畜禽養(yang)殖專業化(hua)與(yu)規模化(hua)集中飼養(yang)方(fang)式,有利(li)于提(ti)高飼養(yang)技術(shu)、防(fang)疫能力(li)和管理水平(ping), 與(yu)傳(chuan)統方(fang)式即農戶分散飼養(yang)相比,規模化(hua)飼養(yang)可大大提(ti)高生(sheng)產效(xiao)率和飼料轉換率,降低生(sheng)產成本,增加經濟效(xiao)益。
1 還田模式
還(huan)田(tian)模式(shi)是畜禽(qin)(qin)養(yang)(yang)(yang)殖(zhi)廢(fei)水(shui)處(chu)(chu)理中(zhong)(zhong)最早期(qi)的(de)模式(shi)。畜禽(qin)(qin)糞(fen)便(bian)污(wu)(wu)(wu)水(shui)還(huan)田(tian)作肥(fei)料為(wei)傳統而經(jing)濟有(you)(you)效的(de)處(chu)(chu)置方法,可使畜禽(qin)(qin)糞(fen)尿(niao)不(bu)(bu)排(pai)(pai)(pai)往外界環境(jing),達到污(wu)(wu)(wu)染物(wu)零排(pai)(pai)(pai)放(fang)。既可有(you)(you)效處(chu)(chu)置污(wu)(wu)(wu)染物(wu),又能將其中(zhong)(zhong)有(you)(you)用(yong)的(de)營養(yang)(yang)(yang)成分循環于土(tu)(tu)(tu)壤 - 植(zhi)物(wu)生(sheng)態系統中(zhong)(zhong), 家(jia)庭(ting)分散戶(hu)養(yang)(yang)(yang)畜禽(qin)(qin)糞(fen)便(bian)污(wu)(wu)(wu)水(shui)處(chu)(chu)理均采用(yong)該法。該模式(shi)適用(yong)于遠離城市、 土(tu)(tu)(tu)地寬(kuan)廣且有(you)(you)足夠農田(tian)消納糞(fen)便(bian)污(wu)(wu)(wu)水(shui)的(de)經(jing)濟落后地區(qu)(qu), 特別是種植(zhi)常年需(xu)施肥(fei)作物(wu)的(de)地區(qu)(qu),要求養(yang)(yang)(yang)殖(zhi)場規模較(jiao)小(xiao)。還(huan)田(tian)模式(shi)主要優點一是污(wu)(wu)(wu)染物(wu)零排(pai)(pai)(pai)放(fang),最大限(xian)度實現資源化,可減(jian)少化肥(fei)施用(yong)量,提高土(tu)(tu)(tu)壤肥(fei)力;二是投資省,不(bu)(bu)耗能,毋需(xu)專人(ren)管理, 運轉費(fei)用(yong)低等(deng)。其存在(zai)的(de)主要問題一是需(xu)要大量土(tu)(tu)(tu)地利用(yong)糞(fen)便(bian)污(wu)(wu)(wu)水(shui),每萬頭豬場至少需(xu) 7hm土(tu)(tu)(tu)地消納糞(fen)便(bian)污(wu)(wu)(wu)水(shui), 故其受條件所限(xian)而適應性弱;二是雨季(ji)及非(fei)用(yong)肥(fei)季(ji)節必(bi)須(xu)考(kao)慮糞(fen)便(bian)污(wu)(wu)(wu)水(shui)或(huo)沼液的(de)出路;三是存在(zai)著傳播(bo)畜禽(qin)(qin)疾(ji)病(bing)和人(ren)畜共患(huan)病(bing)的(de)危險;四是不(bu)(bu)合理的(de)施用(yong)方式(shi)或(huo)連續過量施用(yong)會導致(zhi) NO-
3 、P 及重(zhong)金(jin)屬(shu)沉積,成(cheng)為地(di)表水(shui)(shui)(shui)和(he)(he)地(di)下水(shui)(shui)(shui)污(wu)(wu)(wu)染源之一(yi); 五(wu)是惡臭以及降(jiang)解過(guo)(guo)程所產(chan)生的(de)(de)(de)氨、硫化氫等(deng)有害氣(qi)體釋放(fang)對(dui)大氣(qi)環境構成(cheng)污(wu)(wu)(wu)染威脅。經(jing)濟發達(da)的(de)(de)(de)美(mei)國約 90%的(de)(de)(de)養殖(zhi)場采用(yong)還田(tian)(tian)方法處理(li)(li)(li)畜(chu)禽(qin)廢棄物(wu)(wu)。鑒于(yu)(yu)畜(chu)禽(qin)糞尿(niao)污(wu)(wu)(wu)染的(de)(de)(de)嚴重(zhong)性和(he)(he)處理(li)(li)(li)難度, 英國和(he)(he)其他(ta)歐洲(zhou)國家已開始改(gai)變(bian)飼(si)養工藝,由水(shui)(shui)(shui)沖式(shi)清(qing)洗糞尿(niao)回歸到傳統的(de)(de)(de)稻草(cao)或作物(wu)(wu)秸稈鋪墊吸收(shou)糞尿(niao),然(ran)后(hou)制(zhi)肥(fei)還田(tian)(tian)。日本(ben)曲(qu)徑探尋 10 多年(nian)(nian)后(hou),于(yu)(yu) 20 世紀 70 年(nian)(nian)代始又(you)大力推廣糞便污(wu)(wu)(wu)水(shui)(shui)(shui)還田(tian)(tian)。說(shuo)明還田(tian)(tian)模式(shi)仍有較(jiao)強(qiang)的(de)(de)(de)生命力。我國上海地(di)區在治(zhi)(zhi)理(li)(li)(li)畜(chu)禽(qin)養殖(zhi)污(wu)(wu)(wu)染過(guo)(guo)程中,經(jing)過(guo)(guo)近 10 年(nian)(nian)的(de)(de)(de)達(da)標治(zhi)(zhi)理(li)(li)(li)實踐,又(you)回到還田(tian)(tian)利用(yong)的(de)(de)(de)綜合(he)處理(li)(li)(li)模式(shi)中。美(mei)國糞便污(wu)(wu)(wu)水(shui)(shui)(shui)還田(tian)(tian)前一(yi)般未經(jing)專門厭氧(yang)(yang)消化裝(zhuang)置(zhi)厭氧(yang)(yang)發酵,而是貯存一(yi)定(ding)時間(jian)后(hou)直接灌田(tian)(tian)。由于(yu)(yu)擔(dan)心傳播畜(chu)禽(qin)疾(ji)病和(he)(he)人畜(chu)共(gong)患(huan)病,畜(chu)禽(qin)糞便廢水(shui)(shui)(shui)經(jing)過(guo)(guo)生物(wu)(wu)處理(li)(li)(li)之后(hou)再(zai)適(shi)度應(ying)用(yong)于(yu)(yu)農田(tian)(tian)已成(cheng)為新趨勢。德國等(deng)歐洲(zhou)國家則將畜(chu)禽(qin)糞便污(wu)(wu)(wu)水(shui)(shui)(shui)經(jing)過(guo)(guo)中溫(wen)(wen)或高溫(wen)(wen)厭氧(yang)(yang)消化后(hou)再(zai)進行(xing)還田(tian)(tian)利用(yong),以達(da)到殺滅(mie)寄生蟲卵和(he)(he)病原菌的(de)(de)(de)目(mu)的(de)(de)(de)。我國一(yi)般采用(yong)厭氧(yang)(yang)消化后(hou)再(zai)還田(tian)(tian)利用(yong),可(ke)避免(mian)有機物(wu)(wu)濃度過(guo)(guo)高而引起(qi)的(de)(de)(de)作物(wu)(wu)爛(lan)根和(he)(he)燒(shao)苗,同時經(jing)過(guo)(guo)厭氧(yang)(yang)發酵可(ke)回收(shou)能源CH
4 ,減少(shao)溫室(shi)氣體排放,且(qie)能殺(sha)滅部分寄生(sheng)蟲(chong)卵和(he)病原(yuan)微(wei)生(sheng)物。國外對畜禽(qin)糞便污水(shui)還(huan)田利用(yong)的研究主要側(ce)重(zhong)(zhong)于(yu)安(an)全性評估以及減少(shao)風險(xian)的措施。我(wo)國該方面(mian)(mian)研究則(ze)主要著(zhu)眼(yan)于(yu)畜禽(qin)糞便污水(shui)厭氧消(xiao)化液(沼液)的正面(mian)(mian)影(ying)響即(ji)改良土壤及增(zeng)產效果 [4 ] ,而對其副(fu)作用(yong)即(ji)長期施用(yong)所產生(sheng)的危(wei)害尚未引起足(zu)夠重(zhong)(zhong)視。
2 自然處理(li)模(mo)式
自(zi)(zi)然(ran)(ran)(ran)處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)模(mo)(mo)式(shi)(shi)主(zhu)要(yao)采用(yong)(yong)氧(yang)(yang)(yang)化(hua)(hua)(hua)(hua)(hua)塘(tang)(tang)(tang)(tang)(tang)(tang)、土地(di)(di)(di)(di)(di)處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)系(xi)(xi)(xi)統(tong)(tong)或人工(gong)濕(shi)(shi)(shi)地(di)(di)(di)(di)(di)等(deng)(deng)自(zi)(zi)然(ran)(ran)(ran)處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)系(xi)(xi)(xi)統(tong)(tong)對(dui)養殖(zhi)(zhi)(zhi)場糞(fen)便污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)進(jin)(jin)行(xing)(xing)處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li), 適用(yong)(yong)于(yu)(yu)距城市(shi)較(jiao)(jiao)遠、氣(qi)溫較(jiao)(jiao)高且(qie)土地(di)(di)(di)(di)(di)寬廣(guang)有灘涂、荒地(di)(di)(di)(di)(di)、林地(di)(di)(di)(di)(di)或低(di)洼地(di)(di)(di)(di)(di)可(ke)作(zuo)污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)自(zi)(zi)然(ran)(ran)(ran)處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)系(xi)(xi)(xi)統(tong)(tong)、經(jing)濟欠發(fa)達的(de)(de)(de)(de)地(di)(di)(di)(di)(di)區,要(yao)求養殖(zhi)(zhi)(zhi)場規模(mo)(mo)中(zhong)等(deng)(deng)。自(zi)(zi)然(ran)(ran)(ran)處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)模(mo)(mo)式(shi)(shi)主(zhu)要(yao)優點(dian)(dian)一(yi)是(shi)投資較(jiao)(jiao)省, 能(neng)耗少, 運行(xing)(xing)管理(li)(li)(li)(li)(li)(li)費(fei)用(yong)(yong)低(di); 二(er)是(shi)污(wu)(wu)(wu)(wu)泥量少, 不需(xu)(xu)要(yao)復(fu)雜的(de)(de)(de)(de)污(wu)(wu)(wu)(wu)泥處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)系(xi)(xi)(xi)統(tong)(tong);三是(shi)地(di)(di)(di)(di)(di)下(xia)式(shi)(shi)厭(yan)氧(yang)(yang)(yang)處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)系(xi)(xi)(xi)統(tong)(tong)厭(yan)氧(yang)(yang)(yang)部分(fen)建(jian)(jian)于(yu)(yu)地(di)(di)(di)(di)(di)下(xia),基本無(wu)臭味; 四是(shi)便于(yu)(yu)管理(li)(li)(li)(li)(li)(li),對(dui)周(zhou)圍(wei)環境影(ying)(ying)響小(xiao)且(qie)無(wu)噪音(yin);五是(shi)可(ke)回收能(neng)源 CH 4 。其主(zhu)要(yao)缺(que)(que)點(dian)(dian)一(yi)是(shi)土地(di)(di)(di)(di)(di)占用(yong)(yong)量較(jiao)(jiao)大(da);二(er)是(shi)處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)效(xiao)(xiao)(xiao)果易受季節溫度(du)變化(hua)(hua)(hua)(hua)(hua)的(de)(de)(de)(de)影(ying)(ying)響;三是(shi)建(jian)(jian)于(yu)(yu)地(di)(di)(di)(di)(di)下(xia)的(de)(de)(de)(de)厭(yan)氧(yang)(yang)(yang)系(xi)(xi)(xi)統(tong)(tong)出(chu)泥困(kun)難,且(qie)維修不便;四是(shi)有污(wu)(wu)(wu)(wu)染地(di)(di)(di)(di)(di)下(xia)水(shui)(shui)(shui)(shui)的(de)(de)(de)(de)可(ke)能(neng)。該模(mo)(mo)式(shi)(shi)在(zai)(zai)美國(guo)(guo)(guo)、澳大(da)利(li)亞和(he)(he)(he)東南(nan)(nan)(nan)亞一(yi)些國(guo)(guo)(guo)家應(ying)用(yong)(yong)較(jiao)(jiao)多(duo)(duo),且(qie)國(guo)(guo)(guo)外一(yi)般未經(jing)厭(yan)氧(yang)(yang)(yang)處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)而(er)直接進(jin)(jin)入氧(yang)(yang)(yang)化(hua)(hua)(hua)(hua)(hua)塘(tang)(tang)(tang)(tang)(tang)(tang)處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)畜(chu)禽(qin)糞(fen)便污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui),往往采用(yong)(yong)多(duo)(duo)級厭(yan)氧(yang)(yang)(yang)塘(tang)(tang)(tang)(tang)(tang)(tang)、兼性塘(tang)(tang)(tang)(tang)(tang)(tang)、好氧(yang)(yang)(yang)塘(tang)(tang)(tang)(tang)(tang)(tang)與水(shui)(shui)(shui)(shui)生(sheng)(sheng)植物(wu)(wu)塘(tang)(tang)(tang)(tang)(tang)(tang),污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)停(ting)(ting)(ting)留時(shi)間長(chang)(水(shui)(shui)(shui)(shui)力停(ting)(ting)(ting)留時(shi)間長(chang)達 600d) , 占地(di)(di)(di)(di)(di)面(mian)積大(da), 多(duo)(duo)數(shu)情(qing)況(kuang)下(xia)氧(yang)(yang)(yang)化(hua)(hua)(hua)(hua)(hua)塘(tang)(tang)(tang)(tang)(tang)(tang)只(zhi)作(zuo)為(wei)人工(gong)濕(shi)(shi)(shi)地(di)(di)(di)(di)(di)的(de)(de)(de)(de)預處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)單元。歐洲及美國(guo)(guo)(guo)較(jiao)(jiao)多(duo)(duo)采用(yong)(yong)人工(gong)濕(shi)(shi)(shi)地(di)(di)(di)(di)(di)處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)畜(chu)禽(qin)養殖(zhi)(zhi)(zhi)廢(fei)(fei)水(shui)(shui)(shui)(shui), 美國(guo)(guo)(guo)自(zi)(zi)然(ran)(ran)(ran)資源保(bao)護服(fu)務組(zu)織(NRCS)編制了養殖(zhi)(zhi)(zhi)廢(fei)(fei)水(shui)(shui)(shui)(shui)處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)指南(nan)(nan)(nan),建(jian)(jian)議人工(gong)濕(shi)(shi)(shi)地(di)(di)(di)(di)(di)生(sheng)(sheng)化(hua)(hua)(hua)(hua)(hua)需(xu)(xu)氧(yang)(yang)(yang)量(BOD 5 )負荷為(wei) 73kg / hm2 ·d,水(shui)(shui)(shui)(shui)力停(ting)(ting)(ting)留時(shi)間至少 12d。墨西哥灣項目(GMP)調查收集了 68 處(chu)(chu)(chu)(chu)(chu)(chu)共(gong) 135 個中(zhong)試和(he)(he)(he)生(sheng)(sheng)產規模(mo)(mo)的(de)(de)(de)(de)濕(shi)(shi)(shi)地(di)(di)(di)(di)(di)處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)系(xi)(xi)(xi)統(tong)(tong)約 1300 個運行(xing)(xing)數(shu)據,并建(jian)(jian)立(li)了養殖(zhi)(zhi)(zhi)廢(fei)(fei)水(shui)(shui)(shui)(shui)濕(shi)(shi)(shi)地(di)(di)(di)(di)(di)處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)數(shu)據庫,發(fa)現污(wu)(wu)(wu)(wu)染物(wu)(wu)平均(jun)去除(chu)效(xiao)(xiao)(xiao)率(lv)生(sheng)(sheng)化(hua)(hua)(hua)(hua)(hua)需(xu)(xu)氧(yang)(yang)(yang)量(BOD 5 )為(wei) 65%, 總(zong)懸浮(fu)物(wu)(wu) 53%,NH+4- N 48%,總(zong) N 42% ,總(zong) P 42%。人工(gong)濕(shi)(shi)(shi)地(di)(di)(di)(di)(di)存在(zai)(zai)的(de)(de)(de)(de)主(zhu)要(yao)問題(ti)是(shi)堵塞(sai)(sai), 而(er)引起堵塞(sai)(sai)的(de)(de)(de)(de)主(zhu)要(yao)原因(yin)是(shi)懸浮(fu)物(wu)(wu),微生(sheng)(sheng)物(wu)(wu)生(sheng)(sheng)長(chang)的(de)(de)(de)(de)影(ying)(ying)響卻(que)很小(xiao)。避免堵塞(sai)(sai)的(de)(de)(de)(de)方法主(zhu)要(yao)有加強預處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)、交替進(jin)(jin)水(shui)(shui)(shui)(shui)和(he)(he)(he)濕(shi)(shi)(shi)地(di)(di)(di)(di)(di)床輪(lun)替休(xiu)息, 近年還發(fa)展了“潮汐流”以及反粒級(上(shang)大(da)下(xia)小(xiao))等(deng)(deng)避免堵塞(sai)(sai)。我(wo)國(guo)(guo)(guo)南(nan)(nan)(nan)方地(di)(di)(di)(di)(di)區如江(jiang)西、福建(jian)(jian)和(he)(he)(he)廣(guang)東等(deng)(deng)省也多(duo)(duo)應(ying)用(yong)(yong)自(zi)(zi)然(ran)(ran)(ran)處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)模(mo)(mo)式(shi)(shi),但大(da)多(duo)(duo)采用(yong)(yong)厭(yan)氧(yang)(yang)(yang)預處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)后再進(jin)(jin)入氧(yang)(yang)(yang)化(hua)(hua)(hua)(hua)(hua)塘(tang)(tang)(tang)(tang)(tang)(tang)進(jin)(jin)行(xing)(xing)處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li), 厭(yan)氧(yang)(yang)(yang)處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)系(xi)(xi)(xi)統(tong)(tong)分(fen)地(di)(di)(di)(di)(di)上(shang)式(shi)(shi)和(he)(he)(he)地(di)(di)(di)(di)(di)下(xia)式(shi)(shi), 氧(yang)(yang)(yang)化(hua)(hua)(hua)(hua)(hua)塘(tang)(tang)(tang)(tang)(tang)(tang)為(wei)多(duo)(duo)級塘(tang)(tang)(tang)(tang)(tang)(tang)串聯。我(wo)國(guo)(guo)(guo)在(zai)(zai)人工(gong)濕(shi)(shi)(shi)地(di)(di)(di)(di)(di)處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)養殖(zhi)(zhi)(zhi)廢(fei)(fei)水(shui)(shui)(shui)(shui)方面(mian)進(jin)(jin)行(xing)(xing)的(de)(de)(de)(de)一(yi)些實驗(yan)研究(jiu)和(he)(he)(he)工(gong)程應(ying)用(yong)(yong), 主(zhu)要(yao)著眼于(yu)(yu)植物(wu)(wu)篩選和(he)(he)(he)處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)效(xiao)(xiao)(xiao)果的(de)(de)(de)(de)考察,而(er)在(zai)(zai)氧(yang)(yang)(yang)化(hua)(hua)(hua)(hua)(hua)塘(tang)(tang)(tang)(tang)(tang)(tang)以及人工(gong)濕(shi)(shi)(shi)地(di)(di)(di)(di)(di)處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)養殖(zhi)(zhi)(zhi)廢(fei)(fei)水(shui)(shui)(shui)(shui)設計中(zhong),一(yi)般參照氧(yang)(yang)(yang)化(hua)(hua)(hua)(hua)(hua)塘(tang)(tang)(tang)(tang)(tang)(tang)或人工(gong)濕(shi)(shi)(shi)地(di)(di)(di)(di)(di)處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)其他污(wu)(wu)(wu)(wu)水(shui)(shui)(shui)(shui)的(de)(de)(de)(de)資料作(zuo)為(wei)設計依據或者(zhe)隨意設計, 但針對(dui)畜(chu)禽(qin)養殖(zhi)(zhi)(zhi)廢(fei)(fei)水(shui)(shui)(shui)(shui), 其氧(yang)(yang)(yang)化(hua)(hua)(hua)(hua)(hua)塘(tang)(tang)(tang)(tang)(tang)(tang)、人工(gong)濕(shi)(shi)(shi)地(di)(di)(di)(di)(di)究(jiu)竟需(xu)(xu)要(yao)多(duo)(duo)大(da)面(mian)積, 出(chu)水(shui)(shui)(shui)(shui)才能(neng)達到標準,季節溫度(du)變化(hua)(hua)(hua)(hua)(hua)對(dui)自(zi)(zi)然(ran)(ran)(ran)處(chu)(chu)(chu)(chu)(chu)(chu)理(li)(li)(li)(li)(li)(li)系(xi)(xi)(xi)統(tong)(tong)效(xiao)(xiao)(xiao)果的(de)(de)(de)(de)影(ying)(ying)響等(deng)(deng)方面(mian)尚缺(que)(que)乏深入研究(jiu)和(he)(he)(he)規范(fan)可(ke)依。