解碼污水管網:高水位運行原因及對策措施
A鎮位(wei)于華(hua)南(nan)濱海地區(qu),現(xian)狀排水(shui)(shui)(shui)(shui)(shui)體制為(wei)截流式合流制,鎮內污(wu)水(shui)(shui)(shui)(shui)(shui)管網(wang)密(mi)度2.6 km/km²,已建(jian)截流井約410座。根據(ju)水(shui)(shui)(shui)(shui)(shui)位(wei)觀(guan)測(ce)數據(ju),發(fa)現(xian)污(wu)水(shui)(shui)(shui)(shui)(shui)管網(wang)實際運(yun)行(xing)水(shui)(shui)(shui)(shui)(shui)位(wei)位(wei)于管頂以上(shang)0.94~2.78 m,比(bi)正常運(yun)行(xing)水(shui)(shui)(shui)(shui)(shui)位(wei)偏高1.49~3.33 m,處于高水(shui)(shui)(shui)(shui)(shui)位(wei)運(yun)行(xing)工況。通過分(fen)析污(wu)水(shui)(shui)(shui)(shui)(shui)管網(wang)高水(shui)(shui)(shui)(shui)(shui)位(wei)運(yun)行(xing)的原因,提出增產能(neng)、減污(wu)水(shui)(shui)(shui)(shui)(shui)、擠外水(shui)(shui)(shui)(shui)(shui)和除缺陷等針對性解(jie)決措施。
1 項目概況
1.1 城鎮概況
A鎮位于華(hua)南(nan)濱海(hai)(hai)地區,鎮域面(mian)積約180 km²,建設(she)用地面(mian)積約88 km²,2018年常住(zhu)人口約64萬人。經過(guo)30多年快速發展,從一(yi)個國(guo)內生產總值僅0.7億元(yuan)的(de)海(hai)(hai)濱小鎮,迅速發展成為(wei)生產總值超過(guo)600億元(yuan)的(de)現代化(hua)城鎮。A鎮地勢北(bei)高(gao)南(nan)低(di),自(zi)東北(bei)向(xiang)西南(nan)傾(qing)斜,北(bei)部是丘陵(ling)區和坡(po)度較為(wei)明顯的(de)山(shan)前(qian)傾(qing)斜平原,南(nan)部是坡(po)度很(hen)緩的(de)平原水(shui)鄉(xiang)河網(wang)區,地面(mian)高(gao)程(cheng)自(zi)1 m至(zhi)1.5 m左右,地勢低(di)洼,水(shui)系復(fu)雜。地下(xia)水(shui)位高(gao),地面(mian)下(xia)1 m即(ji)可見地下(xia)水(shui)。
1.2 污水系統概況
(1)污(wu)(wu)(wu)水(shui)管(guan)網(wang)。A鎮污(wu)(wu)(wu)水(shui)處理(li)廠(chang)建(jian)(jian)設過程中,配(pei)套建(jian)(jian)設了污(wu)(wu)(wu)水(shui)干管(guan),總長約(yue)33 km。近幾年(nian),又(you)陸(lu)續建(jian)(jian)設了多批(pi)次污(wu)(wu)(wu)水(shui)次支管(guan)網(wang)。根據(ju)相關工程施工圖或竣工圖,鎮內(nei)已(yi)建(jian)(jian)在建(jian)(jian)污(wu)(wu)(wu)水(shui)管(guan)網(wang)總長度約(yue)231 km,現狀污(wu)(wu)(wu)水(shui)管(guan)網(wang)密度約(yue)2.6 km/km²,已(yi)建(jian)(jian)在建(jian)(jian)截流(liu)井約(yue)410座,截流(liu)井普遍采(cai)用拍門或鴨嘴閥等防(fang)倒灌設施,防(fang)止地(di)表水(shui)倒灌。
(2)污(wu)(wu)水(shui)處理(li)廠。A鎮(zhen)污(wu)(wu)水(shui)處理(li)廠位于鎮(zhen)區東南,規劃占地39 hm²,總規模(mo)為40萬m³/d,一期(qi)工程(2009年建(jian)成)規模(mo)10萬m³/d,二期(qi)工程(2019年底建(jian)成)規模(mo)10萬m³/d,出(chu)水(shui)水(shui)質執行(xing)《城(cheng)鎮(zhen)污(wu)(wu)水(shui)處理(li)廠污(wu)(wu)染物排放標(biao)準(zhun)》(GB 18918-2002)一級(ji)A標(biao)準(zhun)及廣東省地方(fang)標(biao)準(zhun)《水(shui)污(wu)(wu)染物排放限(xian)值》(DB 44/26-2001)的較嚴值。近3年污(wu)(wu)水(shui)處理(li)廠運(yun)行(xing)工況見表(biao)1,污(wu)(wu)水(shui)處理(li)廠處于滿負荷運(yun)行(xing)狀況。
2017年至2019年,污水(shui)(shui)(shui)(shui)處(chu)理廠(chang)(chang)COD進廠(chang)(chang)濃(nong)(nong)度(du)(du)190.1~231.6 mg/L,約為建(jian)城函(han)[2016]198號規定的(de)最(zui)低濃(nong)(nong)度(du)(du)的(de)73%~89%;BOD5進廠(chang)(chang)濃(nong)(nong)度(du)(du)85.8~103.2 mg/L,約為建(jian)城[2019]52號規定最(zui)低濃(nong)(nong)度(du)(du)的(de)86%~103%。由表可知,污水(shui)(shui)(shui)(shui)處(chu)理廠(chang)(chang)進水(shui)(shui)(shui)(shui)水(shui)(shui)(shui)(shui)質與(yu)(yu)設計(ji)進水(shui)(shui)(shui)(shui)水(shui)(shui)(shui)(shui)質有(you)(you)一(yi)定距(ju)(ju)離,與(yu)(yu)國家考(kao)核要求也有(you)(you)一(yi)定距(ju)(ju)離,不過與(yu)(yu)該市30余座已建(jian)污水(shui)(shui)(shui)(shui)處(chu)理廠(chang)(chang)橫(heng)向比(bi)較(jiao),進水(shui)(shui)(shui)(shui)濃(nong)(nong)度(du)(du)處(chu)于第一(yi)梯隊的(de)較(jiao)高(gao)水(shui)(shui)(shui)(shui)平。
2 存在問題及原因分析
2.1 存在問題
項(xiang)目啟動以(yi)后,收集了鎮內相關技術資料,對工作(zuo)范圍地(di)表水(shui)環境進行(xing)(xing)了查(cha)勘,并組織技術力量(liang),對鎮內污(wu)水(shui)系統(tong)運行(xing)(xing)工況進行(xing)(xing)了觀(guan)測(ce)。A鎮污(wu)水(shui)處(chu)理廠廠前(qian)污(wu)水(shui)干管(DN2 200)2019年11月(月降雨量(liang)為0)的運行(xing)(xing)水(shui)位變化(hua)過(guo)程及現場觀(guan)測(ce)結果見圖1。
由(you)圖1可知,觀測點污水(shui)管(guan)管(guan)頂高(gao)程-2.01 m(85高(gao)程,下(xia)同),管(guan)網水(shui)位(wei)-1.07~0.77 m,管(guan)網水(shui)位(wei)位(wei)于管(guan)頂以上0.94~2.78 m,平均2.14 m,月內(nei)日(ri)均水(shui)位(wei)變幅1.84 m。根據《室外排水(shui)設計規范》(GB 50014-2006,2016年版),DN2 200污水(shui)管(guan)道最大充滿度0.75。污水(shui)管(guan)網實際運(yun)行水(shui)位(wei)比正常運(yun)行水(shui)位(wei)偏高(gao)1.49~3.33 m,平均2.69 m,處于高(gao)水(shui)位(wei)運(yun)行狀況。
污(wu)(wu)水(shui)管網(wang)高(gao)水(shui)位運行,導致(zhi)污(wu)(wu)水(shui)無法經污(wu)(wu)水(shui)管網(wang)排入污(wu)(wu)水(shui)處(chu)理廠(chang)集中(zhong)處(chu)理,污(wu)(wu)水(shui)溢流入河(he),部(bu)分河(he)道水(shui)環境依然(ran)受到污(wu)(wu)染,部(bu)分河(he)道水(shui)環境得到了(le)一定程度的改善(shan),但是雨后復黑現象突出(chu),污(wu)(wu)水(shui)系統建設的目標(biao)未能實現。
2.2 原因分析
(1)污水(shui)(shui)(shui)處理能力不(bu)足。根(gen)據統計(ji)資料,A鎮2014年至(zhi)2018年用水(shui)(shui)(shui)量23.53萬(wan)(wan)~26.88萬(wan)(wan)m³/d,平(ping)(ping)均24.95萬(wan)(wan)m³/d。根(gen)據A鎮排(pai)(pai)水(shui)(shui)(shui)專項規劃,污水(shui)(shui)(shui)排(pai)(pai)放系數取(qu)0.85,地下(xia)水(shui)(shui)(shui)滲入量取(qu)污水(shui)(shui)(shui)量的10%,污水(shui)(shui)(shui)量22.0萬(wan)(wan)~25.13萬(wan)(wan)m³/d,平(ping)(ping)均23.32萬(wan)(wan)m³/d。2014年至(zhi)2018年用排(pai)(pai)水(shui)(shui)(shui)量統計(ji)見表2。
由表(biao)2可知,鎮(zhen)內(nei)現(xian)狀污(wu)水(shui)(shui)(shui)處(chu)理能力20萬(wan)m³/d,2014年至(zhi)2018年污(wu)水(shui)(shui)(shui)量22.0萬(wan)~25.13萬(wan)m³/d,平均23.32萬(wan)m³/d,污(wu)水(shui)(shui)(shui)量大(da)于污(wu)水(shui)(shui)(shui)處(chu)理能力,現(xian)有污(wu)水(shui)(shui)(shui)處(chu)理能力與污(wu)水(shui)(shui)(shui)處(chu)理需求不(bu)(bu)配備(bei),存在污(wu)水(shui)(shui)(shui)處(chu)理能力不(bu)(bu)足的問題。污(wu)水(shui)(shui)(shui)處(chu)理能力不(bu)(bu)足,必然導致(zhi)管網運(yun)行(xing)水(shui)(shui)(shui)位被動壅高(gao),致(zhi)使污(wu)水(shui)(shui)(shui)管網高(gao)水(shui)(shui)(shui)位運(yun)行(xing)。
(2)地(di)(di)表(biao)(biao)水(shui)(shui)(shui)(shui)(shui)倒灌。根(gen)據相關資料,A鎮已建(jian)在(zai)建(jian)污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)總長(chang)度約231 km,建(jian)設(she)用地(di)(di)面積88 km²,污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)網密度約2.6 km/km²,管(guan)(guan)網密度處于(yu)較低水(shui)(shui)(shui)(shui)(shui)平(ping),存(cun)在(zai)大量(liang)(liang)污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)網空(kong)白區,市政道路普(pu)(pu)遍(bian)只有一套合流(liu)制(zhi)排水(shui)(shui)(shui)(shui)(shui)系統。由于(yu)污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)網密度低,為了解決污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)直排入(ru)河的問題,已建(jian)在(zai)建(jian)污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)道普(pu)(pu)遍(bian)通過(guo)在(zai)合流(liu)管(guan)(guan)入(ru)河排污(wu)(wu)口末端建(jian)設(she)截流(liu)井(槽(cao)式(shi)為主,少量(liang)(liang)堰式(shi)),期(qi)望將旱季污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)截流(liu)排入(ru)污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)網,最終輸送到(dao)污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)處理(li)廠(chang)(chang)處理(li)。由于(yu)濱(bin)海城鎮地(di)(di)勢低,地(di)(di)表(biao)(biao)水(shui)(shui)(shui)(shui)(shui)位(wei)高,截流(liu)井存(cun)在(zai)地(di)(di)表(biao)(biao)水(shui)(shui)(shui)(shui)(shui)倒灌風險,普(pu)(pu)遍(bian)采用拍門或鴨嘴閥作(zuo)為防(fang)倒灌設(she)施。工(gong)作(zuo)過(guo)程中,對(dui)截流(liu)井運行(xing)工(gong)況進(jin)行(xing)了復(fu)核(he),復(fu)核(he)結果表(biao)(biao)明,部分截流(liu)井防(fang)倒灌效果較差(cha),存(cun)在(zai)地(di)(di)表(biao)(biao)水(shui)(shui)(shui)(shui)(shui)倒灌現(xian)象,見圖(tu)2。地(di)(di)表(biao)(biao)水(shui)(shui)(shui)(shui)(shui)倒灌,不僅降(jiang)低污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)處理(li)廠(chang)(chang)進(jin)廠(chang)(chang)濃度,還會(hui)增加“污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)量(liang)(liang)”,擠占(zhan)了污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)空(kong)間(jian),也會(hui)導(dao)致污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)網高水(shui)(shui)(shui)(shui)(shui)位(wei)運行(xing)。
(3)清污混流(liu)。由(you)于管網密度低,鎮內(nei)市政道路普遍只(zhi)存在(zai)一(yi)套合流(liu)排水(shui)(shui)系(xi)統,為了(le)消除排污口,在(zai)入河排污口附(fu)近或(huo)者(zhe)暗渠(qu)出口處建設截(jie)流(liu)井(jing)。因為清污混流(liu),不屬于污水(shui)(shui)范疇的(de)清水(shui)(shui)也(ye)經合流(liu)系(xi)統排放,如(ru)山溪(泉)溝(渠(qu))水(shui)(shui)、施工降水(shui)(shui)、漏損的(de)自(zi)來水(shui)(shui)、滲(shen)入合流(liu)管網的(de)地(di)下水(shui)(shui)等,全部被截(jie)流(liu)井(jing)截(jie)流(liu)至污水(shui)(shui)系(xi)統,也(ye)增加了(le)“污水(shui)(shui)量”,在(zai)一(yi)定(ding)程度上導致了(le)污水(shui)(shui)管網高水(shui)(shui)位(wei)運行。
(4)管(guan)道(dao)功(gong)(gong)能性(xing)缺(que)陷(xian)(xian)和(he)結構(gou)性(xing)缺(que)陷(xian)(xian)。國內(nei)工(gong)程建(jian)設(she)“重(zhong)建(jian)設(she)輕管(guan)理”是普(pu)遍的現象(xiang),由于維護(hu)管(guan)理不到位(wei),導(dao)致(zhi)排(pai)水(shui)管(guan)道(dao)功(gong)(gong)能性(xing)缺(que)陷(xian)(xian)較為(wei)突出。排(pai)水(shui)管(guan)道(dao)功(gong)(gong)能性(xing)缺(que)陷(xian)(xian)和(he)結構(gou)性(xing)缺(que)陷(xian)(xian)的存在,減(jian)少了管(guan)道(dao)過水(shui)斷面,降低(di)了管(guan)道(dao)的過水(shui)能力(li),導(dao)致(zhi)受影響范圍內(nei)的區域管(guan)網高水(shui)位(wei)運行。
3 對策措施
3.1 增產能
2014年至2018年污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)量22.0萬(wan)~25.13萬(wan)m³/d,平均23.32萬(wan)m³/d,隨著城(cheng)市(shi)建(jian)設及經濟發(fa)展,污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)量還將逐年增大。鎮(zhen)內現狀(zhuang)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)處(chu)(chu)(chu)(chu)理(li)能(neng)力(li)(li)20萬(wan)m³/d,污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)量大于污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)處(chu)(chu)(chu)(chu)理(li)能(neng)力(li)(li),現有(you)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)處(chu)(chu)(chu)(chu)理(li)能(neng)力(li)(li)與(yu)(yu)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)處(chu)(chu)(chu)(chu)理(li)需(xu)求不配備,存(cun)在污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)處(chu)(chu)(chu)(chu)理(li)能(neng)力(li)(li)不足的問題。為此,應(ying)盡快啟動(dong)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)處(chu)(chu)(chu)(chu)理(li)廠三期工程(cheng)建(jian)設,增加(jia)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)處(chu)(chu)(chu)(chu)理(li)能(neng)力(li)(li),確保污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)處(chu)(chu)(chu)(chu)理(li)能(neng)力(li)(li)與(yu)(yu)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)處(chu)(chu)(chu)(chu)理(li)需(xu)求相配備,為污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)管網運(yun)行水(shui)(shui)(shui)(shui)(shui)(shui)位降低創造基(ji)本條件(jian)。
3.2 減污水
根據(ju)(ju)公開資(zi)料,2018年全(quan)國平均萬元GDP用(yong)水(shui)(shui)(shui)量66.8 m³,廣東省萬元GDP用(yong)水(shui)(shui)(shui)量43.3 m³,深圳(zhen)市(shi)萬元GDP用(yong)水(shui)(shui)(shui)量為(wei)8.41 m³(2019年進一(yi)步(bu)下降(jiang)到7.93 m³)。根據(ju)(ju)統(tong)計資(zi)料,A鎮2014年至2018年萬元地區生產(chan)總(zong)值(zhi)用(yong)水(shui)(shui)(shui)量為(wei)21.32~15.20 m³,呈現(xian)逐年下降(jiang)的(de)趨勢(shi),用(yong)水(shui)(shui)(shui)效(xiao)率逐年提升,與2014年比,2018年下降(jiang)萬元地區生產(chan)總(zong)值(zhi)用(yong)水(shui)(shui)(shui)量下降(jiang)28.7%,見表(biao)3。從全(quan)國及廣東省層面(mian)看,A鎮用(yong)水(shui)(shui)(shui)效(xiao)率整體較(jiao)高,但與深圳(zhen)等用(yong)水(shui)(shui)(shui)效(xiao)率先進城市(shi)相比,節(jie)水(shui)(shui)(shui)潛力仍然較(jiao)大。
為此,應該以“節(jie)水(shui)(shui)優先、空間均(jun)衡、系統治(zhi)理(li)、兩(liang)手(shou)發力”的治(zhi)水(shui)(shui)思(si)路(lu)為引領,按(an)照國(guo)家(jia)、省、市(shi)節(jie)水(shui)(shui)行(xing)動(dong)方案確定的任務(wu),深入實施最嚴(yan)格水(shui)(shui)資源管理(li)制度,著力推動(dong)全社會節(jie)水(shui)(shui),營造節(jie)水(shui)(shui)濃厚氛(fen)圍,提升社會節(jie)水(shui)(shui)意識,進一步(bu)提高用水(shui)(shui)效(xiao)率(lv),減少污(wu)水(shui)(shui)產(chan)生(sheng)量,為污(wu)水(shui)(shui)管網運行(xing)水(shui)(shui)位降低創造有利(li)條件(jian)。
3.3 擠外水
(1)推進污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)(guan)(guan)網(wang)建(jian)(jian)(jian)(jian)(jian)設(she)(she),完(wan)善污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)系統。近(jin)年來(lai),A鎮(zhen)所(suo)在的市(shi)級(ji)政(zheng)府大(da)(da)力推進污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)(guan)(guan)網(wang)建(jian)(jian)(jian)(jian)(jian)設(she)(she),近(jin)年來(lai)新(xin)建(jian)(jian)(jian)(jian)(jian)污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)次支管(guan)(guan)(guan)(guan)(guan)數千公里,市(shi)內(nei)同等發展水(shui)(shui)(shui)(shui)(shui)平的兄弟鎮(zhen)街管(guan)(guan)(guan)(guan)(guan)網(wang)密(mi)度(du)(du)(du)接近(jin)8.0 km/km²,廣州市(shi)污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)(guan)(guan)網(wang)密(mi)度(du)(du)(du)目標為(wei)10.0 km/km²,而A鎮(zhen)已建(jian)(jian)(jian)(jian)(jian)在建(jian)(jian)(jian)(jian)(jian)污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)(guan)(guan)網(wang)密(mi)度(du)(du)(du)僅為(wei)2.6 km/km²,污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)(guan)(guan)網(wang)密(mi)度(du)(du)(du)處于較低水(shui)(shui)(shui)(shui)(shui)平,污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)(guan)(guan)網(wang)建(jian)(jian)(jian)(jian)(jian)設(she)(she)欠賬較大(da)(da),存在大(da)(da)量污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)(guan)(guan)網(wang)空白(bai)區。為(wei)此,A鎮(zhen)加大(da)(da)了污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)(guan)(guan)網(wang)建(jian)(jian)(jian)(jian)(jian)設(she)(she)力度(du)(du)(du),計劃1年內(nei)建(jian)(jian)(jian)(jian)(jian)設(she)(she)污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)(guan)(guan)網(wang)500 km(建(jian)(jian)(jian)(jian)(jian)成后污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)(guan)(guan)網(wang)密(mi)度(du)(du)(du)8.3 km/km²),盡快實(shi)現(xian)市(shi)政(zheng)道路污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)(guan)(guan)網(wang)全覆蓋,消除污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)收(shou)集空白(bai)區,補齊污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)(guan)(guan)網(wang)等基礎(chu)設(she)(she)施(shi)短板(ban),努力實(shi)現(xian)污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)(guan)(guan)網(wang)全覆蓋、全收(shou)集、全處理。
(2)開(kai)展源頭雨(yu)(yu)(yu)污(wu)(wu)(wu)(wu)(wu)分(fen)(fen)流(liu)(liu)(liu)(liu)工(gong)(gong)(gong)作(zuo)(zuo),提高(gao)(gao)雨(yu)(yu)(yu)污(wu)(wu)(wu)(wu)(wu)分(fen)(fen)流(liu)(liu)(liu)(liu)比例。A鎮(zhen)污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)管(guan)網(wang)密度(du)僅為(wei)2.6 km/km²,管(guan)網(wang)密度(du)處(chu)于(yu)較(jiao)(jiao)低(di)水(shui)(shui)(shui)平,存在(zai)(zai)(zai)大量(liang)(liang)污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)管(guan)網(wang)空白區(qu)(qu)(qu)(qu),普遍采用末(mo)端截(jie)流(liu)(liu)(liu)(liu)的(de)(de)(de)方式(shi)解(jie)決污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)直排(pai)入河的(de)(de)(de)問題,建設了(le)約410座截(jie)流(liu)(liu)(liu)(liu)井(jing)。A鎮(zhen)位(wei)于(yu)濱海地(di)區(qu)(qu)(qu)(qu),地(di)勢(shi)較(jiao)(jiao)低(di),河道(dao)水(shui)(shui)(shui)位(wei)受潮(chao)汐影響周期性變(bian)化,存在(zai)(zai)(zai)較(jiao)(jiao)為(wei)突出的(de)(de)(de)地(di)表(biao)水(shui)(shui)(shui)倒灌(guan)問題,導(dao)致“污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)量(liang)(liang)”增加(jia),污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)處(chu)理(li)廠(chang)進廠(chang)濃(nong)度(du)降低(di),污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)管(guan)網(wang)高(gao)(gao)水(shui)(shui)(shui)位(wei)運(yun)行。在(zai)(zai)(zai)推進污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)管(guan)網(wang)建設力(li)度(du),1年內(nei)建設500 km污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)管(guan)網(wang)的(de)(de)(de)同(tong)時,A鎮(zhen)也同(tong)步(bu)源頭雨(yu)(yu)(yu)污(wu)(wu)(wu)(wu)(wu)分(fen)(fen)流(liu)(liu)(liu)(liu)工(gong)(gong)(gong)作(zuo)(zuo),大力(li)推進工(gong)(gong)(gong)廠(chang)、住宅(zhai)小區(qu)(qu)(qu)(qu)、公(gong)共建筑及新村的(de)(de)(de)雨(yu)(yu)(yu)污(wu)(wu)(wu)(wu)(wu)分(fen)(fen)流(liu)(liu)(liu)(liu)工(gong)(gong)(gong)作(zuo)(zuo),滿足雨(yu)(yu)(yu)污(wu)(wu)(wu)(wu)(wu)分(fen)(fen)流(liu)(liu)(liu)(liu)條件(jian)的(de)(de)(de)區(qu)(qu)(qu)(qu)域應分(fen)(fen)盡分(fen)(fen),通過源頭雨(yu)(yu)(yu)污(wu)(wu)(wu)(wu)(wu)分(fen)(fen)流(liu)(liu)(liu)(liu)工(gong)(gong)(gong)作(zuo)(zuo),逐步(bu)提高(gao)(gao)雨(yu)(yu)(yu)污(wu)(wu)(wu)(wu)(wu)分(fen)(fen)流(liu)(liu)(liu)(liu)排(pai)水(shui)(shui)(shui)區(qu)(qu)(qu)(qu)域的(de)(de)(de)比例,降低(di)雨(yu)(yu)(yu)污(wu)(wu)(wu)(wu)(wu)合流(liu)(liu)(liu)(liu)排(pai)水(shui)(shui)(shui)區(qu)(qu)(qu)(qu)域的(de)(de)(de)比例。完成(cheng)雨(yu)(yu)(yu)污(wu)(wu)(wu)(wu)(wu)分(fen)(fen)流(liu)(liu)(liu)(liu)區(qu)(qu)(qu)(qu)域內(nei)的(de)(de)(de)現況截(jie)流(liu)(liu)(liu)(liu)井(jing),全部予以關閉,改建為(wei)普通的(de)(de)(de)檢查(cha)井(jing);維持雨(yu)(yu)(yu)污(wu)(wu)(wu)(wu)(wu)合流(liu)(liu)(liu)(liu)的(de)(de)(de)排(pai)水(shui)(shui)(shui)區(qu)(qu)(qu)(qu)域,現況截(jie)流(liu)(liu)(liu)(liu)井(jing)努(nu)力(li)上(shang)移至地(di)勢(shi)較(jiao)(jiao)高(gao)(gao)的(de)(de)(de)區(qu)(qu)(qu)(qu)域,降低(di)地(di)表(biao)水(shui)(shui)(shui)倒灌(guan)風險,減少(shao)進入污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)系統的(de)(de)(de)外水(shui)(shui)(shui),減少(shao)污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)量(liang)(liang),降低(di)污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)管(guan)網(wang)運(yun)行水(shui)(shui)(shui)位(wei)。
(3)改(gai)造防(fang)倒(dao)(dao)灌(guan)設(she)(she)(she)(she)(she)施(shi),減少地(di)表(biao)水(shui)(shui)(shui)(shui)倒(dao)(dao)灌(guan)。由于(yu)(yu)污(wu)水(shui)(shui)(shui)(shui)管網(wang)密度(du)低(di)(di),污(wu)水(shui)(shui)(shui)(shui)系(xi)統不(bu)(bu)完善,現(xian)狀建設(she)(she)(she)(she)(she)了(le)約410個(ge)截(jie)(jie)(jie)流(liu)(liu)(liu)井,為了(le)防(fang)止地(di)表(biao)水(shui)(shui)(shui)(shui)倒(dao)(dao)灌(guan),普遍采用拍(pai)(pai)門(men)(men)或(huo)(huo)(huo)鴨嘴閥作為防(fang)倒(dao)(dao)灌(guan)設(she)(she)(she)(she)(she)施(shi)。根(gen)據(ju)(ju)《室外排水(shui)(shui)(shui)(shui)設(she)(she)(she)(she)(she)計規(gui)范(fan)(fan)》(GB 50014-2006,2016年版(ban)),截(jie)(jie)(jie)流(liu)(liu)(liu)井溢流(liu)(liu)(liu)水(shui)(shui)(shui)(shui)位應在(zai)設(she)(she)(she)(she)(she)計洪水(shui)(shui)(shui)(shui)位或(huo)(huo)(huo)受納(na)管道(dao)設(she)(she)(she)(she)(she)計水(shui)(shui)(shui)(shui)位以上(shang)(shang),當不(bu)(bu)能(neng)滿(man)足要求時(shi)(shi),應設(she)(she)(she)(she)(she)置閘(zha)門(men)(men)等防(fang)倒(dao)(dao)灌(guan)設(she)(she)(she)(she)(she)施(shi)。根(gen)據(ju)(ju)《泵站拍(pai)(pai)門(men)(men)技(ji)術(shu)導(dao)則》(SL 656-2014),拍(pai)(pai)門(men)(men)等防(fang)倒(dao)(dao)灌(guan)設(she)(she)(she)(she)(she)施(shi),適用于(yu)(yu)泵站出水(shui)(shui)(shui)(shui)口,防(fang)止泵站停機時(shi)(shi)水(shui)(shui)(shui)(shui)流(liu)(liu)(liu)倒(dao)(dao)灌(guan),保(bao)護水(shui)(shui)(shui)(shui)泵機組安全等要求較低(di)(di)的場合(he)。拍(pai)(pai)門(men)(men)或(huo)(huo)(huo)鴨嘴閥等設(she)(she)(she)(she)(she)施(shi)可以依靠水(shui)(shui)(shui)(shui)流(liu)(liu)(liu)及自重實(shi)現(xian)自動啟閉,較閘(zha)門(men)(men)等防(fang)倒(dao)(dao)灌(guan)設(she)(she)(she)(she)(she)施(shi)管理更方便,但是容易掛扯垃圾,濱海地(di)區還(huan)容易生(sheng)長(chang)生(sheng)蠔等海洋生(sheng)物,導(dao)致閉合(he)不(bu)(bu)嚴,所以防(fang)倒(dao)(dao)灌(guan)效果非常(chang)一般,應用于(yu)(yu)截(jie)(jie)(jie)流(liu)(liu)(liu)井這類防(fang)倒(dao)(dao)灌(guan)要求較高的場合(he),缺乏規(gui)范(fan)(fan)依據(ju)(ju)。由于(yu)(yu)源頭雨(yu)污(wu)分(fen)流(liu)(liu)(liu)工作受多種因(yin)素影響(xiang),實(shi)施(shi)難度(du)大,周期長(chang),徹底實(shi)現(xian)雨(yu)污(wu)分(fen)流(liu)(liu)(liu)也不(bu)(bu)現(xian)實(shi),部分(fen)區域必然還(huan)需(xu)(xu)保(bao)持雨(yu)污(wu)合(he)流(liu)(liu)(liu)的排水(shui)(shui)(shui)(shui)體制,部分(fen)現(xian)況截(jie)(jie)(jie)流(liu)(liu)(liu)井需(xu)(xu)要予以保(bao)留(liu)。針對這些需(xu)(xu)要保(bao)留(liu)的截(jie)(jie)(jie)流(liu)(liu)(liu)井,可考慮將截(jie)(jie)(jie)流(liu)(liu)(liu)井上(shang)(shang)移至雨(yu)污(wu)合(he)流(liu)(liu)(liu)地(di)塊(kuai)附近,也可以考慮將截(jie)(jie)(jie)流(liu)(liu)(liu)井形式由槽(cao)式改(gai)為堰式,或(huo)(huo)(huo)者將拍(pai)(pai)門(men)(men)、鴨嘴閥等防(fang)倒(dao)(dao)灌(guan)設(she)(she)(she)(she)(she)施(shi),改(gai)造為閘(zha)門(men)(men)或(huo)(huo)(huo)下開式堰門(men)(men)等防(fang)倒(dao)(dao)灌(guan)效果較好的防(fang)倒(dao)(dao)灌(guan)設(she)(she)(she)(she)(she)施(shi),降(jiang)低(di)(di)地(di)表(biao)水(shui)(shui)(shui)(shui)倒(dao)(dao)灌(guan)風(feng)險,減少進(jin)入污(wu)水(shui)(shui)(shui)(shui)系(xi)統的外水(shui)(shui)(shui)(shui),減少污(wu)水(shui)(shui)(shui)(shui)量,降(jiang)低(di)(di)污(wu)水(shui)(shui)(shui)(shui)管網(wang)運行水(shui)(shui)(shui)(shui)位。
(4)降低(di)自(zi)然水(shui)(shui)(shui)(shui)(shui)(shui)體(ti)常水(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei),降低(di)地表(biao)水(shui)(shui)(shui)(shui)(shui)(shui)倒灌風(feng)(feng)險(xian)。合(he)流(liu)制(zhi)排(pai)水(shui)(shui)(shui)(shui)(shui)(shui)系統(tong)(tong)晴(qing)天承(cheng)擔著(zhu)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)排(pai)放任(ren)務(wu),雨(yu)(yu)天承(cheng)擔著(zhu)雨(yu)(yu)水(shui)(shui)(shui)(shui)(shui)(shui)排(pai)放任(ren)務(wu)。截(jie)流(liu)式合(he)流(liu)制(zhi)排(pai)水(shui)(shui)(shui)(shui)(shui)(shui)體(ti)制(zhi)中,污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)系統(tong)(tong)-截(jie)流(liu)管-合(he)流(liu)管-自(zi)然水(shui)(shui)(shui)(shui)(shui)(shui)體(ti)貫通在(zai)一起,當排(pai)水(shui)(shui)(shui)(shui)(shui)(shui)口淹沒在(zai)水(shui)(shui)(shui)(shui)(shui)(shui)體(ti)水(shui)(shui)(shui)(shui)(shui)(shui)中時,河(he)(he)湖(hu)(hu)(hu)等(deng)自(zi)然水(shui)(shui)(shui)(shui)(shui)(shui)體(ti)水(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei)高(gao)于(yu)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)系統(tong)(tong)水(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei),水(shui)(shui)(shui)(shui)(shui)(shui)往低(di)處(chu)流(liu),河(he)(he)湖(hu)(hu)(hu)水(shui)(shui)(shui)(shui)(shui)(shui)就(jiu)(jiu)存在(zai)著(zhu)往污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)系統(tong)(tong)倒灌的(de)(de)(de)風(feng)(feng)險(xian),河(he)(he)湖(hu)(hu)(hu)水(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei)越高(gao),存在(zai)地表(biao)水(shui)(shui)(shui)(shui)(shui)(shui)倒灌風(feng)(feng)險(xian)的(de)(de)(de)截(jie)流(liu)井(jing)數量就(jiu)(jiu)會越多(duo),反(fan)之亦然。為此,在(zai)條(tiao)件容許的(de)(de)(de)情況下(xia),適當降低(di)河(he)(he)湖(hu)(hu)(hu)水(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei),降低(di)地表(biao)水(shui)(shui)(shui)(shui)(shui)(shui)倒灌風(feng)(feng)險(xian),考(kao)慮(lv)將(jiang)A鎮(zhen)內河(he)(he)涌常水(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei)由1.0 m降低(di)到0.5 m。傳統(tong)(tong)的(de)(de)(de)城市(shi)建設管理思(si)路中,普(pu)遍認為水(shui)(shui)(shui)(shui)(shui)(shui)滿則景美,為此不惜(xi)在(zai)河(he)(he)道中筑壩設閘,增加(jia)水(shui)(shui)(shui)(shui)(shui)(shui)面面積,壅高(gao)河(he)(he)道水(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei)。降低(di)河(he)(he)湖(hu)(hu)(hu)等(deng)自(zi)然水(shui)(shui)(shui)(shui)(shui)(shui)體(ti)水(shui)(shui)(shui)(shui)(shui)(shui)位(wei)(wei),不僅可以減少地表(biao)水(shui)(shui)(shui)(shui)(shui)(shui)倒灌風(feng)(feng)險(xian),還可以增加(jia)城市(shi)海綿體(ti)。晴(qing)天水(shui)(shui)(shui)(shui)(shui)(shui)淺(qian),魚翔淺(qian)底,百姓賞景戲水(shui)(shui)(shui)(shui)(shui)(shui);雨(yu)(yu)天水(shui)(shui)(shui)(shui)(shui)(shui)深,蓄(xu)水(shui)(shui)(shui)(shui)(shui)(shui)儲雨(yu)(yu),讓城市(shi)無憂,體(ti)現城市(shi)水(shui)(shui)(shui)(shui)(shui)(shui)體(ti)的(de)(de)(de)兩大功能,也是海綿城市(shi)“自(zi)然滯蓄(xu)”的(de)(de)(de)重要載體(ti)。
3.4 除缺陷
排水(shui)(shui)(shui)系統(tong)是(shi)現代城(cheng)市(shi)的(de)(de)重(zhong)(zhong)要(yao)基(ji)礎設施,是(shi)城(cheng)市(shi)的(de)(de)血脈,其結(jie)構(gou)穩固和功(gong)(gong)能(neng)保(bao)障(zhang)是(shi)城(cheng)市(shi)排水(shui)(shui)(shui)安全的(de)(de)重(zhong)(zhong)要(yao)保(bao)證。管(guan)道存在功(gong)(gong)能(neng)性(xing)缺(que)陷和結(jie)構(gou)性(xing)缺(que)陷,也會影響管(guan)道的(de)(de)收水(shui)(shui)(shui)和輸(shu)水(shui)(shui)(shui)功(gong)(gong)能(neng),導致污水(shui)(shui)(shui)管(guan)網高水(shui)(shui)(shui)位(wei)運(yun)行(xing)。為此,應(ying)加(jia)強工程質(zhi)量管(guan)理,避免新建(jian)排水(shui)(shui)(shui)管(guan)道帶(dai)病上崗,同時還應(ying)加(jia)大排水(shui)(shui)(shui)管(guan)道養(yang)護(hu)投入,組建(jian)專業養(yang)護(hu)隊伍(wu),落實養(yang)護(hu)資金,加(jia)強排水(shui)(shui)(shui)系統(tong)維護(hu)管(guan)養(yang)工作,提高養(yang)護(hu)水(shui)(shui)(shui)平,消(xiao)(xiao)除管(guan)道功(gong)(gong)能(neng)性(xing)缺(que)陷和結(jie)構(gou)性(xing)缺(que)陷,恢復管(guan)道收水(shui)(shui)(shui)和輸(shu)水(shui)(shui)(shui)功(gong)(gong)能(neng),消(xiao)(xiao)除因(yin)管(guan)道功(gong)(gong)能(neng)性(xing)缺(que)陷和結(jie)構(gou)性(xing)缺(que)陷造成的(de)(de)區(qu)域(yu)性(xing)管(guan)網高水(shui)(shui)(shui)位(wei)運(yun)行(xing)現象。
4 結語
污(wu)水(shui)(shui)(shui)(shui)(shui)(shui)管網高水(shui)(shui)(shui)(shui)(shui)(shui)位(wei)運(yun)(yun)(yun)行(xing)是現象(xiang),污(wu)水(shui)(shui)(shui)(shui)(shui)(shui)系(xi)統(tong)不完善(shan)是本質,應通(tong)過詳細的(de)(de)內業(ye)評估和外(wai)業(ye)復(fu)核(he)工(gong)作,查明造(zao)成污(wu)水(shui)(shui)(shui)(shui)(shui)(shui)系(xi)統(tong)高水(shui)(shui)(shui)(shui)(shui)(shui)位(wei)運(yun)(yun)(yun)行(xing)的(de)(de)根本原因。在此基礎上,采取(qu)增產能,減(jian)污(wu)水(shui)(shui)(shui)(shui)(shui)(shui),擠外(wai)水(shui)(shui)(shui)(shui)(shui)(shui),除(chu)缺(que)陷等措施,降低(di)污(wu)水(shui)(shui)(shui)(shui)(shui)(shui)管網運(yun)(yun)(yun)行(xing)水(shui)(shui)(shui)(shui)(shui)(shui)位(wei)。另外(wai),濱海城市(shi)一般地(di)勢較低(di),合流制排水(shui)(shui)(shui)(shui)(shui)(shui)系(xi)統(tong)容易發生地(di)表水(shui)(shui)(shui)(shui)(shui)(shui)倒灌,增加(jia)“污(wu)水(shui)(shui)(shui)(shui)(shui)(shui)量(liang)”,導致污(wu)水(shui)(shui)(shui)(shui)(shui)(shui)管網高水(shui)(shui)(shui)(shui)(shui)(shui)位(wei)運(yun)(yun)(yun)行(xing),污(wu)水(shui)(shui)(shui)(shui)(shui)(shui)空間被(bei)外(wai)水(shui)(shui)(shui)(shui)(shui)(shui)擠占,致使污(wu)水(shui)(shui)(shui)(shui)(shui)(shui)直排入河,污(wu)染(ran)河道水(shui)(shui)(shui)(shui)(shui)(shui)環(huan)境,從(cong)系(xi)統(tong)穩定性(xing)和安全(quan)性(xing)方面考慮,分流制是一個更(geng)為妥當的(de)(de)選擇(ze)。

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