水生植物凈化系統的原理與優點分析
來源： 閱讀：5193 更新時(shi)間(jian)：2013-03-19 10:09該水(shui)生(sheng)(sheng)植(zhi)物(wu)(wu)(wu)(wu)凈化系統將污(wu)染(ran)(ran)湖水(shui)或(huo)河(he)(he)水(shui)引入(ru)現存(cun)的(de)濕地(di)塘或(huo)以創建的(de)濕地(di)塘中，通過水(shui)生(sheng)(sheng)植(zhi)物(wu)(wu)(wu)(wu)對(dui)污(wu)染(ran)(ran)物(wu)(wu)(wu)(wu)的(de)攔截(jie)作用、水(shui)生(sheng)(sheng)植(zhi)物(wu)(wu)(wu)(wu)根系形成的(de)微生(sheng)(sheng)物(wu)(wu)(wu)(wu)膜對(dui)有(you)機質的(de)降解作用和植(zhi)物(wu)(wu)(wu)(wu)本身對(dui)營養鹽的(de)吸收作用而去除(chu)污(wu)染(ran)(ran)物(wu)(wu)(wu)(wu)，由于生(sheng)(sheng)長的(de)挺(ting)水(shui)植(zhi)物(wu)(wu)(wu)(wu)具良(liang)好(hao)的(de)遮(zhe)光作用，可(ke)有(you)效抑制藻(zao)類的(de)增殖，凈化后(hou)的(de)水(shui)重新(xin)排回湖泊或(huo)河(he)(he)流。
該凈(jing)化系(xi)統(tong)(tong)最(zui)常用的(de)(de)水(shui)(shui)(shui)(shui)生(sheng)(sheng)植(zhi)物(wu)是(shi)蘆葦，但當水(shui)(shui)(shui)(shui)較(jiao)深，進(jin)(jin)水(shui)(shui)(shui)(shui)BOD較(jiao)高(gao)(gao)時，茭草或香蒲就(jiu)更合(he)適，即使一開始沒有(you)種(zhong)植(zhi)，若干年后(hou)這兩種(zhong)植(zhi)物(wu)也會替代蘆葦。由于種(zhong)植(zhi)與(yu)水(shui)(shui)(shui)(shui)質條(tiao)件(jian)相適應(ying)的(de)(de)植(zhi)物(wu)可(ke)(ke)更好地(di)吸收營養鹽，因而最(zui)好的(de)(de)方(fang)法是(shi)同時種(zhong)植(zhi)三種(zhong)水(shui)(shui)(shui)(shui)生(sheng)(sheng)植(zhi)物(wu)進(jin)(jin)行(xing)競(jing)爭。該系(xi)統(tong)(tong)還需建(jian)立(li)進(jin)(jin)水(shui)(shui)(shui)(shui)、排水(shui)(shui)(shui)(shui)系(xi)統(tong)(tong)及攔水(shui)(shui)(shui)(shui)堤。進(jin)(jin)行(xing)設(she)計時，盡量使水(shui)(shui)(shui)(shui)能自流進(jin)(jin)人凈(jing)化系(xi)統(tong)(tong)，不需用泵提升(sheng)，以便(bian)降低運行(xing)與(yu)維持(chi)費(fei)用，挺水(shui)(shui)(shui)(shui)植(zhi)物(wu)從葉片(pian)向根(gen)系(xi)輸氧(yang)、從根(gen)系(xi)向周圍(wei)水(shui)(shui)(shui)(shui)體及底泥泌氧(yang)以保護其組織。蘆葦、野(ye)生(sheng)(sheng)水(shui)(shui)(shui)(shui)稻(dao)、香蒲具有(you)維持(chi)根(gen)系(xi)兼(jian)氧(yang)環(huan)境促進(jin)(jin)反(fan)硝(xiao)化作用的(de)(de)能力(li)。另一個簡單易行(xing)的(de)(de)污(wu)水(shui)(shui)(shui)(shui)處(chu)理方(fang)法是(shi)湖(hu)中(zhong)湖(hu)凈(jing)化方(fang)法，但當進(jin)(jin)水(shui)(shui)(shui)(shui)BOD濃(nong)度(du)高(gao)(gao)于50mg/L，即適合(he)挺水(shui)(shui)(shui)(shui)植(zhi)物(wu)生(sheng)(sheng)長時，采用濕地(di)凈(jing)化方(fang)法往往比湖(hu)中(zhong)湖(hu)凈(jing)化方(fang)法更為有(you)效，且還可(ke)(ke)使溫室氣體的(de)(de)產生(sheng)(sheng)量受到(dao)限制。
垂(chui)直(zhi)流(liu)(liu)(liu)(liu)濕地凈(jing)化方法(fa)能在提(ti)高氮磷污染(ran)(ran)物去除率的同時(shi)抑(yi)制溫室(shi)氣(qi)體的產生(sheng)量。 該凈(jing)化系統中水(shui)(shui)位低于土(tu)壤(rang)表(biao)面(mian)(mian)，進水(shui)(shui)垂(chui)直(zhi)滲人濕地土(tu)壤(rang)，土(tu)壤(rang)表(biao)面(mian)(mian)由于水(shui)(shui)/氣(qi)界面(mian)(mian)的存(cun)在形(xing)(xing)成(cheng)好(hao)氧層，使產生(sheng)的溫室(shi)氣(qi)體被還原。與(yu)表(biao)面(mian)(mian)流(liu)(liu)(liu)(liu)形(xing)(xing)式污水(shui)(shui)流(liu)(liu)(liu)(liu)過植物根系的情況相比(bi)，垂(chui)直(zhi)流(liu)(liu)(liu)(liu)形(xing)(xing)式時(shi)，水(shui)(shui)流(liu)(liu)(liu)(liu)過土(tu)壤(rang)使其中的污染(ran)(ran)物被有效吸附，因而，垂(chui)直(zhi)流(liu)(liu)(liu)(liu)形(xing)(xing)式比(bi)表(biao)面(mian)(mian)流(liu)(liu)(liu)(liu)具更(geng)高的去除率。但垂(chui)直(zhi)流(liu)(liu)(liu)(liu)方法(fa)處理流(liu)(liu)(liu)(liu)量較小，流(liu)(liu)(liu)(liu)速比(bi)水(shui)(shui)平(ping)流(liu)(liu)(liu)(liu)低，且要求(qiu)進水(shui)(shui)與(yu)出水(shui)(shui)存(cun)在一定(ding)的水(shui)(shui)位差(cha)，相應的安裝與(yu)運行(xing)費用都較高。
