近年來,為進一步提高整體水環境質量,保護自然水體,我國城鎮汙水排放標準已逐步從“一級B”升級為“一級A”。2015年,國家出台《水汙染防治行動計劃》,部分省份和地區將進一步提高到“地表Ⅳ類水”排放標準,其化學需氧量、五日生化需氧量、氨氮、總氮和總磷的排放限值低至30、6.0、1.5、1.5和0.3 mg/L。因此,為滿足不斷提高的排放標準,傳統市政汙水處理工藝升級改造勢在必行。
市政汙水處理升級改造工藝現狀
目(mu)前(qian),市(shi)政(zheng)汙(wu)水(shui)處(chu)理(li)主(zhu)要(yao)采(cai)用(yong)以(yi)活(huo)性(xing)汙(wu)泥(ni)法(fa)為(wei)核(he)心(xin)的(de)生(sheng)物(wu)處(chu)理(li)工(gong)藝(yi),其(qi)出(chu)水(shui)水(shui)質(zhi)難(nan)以(yi)達(da)到(dao)日(ri)益(yi)嚴(yan)格(ge)的(de)排(pai)放(fang)標(biao)準(zhun)。已(yi)有(you)的(de)工(gong)藝(yi)升(sheng)級(ji)改(gai)造(zao)主(zhu)要(yao)采(cai)用(yong)在(zai)傳(chuan)統(tong)生(sheng)物(wu)處(chu)理(li)過(guo)程(cheng)後(hou)疊(die)加(jia)深(shen)度(du)處(chu)理(li)工(gong)藝(yi)的(de)方(fang)法(fa),常(chang)用(yong)的(de)深(shen)度(du)處(chu)理(li)工(gong)藝(yi)有(you)混(hun)凝(ning)沉(chen)澱(dian),反(fan)硝(xiao)化(hua)濾(lv)池(chi),曝(pu)氣(qi)生(sheng)物(wu)濾(lv)池(chi),高(gao)級(ji)氧(yang)化(hua)等(deng)。例(li)如(ru),經(jing)傳(chuan)統(tong)生(sheng)物(wu)處(chu)理(li)後(hou)汙(wu)水(shui)中(zhong)有(you)機(ji)物(wu)大(da)多(duo)以(yi)難(nan)生(sheng)物(wu)降(jiang)解(jie)物(wu)質(zhi)為(wei)主(zhu),為(wei)將(jiang)其(qi)濃(nong)度(du)降(jiang)至(zhi)30 mg/L以下,則需要增加高級氧化工藝或者吸附反應池來實現;出水氨氮濃度低至1.5 mg/L,需要增加曝氣生物濾池,折點加氯等工藝;總氮若要達到1.5 mg/L的高標準,則須增加反硝化濾池,自養反硝化,高級氧化,吸附或反滲透工藝等;同時需要增加化學除磷或混凝沉澱等工藝將總磷降至0.3 mg/L以下。
市政汙水處理升級改造工藝“再思考”
能耗和費用
目mu前qian,市shi政zheng汙wu水shui處chu理li采cai用yong的de疊die加jia式shi升sheng級ji改gai造zao方fang法fa不bu僅jin延yan長chang了le工gong藝yi處chu理li流liu程cheng,增zeng加jia了le整zheng個ge處chu理li係xi統tong的de複fu雜za性xing和he運yun行xing難nan度du,而er且qie相xiang應ying地di提ti高gao了le運yun行xing費fei用yong和he能neng源yuan消xiao耗hao。據ju測ce算suan,隨sui著zhe升sheng級ji改gai造zao的de實shi施shi,汙wu水shui處chu理li廠chang直zhi接jie運yun營ying成cheng本ben會hui增zeng加jia約yue30%,總體成本增加30~50%。
占地麵積
占zhan地di麵mian積ji擴kuo大da。在zai高gao度du城cheng市shi化hua導dao致zhi土tu地di資zi源yuan短duan缺que的de背bei景jing下xia,汙wu水shui處chu理li廠chang麵mian臨lin著zhe購gou地di費fei用yong高gao昂ang,甚shen至zhi無wu地di可ke用yong的de難nan題ti。大da部bu分fen汙wu水shui處chu理li廠chang需xu要yao盡jin量liang在zai原yuan廠chang址zhi範fan圍wei內nei進jin行xing擴kuo建jian、升sheng級ji改gai造zao提ti標biao。因yin此ci,隨sui著zhe汙wu水shui排pai放fang量liang的de不bu斷duan增zeng加jia與yu標biao準zhun的de日ri益yi提ti高gao,在zai現xian有you用yong地di上shang,疊die加jia深shen度du處chu理li工gong藝yi,無wu疑yi帶dai來lai了le更geng多duo的de用yong地di挑tiao戰zhan。不bu可ke避bi免mian的de,目mu前qian的de水shui平ping設she計ji需xu要yao逐zhu步bu過guo渡du到dao立li體ti設she計ji,最zui大da可ke能neng地di利li用yong地di上shang和he地di下xia空kong間jian。
新興微汙染物
suizherenmenduishuizhihuanjingyaoqiudebuduantigao,xinxingweiwuranwuzhujianjinrudazhongdeshiye,qizaishizhengwushuizhongdecunzaizhuangkuangyuelaiyueshoudaoguanzhu。xinxingweiwuranwu,baokuokangshengsu、鹵化物、塑料、藥品和個人護理品、雌激素、工業化合物如全氟辛烷磺酸和全氟辛酸等。其主要來自於人類活動,種類繁多,結構複雜,且數量及種類仍在持續增長。
例(li)如(ru),我(wo)國(guo)抗(kang)生(sheng)素(su)使(shi)用(yong)量(liang)持(chi)續(xu)增(zeng)加(jia),而(er)其(qi)中(zhong)大(da)部(bu)分(fen)會(hui)隨(sui)排(pai)泄(xie)物(wu)等(deng)進(jin)入(ru)水(shui)環(huan)境(jing)。抗(kang)生(sheng)素(su)的(de)殘(can)留(liu)會(hui)對(dui)生(sheng)物(wu)處(chu)理(li)單(dan)元(yuan)中(zhong)微(wei)生(sheng)物(wu)產(chan)生(sheng)一(yi)定(ding)的(de)抑(yi)製(zhi)作(zuo)用(yong),而(er)且(qie)長(chang)期(qi)暴(bao)露(lu)在(zai)低(di)劑(ji)量(liang)的(de)抗(kang)生(sheng)素(su)環(huan)境(jing)中(zhong),會(hui)被(bei)誘(you)導(dao)產(chan)生(sheng)抗(kang)性(xing)細(xi)菌(jun)和(he)抗(kang)性(xing)基(ji)因(yin)。抗(kang)性(xing)基(ji)因(yin)可(ke)通(tong)過(guo)水(shui)平(ping)轉(zhuan)移(yi)等(deng)傳(chuan)遞(di)給(gei)其(qi)他(ta)微(wei)生(sheng)物(wu),造(zao)成(cheng)更(geng)大(da)的(de)生(sheng)態(tai)係(xi)統(tong)危(wei)機(ji)。已(yi)有(you)調(tiao)查(zha)研(yan)究(jiu)表(biao)明(ming),歐(ou)洲(zhou)汙(wu)水(shui)處(chu)理(li)廠(chang)汙(wu)水(shui)中(zhong)存(cun)在(zai)抗(kang)性(xing)基(ji)因(yin)的(de)豐(feng)度(du)與(yu)汙(wu)水(shui)中(zhong)存(cun)在(zai)抗(kang)生(sheng)素(su)的(de)濃(nong)度(du)成(cheng)正(zheng)比(bi)。因(yin)此(ci),為(wei)減(jian)小(xiao)抗(kang)性(xing)細(xi)菌(jun)/基因的影響,抗生素的控製至關重要。
另一個例子,Covid-2019公(gong)共(gong)衛(wei)生(sheng)事(shi)件(jian)中(zhong),大(da)量(liang)消(xiao)毒(du)劑(ji)被(bei)用(yong)於(yu)殺(sha)滅(mie)水(shui)體(ti)中(zhong)的(de)致(zhi)病(bing)菌(jun)及(ji)病(bing)毒(du)以(yi)保(bao)證(zheng)水(shui)環(huan)境(jing)安(an)全(quan)。含(han)氯(lv)消(xiao)毒(du)劑(ji)是(shi)普(pu)遍(bian)使(shi)用(yong)的(de)消(xiao)毒(du)劑(ji),可(ke)有(you)效(xiao)殺(sha)滅(mie)水(shui)中(zhong)的(de)致(zhi)病(bing)菌(jun)和(he)病(bing)毒(du)。但(dan)帶(dai)來(lai)了(le)一(yi)個(ge)需(xu)要(yao)慎(shen)重(zhong)考(kao)慮(lv)的(de)問(wen)題(ti),即(ji)施(shi)用(yong)大(da)量(liang)含(han)氯(lv)消(xiao)毒(du)劑(ji),可(ke)導(dao)致(zhi)其(qi)與(yu)水(shui)體(ti)中(zhong)殘(can)餘(yu)或(huo)天(tian)然(ran)有(you)機(ji)物(wu)反(fan)應(ying)生(sheng)成(cheng)具(ju)有(you)毒(du)性(xing)的(de)鹵(lu)化(hua)消(xiao)毒(du)副(fu)產(chan)物(wu)。
盡管上述微汙染物在汙水中的濃度範圍很低(納克~微克/升),但dan其qi化hua學xue性xing質zhi穩wen定ding,難nan以yi生sheng物wu降jiang解jie,具ju有you持chi久jiu性xing。研yan究jiu發fa現xian,傳chuan統tong汙wu水shui處chu理li工gong藝yi在zai二er級ji甚shen至zhi三san級ji出chu水shui中zhong仍reng能neng檢jian測ce到dao一yi些xie新xin興xing微wei汙wu染ran的de存cun在zai 。這zhe極ji有you可ke能neng導dao致zhi微wei汙wu染ran物wu通tong過guo水shui體ti,進jin一yi步bu積ji累lei在zai水shui生sheng生sheng物wu和he水shui生sheng植zhi物wu的de食shi物wu鏈lian中zhong,並bing通tong過guo食shi物wu鏈lian的de富fu集ji效xiao應ying對dui環huan境jing和he人ren類lei造zao成cheng潛qian在zai風feng險xian。
政策驅動和技術突破
微汙染物因其濃度低、duihongguanzonghezhibiaogongxianjiaoxiaoerchangbeihushi。zaiwoguoxianyoudeshuizhiwuranbiaozhunzhongshangweimingqueguidingdabufenxinxingweiwuranwudepaifangzhunzehelianghuabiaozhun。lingyifangmian,muqianwoguowushuichulizaishengjigaizaogongyiguochengzhongwangwangyichangguiwuranwuheyingyangyandabiaoweizhuyaoxuanzeyiju,weijiangweiwuranwudeyouxiaoquchunarukaoliang。dankeyiyujian,ruoweiwuranwuzaiwushuichulizhongbunengyouxiaoquchu,huishiwushuichangchengweiweiwuranwuzhongyaodewurandianyuan,daozhidaliangweiwuranwupairuziranshuiti,zaochengyidingdehuanjingfengxian。ciwai,woguohenduodiquzhengzaizhubushixianchengshiwushuidezaishengliyong,huoyongyubuchongdibiaoshui、dixiashuishenzhiyinyongshuishuiyuanshui。zhejiangjinyibujiadashuixunhuanxitongzhong,xinxingweiwuranwudeqianyizhuanhuaduishengtaianquanherenleijiankangdeqianzaiweixie。yinci,wushuichulishengjigaizaogongyidexuanzeyingzaimanzuchangguiwuranwuyouxiaoquchudetongshi,jianguweiwuranwudekongzhi。
zhenduiweiwuranwudezhili,shouxianyingzaibiaozhunhezhengceshangyuyizhongshi。muqianwoguoshuizhizhibiaozhongquefajuedaduoshuxinxingweiwuranwudexianzhibiaozhunheduxingpinggu,jidaiwanshan,yingzhubujiangjuyouqianzaiweihaidexinxingweiwuranwunaruxinpaifangbiaozhun。ruishilianbanghuanjingbangongshi(FOEN)在2015年通過啟動《水保護條例》,將12種汙水中生物處理階段難以去除的有機微汙染物納入排放標準,要求在汙水處理過程中,必須對其中至少6種微汙染物進行有效控製。
其(qi)次(ci),要(yao)重(zhong)視(shi)先(xian)進(jin)技(ji)術(shu)對(dui)新(xin)興(xing)微(wei)汙(wu)染(ran)物(wu)去(qu)除(chu)的(de)有(you)效(xiao)性(xing),即(ji)針(zhen)對(dui)性(xing)的(de)選(xuan)擇(ze)同(tong)時(shi)具(ju)有(you)對(dui)微(wei)汙(wu)染(ran)物(wu)有(you)效(xiao)去(qu)除(chu)的(de)升(sheng)級(ji)改(gai)造(zao)工(gong)藝(yi)。例(li)如(ru),在(zai)瑞(rui)士(shi),基(ji)於(yu)臭(chou)氧(yang)的(de)高(gao)級(ji)氧(yang)化(hua)及(ji)活(huo)性(xing)炭(tan)吸(xi)附(fu)工(gong)藝(yi)應(ying)用(yong)於(yu)水(shui)體(ti)中(zhong)微(wei)汙(wu)染(ran)物(wu)的(de)去(qu)除(chu),可(ke)達(da)到(dao)至(zhi)少(shao)80%的去除率 ;在zai新xin加jia坡po,作zuo為wei新xin生sheng水shui工gong藝yi核he心xin的de反fan滲shen透tou工gong藝yi能neng夠gou有you效xiao截jie留liu已yi知zhi的de新xin興xing微wei汙wu染ran物wu。這zhe些xie技ji術shu可ke為wei我wo國guo正zheng在zai進jin行xing的de汙wu水shui處chu理li升sheng級ji改gai造zao提ti供gong有you意yi義yi的de參can考kao借jie鑒jian。
結語
隨著生態文明建設的深入推進和人們對水環境質量要求的不斷提高,汙水排放標準日益嚴格。升級改造工藝所帶來的能耗、費(fei)用(yong)和(he)占(zhan)地(di)等(deng)一(yi)係(xi)列(lie)問(wen)題(ti),有(you)一(yi)種(zhong)觀(guan)點(dian)認(ren)為(wei)是(shi)目(mu)前(qian)製(zhi)定(ding)的(de)汙(wu)水(shui)排(pai)放(fang)標(biao)準(zhun)過(guo)高(gao)。然(ran)而(er),值(zhi)得(de)探(tan)討(tao)的(de)是(shi),在(zai)提(ti)標(biao)改(gai)造(zao)已(yi)成(cheng)趨(qu)勢(shi)的(de)情(qing)況(kuang)下(xia),應(ying)慎(shen)重(zhong)考(kao)慮(lv)目(mu)前(qian)升(sheng)級(ji)改(gai)造(zao)技(ji)術(shu)路(lu)線(xian)是(shi)否(fou)能(neng)有(you)效(xiao)滿(man)足(zu)未(wei)來(lai)社(she)會(hui)與(yu)環(huan)境(jing)的(de)可(ke)持(chi)續(xu)發(fa)展(zhan)。





