有两种情况：一是先进个人，如先进工作者、优秀党员、劳动模范等；一是先进集体或先进单位，如先进党支部、先进车间或科室，抗洪抢险先进集体等。无论是先进个人还是先进集体，他们的先进事迹，内容各不相同，因此要整理材料，不可能固定一个模式。一般来说，可大体从以下方面进行整理。 (1)要拟定恰当的标题。先进事迹材料的标题，有两部分内容必不可少，一是要写明先进个人姓名和先进集体的名称，使人一眼便看出是哪个人或哪个集体、哪个单位的先进事迹。二是要概括标明先进事迹的主要内容或材料的用途。例如《王鬃同志端正党风的先进事迹》、《关于评选张鬃同志为全国新长征突击手的材料》、《关于评选鬃处党支部为省直机关先进党支部的材料》等。 (2)正文。正文的开头，要写明先进个人的简要情况，包括：姓名、性别、年龄、工作单位、职务、是否党团员等。此外，还要写明有关单位准备授予他(她)什么荣誉称号，或给予哪种形式的奖励。对先进集体、先进单位，要根据其先进事迹的主要内容，寥寥数语即应写明，不须用更多的文字。然后，要写先进人物或先进集体的主要事迹。这部分内容是全篇材料

的主体，要下功夫写好，关键是要写得既具体，又不繁琐；既概括，又不抽象；既生动形象，又很实在。总之，就是要写得很有说服力，让人一看便可得出够得上先进的结论。比如，写一位端正党风先进人物的事迹材料，就应当着重写这位同志在发扬党的优良传统和作风方面都有哪些突出的先进事迹，在同不正之风作斗争中有哪些突出的表现。又如，写一位搞改革的先进人物的事迹材料，就应当着力写这位同志是从哪些方面进行改革的，已经取得了哪些突出的成果，特别是改革前后的．经济效益或社会效益都有了哪些明显的变化。在写这些先进事迹时，无论是先进个人还是先进集体的，都应选取那些具有代表性的具体事实来说明。必要时还可运用一些数字，以增强先进事迹材料的说服力。为了使先进事迹的内容眉目清晰、更加条理化，在文字表述上还可分成若干自然段来写，特别是对那些涉及较多方面的先进事迹材料，采取这种写法尤为必要。如果将各方面内容材料都混在一起，是不易写明的。在分段写时，最好在每段之前根据内容标出小标题，或以明确的观点加以概括，使标题或观点与内容浑然一体。最后，是先进事迹材料的署名。一般说，整理先进个人和先进集体的材料，都是以本级组织或上级组织的名义；是代表组织意见的。因此，材料整理完后，应经有关领导同志审定，以相应一级组织正式署名上报。这类材料不宜以个人名义署名。写作典型经验材料-般包括以下几部分： (1)标题。有多种写法，通常是把典型经验高度集中地概括出来，一

关于时间管理的英语作文 manage time

How to manage time Time treats everyone fairly that we all have 24 hours per day. Some of us are capable to make good use of time while some find it hard to do so. Knowing how to manage them is essential in our life. Take myself as an example. When I was still a senior high student, I was fully occupied with my studies. Therefore, I hardly had spare time to have fun or develop my hobbies. But things were changed after I entered university. I got more free time than ever before. But ironically, I found it difficult to adjust this kind of brand-new school life and there was no such thing called time management on my mind. It was not until the second year that I realized I had wasted my whole year doing nothing. I could have taken up a Spanish course. I could have read ten books about the stories of successful people. I could have applied for a part-time job to earn some working experiences. B ut I didn’t spend my time on any of them. I felt guilty whenever I looked back to the moments that I just sat around doing nothing. It’s said that better late than never. At least I had the consciousness that I should stop wasting my time. Making up my mind is the first step for me to learn to manage my time. Next, I wrote a timetable, setting some targets that I had to finish each day. For instance, on Monday, I must read two pieces of news and review all the lessons that I have learnt on that day. By the way, the daily plan that I made was flexible. If there’s something unexpected that I had to finish first, I would reduce the time for resting or delay my target to the next day. Also, I would try to achieve those targets ahead of time that I planed so that I could reserve some more time to relax or do something out of my plan. At the beginning, it’s kind of difficult to s tick to the plan. But as time went by, having a plan for time in advance became a part of my life. At the same time, I gradually became a well-organized person. Now I’ve grasped the time management skill and I’m able to use my time efficiently.

英语演讲稿：未来的工作

英语演讲稿：未来的工作这篇《英语演讲稿范文：未来的工作》，是特地，希望对大家有所帮助！热门演讲推荐：竞聘演讲稿 | 国旗下演讲稿 | 英语演讲稿 | 师德师风演讲稿 | 年会主持词 | 领导致辞 everybody good afternoon:. first of all thank the teacher gave me a story in my own future ideal job. everyone has a dream job. my dream is to bee a boss, own a pany. in order to achieve my dreams, i need to find a good job, to accumulate some experience and wealth, it is the necessary things of course, in the school good achievement and rich knowledge is also very important. good achievement and rich experience can let me work to make the right choice, have more opportunities and achievements. at the same time, munication is very important, because it determines whether my pany has a good future development. so i need to exercise their municative ability. i need to use all of the free time to learn

关于坚持的英语演讲稿

关于坚持的英语演讲稿 Results are not important, but they can persist for many years as a commemoration of. Many years ago, as a result of habits and overeating formed one of obesity, as well as indicators of overall physical disorders, so that affects my work and life. In friends to encourage and supervise, the participated in the team Now considered to have been more than three years, neither the fine rain, regardless of winter heat, a day out with 5:00 time. The beginning, have been discouraged, suffering, and disappointment, but in the end of the urging of friends, to re-get up, stand on the playground. 成绩并不重要，但可以作为坚持多年晨跑的一个纪念。多年前，由于庸懒习惯和暴饮暴食，形成了一身的肥胖，以及体检指标的全盘失常，以致于影响到了我的工作和生活。在好友的鼓励和督促下，参加了晨跑队伍。现在算来，已经三年多了，无论天晴下雨，不管寒冬酷暑，每天五点准时起来出门晨跑。开始时，也曾气馁过、痛苦过、失望过，但最后都在好友们的催促下，重新爬起来，站到了操场上。 In fact, I did not build big, nor strong muscles, not a sport-born people. Over the past few years to adhere to it, because I have a team behind, the strength of a strongteam here, very grateful to our team, for a long time, we encourage each other, and with sweat, enjoying common health happy. For example, Friends of the several run in order to maintain order and unable to attend the 10，000 meters race, and they are always concerned about the brothers and promptly inform the place and time, gives us confidence and courage. At the same time, also came on their own inner desire and pursuit for a good health, who wrote many of their own log in order to refuel for their own, and inspiring. 其实我没有高大身材，也没健壮肌肉，天生不属于运动型的人。几年来能够坚持下来，因为我的背后有一个团队，有着强大团队的力量，在这里，非常感谢我们的晨跑队，长期以来，我们相互鼓励着，一起流汗，共同享受着健康带来的快

关于管理的英语演讲

1.How to build a business that lasts100years 0:11Imagine that you are a product designer.And you've designed a product,a new type of product,called the human immune system.You're pitching this product to a skeptical,strictly no-nonsense manager.Let's call him Bob.I think we all know at least one Bob,right?How would that go? 0:34Bob,I've got this incredible idea for a completely new type of personal health product.It's called the human immune system.I can see from your face that you're having some problems with this.Don't worry.I know it's very complicated.I don't want to take you through the gory details,I just want to tell you about some of the amazing features of this product.First of all,it cleverly uses redundancy by having millions of copies of each component--leukocytes,white blood cells--before they're actually needed,to create a massive buffer against the unexpected.And it cleverly leverages diversity by having not just leukocytes but B cells,T cells,natural killer cells,antibodies.The components don't really matter.The point is that together,this diversity of different approaches can cope with more or less anything that evolution has been able to throw up.And the design is completely modular.You have the surface barrier of the human skin,you have the very rapidly reacting innate immune system and then you have the highly targeted adaptive immune system.The point is,that if one system fails,another can take over,creating a virtually foolproof system. 1:54I can see I'm losing you,Bob,but stay with me,because here is the really killer feature.The product is completely adaptive.It's able to actually develop targeted antibodies to threats that it's never even met before.It actually also does this with incredible prudence,detecting and reacting to every tiny threat,and furthermore, remembering every previous threat,in case they are ever encountered again.What I'm pitching you today is actually not a stand-alone product.The product is embedded in the larger system of the human body,and it works in complete harmony with that system,to create this unprecedented level of biological protection.So Bob,just tell me honestly,what do you think of my product? 2:47And Bob may say something like,I sincerely appreciate the effort and passion that have gone into your presentation,blah blah blah-- 2:56(Laughter) 2:58But honestly,it's total nonsense.You seem to be saying that the key selling points of your product are that it is inefficient and complex.Didn't they teach you 80-20?And furthermore,you're saying that this product is siloed.It overreacts, makes things up as it goes along and is actually designed for somebody else's benefit. I'm sorry to break it to you,but I don't think this one is a winner.

关于工作的优秀英语演讲稿

关于工作的优秀英语演讲稿 Different people have various ambitions. Some want to be engineers or doctors in the future. Some want to be scientists or businessmen. Still some wish to be teachers or lawers when they grow up in the days to come. Unlike other people, I prefer to be a farmer. However, it is not easy to be a farmer for Iwill be looked upon by others. Anyway,what I am trying to do is to make great contributions to agriculture. It is well known that farming is the basic of the country. Above all, farming is not only a challenge but also a good opportunity for the young. We can also make a big profit by growing vegetables and food in a scientific way. Besides we can apply what we have learned in school to farming. Thus our countryside will become more and more properous. I believe that any man with knowledge can do whatever they can so long as this job can meet his or her interest. All the working position can provide him with a good chance to become a talent. 1 ————来源网络整理，仅供供参考

个人先进事迹简介

个人先进事迹简介 01 在思想政治方面,xxxx同学积极向上,热爱祖国、热爱中国共产党,拥护中国共产党的领导.利用课余时间和党课机会认真学习政治理论,积极向党组织靠拢. 在学习上,xxxx同学认为只有把学习成绩确实提高才能为将来的实践打下扎实的基础,成为社会有用人才.学习努力、成绩优良. 在生活中,善于与人沟通,乐观向上,乐于助人.有健全的人格意识和良好的心理素质和从容、坦诚、乐观、快乐的生活态度,乐于帮助身边的同学,受到师生的好评. 02 xxx同学认真学习政治理论,积极上进,在校期间获得原院级三好生,和校级三好生,优秀团员称号,并获得三等奖学金. 在学习上遇到不理解的地方也常常向老师请教,还勇于向老师提出质疑.在完成自己学业的同时,能主动帮助其他同学解决学习上的难题,和其他同学共同探讨,共同进步. 在社会实践方面,xxxx同学参与了中国儿童文学精品“悦”读书系,插画绘制工作,xxxx同学在班中担任宣传委员,工作积极主动,认真负责,有较强的组织能力.能够在老师、班主任的指导下独立完成学院、班级布置的各项工作. 03 xxx同学在政治思想方面积极进取,严格要求自己.在学习方面刻苦努力,不断钻研,学习成绩优异,连续两年荣获国家励志奖学金；作

为一名学生干部,她总是充满激情的迎接并完成各项工作,荣获优秀团干部称号.在社会实践和志愿者活动中起到模范带头作用. 04 xxxx同学在思想方面,积极要求进步,为人诚实,尊敬师长.严格要求自己.在大一期间就积极参加了党课初、高级班的学习,拥护中国共产党的领导,并积极向党组织靠拢. 在工作上,作为班中的学习委员,对待工作兢兢业业、尽职尽责的完成班集体的各项工作任务.并在班级和系里能够起骨干带头作用.热心为同学服务,工作责任心强. 在学习上,学习目的明确、态度端正、刻苦努力,连续两学年在班级的综合测评排名中获得第1.并荣获院级二等奖学金、三好生、优秀班干部、优秀团员等奖项. 在社会实践方面,积极参加学校和班级组织的各项政治活动,并在志愿者活动中起到模范带头作用.积极锻炼身体.能够处理好学习与工作的关系,乐于助人,团结班中每一位同学,谦虚好学,受到师生的好评. 05 在思想方面,xxxx同学积极向上,热爱祖国、热爱中国共产党,拥护中国共产党的领导.作为一名共产党员时刻起到积极的带头作用,利用课余时间和党课机会认真学习政治理论. 在工作上,作为班中的团支部书记,xxxx同学积极策划组织各类团活动,具有良好的组织能力. 在学习上,xxxx同学学习努力、成绩优良、并热心帮助在学习上有困难的同学,连续两年获得二等奖学金. 在生活中,善于与人沟通,乐观向上,乐于助人.有健全的人格意识和良好的心理素质.

自我管理演讲稿英语翻译

尊敬的领导，老师，亲爱的同学们，大家好！我是5班的梁浩东。今天早上我坐车来学校的路上，我仔细观察了路上形形色色的人，有开着小车衣着精致的叔叔阿姨，有市场带着倦容的卖各种早点的阿姨，还有偶尔穿梭于人群中衣衫褴褛的乞丐。于是我问自己，十几年后我会成为怎样的自己，想成为社会成功人士还是碌碌无为的人呢，答案肯定是前者。那么十几年后我怎样才能如愿以偿呢，成为一个受人尊重，有价值的人呢？正如我今天演讲的题目是：自主管理。大家都知道爱玩是我们孩子的天性，学习也是我们的责任和义务。要怎样处理好这些矛盾，提高自主管理呢？首先，我们要有小主人翁思想，自己做自己的主人，要认识到我们学习，生活这一切都是我们自己走自己的人生路，并不是为了报答父母，更不是为了敷衍老师。我认为自主管理又可以理解为自我管理，在学习和生活中无处不在，比如通过老师，小组长来管理约束行为和同学们对自身行为的管理都属于自我管理。比如我们到一个旅游景点，看到一块大石头，有的同学特别兴奋，会想在上面刻上：某某某到此一游话。这时你就需要自我管理，你需要提醒自己，这样做会破坏景点，而且是一种素质低下的表现。你设想一下，如果别人家小孩去你家墙上乱涂乱画，你是何种感受。同样我们把自主管理放到学习上，在我们想偷懒，想逃避，想放弃的时候，我们可以通过自主管理来避免这些，通过他人或者自己的力量来完成。例如我会制定作息时间计划表，里面包括学习，运动，玩耍等内容的完成时间。那些学校学习尖子，他们学习好是智商高于我们吗，其实不然，在我所了解的哪些优秀的学霸传授经验里，就提到要能够自我管理，规范好学习时间的分分秒秒，只有辛勤的付出，才能取得优异成绩。在现实生活中，无数成功人士告诉我们自主管理的重要性。十几年后我想成为一位优秀的，为国家多做贡献的人。亲爱的同学们，你们们？让我们从现在开始重视和执行自主管理，十几年后成为那个你想成为的人。谢谢大家！

关于工作的英语演讲稿

关于工作的英语演讲稿【篇一：关于工作的英语演讲稿】关于工作的英语演讲稿 different people have various ambitions. some want to be engineers or doctors in the future. some want to be scientists or businessmen. still some wish to be teachers or lawers when they grow up in the days to come. unlike other people, i prefer to be a farmer. however, it is not easy to be a farmer for iwill be looked upon by others. anyway,what i am trying to do is to make great contributions to agriculture. it is well known that farming is the basic of the country. above all, farming is not only a challenge but also a good opportunity for the young. we can also make a big profit by growing vegetables and food in a scientific way. besides we can apply what we have learned in school to farming. thus our countryside will become more and more properous. i believe that any man with knowledge can do whatever they can so long as this job can meet his or her interest. all the working position can provide him with a good chance to become a talent. 【篇二：关于责任感的英语演讲稿】 im grateful that ive been given this opportunity to stand here as a spokesman. facing all of you on the stage, i have the exciting feeling of participating in this speech competition. the topic today is what we cannot afford to lose. if you ask me this question, i must tell you that i think the answer is a word---- responsibility. in my elementary years, there was a little girl in the class who worked very hard, however she could never do satisfactorily in her lessons. the teacher asked me to help her, and it was obvious that she expected a lot from me. but as a young boy, i was so restless and thoughtless, i always tried to get more time to play and enjoy myself. so she was always slighted over by me. one day before the final exam, she came up to me and said, could you please explain this to me? i can not understand it. i

关于时间管理的英语演讲

Dear teacher and colleagues: my topic is on “spare time”. It is a huge blessing that we can work 996. Jack Ma said at an Ali's internal communication activity, That means we should work at 9am to 9pm, 6 days a week .I question the entire premise of this piece. but I'm always interested in hearing what successful and especially rich people come up with time .So I finally found out Jack Ma also had said :”i f you don’t put out more time and energy than others ,how can you achieve the success you want? If you do not do 996 when you are young ,when will you ?”I quite agree with the idea that young people should fight for success .But there are a lot of survival activities to do in a day ,I want to focus on how much time they take from us and what can we do with the rest of the time. As all we known ,There are 168 hours in a week .We sleep roughly seven-and-a-half and eight hours a day .so around 56 hours a week . maybe it is slightly different for someone . We do our personal things like eating and bathing and maybe looking after kids -about three hours a day .so around 21 hours a week .And if you are working a full time job ,so 40 hours a week , Oh! Maybe it is impossible for us at

关于人英语演讲稿(精选多篇)

关于人英语演讲稿(精选多篇) 关于人的优美句子 1、“黑皮小子”是我对在公交车上偶遇两次的一个男孩的称呼代号。一听这个外号，你也定会知道他极黑了。他的脸总是黑黑的；裸露在短袖外的胳膊也是黑黑的；就连两只有厚厚耳垂的耳朵也那么黑黑的，时不时像黑色的猎犬竖起来倾听着什么；黑黑的扁鼻子时不时地深呼吸着，像是在警觉地嗅着什么异样的味道。 2、我不知道，如何诠释我的母亲，因为母亲淡淡的生活中却常常跳动着不一样的间最无私、最伟大、最崇高的爱，莫过于母爱。无私，因为她的爱只有付出，无需回报；伟大，因为她的爱寓于

普通、平凡和简单之中；崇高，是因为她的爱是用生命化作乳汁，哺育着我，使我的生命得以延续，得以蓬勃，得以灿烂。 3、我的左撇子伙伴是用左手写字的，就像我们的右手一样挥洒自如。在日常生活中，曾见过用左手拿筷子的，也有像超级林丹用左手打羽毛球的，但很少碰见用左手写字的。中国汉字笔画笔顺是左起右收，适合用右手写字。但我的左撇子伙伴写字是右起左收的，像鸡爪一样迈出田字格，左看右看，上看下看，每一个字都很难看。平时考试时间终了，他总是做不完试卷。于是老师就跟家长商量，决定让他左改右写。经过老师引导，家长配合，他自己刻苦练字，考试能够提前完成了。现在他的字像他本人一样阳光、帅气。 4、老师，他们是辛勤的园丁，帮助着那些幼苗茁壮成长。他们不怕辛苦地给我们改厚厚一叠的作业，给我们上课。一步一步一点一点地给我们知识。虽然

他们有时也会批评一些人，但是他们的批评是对我们有帮助的，我们也要理解他们。那些学习差的同学，老师会逐一地耐心教导，使他们的学习突飞猛进。使他们的耐心教导培养出了一批批优秀的人才。他们不怕辛苦、不怕劳累地教育着我们这些幼苗，难道不是美吗？ 5、我有一个表妹，还不到十岁，她那圆圆的小脸蛋儿，粉白中透着粉红，她的头发很浓密，而且好像马鬓毛一样的粗硬，但还是保留着孩子一样的蓬乱的美，卷曲的环绕着她那小小的耳朵。说起她，她可是一个古灵精怪的小女孩。 6、黑皮小子是一个善良的人，他要跟所有见过的人成为最好的朋友！这样人人都是他的好朋友，那么人人都是好友一样坦诚、关爱相交，这样人与人自然会和谐起来，少了许多争执了。 7、有人说，老师是土壤，把知识化作养分，传授给祖国的花朵，让他们茁壮成长。亦有人说，老师是一座知识的桥梁，把我们带进奇妙的科学世界，让

优秀党务工作者事迹简介范文

优秀党务工作者事迹简介范文优秀党务工作者事迹简介范文 ***，男，198*年**月出生，200*年加入党组织，现为***支部书记。从事党务工作以来，兢兢业业、恪尽职守、辛勤工作，出色地完成了各项任务，在思想上、政治上同党中央保持高度一致，在业务上不断进取，团结同事，在工作岗位上取得了一定成绩。一、严于律己，勤于学习作为一名党务工作者，平时十分注重知识的更新，不断加强党的理论知识的学习，坚持把学习摆在重要位置，学习领会和及时掌握党和国家的路线、方针、政策，特别是党的十九大精神，注重政治理论水平的提高，具有坚定的理论信念;坚持党的基本路线，坚决执行党的各项方针政策，自觉履行党员义务，正确行使党员权利。平时注重加强业务和管理知识的学习，并运用到工作中去，不断提升自身工作能力，具有开拓创新精神，在思想上、政治上和行动上时刻同党中央保持高度一致。二、求真务实，开拓进取在工作中任劳任怨，踏实肯干，坚持原则，认真做好学院的党务工作，按照党章的要求，严格发展党员的每一个步骤，认真细致的对待每一份材料。配合党总支书记做好学院的党建工作，完善党总支建设方面的文件、材料和工作制度、管理制度等。

三、生活朴素，乐于助人平时重视与同事间的关系，主动与同事打成一片，善于发现他人的难处，及时妥善地给予帮助。在其它同志遇到困难时，积极主动伸出援助之手，尽自己最大努力帮助有需要的人。养成了批评与自我批评的优良作风，时常反省自己的工作，学习和生活。不但能够真诚的指出同事的缺点，也能够正确的对待他人的批评和意见。面对误解，总是一笑而过，不会因为误解和批评而耿耿于怀，而是诚恳的接受，从而不断的提高自己。在生活上勤俭节朴，不铺张浪费。身为一名老党员，我感到责任重大，应该做出表率，挤出更多的时间来投入到**党总支的工作中，不找借口，不讲条件，不畏困难，将总支建设摆在更重要的位置，解开工作中的思想疙瘩，为攻坚克难铺平道路，以支部为纽带，像战友一样团结，像家庭一样维系，像亲人一样关怀，践行入党誓言。把握机遇，迎接挑战，不负初心。

关于时间的英语演讲稿范文_演讲稿.doc

关于时间的英语演讲稿范文_演讲稿 and organizing people to learn from advanced areas to broaden their horizons in order to understand the team of cadres working conditions in schools, the ministry of education has traveled a number of primary and secondary schools to conduct research, listen to the views of the school party and government leaders to make school leadership cadres receive attention and guidance of the ministry of education to carry out a variety of practical activities to actively lead the majority of young teachers work hard to become qualified personnel and for them to put up the cast talent stage, a single sail swaying, after numerous twists and turns arrived in port, if there is wind, a hand, and naturally smooth arrival and guide students to strive to e xcel, need to nazhen “wind” - teacher. teachers should be ideological and moral education, culture education and the needs of students organically combining various activities for the students or students to carry out their own. for example: school quiz competitions, essay contests, ke benju performances and other activities to enable students to give full play to their talents. teachers rush toil, in order to that will enable students to continue to draw nutrients, to help them grow up healthily and become pillars of the country before. for all students in general education, the government departments have also not forget those who cared about the