本文選題：養(yǎng)豬廢水　切入點：土壤滲濾　出處：《哈爾濱工業(yè)大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：采用干清糞方式收集的養(yǎng)豬廢水中仍然含有大量的有機物、氨氮、總磷、病蟲卵等有害物質(zhì),若不經(jīng)處理直接排放,不僅會造成環(huán)境污染還會危及人類健康。本研究對現(xiàn)有的土壤滲濾系統(tǒng)(SIT)進行工藝改進研究,通過向土壤填料中摻雜木片的方式構(gòu)建了木片土壤滲濾系統(tǒng)(WSIT),并對該系統(tǒng)的啟動方式和運行條件進行對比優(yōu)化,同時采用熒光定量PCR技術(shù)對WSIT系統(tǒng)中的氮元素轉(zhuǎn)化去除的微生物學(xué)原理進行分析。在WSIT的結(jié)構(gòu)優(yōu)化實驗中,選取3個相同體積的反應(yīng)器。1號反應(yīng)器自下而上每間隔20 cm設(shè)置一組隔板,填料中木片與土壤的比例為1∶3;2號反應(yīng)器滲濾柱中未設(shè)置隔板,填料中木片與土壤的比例為1∶3;3號反應(yīng)器未設(shè)置隔板,填料中木片與土壤的比例為1∶4。研究表明,在表面水力負荷為0.2m3/m2?d,溫度控制為25℃的條件下,3個WSIT均能在40天左右啟動成功并穩(wěn)定運行,然而其對廢水中污染物的去除效果有所差異。1號WSIT對廢水中COD、NH4+-N和TN的去除率分別為67.3%、87.7%和24.7%,2號WSIT對COD、NH4+-N和TN的去除率分別為61.0%、84.9%和35.2%,而3號WSIT對COD、NH4+-N和TN的去除率分別為68.5%、94.5%和45.0%。隔板的消除削弱了WSIT與外界交換氧氣的能力,使其內(nèi)部的氧濃度更低,產(chǎn)生更多的厭氧或缺氧區(qū)域,然而,這并沒有降低WSIT對COD和NH4+-N的去除能力,反而強化了其對TN的去除作用。填料中土壤比例的增加,使得WSIT內(nèi)部微生物量隨之增加,進而使WSIT對NH4+-N和TN的去除能力有所增強。表面水力負荷對WSIT對COD的去除能力影響不大,但是,其對NH4+-N和TN的去除有顯著影響。當(dāng)水力負荷提升至0.3 m3/m2?d后,WSIT對NH4+-N和TN的去除能力明顯下降,去除率為80.8%和37.9%左右。WSIT填料中的木片,不僅能夠提高填料床的機械強度,使之能夠承受較高的表面水力負荷,還可作為緩釋碳源,為系統(tǒng)中的反硝化脫氮作用提供一定量的碳源。由于干清糞養(yǎng)豬廢水中碳源嚴重不足,WSIT對TN的去除主要是通過短程硝化反硝化途徑實現(xiàn)的,進水中的NH4+-N被氧化成NO2--N后,一部分被還原成氣態(tài)氮排出系統(tǒng),另一部分進一步被氧化成NO3--N并隨出水流出系統(tǒng)。通過熒光定量PCR對系統(tǒng)中與氮代謝有關(guān)的微生物數(shù)量的分析表明,在WSIT中,表層的微生物含量較低,這可能是由營養(yǎng)物質(zhì)分布不均勻和高濃度的氨氮抑制所導(dǎo)致的,在濾床縱深0.2 m處,細菌的拷貝數(shù)僅有3.55×107 copies/μL。微生物主要聚集在濾床高度為0.4-1.0 m的區(qū)域內(nèi),而這段區(qū)域也是廢水中污染物降解的主要區(qū)域。亞硝酸鹽還原菌和氨氧化細菌(AOB)變化規(guī)律一致,說明WSIT對氮元素的去除主要依靠短程反硝化過程,其最大拷貝數(shù)分別為2.67×107和4.70×107 copies/μL。在濾床縱深1.0-1.2 m的區(qū)域內(nèi),營養(yǎng)物質(zhì)的匱乏成為微生物生長的限制因素,導(dǎo)致其含量迅速降低,系統(tǒng)內(nèi)細菌的總拷貝數(shù)為1.03×108 copies/μL。
[Abstract]:The pig wastewater collected by dry defecation still contains a large amount of organic matter, ammonia nitrogen, total phosphorus, diseased eggs and other harmful substances, if it is discharged directly without treatment, Not only will it cause environmental pollution, but also endanger human health. In this study, the existing soil leachate system (SITs) was studied for technological improvement. The soil leachate system of wood chips was constructed by mixing wood chips into soil fillers, and the startup mode and operation conditions of the system were compared and optimized. At the same time, the principle of microbiology of nitrogen conversion and removal in WSIT system was analyzed by fluorescence quantitative PCR. In the structure optimization experiment of WSIT, Three reactors of the same volume were selected. A group of compartments were set up at 20 cm intervals from bottom to top in reactor 1. The ratio of wood slice to soil in packing was 1: 3; no partition was set in leachate column of reactor 2. The ratio of wood slice to soil in packing was 1: 3; in reactor 3, there was no partition, and the ratio of wood slice to soil in packing was 1: 4. The results showed that the hydraulic load on the surface was 0.2 m3 / m2? D, temperature is 25 鈩，

本文編號：1622312