简介：Aseriesof9soilsamplesweretakenatatimbertreatmentsiteinSWFrancewhereCusulphateandchromatedcopperarsenate(CCA)havebeenusedaswoodpreservatives(SitesP1toP9)andonesoilsamplewascollectedatanadjacentsiteonthesamesoiltype(SiteP10).Copperwasamajorcontaminantinalltopsoils,varyingfrom65(SoilP5)to2600mgCukg-1(SoilP7),exceedingbackgroundvaluesforFrenchsandysoils.AsandCrdidnotaccumulateinsoil,exceptatSiteP8(52mgAskg-1and87mgCrkg-1)whereCCA-treatedpostswerestacked.Soilecotoxicitywasassessedwithbioassaysusingradish,lettuce,slugArionrufusL.,andearthwormDendrobaenaoctaedra(Savigny).Thereweresignificantlydifferencesinlettucegerminationrate,lettuceleafyield,radishrootandleafyields,slugherbivory,andearthwormavoidance.Anadditionalbioassayshowedhighernegativeimpactsonbeanshootandrootyields,RhizobiumnodulecountsonBeanroots,andguaiacolperoxidaseactivityinprimaryBeanleavesforsoilfromSiteP7,withandwithoutfertilisation,thanforsoilfromSiteP10,despitebothsoilshavingasimilarvalueforcomputedfreeionCu2+activityinthesoilsolution(pCu2+).BeansgrowninsoilfromSiteP7thathadbeenfertilisedshowedelevatedfoliarCucontentandphytotoxicsymptoms.SoilsfromSitesP7(treatmentplant)andP6(storageoftreatedutilitypoles)hadthehighestecotoxicity,whereassoilfromSiteP10(highorganicmattercontentandcationexchangecapacity)hadthelowest.ExceptatSiteP10,thesoilfactorpCu2+computedwithsoilpHandtotalsoilCucouldbeusedtopredictsoilecotoxicity.

简介：Metalcontentandbioavailabilityareoftenthelimitingfactorsforapplicationofsewagesludgeinagriculturalfields.SewagesludgesampleswerecollectedfromfivetypicalurbanwastewatertreatmentplantsinChinatoinvestigatetheircontentsanddistributionofvariouschemicalfractionsofCu,Zn,Ni,Cr,PbandMobyusingtheBCR(CommunityBureauofReference)sequentialextractionprocedure.Thesludgescontainedconsiderableamountsoforganicmatter(31.8%-48.0%),totalN(16.3-26.4gkg-1)andtotalP(15.1-23.9gkg-1),indicatinghighpotentialagriculturalbenefitsoftheirpracticalapplications.However,totalZnandNicontentsinthesludgeexceededthevaluespermittedinChina'scontrolstandardsforpollutantsinsludgesfromagriculturaluse(GB4284-1984).TheresidualfractionwasthepredominantfractionforMo,NiandCr,theoxidizablefractionwastheprimaryfractionforCuandPb,andtheexchangeableandreduciblefractionswereprincipalforZn.Thedistributionofdifferentchemicalfractionsamongthesludgesamplesreflecteddifferencesintheirphysicochemicalproperties,especiallypH.ThesludgepHwasnegativelycorrelatedwiththepercentagesofreduciblefractionofCuandexchangeablefractionofZn.ThesludgesfromtheseplantsmightnotbesuitableforagriculturalapplicationsduetotheirhighcontentsofZn,NiandCr,aswellashighpotentialofmobilityandbioavailabilityofZn.

简介：Thelowremovaleffciencyoftotalnitrogen(TN)isoneofthemaindisadvantagesoftraditionalsinglestagesubsurfaceinfiltrationsystem,whichcombinesananaerobictankandasoilfilterfield.Inthisstudy,afull-scale,two-stageanaerobictankandsoiltrenchsystemwasdesignedandoperatedtoevaluatethefeasibilityandperformancesintreatingsewagefromaschoolcampusforoveraone-yearmonitoringperiod.Therawsewagewaspreparedandfedintothefirstanaerobictankandsecondtankby60%and40%,respectively.Thisnovelprocesscoulddecreasechemicaloxygendemandwiththedichromatemethodby89%-96%,suspendedsolidsby91%-97%,andtotalphosphorusby91%-97%.Thedenitrificationwassatisfactoryinthesecondstagesoiltrench,sotheremovalsofTNaswellasammonianitrogen(NH+4-N)reached68%-75%and96%-99%,respectively.ItappearedthattheremovaleffciencyofTNinthistwo-stageanaerobictankandsoiltrenchsystemwasmoreeffectivethanthatinthesinglestagesoilinfiltrationsystem.Theeffuentmetthedischargestandardforthesewagetreatmentplant(GB18918-2002)ofChina.