农药污染及处理方法treatment Approaches.docx

农药污染及处理方法treatment Approaches.docx

《农药污染及处理方法treatment Approaches.docx》由会员分享，可在线阅读，更多相关《农药污染及处理方法treatment Approaches.docx（17页珍藏版）》请在冰豆网上搜索。

农药污染及处理方法treatmentApproaches

TheEnvironmentalConcentrationofPrometrynPlus®andRelevantTreatmentApproaches

Summary

OurcompanylaunchedtheherbicideproductPrometrynPluslastyear.Afterone-yearapplication,theenvironmentalagencyandthewatercompanydiscoveredsurfacewatershadbeenpollutedbythisherbicide,andtheyexpressedconcernabouttheensuingenvironmentalandecologicalproblems.Theseissuesmayaffectthecorporateimageandinterests,therefore,howtoreducetheconcentrationofPrometrynPlusintheenvironmenthasbecomethetoppriorityofourenvironmentalwork.Firstly,thisarticlereviewedpotentialsourcesoftheleakedproductandthewayitenteredtheenvironment.ThefateandpotentialharmofPrometrynPlusintheenvironmenthavebeendiscussed.Next,aseriesofgovernanceapproachesanddiscussionswereputforwardfortheUzibasin.Theinformationtheyneedisalsoproposedtohelpdeterminethefinalmanagementstrategy,however,whichcannotbeproducedatthisstageduetothelackofalargeamountofrelevantinformation.

Background

TheCase

PrometrynPlushasbeenwidelyappliedbylocalagriculturalactivitiesintheUzicatchmentasthelowcostandhighperformanceoftheproduct.Accordingtothestatisticsofrelevantdepartments,therehasbeenasignificantpromotionincropyieldandagriculturallandscape;Nevertheless,recently,theEnvironmentalAgencyhascollectedthePrometrynPlusinsurfacewatersoftheUzicatchment,thepollutionmightbepersistent.WaterAgencyalsofoundtheherbicideconcentrationindrinkingwatersupplysystems.TheUzicatchmentbasedontheUziriver,withpeatlands,fertilesoillandsandrichbiologicaldiversity.Localresidencesaremakinglifewithfisheriesandagriculture,servingnearbycitiesatthemeantime.Theconcentrationsoftheherbicidemightresultinthelocalenvironmentandhumanhealthproblem.

PotentialHazards

Thehazardsofherbicidescouldbeverybroad,inthiscase,theenvironmentwouldbetheinitialacceptor.Inthecatchment,theherbicidecontaminatessoil,water,grassandwoods.Inadditiontokillingweedsthatistheoriginalfunction,butalsopoisontobirds,fish,beneficialinsects,andnon-targetplants,andotherorganisms（Aktaretal.,2009）.Especiallyforthesoilandagriculturalenvironmentcontributorslikebees（VoluntaryInitiative,2018）,earthworms（Gaupp-Berghausenetal.,2015）.Soilcontaminationproducedbytheherbicideanditstransformationproductsisalsomanifestedbychangesinsoilproperties,includingpH,chemicalcomposition,organicmattercontent,microbialcomposition,fertilitybytheeffectonnitrogencyclingetc.（Robertsetal.,2007;DaminandTriveli,2011）.

PrometrynPlusdriftsorvolatilisesintheairandmovesfromthetreatmentareatootherareasmayevenformnon-pointsourcepollution.Itisestimatedthatdriftcanresultina2%to25%lossofappliedchemicals,spreadingfromafewmeterstohundredsofmiles（MajewskiandCapel,1996）.ContaminationsofthesurfaceandgroundwaterintheUzibasinissignificant.Itdirectlyaffectsaquaticanimals,plants,andultimatelypolluteshumandrinkingwater.Regardingtheinfluenceonhuman,drinkingwaterintake,environmentalbioaccumulation,air,andsoilcontactwillbethereason.Therearethreemainwaysofherbicideharmtothehumanbody:

Oneismassiveaccidentalexposure.Twolong-termexposuretoaparticularconcentrationofherbicides;threeisexposuretoresidualherbicidesinenvironmentandfoodindailylife.Theresultmaybeimmunemechanismsandhormonaldisruption,mentalretardation（tochildren）,endocrineabnormalities,nervoussystemdamage（Crispetal.,1998）.Also,themixtureeffectsthatgeneratedfromadditivity,synergies,potentiationbetweenPrometrynPlusandothercontaminantshavemoredangerousconsequencesthansingleeffects.

SourcesandPathways

Theinitialsourcesoftheherbicidewouldbethemanufacturingfacility.Wastewaterwasdischargeddirectlytothelocalsewagesystemwithoutanypre-treatment.Thiswouldbeamassivesourceofthewaterbodyandsoil.WastewaterwastreatedbyanetworkofprimarysettlementandactivatedsludgewherethePrometrynPlusconcentratedin.Localfarmersalsousedthesludgeasfertilisers,whichintroducedtheherbicideintosoils.What’smore,solidwastesweredisposedatlocallandfillsites,theleak,spill,leachwillleadtoenvironmentalandhealthrisks.TheUziriveristheprimarysourceofdrinkingwaterforlocalpeopleandwatercompany,thecontentofPrometrynPlusintheriverenteredeveryhouseholdthroughthesupplysystem,andtherewerenottreatedspecially.

Secondly,agriculturalactivitiesarethedominantsource.Evenwiththecarefuluse,tracesofherbicidesmayreachwaterbodies.ThispresentsachallengeforwatercompanieseffortstocomplywithUKwaterqualitylegislationanddrinkingwaterstandards.Sprayingandspillageofpesticides;improperstorageafteruse;inappropriateweather;surfacerunoffanddrainageinagriculturalactivities;andsoilconditions,especiallybarrensoil,drainflowlosses;run-offdrifts;channelstransferpesticidesintotheenvironment（Aktaretal.,2009;CropProtectionAssociation,2017）.Theresidueofherbicideshasbecomethemostsevereproblemforlocalcatchment,makingthedeterminationoftheresiduesofherbicidesoutofthewaterandsoilsbecomethepreconditionfortheapplicationoftheherbicide.

Fateintheenvironment

Herbicidesresiduesinsurfacewatercanproduceaseriesofphysicalandchemicalprocessessuchasvolatilisation,migration,photolysis,hydrolysis,aquaticorganismmetabolism,absorption,enrichment,andsedimentadsorption.Thefollowingdiagramrepresentstheenvironmentalbehaviour.

PrometrynPlus

Figure1.Thefateoftheherbicideintheenvironmental（Braschietal.,2011）

Table1.Physicalandchemicalprocessesoftheherbicideintheenvironment（Pierzynskietal.,2000）.

Processes

How

Drivers

Movement（operationsthatrelocateagrochemicalswithoutchangingtheirstructure）

Physicaldrift

Movementduetowindaction

Windspeed,dropsizes

Volatilisation

Lossduetoevaporationfromsoils,plants,andwaters

Vapourpressure,windspeed,temperature

Adsorption

Removalduetointeractionwithsoils,plants,andsediments

Claycontent,organicmatter,moisture

Absorption

Uptakebyplantrootsoranimalingestion

Cellmembranetransport,contacttime

Leaching

Horizontalandverticalmovementdownwardthroughthesoil

Watercontent,soiltexture,clay,andorganicmattercontents

Erosion

Windandwateraction

Rainfall,windspeed,sizesofclayandorganicmatter

Degradation（processesthatmodifythechemicalstructure）

Photochemical

Absorptionofsunlight（UV）

Chemicalcomposition,intensity,anddurationofexposure

Microbial

Degradationbymicroorganisms

Environmentalfactors（pH,moisture,temperature）organicmattercontent

Chemical

Hydrolysisandredoxreactions

pHmodifications,same

factorsasmicrobial

degradation

Metabolism

Adsorptionbyplantsoranimals

Adsorptioncapacity,

metabolism,interactionswithmicroorganisms

TreatmentStrategies（theaimistoreducetheconcentrationsoftheherbicideinthelocalwaterbodies）

Inthecurrentsituation,themagnitudeoftheenvironmentalimpactislargelyunknown.AgenciessuchasEnvironmentalProtectionAgencydoesnothavesuchbudgetstomonitorandtreatherbicideconcentrationthroughoutthecatchment.However,problemssuchasindustrialprocessing,waterconservation,andagriculturalmanagementcanbesolved,whichisveryimportanttoprotectthelocalenvironmentandreduceitsconcentrationsofherbicides.

Currenttreatments

ThelocalWaterAgencyappliedasimpletreatmentsystemofcoagulation,flocculation,sandfiltrationandchlorination.Theseprocessescanremovesuspendedsolids,organicsandinorganics,bacteria,algae,viruses,andminerals.However,itishardtoknowwhethertheherbicidehasbeenremoved,andthereisnotestforit.TheresearchfromPetrieetal.（1993）provedthatsandfiltrationisineffectiveineliminatingtheherbicides,clayandpeatareusefulinthat.Hence,thewateragencymayneedtoconsiderreplacingthemediafiltrationoraddingclay,peatfiltrationprocesses.Nevertheless,theprojectrequiresaspecificcost.Introductionofnewtreatmentprocessesandequipmentatthewatercompanymayneedtodevelopnewsites,labourandlandwillbeconsiderableexpenditures.Evenso,itisthebestchoiceforlocalwateragencybecausethiseffectivelyeradicatesPrometrynPlusfromenteringdrinkingwatersystems,eliminatinghealthrisks.Anothermethodmayleadtomeditation.Thepesticideremovalabilityofbiochar,whichisso-calledblackcarbon,hasbeenapproved.Itcanbemadeofwood,straworcropwastesthatburninanoxicenvironments,andithasadditionsonthesorptionandefficacyofherbicides.Butlarge-scaleindustrialapplicationsarestillbeingdeveloped（CabreraandSpokas,2011）.

Sourcescontrol

Greenchemistryofthemanufacturingcompany

Sourcecontrolisaneffectiveandthestraightforwardapproach,GreenChemistrywouldsolvethisaccurately,andthatwillbeatestforourcompanyandresearchdepartment.Thefollowingsuggestionsareonaccountoftheprinciplesofgreenchemistry（AnastasandWarner,1998;ACS,2017）

∙Prevention

Topreventthechemicalwastewouldbebetterthantreatafterithasbeendischarged.Areductioninwasteduringaproductionordevelopmentprocessmighthaveamultipliereffectonsubsequentoperationswastechemicalsproducedbythemanufacturingorresearchfacilitieswillberemarkablydeclined（Sheldon,2007）.

∙LessHazardousChemicalSyntheses

Improv