实验室污水处理英文版 3页

LaboratoryWastewaterdisposal(Read748times)Herethechemicalusedineverytestperformed.1. ChloridecontentofcementConc.NitricaciddiluteNitricacid(1+2)&(1+100)silvernitrate(8.494g/L)AmmniumThiocyante(3.8g/LAmmoniumironsulphate-saturatedsolution2.InsolubleresidueConc.Hydrochloricacid&(1+19)sodiumcarbonate(50g/L03.sulphatecontentconcHCl&(1+19)Naoh(1+16)Bariumchloride(100g/L)4.SilicaAmmoniumchloride(0.5gaddto250mlwaterHClSulpuricacidhydrofluricacidsulpuricandhydroflouricareaddedtotheprecipiateinacrucibleandthenignited(soitsnotaddedtowastewater)filtratesolniskeptfortotaloxidedetermination4.totaloxidesmethyred(2g/linethanol)concnitricacidammoniasoln(1:1)ammoniumnitratesoln(2%)filtratesolutioniskeptforcalciumoxidedetermination5.calciumoxideDiluteAmmnia(1:4)diluteHCl(1:4)ammniumOxalate(1g/L)OxalicacidfiltratesolutionisreservedforMagnesiadetermination6.MagnesiatestconcnitricdiluteHClDiammniumhydrogenphosphate(saturated)concammoniadilute(25ml/L)&(1:3)ammoniumnitrate(2g\n/L)7.Ferricoxidedeterminationstannouschloridesoln-5gaddedto10mlHClanddiluteto100mlbariumdiphenylamoinesulphonate-0.3gin100mlwaterpotassiumdichromate-2.457g/LstauratedsolnofmercuricchlorideMostlythetestiscarriedoutbyheating/boiling,washingwithacid,filtering.precipiateburnatfurnace1000Cthenweigh.Thefiltrateisdiposedirectlyintothesinkthenatthedrainageandeventuallytothesea..pHnormallyisacidic.butweneutraliseitwithdiluteammoniumhydroxide. Isthissufficientenough? IboughtaplasticwatertanksoIcancollectallthefiltratesandflushitlargevolumeofwaterbeforeIdisposeittothedrainage Thefiltratesaftereachtestislessthan4liters.Pleasehelp.Canyoupleasesuggestwhatisthebestwayandeasiestwaytotreatthissmllamountofwastewaterinthelab.THEPROCESSTheFacultyofSciencethroughtheirresearchactivitiesandtheirAwardProgramsproduceasignificantquantityofchemicalwastewater.Priortotheadoptionoftheircleanerproductioninitiative,thechemicalwastewaterwascollected,treatedanddisposedofbyawastecontractservice.Giventhesignificantquantitiesofwastewaterproduced,thisoptionforcollectionanddisposalprovedtobeextremelycostly.Directdischargetosewerprovidesthemosteconomicallyviableoptionforthelaboratorywastewaterofanacceptableofstandard.DespitetheFacultyofScience抯wastewaterundergoingminimalpre-treatmentwithinthelaboratoriespriortodisposalitdidnotattaintheacceptablepHstandardfordirectdischargetothePowerandWaterAuthority(PAWA)sewer.Forwastewatereffluenttobedischargeddirectlytothesewer,thepHshouldgenerallynotbelowerthan6.5andnothigherthan11.TheacidandalkaliwastestreamsthatdonotoccurwithinthisrangehavethepotentialtoseriouslyaffectthepHvalueofthereceivingwateriftheyaredischargeddirectlywithoutacceptablepre-treatment.Theacidwastewaterreactswiththealkalinityofthereceivingwaterby:Ca(HCO3)2+2HCl=CaCl2+2H2O+2CO2Alkalisreactwithfreecarbondioxidedissolvedinthereceivingwaterandincreaseitsalkalinityby:\n2NaOH+CO2=Na2CO3+H2OIftheFacultyofSciencehaddischargedtheirwastewaterdirectlytosewerandhadnotadjustedthereactionofthepH,thenthefollowingproblemswouldhaveoccurred:1．Biocoensisasbothanimalandplantorganismsperishinexcessivelyacidandexcessivelyalkalinemedia.2．DamagetoPAWAsewerlinesandplantstructuresfromuntreatedeffluentthatwouldcorrodebothconcreteandmetals.3．Alkalishavethepotentialtocauseseriousdifficultiesintheoperationofthereceivingtreatmentplant.Sealantsusedinconduitsmaybeattackedbyalkalis,causingleakageanddamageinthenetworkaswellascausingprecipitationofvariousdepositsandhencechokingofthepipes.4.Increaseddemandforexcessivechemicalsnecessaryforcoagulationwhenemployedasatreatmentmethod;5.Insufficientprovisionforoptimumbacterialactivityinthebiologicaltreatmentofwastes;6.ProductionofnoxiousodourswhichmayemittedatloworhighpHvalues;7.DamagetothereceivingDarwinwatersandenvironsduetothedetrimentaleffectsoftheLaboratorywastewater.Consciousofthepossibledetrimentalimpactsoftheuntreatedwastewaterandtheincreasingcostofemployingawastecontractservice,theFacultyofScienceidentifiedtheneedtoinstalltheirowntreatmentsystemwhichcouldbeutilisedsoasallowforappropriatestandardofdirectdischargetosewer.TheprimaryfunctionofsuchatreatmentsystemwouldbetoneutralizetheacidityoralkalinityoftheFaculty抯wastewaterandinturnreducethecostsoftreatment.