造纸工业废水的综合治理的几种方法1造纸工业废水的来源及特点1papersourceandcharacteristicsofindustrialwastewater造纸工业是世界6大工业污染源之一,占我国工业总废水量的10%左右。造纸废水主要为高浓度有机废水,并含木素、残碱、硫化物、氯化物等污染物。其特点是废水量大,COD质量浓度高,废水中的纤维悬浮物多,而且含二价硫元素,色度高,有硫醇类恶臭气味。造纸废水主要有三个来源:制浆废液(黑液)、中段水、纸机白水。造纸废水会给周围水体带来严重污染和生态环境的破坏。据近年统计资料介绍,全国制浆造纸工业污水排放量约占全国污水排放总量的10%~12%,居第三位;排放污水中化学耗氧量(COD)约占全国排放总量的40%-45%,居第一位。造纸工业废水的严重污染和危害已经引起了人们的广泛关注。随着人们环保意识的不断增强,彻底解决造纸工业废水对环境的污染已迫在眉睫。Papermakingindustryisoneoftheworld'ssixmajorindustrialpollutionsources,accountsforsome10%ofthetotalamountofwastewaterofChina'sindustry.Papermakingwastewatermainlyforhighconcentrationorganicwastewater,andcontainlignin,theresidualalkali,sulfide,chlorideandotherpollutants.Characterizedbylargeamountofwastewater,CODconcentration,highfibersuspendedsolidsinthewastewater,andcontainingthebivalentsulfur,highchromaticity,mercaptankindbadodor.Papermakingwastewaterhasthreemainsources:pulpingwasteliquor(blackliquor),ZhongDuanShui,papermachinewhitewater.Papermakingwastewatercanbringseriouspollutiontowateraroundandthedestructionoftheecologicalenvironment.Accordingtorecentstatistics,nationalpulpandpaperindustrywastewateremissionsaccountedforabout10%~12%oftotalsewagedischargeinthethird;Dischargeofchemicaloxygenconsumption(COD)accountedforabout40%ofthenationalemissions-40%inthefirstplace.Seriouspollutionandharmofpapermakingwastewaterhasattractedwidespreadattention.Alongwiththepeopleunceasingenhancementinenvironmentalconsciousness,completelysolvepaperindustrywastewaterpollutiontotheenvironmentisimminent.在制浆(化学法)和造纸生产过程中主要产生三类废水:黑(红)液、中段废水和纸机白水。黑(红)液主要是蒸煮制浆废水,中段水包括纸浆洗涤、筛选、漂白废水,纸机白水为抄纸车间废水。其中蒸煮废水的环境污染最严重,占整个造纸工业污染的90%。黑液的主要成分是木质素、纤维素、半纤维素、单糖、有机酸及氢氧化钠等,可以综合回收其中的有用物质;中段废水污染物复杂,含有较高浓度的木质素、纤维素和树脂酸盐等较难生物降解的物质成分,而且富含漂白阶段产生的对环境危害大的有机氯化物,具有很深的颜色和很大的毒性,pH为9~11,悬浮物1000mg/l左右,COD600-2500mg/1;抄纸废水,又称“白水”,主要来自打浆、浆料的净化筛选和造纸机湿部。废水中的污染物主要包括悬浮固形物,如纤维、填料、涂料,以及溶解的木材成分、添加的湿强剂、防腐剂等。(chemicalmethod)inpulpingandpapermakingprocessmainlyhavethreekindsofwastewater:black(red)fluid,midcoursewastewaterandpapermachinewhitewater.Black(red)fluidaremainlycookingpulpingwastewater,ZhongDuanShuiincludingpulpwashing,screeningandbleachingwastewater,wastepapermachinewhitewateriswritingworkshop.Includingcookingwastewaterpollutionismostserious,accountingfor90%ofthewholepaperindustrypollution.Isamajorcomponentofblackliquorlignin,cellulose,hemicellulose,andsimplesugars,organicacids,sodiumhydroxide,etc.,cancomprehensiverecoveryofusefulsubstances;Midcoursewastewaterpollutantscomplex,containingrelativelyhighconcentrationsofacidsalt,celluloseandligninresin,etc.,aredifficulttobiodegradablematerialcompositionandhighinbleachingstageofgreatdamagetotheenvironmentoforganicchloride,withdeepcolorandalotoftoxicity,pHfor9~11,suspendedmatterabout1000...
