導讀

城市污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)處(chu)(chu)理廠(chang)(chang)進(jin)(jin)(jin)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)濃度偏低(di)的(de)(de)(de)(de)問題受到行業(ye)的(de)(de)(de)(de)高度關注，研究確認普遍(bian)存在的(de)(de)(de)(de)管網沉(chen)積衰減(jian)、非(fei)生(sheng)活污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)稀釋及其“氧化(hua)性”對(dui)生(sheng)活污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)還(huan)(huan)原(yuan)性污(wu)(wu)(wu)(wu)(wu)染物的(de)(de)(de)(de)氧化(hua)還(huan)(huan)原(yuan)衰減(jian)等是城市污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)處(chu)(chu)理廠(chang)(chang)進(jin)(jin)(jin)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)BOD濃度偏低(di)的(de)(de)(de)(de)根本原(yuan)因，而(er)(er)沉(chen)積衰減(jian)、氧化(hua)還(huan)(huan)原(yuan)衰減(jian)及非(fei)生(sheng)活污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)擠占管網和污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)處(chu)(chu)理廠(chang)(chang)容積導(dao)(dao)致的(de)(de)(de)(de)污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)溢流排放則是城市生(sheng)活污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)集(ji)(ji)(ji)中(zhong)收集(ji)(ji)(ji)率(lv)偏低(di)的(de)(de)(de)(de)重要原(yuan)因，是我國排水(shui)(shui)(shui)(shui)(shui)(shui)(shui)系統有別于歐(ou)美發(fa)達國家的(de)(de)(de)(de)最(zui)典型特征。生(sheng)活污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)中(zhong)的(de)(de)(de)(de)有機氮(dan)(dan)磷(lin)(lin)會(hui)隨著污(wu)(wu)(wu)(wu)(wu)染物衰減(jian)過程(cheng)(cheng)而(er)(er)釋放到水(shui)(shui)(shui)(shui)(shui)(shui)(shui)中(zhong)，導(dao)(dao)致管道積泥呈現高碳(tan)低(di)氮(dan)(dan)磷(lin)(lin)特征，也會(hui)直接影響污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)處(chu)(chu)理廠(chang)(chang)進(jin)(jin)(jin)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)的(de)(de)(de)(de)碳(tan)氮(dan)(dan)磷(lin)(lin)比例。提出(chu)綜合(he)采取(qu)工(gong)程(cheng)(cheng)措(cuo)施和技術手段實現，是現階(jie)段快(kuai)速實現污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)處(chu)(chu)理廠(chang)(chang)進(jin)(jin)(jin)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)BOD濃度和城市生(sheng)活污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)集(ji)(ji)(ji)中(zhong)收集(ji)(ji)(ji)率(lv)提升的(de)(de)(de)(de)重要舉(ju)措(cuo)，對(dui)恢復(fu)污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)處(chu)(chu)理廠(chang)(chang)正常的(de)(de)(de)(de)碳(tan)氮(dan)(dan)磷(lin)(lin)比例關系具有重要的(de)(de)(de)(de)工(gong)程(cheng)(cheng)價值。

經過多個(ge)五年(nian)規劃(hua)的(de)全面推進(jin)，我國(guo)城(cheng)市(shi)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)(li)(li)設(she)施(shi)得(de)到快(kuai)速(su)普及，污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)(li)(li)率得(de)到大(da)幅度(du)(du)提(ti)升(sheng)，但(dan)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)(li)(li)廠(chang)進(jin)水(shui)(shui)(shui)(shui)濃度(du)(du)偏低(di)的(de)問(wen)題(ti)還(huan)比較(jiao)普遍(bian)，污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)直(zhi)排(pai)問(wen)題(ti)仍時有發(fa)(fa)生，與綠色高質量(liang)(liang)發(fa)(fa)展(zhan)的(de)國(guo)家(jia)(jia)戰(zhan)略(lve)導向存(cun)在較(jiao)大(da)差距。2019年(nian)住房(fang)城(cheng)鄉建(jian)設(she)部(bu)(bu)(bu)、生態環境(jing)部(bu)(bu)(bu)、國(guo)家(jia)(jia)發(fa)(fa)改委聯合印發(fa)(fa)《城(cheng)鎮(zhen)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)(li)(li)提(ti)質增效(xiao)(xiao)三(san)年(nian)行(xing)(xing)動方案（2019—2021年(nian)）》，提(ti)出(chu)“三(san)個(ge)基本消(xiao)除”（直(zhi)排(pai)口(kou)、空白區、黑臭水(shui)(shui)(shui)(shui)體）和(he)“兩個(ge)提(ti)升(sheng)”（城(cheng)市(shi)生活污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)收集(ji)(ji)效(xiao)(xiao)能(neng)、污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)(li)(li)廠(chang)進(jin)水(shui)(shui)(shui)(shui)BOD濃度(du)(du)）的(de)工作要求，排(pai)水(shui)(shui)(shui)(shui)行(xing)(xing)業(ye)逐(zhu)步(bu)實現了由(you)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)(li)(li)向污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)收集(ji)(ji)、由(you)水(shui)(shui)(shui)(shui)量(liang)(liang)處(chu)(chu)理(li)(li)(li)(li)向污(wu)(wu)(wu)染物(wu)處(chu)(chu)理(li)(li)(li)(li)的(de)轉變；2022年(nian)住房(fang)城(cheng)鄉建(jian)設(she)部(bu)(bu)(bu)、生態環境(jing)部(bu)(bu)(bu)、國(guo)家(jia)(jia)發(fa)(fa)改委、水(shui)(shui)(shui)(shui)利部(bu)(bu)(bu)聯合印發(fa)(fa)的(de)《深入打好城(cheng)市(shi)黑臭水(shui)(shui)(shui)(shui)體治(zhi)理(li)(li)(li)(li)攻(gong)堅(jian)戰(zhan)實施(shi)方案》更進(jin)一步(bu)明確提(ti)出(chu)城(cheng)市(shi)生活污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)集(ji)(ji)中收集(ji)(ji)率力(li)爭達(da)到70%和(he)進(jin)水(shui)(shui)(shui)(shui)BOD濃度(du)(du)高于100mg/L的(de)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)(li)(li)規模(mo)達(da)到90%以上的(de)目標要求，對(dui)排(pai)水(shui)(shui)(shui)(shui)行(xing)(xing)業(ye)效(xiao)(xiao)能(neng)提(ti)升(sheng)提(ti)出(chu)了更高要求。系(xi)統(tong)識別污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)(li)(li)廠(chang)進(jin)水(shui)(shui)(shui)(shui)濃度(du)(du)和(he)排(pai)水(shui)(shui)(shui)(shui)系(xi)統(tong)效(xiao)(xiao)能(neng)偏低(di)的(de)真正原因，合理(li)(li)(li)(li)選(xuan)用工程措施(shi)和(he)技(ji)術手(shou)段，快(kuai)速(su)實現進(jin)水(shui)(shui)(shui)(shui)濃度(du)(du)和(he)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)收集(ji)(ji)轉輸(shu)效(xiao)(xiao)能(neng)提(ti)升(sheng)的(de)目標要求，成為綠色高質量(liang)(liang)發(fa)(fa)展(zhan)新時代背(bei)景下(xia)排(pai)水(shui)(shui)(shui)(shui)行(xing)(xing)業(ye)的(de)重大(da)需求與挑(tiao)戰(zhan)。

01 排(pai)水管網的建設運行(xing)現(xian)狀與問(wen)題

1.1 分流制成為我國排水系統(tong)的主(zhu)要形(xing)式

近年(nian)(nian)(nian)來我國(guo)(guo)城(cheng)(cheng)(cheng)市排水管(guan)(guan)網(wang)(wang)的建設進度(du)(du)基(ji)本(ben)實現(xian)了與污水處(chu)(chu)理能力(li)(li)增(zeng)長(chang)(chang)(chang)率(lv)持平，根據住房城(cheng)(cheng)(cheng)鄉建設部《城(cheng)(cheng)(cheng)市建設統計年(nian)(nian)(nian)鑒》，2021年(nian)(nian)(nian)設市城(cheng)(cheng)(cheng)市污水管(guan)(guan)道(dao)和(he)(he)(he)雨水管(guan)(guan)道(dao)長(chang)(chang)(chang)度(du)(du)為(wei)36.68萬公(gong)里(li)和(he)(he)(he)33.48萬公(gong)里(li)，分(fen)(fen)別達(da)到(dao)2012年(nian)(nian)(nian)16.44萬公(gong)里(li)和(he)(he)(he)14.49萬公(gong)里(li)的2.23倍和(he)(he)(he)2.31倍，年(nian)(nian)(nian)增(zeng)長(chang)(chang)(chang)率(lv)可達(da)5%~10%，與6%~8%左(zuo)右的年(nian)(nian)(nian)均污水處(chu)(chu)理規模增(zeng)長(chang)(chang)(chang)率(lv)基(ji)本(ben)相當。另外，我國(guo)(guo)的分(fen)(fen)流制(zhi)(zhi)管(guan)(guan)網(wang)(wang)占比要明顯高于日(ri)本(ben)、美國(guo)(guo)、德國(guo)(guo)等(deng)發達(da)國(guo)(guo)家大都市水平，尤(you)其(qi)是(shi)(shi)隨著分(fen)(fen)流制(zhi)(zhi)管(guan)(guan)網(wang)(wang)建設和(he)(he)(he)雨污分(fen)(fen)流改(gai)造(zao)工(gong)作的持續推(tui)進，合(he)(he)(he)流制(zhi)(zhi)管(guan)(guan)道(dao)長(chang)(chang)(chang)度(du)(du)占排水管(guan)(guan)道(dao)總長(chang)(chang)(chang)度(du)(du)的比例也(ye)已(yi)經(jing)由2012年(nian)(nian)(nian)的接(jie)近27%降(jiang)(jiang)低(di)至(zhi)2021年(nian)(nian)(nian)的低(di)于12%，合(he)(he)(he)流制(zhi)(zhi)已(yi)經(jing)不再(zai)是(shi)(shi)我國(guo)(guo)城(cheng)(cheng)(cheng)市排水管(guan)(guan)網(wang)(wang)的主(zhu)要形(xing)式(shi)。2012-2018年(nian)(nian)(nian)我國(guo)(guo)的合(he)(he)(he)流制(zhi)(zhi)管(guan)(guan)網(wang)(wang)長(chang)(chang)(chang)度(du)(du)一直處(chu)(chu)于10.30~11.10萬公(gong)里(li)上下(xia)浮動，而2019年(nian)(nian)(nian)提質增(zeng)效(xiao)工(gong)作推(tui)進以來，合(he)(he)(he)流制(zhi)(zhi)管(guan)(guan)網(wang)(wang)總長(chang)(chang)(chang)度(du)(du)呈現(xian)逐(zhu)年(nian)(nian)(nian)降(jiang)(jiang)低(di)的趨(qu)勢，2021年(nian)(nian)(nian)已(yi)經(jing)降(jiang)(jiang)低(di)至(zhi)9.25萬公(gong)里(li)，充分(fen)(fen)體現(xian)了各地雨污分(fen)(fen)流改(gai)造(zao)工(gong)作的努力(li)(li)與成效(xiao)，也(ye)顯現(xian)了在城(cheng)(cheng)(cheng)市建成區(qu)，尤(you)其(qi)是(shi)(shi)老舊(jiu)城(cheng)(cheng)(cheng)區(qu)開(kai)展雨污分(fen)(fen)流改(gai)造(zao)工(gong)作的實施難度(du)(du)。圖1為(wei)2012-2021期間設市城(cheng)(cheng)(cheng)市污水管(guan)(guan)道(dao)、雨水管(guan)(guan)道(dao)和(he)(he)(he)合(he)(he)(he)流制(zhi)(zhi)管(guan)(guan)道(dao)長(chang)(chang)(chang)度(du)(du)的變化(hua)曲線。

圖(tu)1  2012-2021年期間全(quan)國排水管網發展趨勢(shi)圖(tu)

1.2 污水(shui)水(shui)質的季節性差異并(bing)不顯著(zhu)

無論是合流(liu)(liu)制管(guan)(guan)網還是分(fen)流(liu)(liu)制污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)管(guan)(guan)網，旱(han)(han)季(ji)(ji)(ji)(ji)的(de)(de)(de)(de)(de)(de)(de)核心功能(neng)都是居民生活污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)污(wu)(wu)(wu)(wu)(wu)染(ran)物的(de)(de)(de)(de)(de)(de)(de)收集轉輸，因此(ci)在沒(mei)有雨(yu)水(shui)(shui)(shui)(shui)排入(ru)摻混的(de)(de)(de)(de)(de)(de)(de)情況下，污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)廠(chang)進水(shui)(shui)(shui)(shui)應(ying)表(biao)現(xian)(xian)出(chu)(chu)相(xiang)對(dui)較(jiao)高的(de)(de)(de)(de)(de)(de)(de)濃(nong)(nong)(nong)(nong)(nong)度(du)水(shui)(shui)(shui)(shui)平(ping)(ping)；而降(jiang)雨(yu)期間因雨(yu)水(shui)(shui)(shui)(shui)排入(ru)稀釋，合流(liu)(liu)制管(guan)(guan)網服務范圍內的(de)(de)(de)(de)(de)(de)(de)污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)廠(chang)進水(shui)(shui)(shui)(shui)濃(nong)(nong)(nong)(nong)(nong)度(du)會明(ming)(ming)顯低于旱(han)(han)季(ji)(ji)(ji)(ji)水(shui)(shui)(shui)(shui)平(ping)(ping)。為(wei)此(ci)以全(quan)國(guo)2000多座(zuo)城(cheng)市污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)廠(chang)7月(yue)(yue)（代表(biao)雨(yu)季(ji)(ji)(ji)(ji)水(shui)(shui)(shui)(shui)平(ping)(ping)）和(he)12月(yue)(yue)（代表(biao)旱(han)(han)季(ji)(ji)(ji)(ji)水(shui)(shui)(shui)(shui)平(ping)(ping)）的(de)(de)(de)(de)(de)(de)(de)進水(shui)(shui)(shui)(shui)BOD濃(nong)(nong)(nong)(nong)(nong)度(du)為(wei)例進行分(fen)析(xi)，結果(guo)(guo)表(biao)明(ming)(ming)12月(yue)(yue)進水(shui)(shui)(shui)(shui)BOD大(da)于150 mg/L的(de)(de)(de)(de)(de)(de)(de)污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)廠(chang)數量和(he)規(gui)模占比分(fen)別為(wei)16.7%和(he)22.7%，意(yi)味著旱(han)(han)季(ji)(ji)(ji)(ji)進水(shui)(shui)(shui)(shui)BOD濃(nong)(nong)(nong)(nong)(nong)度(du)相(xiang)對(dui)較(jiao)高的(de)(de)(de)(de)(de)(de)(de)污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)廠(chang)占比并(bing)(bing)(bing)不高，大(da)部(bu)分(fen)并(bing)(bing)(bing)沒(mei)有顯示出(chu)(chu)非降(jiang)雨(yu)期間應(ying)有的(de)(de)(de)(de)(de)(de)(de)高濃(nong)(nong)(nong)(nong)(nong)度(du)水(shui)(shui)(shui)(shui)平(ping)(ping)，而且近(jin)年來部(bu)分(fen)城(cheng)市還出(chu)(chu)現(xian)(xian)了(le)旱(han)(han)季(ji)(ji)(ji)(ji)濃(nong)(nong)(nong)(nong)(nong)度(du)降(jiang)低的(de)(de)(de)(de)(de)(de)(de)趨勢(shi)，可能(neng)與入(ru)河排污(wu)(wu)(wu)(wu)(wu)口旱(han)(han)季(ji)(ji)(ji)(ji)過度(du)截(jie)(jie)污(wu)(wu)(wu)(wu)(wu)，大(da)量低濃(nong)(nong)(nong)(nong)(nong)度(du)非生活污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)截(jie)(jie)流(liu)(liu)排入(ru)污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)管(guan)(guan)網造成的(de)(de)(de)(de)(de)(de)(de)污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)稀釋等做法直接相(xiang)關；而7月(yue)(yue)進水(shui)(shui)(shui)(shui)BOD小于50 mg/L的(de)(de)(de)(de)(de)(de)(de)污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)廠(chang)數量和(he)規(gui)模占比分(fen)別為(wei)16.8%和(he)11.2%，雨(yu)季(ji)(ji)(ji)(ji)進水(shui)(shui)(shui)(shui)濃(nong)(nong)(nong)(nong)(nong)度(du)降(jiang)低的(de)(de)(de)(de)(de)(de)(de)問題也并(bing)(bing)(bing)不顯著，降(jiang)雨(yu)對(dui)BOD的(de)(de)(de)(de)(de)(de)(de)影響并(bing)(bing)(bing)不突出(chu)(chu)。以上數據(ju)分(fen)析(xi)結果(guo)(guo)表(biao)明(ming)(ming)，合流(liu)(liu)制并(bing)(bing)(bing)非我國(guo)污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)廠(chang)進水(shui)(shui)(shui)(shui)濃(nong)(nong)(nong)(nong)(nong)度(du)偏低的(de)(de)(de)(de)(de)(de)(de)根本原因，大(da)部(bu)分(fen)污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)廠(chang)雨(yu)季(ji)(ji)(ji)(ji)并(bing)(bing)(bing)未呈現(xian)(xian)出(chu)(chu)明(ming)(ming)顯的(de)(de)(de)(de)(de)(de)(de)降(jiang)雨(yu)稀釋問題，而旱(han)(han)季(ji)(ji)(ji)(ji)也并(bing)(bing)(bing)沒(mei)有表(biao)現(xian)(xian)出(chu)(chu)應(ying)有的(de)(de)(de)(de)(de)(de)(de)高濃(nong)(nong)(nong)(nong)(nong)度(du)水(shui)(shui)(shui)(shui)平(ping)(ping)，污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)廠(chang)旱(han)(han)季(ji)(ji)(ji)(ji)濃(nong)(nong)(nong)(nong)(nong)度(du)提(ti)升必將成為(wei)今后(hou)提(ti)質增(zeng)效工作的(de)(de)(de)(de)(de)(de)(de)重要(yao)內容。

02 低收集率及污水低濃度的成因分析

2.1 關(guan)于城(cheng)市生活污(wu)水集(ji)中收(shou)集(ji)率

城(cheng)(cheng)市生(sheng)活污水集(ji)中(zhong)收集(ji)率是應對(dui)排(pai)水行業(ye)綠色高(gao)質量發展戰略(lve)導向(xiang)，實現排(pai)水行業(ye)由水量處理(li)考(kao)核向(xiang)污染物收集(ji)處理(li)考(kao)核轉(zhuan)變的(de)重要指標，也是排(pai)水行業(ye)管理(li)方式(shi)轉(zhuan)變的(de)一次探(tan)索。該指標于2019年通過《城(cheng)(cheng)鎮污水處理(li)提質增效三年行動(dong)方案（2019—2021年）》政策文件首次向(xiang)社(she)會公(gong)(gong)開，2021年4月住房城(cheng)(cheng)鄉建設部、國家統(tong)計局《城(cheng)(cheng)市（縣城(cheng)(cheng)）和村鎮建設統(tong)計調查制度》正(zheng)式(shi)向(xiang)社(she)會公(gong)(gong)布了該指標的(de)定(ding)義(yi)和核算方法，即(ji)報告(gao)期內向(xiang)污水處理(li)廠排(pai)水的(de)城(cheng)(cheng)區人(ren)口占城(cheng)(cheng)區用水總(zong)人(ren)口的(de)比例，計算公(gong)(gong)式(shi)表述為：

其中：

其(qi)中(zhong)，人(ren)均日生(sheng)活污染(ran)物排(pai)(pai)放(fang)量指每人(ren)每天排(pai)(pai)放(fang)的生(sheng)活污水污染(ran)物的量，以BOD計(ji)，根(gen)(gen)據《室外排(pai)(pai)水設計(ji)規(gui)范》(GB50014-2006)確定為45g/(人(ren)·d)，各地也可(ke)根(gen)(gen)據中(zhong)國城(cheng)鎮供水排(pai)(pai)水協(xie)會(hui)團體標準《城(cheng)鎮居(ju)民生(sheng)活污水污染(ran)物產(chan)生(sheng)量測(ce)定》（T/CUWA 10101—2021）開展測(ce)定并提出(chu)修改建議(yi)。

根據公式(1)和(3)，城市生活污水集中收(shou)集率計算公式最終可表述為：

根(gen)據公式(shi)(4)，其分(fen)(fen)母是(shi)指(zhi)居民日常生(sheng)(sheng)活(huo)(huo)產生(sheng)(sheng)，隨(sui)污(wu)(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)排放并應(ying)被污(wu)(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)處(chu)(chu)理廠(chang)收集(ji)處(chu)(chu)理的污(wu)(wu)(wu)(wu)(wu)(wu)染物量，而分(fen)(fen)子(zi)則是(shi)指(zhi)城(cheng)鎮污(wu)(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)處(chu)(chu)理廠(chang)接納的生(sheng)(sheng)活(huo)(huo)污(wu)(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)污(wu)(wu)(wu)(wu)(wu)(wu)染物總量，也即城(cheng)市生(sheng)(sheng)活(huo)(huo)污(wu)(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)集(ji)中收集(ji)率可以更直觀(guan)的表征為污(wu)(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)處(chu)(chu)理廠(chang)收集(ji)的生(sheng)(sheng)活(huo)(huo)污(wu)(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)污(wu)(wu)(wu)(wu)(wu)(wu)染物量占應(ying)收集(ji)生(sheng)(sheng)活(huo)(huo)污(wu)(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)污(wu)(wu)(wu)(wu)(wu)(wu)染物量的比值。生(sheng)(sheng)活(huo)(huo)污(wu)(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)污(wu)(wu)(wu)(wu)(wu)(wu)染物在(zai)管網系統內沉積(ji)、反應(ying)衰減，以及(ji)非生(sheng)(sheng)活(huo)(huo)污(wu)(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)擠占污(wu)(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)管道和(he)污(wu)(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)處(chu)(chu)理廠(chang)所致的生(sheng)(sheng)活(huo)(huo)污(wu)(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)溢(yi)流排放流失都可能是(shi)造成污(wu)(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)處(chu)(chu)理廠(chang)進水(shui)(shui)(shui)濃(nong)度和(he)城(cheng)市生(sheng)(sheng)活(huo)(huo)污(wu)(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)集(ji)中收集(ji)率偏低(di)的直接原因(yin)。

2.2 管網沉積對濃度和(he)收集(ji)率的影響

污水收集系統污染物(wu)的沉積衰減會同時影響污水處(chu)理(li)廠(chang)進水濃度和(he)城市生活(huo)污水集中收集率(lv)(lv)指標，尤其是沉積物(wu)的厭氧水解和(he)降雨(yu)沖刷入河，是導致很多城市生活(huo)污水集中收集率(lv)(lv)長期偏(pian)低的重要原因。

化(hua)(hua)(hua)糞(fen)(fen)池(chi)(chi)(chi)不一(yi)定會成為污(wu)染(ran)(ran)物(wu)(wu)衰(shuai)減的(de)(de)(de)(de)(de)(de)主要貢獻者(zhe)。化(hua)(hua)(hua)糞(fen)(fen)池(chi)(chi)(chi)是城市(shi)排(pai)水系統不健全階段的(de)(de)(de)(de)(de)(de)重要產物(wu)(wu)，作為城市(shi)污(wu)水收集(ji)系統重要的(de)(de)(de)(de)(de)(de)源頭“沉(chen)淀(dian)池(chi)(chi)(chi)”，正常(chang)運(yun)維(wei)(wei)的(de)(de)(de)(de)(de)(de)化(hua)(hua)(hua)糞(fen)(fen)池(chi)(chi)(chi)通常(chang)可以去(qu)除(chu)60%~80%的(de)(de)(de)(de)(de)(de)SS和20%~30%的(de)(de)(de)(de)(de)(de)COD。但化(hua)(hua)(hua)糞(fen)(fen)池(chi)(chi)(chi)對污(wu)染(ran)(ran)物(wu)(wu)的(de)(de)(de)(de)(de)(de)去(qu)除(chu)能力與運(yun)維(wei)(wei)狀態，尤其是實際停留時(shi)間(jian)直接(jie)相關，按規范(fan)要求化(hua)(hua)(hua)糞(fen)(fen)池(chi)(chi)(chi)一(yi)般(ban)應3~12個(ge)月進行(xing)清(qing)掏，因此剛投入運(yun)行(xing)或定期清(qing)掏的(de)(de)(de)(de)(de)(de)化(hua)(hua)(hua)糞(fen)(fen)池(chi)(chi)(chi)，實際停留時(shi)間(jian)相對較長，對污(wu)染(ran)(ran)物(wu)(wu)的(de)(de)(de)(de)(de)(de)去(qu)除(chu)效率(lv)一(yi)般(ban)也相對較高。但由于權屬和相關費用問題，我國大部(bu)分居民(min)小區的(de)(de)(de)(de)(de)(de)化(hua)(hua)(hua)糞(fen)(fen)池(chi)(chi)(chi)通常(chang)只有在出現冒溢或其他事故(gu)時(shi)才會進行(xing)清(qing)掏作業(ye)，從而導致(zhi)許多化(hua)(hua)(hua)糞(fen)(fen)池(chi)(chi)(chi)長期被沉(chen)淀(dian)物(wu)(wu)填滿，變(bian)成了污(wu)水的(de)(de)(de)(de)(de)(de)常(chang)規排(pai)放通道，基本不具(ju)備污(wu)染(ran)(ran)物(wu)(wu)沉(chen)淀(dian)去(qu)除(chu)的(de)(de)(de)(de)(de)(de)功效。因此化(hua)(hua)(hua)糞(fen)(fen)池(chi)(chi)(chi)的(de)(de)(de)(de)(de)(de)污(wu)染(ran)(ran)物(wu)(wu)去(qu)除(chu)效率(lv)評價(jia)，一(yi)般(ban)應兼顧化(hua)(hua)(hua)糞(fen)(fen)池(chi)(chi)(chi)的(de)(de)(de)(de)(de)(de)運(yun)維(wei)(wei)和清(qing)掏狀況。

低流(liu)(liu)(liu)(liu)速管(guan)(guan)(guan)網可(ke)(ke)能成(cheng)為(wei)(wei)污(wu)(wu)(wu)染(ran)物(wu)(wu)(wu)沉(chen)(chen)積的(de)重(zhong)(zhong)要(yao)場所。污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)收集管(guan)(guan)(guan)網，尤其(qi)是(shi)合流(liu)(liu)(liu)(liu)制管(guan)(guan)(guan)網也會(hui)成(cheng)為(wei)(wei)生(sheng)活(huo)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)污(wu)(wu)(wu)染(ran)物(wu)(wu)(wu)的(de)重(zhong)(zhong)要(yao)“沉(chen)(chen)淀池”，其(qi)沉(chen)(chen)淀狀況與管(guan)(guan)(guan)網日(ri)常(chang)運(yun)行流(liu)(liu)(liu)(liu)速直接相關(guan)。《室外(wai)排水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)設(she)計(ji)標(biao)準》GB 50014要(yao)求(qiu)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)道(dao)在(zai)設(she)計(ji)充(chong)滿(man)度下的(de)流(liu)(liu)(liu)(liu)速應為(wei)(wei)0.6 m/s，雨(yu)(yu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)道(dao)和(he)合流(liu)(liu)(liu)(liu)管(guan)(guan)(guan)道(dao)在(zai)滿(man)流(liu)(liu)(liu)(liu)時的(de)流(liu)(liu)(liu)(liu)速應為(wei)(wei)0.75 m/s，這不(bu)(bu)(bu)僅是(shi)對(dui)工程設(she)計(ji)的(de)要(yao)求(qiu)，也是(shi)對(dui)確(que)保顆粒(li)物(wu)(wu)(wu)不(bu)(bu)(bu)發生(sheng)沉(chen)(chen)積的(de)管(guan)(guan)(guan)網日(ri)常(chang)運(yun)行要(yao)求(qiu)，部分發達(da)國家甚(shen)至(zhi)(zhi)要(yao)求(qiu)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)網的(de)日(ri)常(chang)運(yun)行流(liu)(liu)(liu)(liu)速應不(bu)(bu)(bu)低于0.75 m/s。但我(wo)國很多城(cheng)市的(de)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)道(dao)流(liu)(liu)(liu)(liu)速只有(you)(you)0.1 ~ 0.3 m/s甚(shen)至(zhi)(zhi)更低的(de)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)平(ping)，污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)中(zhong)的(de)顆粒(li)物(wu)(wu)(wu)攜帶可(ke)(ke)吸附污(wu)(wu)(wu)染(ran)物(wu)(wu)(wu)在(zai)管(guan)(guan)(guan)道(dao)內(nei)沉(chen)(chen)積，使污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)道(dao)成(cheng)為(wei)(wei)典型的(de)“沉(chen)(chen)淀池”，部分城(cheng)市污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)道(dao)雨(yu)(yu)季來(lai)臨前的(de)沉(chen)(chen)積深度甚(shen)至(zhi)(zhi)可(ke)(ke)達(da)到50%，其(qi)VSS/SS比值達(da)到20%以上，是(shi)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)處(chu)理廠進水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)濃(nong)(nong)度偏低的(de)一個重(zhong)(zhong)要(yao)原因；而后這些沉(chen)(chen)積物(wu)(wu)(wu)會(hui)在(zai)降(jiang)雨(yu)(yu)期間隨雨(yu)(yu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)沖刷進入(ru)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)處(chu)理廠或城(cheng)市河湖水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)體，成(cheng)為(wei)(wei)生(sheng)活(huo)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)污(wu)(wu)(wu)染(ran)物(wu)(wu)(wu)流(liu)(liu)(liu)(liu)失、城(cheng)市生(sheng)活(huo)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)集中(zhong)收集率(lv)偏低的(de)重(zhong)(zhong)要(yao)原因。提高污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)網流(liu)(liu)(liu)(liu)速，避免管(guan)(guan)(guan)網沉(chen)(chen)積是(shi)現(xian)階段(duan)快速實現(xian)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)處(chu)理廠進水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)濃(nong)(nong)度和(he)城(cheng)市生(sheng)活(huo)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)集中(zhong)收集率(lv)同步提升的(de)最簡單有(you)(you)效措施。

污(wu)水(shui)(shui)(shui)管(guan)道(dao)沉(chen)(chen)積或(huo)許是(shi)污(wu)水(shui)(shui)(shui)處(chu)理(li)(li)廠低(di)(di)(di)碳(tan)(tan)高氮磷(lin)的(de)重(zhong)(zhong)要(yao)原(yuan)因。居民生(sheng)(sheng)活(huo)污(wu)染物(wu)(wu)(wu)在污(wu)水(shui)(shui)(shui)管(guan)道(dao)沉(chen)(chen)積過(guo)程中(zhong)(zhong)還(huan)會(hui)發生(sheng)(sheng)厭(yan)氧(yang)水(shui)(shui)(shui)解(jie)或(huo)微好氧(yang)反(fan)應，有(you)機氮磷(lin)很容易(yi)被氨化或(huo)磷(lin)酸鹽(yan)化，由沉(chen)(chen)淀(dian)物(wu)(wu)(wu)轉(zhuan)變為離(li)子(zi)態并再次進(jin)(jin)入污(wu)水(shui)(shui)(shui)中(zhong)(zhong)，從而(er)使管(guan)道(dao)底(di)泥(ni)(ni)具有(you)高碳(tan)(tan)低(di)(di)(di)氮磷(lin)的(de)特征(zheng)。筆(bi)者完成的(de)北方某城(cheng)市(shi)污(wu)水(shui)(shui)(shui)管(guan)網(wang)底(di)泥(ni)(ni)檢測結果(guo)顯示，COD/TN通常可達（30~50）:1，COD/TP可達（80~100）:1。按照排(pai)水(shui)(shui)(shui)系(xi)(xi)(xi)統污(wu)染物(wu)(wu)(wu)的(de)物(wu)(wu)(wu)料平衡關(guan)系(xi)(xi)(xi)，沉(chen)(chen)積物(wu)(wu)(wu)中(zhong)(zhong)的(de)COD/TN和(he)COD/TP比(bi)增大(da)也就(jiu)意味(wei)著(zhu)污(wu)水(shui)(shui)(shui)處(chu)理(li)(li)廠進(jin)(jin)水(shui)(shui)(shui)通常呈現低(di)(di)(di)COD/TN和(he)COD/TP比(bi)問(wen)題(ti)，因此管(guan)道(dao)沉(chen)(chen)積及沉(chen)(chen)積物(wu)(wu)(wu)的(de)生(sheng)(sheng)化反(fan)應可能(neng)是(shi)我國城(cheng)鎮污(wu)水(shui)(shui)(shui)處(chu)理(li)(li)廠普(pu)遍存在低(di)(di)(di)碳(tan)(tan)高氮磷(lin)問(wen)題(ti)的(de)重(zhong)(zhong)要(yao)原(yuan)因，污(wu)水(shui)(shui)(shui)管(guan)網(wang)沉(chen)(chen)積控(kong)制可能(neng)是(shi)緩解(jie)污(wu)水(shui)(shui)(shui)處(chu)理(li)(li)廠碳(tan)(tan)源不足，降低(di)(di)(di)碳(tan)(tan)源和(he)除磷(lin)藥劑投加量，實現排(pai)水(shui)(shui)(shui)系(xi)(xi)(xi)統低(di)(di)(di)碳(tan)(tan)運行(xing)的(de)重(zhong)(zhong)要(yao)途徑。

管(guan)(guan)(guan)(guan)道(dao)降(jiang)(jiang)(jiang)(jiang)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei)(wei)(wei)提流(liu)速(su)(su)要提前研判河湖水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)倒(dao)灌(guan)(guan)風險。根據流(liu)量(liang)(liang)、流(liu)速(su)(su)和過(guo)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)斷(duan)(duan)面(mian)(mian)面(mian)(mian)積的(de)(de)計算關(guan)系，在(zai)(zai)流(liu)量(liang)(liang)一定的(de)(de)情(qing)況(kuang)下(xia)，過(guo)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)斷(duan)(duan)面(mian)(mian)面(mian)(mian)積越小(xiao)則流(liu)速(su)(su)越高，而減小(xiao)過(guo)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)斷(duan)(duan)面(mian)(mian)面(mian)(mian)積則意味(wei)著(zhu)(zhu)需要降(jiang)(jiang)(jiang)(jiang)低(di)(di)管(guan)(guan)(guan)(guan)網(wang)(wang)(wang)運(yun)行(xing)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei)(wei)(wei)，也就(jiu)是說在(zai)(zai)處(chu)理水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)量(liang)(liang)一定的(de)(de)情(qing)況(kuang)下(xia)提升流(liu)速(su)(su)就(jiu)必須要降(jiang)(jiang)(jiang)(jiang)低(di)(di)運(yun)行(xing)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei)(wei)(wei)。但位(wei)(wei)(wei)(wei)于(yu)城(cheng)(cheng)市(shi)河湖周邊或(huo)埋在(zai)(zai)地(di)(di)下(xia)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei)(wei)(wei)線之(zhi)下(xia)的(de)(de)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)(guan)網(wang)(wang)(wang)，多(duo)數會因各種(zhong)原(yuan)因而與(yu)城(cheng)(cheng)市(shi)河湖或(huo)地(di)(di)下(xia)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)之(zhi)間(jian)形(xing)成通(tong)道(dao)，而且部分通(tong)道(dao)還(huan)涉及到城(cheng)(cheng)市(shi)排水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)安全(quan)等(deng)問題，在(zai)(zai)這種(zhong)情(qing)況(kuang)下(xia)降(jiang)(jiang)(jiang)(jiang)低(di)(di)管(guan)(guan)(guan)(guan)道(dao)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei)(wei)(wei)必然導致更多(duo)的(de)(de)河湖水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)或(huo)地(di)(di)下(xia)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)進入污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)(guan)網(wang)(wang)(wang)，如(ru)(ru)長(chang)(chang)江(jiang)經(jing)濟(ji)帶(dai)某污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)處(chu)理廠(chang)(chang)進行(xing)集水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)井降(jiang)(jiang)(jiang)(jiang)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei)(wei)(wei)運(yun)行(xing)試驗期間(jian)發現大量(liang)(liang)河水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)通(tong)過(guo)沿(yan)河主干(gan)管(guan)(guan)(guan)(guan)涌入，導致污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)處(chu)理廠(chang)(chang)濃度持續降(jiang)(jiang)(jiang)(jiang)低(di)(di)。部分城(cheng)(cheng)市(shi)降(jiang)(jiang)(jiang)(jiang)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei)(wei)(wei)經(jing)驗表明(ming)，只有(you)(you)做好管(guan)(guan)(guan)(guan)網(wang)(wang)(wang)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei)(wei)(wei)與(yu)城(cheng)(cheng)市(shi)河湖水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei)(wei)(wei)的(de)(de)協調，適度降(jiang)(jiang)(jiang)(jiang)低(di)(di)城(cheng)(cheng)市(shi)河湖運(yun)行(xing)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei)(wei)(wei)，才可能(neng)真正意義上實現管(guan)(guan)(guan)(guan)網(wang)(wang)(wang)降(jiang)(jiang)(jiang)(jiang)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei)(wei)(wei)提流(liu)速(su)(su)，如(ru)(ru)南方某城(cheng)(cheng)市(shi)部分河道(dao)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei)(wei)(wei)由(you)2~3米降(jiang)(jiang)(jiang)(jiang)低(di)(di)至(zhi)0.5米左(zuo)右(you)后，原(yuan)長(chang)(chang)期滿流(liu)的(de)(de)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)(guan)網(wang)(wang)(wang)非常容易的(de)(de)實現了運(yun)行(xing)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei)(wei)(wei)降(jiang)(jiang)(jiang)(jiang)低(di)(di)至(zhi)60%左(zuo)右(you)設計充滿度的(de)(de)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)平；長(chang)(chang)江(jiang)經(jing)濟(ji)帶(dai)某個被中央環保督(du)察通(tong)報的(de)(de)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)處(chu)理廠(chang)(chang)前溢流(liu)口，因上游(you)河道(dao)降(jiang)(jiang)(jiang)(jiang)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei)(wei)(wei)整治，污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)處(chu)理廠(chang)(chang)進水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)量(liang)(liang)由(you)超過(guo)10萬m3/d銳減至(zhi)不足(zu)6萬m3/d。大量(liang)(liang)工(gong)程經(jing)驗表明(ming)，城(cheng)(cheng)市(shi)河湖降(jiang)(jiang)(jiang)(jiang)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei)(wei)(wei)對恢(hui)復(fu)管(guan)(guan)(guan)(guan)網(wang)(wang)(wang)正常運(yun)行(xing)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei)(wei)(wei)，減少河湖水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)體(ti)倒(dao)灌(guan)(guan)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)(guan)網(wang)(wang)(wang)具(ju)有(you)(you)非常顯(xian)著(zhu)(zhu)的(de)(de)作用(yong)。

2.3 非(fei)生(sheng)活(huo)污水(shui)摻混對濃度(du)和收集率的影響

氨(an)(an)(an)(an)氮(dan)(dan)屬(shu)于(yu)物(wu)態相對(dui)穩定(ding)的(de)(de)(de)(de)離子(zi)態物(wu)質，在(zai)有(you)(you)(you)COD和(he)BOD存在(zai)的(de)(de)(de)(de)污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)(guan)(guan)網(wang)中(zhong)(zhong)(zhong)一般不會(hui)發生(sheng)(sheng)(sheng)明(ming)顯(xian)的(de)(de)(de)(de)硝(xiao)化或(huo)其(qi)他(ta)反應而消耗(hao)。另外(wai)，污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)中(zhong)(zhong)(zhong)含(han)有(you)(you)(you)的(de)(de)(de)(de)氨(an)(an)(an)(an)基(ji)酸等(deng)有(you)(you)(you)機(ji)氮(dan)(dan)類物(wu)質還會(hui)在(zai)管(guan)(guan)(guan)(guan)(guan)道(dao)轉輸過(guo)程中(zhong)(zhong)(zhong)氨(an)(an)(an)(an)化為氨(an)(an)(an)(an)氮(dan)(dan)并釋放到水(shui)(shui)(shui)(shui)(shui)中(zhong)(zhong)(zhong)，使(shi)污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)中(zhong)(zhong)(zhong)的(de)(de)(de)(de)氨(an)(an)(an)(an)氮(dan)(dan)濃(nong)度通(tong)常可以保持在(zai)40 mg/L甚至(zhi)更高水(shui)(shui)(shui)(shui)(shui)平。而隨著環(huan)境監管(guan)(guan)(guan)(guan)(guan)力度的(de)(de)(de)(de)加大，入(ru)(ru)滲入(ru)(ru)流(liu)或(huo)排入(ru)(ru)污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)(guan)(guan)網(wang)的(de)(de)(de)(de)地(di)表水(shui)(shui)(shui)(shui)(shui)、地(di)下水(shui)(shui)(shui)(shui)(shui)、工業(ye)廢水(shui)(shui)(shui)(shui)(shui)等(deng)通(tong)常具有(you)(you)(you)低(di)氨(an)(an)(an)(an)氮(dan)(dan)濃(nong)度的(de)(de)(de)(de)顯(xian)著特(te)征。也(ye)就是(shi)說排入(ru)(ru)污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)(guan)(guan)網(wang)的(de)(de)(de)(de)非(fei)(fei)生(sheng)(sheng)(sheng)活(huo)(huo)(huo)污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)氨(an)(an)(an)(an)氮(dan)(dan)濃(nong)度會(hui)明(ming)顯(xian)低(di)于(yu)居民生(sheng)(sheng)(sheng)活(huo)(huo)(huo)污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)氨(an)(an)(an)(an)氮(dan)(dan)濃(nong)度，因此可將氨(an)(an)(an)(an)氮(dan)(dan)作為非(fei)(fei)生(sheng)(sheng)(sheng)活(huo)(huo)(huo)污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)排入(ru)(ru)情況的(de)(de)(de)(de)重(zhong)(zhong)要評價核算指標(biao)，作為污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)收(shou)(shou)集管(guan)(guan)(guan)(guan)(guan)網(wang)效能評估的(de)(de)(de)(de)重(zhong)(zhong)要參(can)考指標(biao)。南方地(di)區污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)處(chu)(chu)理(li)廠(chang)旱季相對(dui)較(jiao)低(di)的(de)(de)(de)(de)氨(an)(an)(an)(an)氮(dan)(dan)濃(nong)度，實際上(shang)是(shi)上(shang)游大量低(di)氨(an)(an)(an)(an)氮(dan)(dan)濃(nong)度非(fei)(fei)生(sheng)(sheng)(sheng)活(huo)(huo)(huo)污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)排入(ru)(ru)摻混的(de)(de)(de)(de)直接結果。低(di)氨(an)(an)(an)(an)氮(dan)(dan)濃(nong)度非(fei)(fei)生(sheng)(sheng)(sheng)活(huo)(huo)(huo)污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)排入(ru)(ru)污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)(guan)(guan)網(wang)，不僅會(hui)對(dui)生(sheng)(sheng)(sheng)活(huo)(huo)(huo)污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)形(xing)成稀釋，還會(hui)擠(ji)占(zhan)管(guan)(guan)(guan)(guan)(guan)網(wang)和(he)污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)處(chu)(chu)理(li)廠(chang)的(de)(de)(de)(de)有(you)(you)(you)效空間，引(yin)發污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)溢流(liu)問(wen)題，導致城市生(sheng)(sheng)(sheng)活(huo)(huo)(huo)污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)集中(zhong)(zhong)(zhong)收(shou)(shou)集率(lv)持續偏低(di)，是(shi)排水(shui)(shui)(shui)(shui)(shui)行業(ye)的(de)(de)(de)(de)重(zhong)(zhong)大痛點難點，也(ye)是(shi)污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)處(chu)(chu)理(li)提質增(zeng)效工作的(de)(de)(de)(de)重(zhong)(zhong)點方向。通(tong)過(guo)氨(an)(an)(an)(an)氮(dan)(dan)或(huo)其(qi)他(ta)簡單(dan)有(you)(you)(you)效的(de)(de)(de)(de)指標(biao)快(kuai)(kuai)速識別非(fei)(fei)生(sheng)(sheng)(sheng)活(huo)(huo)(huo)污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)摻混問(wen)題，并通(tong)過(guo)工程或(huo)技術手(shou)段將非(fei)(fei)生(sheng)(sheng)(sheng)活(huo)(huo)(huo)污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)清退出污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)(guan)(guan)網(wang)是(shi)快(kuai)(kuai)速提升污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)處(chu)(chu)理(li)廠(chang)進水(shui)(shui)(shui)(shui)(shui)濃(nong)度和(he)城市生(sheng)(sheng)(sheng)活(huo)(huo)(huo)污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)集中(zhong)(zhong)(zhong)收(shou)(shou)集率(lv)的(de)(de)(de)(de)最有(you)(you)(you)效措施。

非生活(huo)污(wu)水(shui)(shui)(shui)(shui)(shui)對(dui)污(wu)水(shui)(shui)(shui)(shui)(shui)污(wu)染(ran)物(wu)(wu)影響的(de)(de)另一個重(zhong)要特征是氧(yang)(yang)化還(huan)原(yuan)反應(ying)或生物(wu)(wu)合(he)成反應(ying)導致的(de)(de)污(wu)染(ran)物(wu)(wu)衰(shuai)減。T. Hvitved-Jacobsen等研(yan)究(jiu)提(ti)出(chu)(chu)(chu)污(wu)水(shui)(shui)(shui)(shui)(shui)管網好氧(yang)(yang)狀(zhuang)(zhuang)態(tai)下(xia)(xia)的(de)(de)溶(rong)(rong)解(jie)性(xing)COD衰(shuai)減速(su)率(lv)通常可達(da)10~30 mg/(L·h)，Kamma Raunkj?r等提(ti)出(chu)(chu)(chu)好氧(yang)(yang)狀(zhuang)(zhuang)態(tai)下(xia)(xia)的(de)(de)COD和(he)(he)溶(rong)(rong)解(jie)性(xing)COD衰(shuai)減去除率(lv)分別可達(da)14%和(he)(he)25%，Naoya Tanaka提(ti)出(chu)(chu)(chu)厭氧(yang)(yang)狀(zhuang)(zhuang)態(tai)下(xia)(xia)的(de)(de)溶(rong)(rong)解(jie)性(xing)COD衰(shuai)減速(su)率(lv)一般在(zai)(zai)0~12 mg/(L·h)。上述好氧(yang)(yang)狀(zhuang)(zhuang)態(tai)的(de)(de)研(yan)究(jiu)結論(lun)多數是基于(yu)溶(rong)(rong)解(jie)氧(yang)(yang)的(de)(de)影響，實際(ji)上我國摻(chan)混污(wu)水(shui)(shui)(shui)(shui)(shui)管網的(de)(de)高(gao)排放標準工業廢水(shui)(shui)(shui)(shui)(shui)、施工降水(shui)(shui)(shui)(shui)(shui)或基坑(keng)排水(shui)(shui)(shui)(shui)(shui)、地表地下(xia)(xia)水(shui)(shui)(shui)(shui)(shui)，以及(ji)再生水(shui)(shui)(shui)(shui)(shui)補水(shui)(shui)(shui)(shui)(shui)型(xing)(xing)和(he)(he)水(shui)(shui)(shui)(shui)(shui)生植(zhi)物(wu)(wu)生態(tai)型(xing)(xing)城(cheng)市河湖水(shui)(shui)(shui)(shui)(shui)，不僅存在(zai)(zai)溶(rong)(rong)解(jie)氧(yang)(yang)，還(huan)存在(zai)(zai)各種化學氧(yang)(yang)化物(wu)(wu)，呈現出(chu)(chu)(chu)相對(dui)較高(gao)的(de)(de)ORP，這些氧(yang)(yang)化性(xing)物(wu)(wu)質(zhi)也會與污(wu)水(shui)(shui)(shui)(shui)(shui)中(zhong)的(de)(de)還(huan)原(yuan)性(xing)有機物(wu)(wu)發生反應(ying)，導致還(huan)原(yuan)性(xing)有機物(wu)(wu)衰(shuai)減，成為污(wu)水(shui)(shui)(shui)(shui)(shui)處(chu)理廠進水(shui)(shui)(shui)(shui)(shui)BOD濃度和(he)(he)城(cheng)市生活(huo)污(wu)水(shui)(shui)(shui)(shui)(shui)集(ji)中(zhong)收集(ji)率(lv)偏(pian)低的(de)(de)重(zhong)要原(yuan)因。

高(gao)(gao)排(pai)放(fang)標準(zhun)工(gong)(gong)業(ye)廢水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)多(duo)數采用了強(qiang)化(hua)(hua)生物(wu)處理和(he)高(gao)(gao)級氧化(hua)(hua)深(shen)度(du)處理工(gong)(gong)藝，出水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)表(biao)征為相對較高(gao)(gao)的(de)DO和(he)ORP值(zhi)(zhi)(zhi)，尤其是芬頓、催化(hua)(hua)氧化(hua)(hua)等(deng)強(qiang)氧化(hua)(hua)工(gong)(gong)藝的(de)出水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)ORP值(zhi)(zhi)(zhi)可(ke)達(da)1000 mV甚至更高(gao)(gao)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)平(ping)，具(ju)有(you)比(bi)較高(gao)(gao)的(de)“氧化(hua)(hua)性”。施(shi)工(gong)(gong)降水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)或基坑排(pai)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)多(duo)數來自于(yu)地(di)下水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)、淺層地(di)下水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)，以及城市(shi)河湖水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)等(deng)，通(tong)常(chang)具(ju)有(you)一定的(de)ORP值(zhi)(zhi)(zhi)和(he)NO3--N濃度(du)，部分地(di)區的(de)地(di)表(biao)、地(di)下水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)NO3--N濃度(du)甚至可(ke)高(gao)(gao)達(da)20多(duo)mg/L水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)平(ping)。污(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)處理廠尾(wei)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)通(tong)常(chang)也表(biao)征為比(bi)較高(gao)(gao)的(de)ORP值(zhi)(zhi)(zhi)，尤其是隨著疫(yi)情(qing)防控(kong)對污(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)處理廠尾(wei)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)消毒要求的(de)提(ti)高(gao)(gao)，出水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)ORP值(zhi)(zhi)(zhi)達(da)到400 mV以上的(de)情(qing)況變得非常(chang)普遍。這些水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)進(jin)入污(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)管網，必然會與生活污(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)中的(de)有(you)機物(wu)發生反(fan)硝化(hua)(hua)反(fan)應或氧化(hua)(hua)還原反(fan)應而使污(wu)染物(wu)衰減，導致生活污(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)(shui)污(wu)染物(wu)濃度(du)降低。

城市(shi)水(shui)(shui)(shui)體中的(de)沉(chen)水(shui)(shui)(shui)植物(wu)會(hui)通過日間的(de)光合作用向(xiang)水(shui)(shui)(shui)體持續緩慢釋放“純(chun)氧”，使(shi)沉(chen)水(shui)(shui)(shui)植物(wu)周(zhou)邊區(qu)域水(shui)(shui)(shui)的(de)日間DO長期保持在(zai)超飽和(he)的(de)10 mg/L以上水(shui)(shui)(shui)平，而ORP值多數可(ke)達300 mV以上水(shui)(shui)(shui)平；夜間則因沉(chen)水(shui)(shui)(shui)植物(wu)的(de)呼(hu)吸(xi)作用，DO值可(ke)降(jiang)低(di)至接近(jin)0 mg/L，ORP降(jiang)低(di)至50 mV以下。因此如(ru)果沉(chen)水(shui)(shui)(shui)植物(wu)為主(zhu)的(de)城市(shi)河(he)湖水(shui)(shui)(shui)滲漏或(huo)倒灌至污(wu)水(shui)(shui)(shui)收集管網(wang)，也(ye)會(hui)導致生(sheng)活污(wu)水(shui)(shui)(shui)污(wu)染物(wu)的(de)衰減損(sun)耗。

當然，不規律或不連(lian)續排放的非(fei)生活(huo)污(wu)水(shui)還可(ke)(ke)能導致污(wu)水(shui)管(guan)網的階(jie)段(duan)性溢(yi)流(liu)，很大程(cheng)度(du)上(shang)影響污(wu)水(shui)處理廠進(jin)水(shui)濃度(du)和(he)(he)城市生活(huo)污(wu)水(shui)集中收(shou)集率。實(shi)際工程(cheng)證明，通(tong)過(guo)污(wu)水(shui)管(guan)網降(jiang)水(shui)位(wei)(wei)的模式(shi)增(zeng)大管(guan)網調蓄空間，可(ke)(ke)有效(xiao)應(ying)對排入水(shui)量波動所(suo)引發的階(jie)段(duan)性冒(mao)溢(yi)問題，真正意(yi)義(yi)上(shang)實(shi)現健康的排水(shui)系統(tong)和(he)(he)城市水(shui)環(huan)境系統(tong)，如某服務(wu)業每天(tian)中午(wu)1點(dian)左右開(kai)始向管(guan)網排放3000 m3左右污(wu)水(shui)，導致下游點(dian)位(wei)(wei)每天(tian)下午(wu)2~5點(dian)期間溢(yi)流(liu)而被中央環(huan)保督察通(tong)報(bao)，在綜合(he)采(cai)取了(le)服務(wu)業調蓄均勻排水(shui)、管(guan)網運維單位(wei)(wei)提前降(jiang)水(shui)位(wei)(wei)騰容積和(he)(he)溢(yi)流(liu)口(kou)增(zeng)高改(gai)造擴(kuo)容積等綜合(he)措施后，徹底(di)解決了(le)下游點(dian)位(wei)(wei)的階(jie)段(duan)性溢(yi)流(liu)問題。

03 結(jie)論(lun)與(yu)建(jian)議

（1）我國(guo)合(he)流(liu)(liu)制管網占比明顯低(di)于(yu)歐美等發(fa)達國(guo)家，但污水處理廠進水BOD濃(nong)(nong)度，尤其是(shi)旱(han)季(ji)濃(nong)(nong)度偏低(di)的問題比較突出，合(he)流(liu)(liu)制并不是(shi)引發(fa)BOD濃(nong)(nong)度偏低(di)的根(gen)本(ben)原因(yin)，應將旱(han)季(ji)濃(nong)(nong)度提升作為(wei)下一(yi)步(bu)提質增效工作的重點方向(xiang)。

（2）污水收集(ji)管(guan)網非降雨時段(duan)污染物(wu)沉積與降雨時段(duan)的(de)高(gao)流(liu)速(su)(su)沖刷流(liu)失是(shi)我國很(hen)多城市(shi)生活(huo)污水集(ji)中收集(ji)率偏低(di)的(de)重要原因，基于日常(chang)運行(xing)流(liu)速(su)(su)提(ti)升(sheng)的(de)管(guan)道沉積控制應作為現階段(duan)的(de)主要攻關方向(xiang)。

（3）污(wu)水管網降水位提流(liu)速要強化排水的系統性，重點關注(zhu)水體沿線(xian)管網受水體水位的影(ying)響以及(ji)大埋(mai)深管網受地下(xia)水的影(ying)響等問題(ti)。

（4）高排(pai)放標準(zhun)工(gong)業廢水(shui)、施(shi)工(gong)降水(shui)或基(ji)坑排(pai)水(shui)、地下水(shui)和(he)城市河湖水(shui)等相對“清潔”的(de)(de)非生活污(wu)(wu)水(shui)倒(dao)灌(guan)或入(ru)滲污(wu)(wu)水(shui)管(guan)網(wang)(wang)，是(shi)污(wu)(wu)水(shui)處理廠進(jin)水(shui)濃(nong)(nong)度(du)，尤其(qi)NH3-N、磷酸(suan)鹽等相對穩態的(de)(de)溶解性(xing)(xing)水(shui)質(zhi)指標降低的(de)(de)主要(yao)(yao)根源；非生活污(wu)(wu)水(shui)的(de)(de)高DO和(he)ORP所表征的(de)(de)強“氧化性(xing)(xing)”更是(shi)造成生活污(wu)(wu)水(shui)還原(yuan)性(xing)(xing)物質(zhi)衰減，導(dao)致污(wu)(wu)水(shui)處理廠進(jin)水(shui)BOD（COD）濃(nong)(nong)度(du)和(he)城市生活污(wu)(wu)水(shui)集(ji)中(zhong)收(shou)集(ji)率普(pu)遍偏低的(de)(de)重要(yao)(yao)原(yuan)因。污(wu)(wu)水(shui)收(shou)集(ji)管(guan)網(wang)(wang)的(de)(de)非生活污(wu)(wu)水(shui)治理應作(zuo)(zuo)為現階段(duan)濃(nong)(nong)度(du)和(he)效能提升的(de)(de)重點(dian)工(gong)作(zuo)(zuo)。

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