【摘要】：隨著工業(yè)、農(nóng)業(yè)以及人們生活水平的提高,氮素污染已經(jīng)成為全球性的重大環(huán)境問題,引起了社會(huì)各界的廣泛關(guān)注,促使了生物脫氮技術(shù)的快速發(fā)展,新型生物脫氮技術(shù)也不斷出現(xiàn)。其中異養(yǎng)硝化-好氧反硝化菌的出現(xiàn)使得硝化過程與反硝化過程得以在時(shí)間上和空間上實(shí)現(xiàn)統(tǒng)一,大大提高了脫氮的效率;微生物固定化技術(shù)的出現(xiàn)則克服了微生物不易保存運(yùn)輸,以及投加到后流失嚴(yán)重等問題。本研究從南昌市某污水處理廠二沉池污泥及南昌大學(xué)某湖泊底泥中篩選出了3株脫氮性能較好的異養(yǎng)硝化-好氧反硝化菌WN1、WN3和DN02,3株菌的氨氮去除率分別為68.9%、71.7%和66.2%。從混合培養(yǎng)初探實(shí)驗(yàn)結(jié)果看出三株菌可共生培養(yǎng),通過混料設(shè)計(jì)得出了三株菌構(gòu)成菌劑的最佳配比為WN1:WN3:DN02=0.935:0.965:1.100,在此最佳復(fù)合比下菌劑的氨氮去除率達(dá)到90.37%,NO_3~--N的最大濃度為7.58mg/L,NO2--N的濃度始終為0。進(jìn)一步研究了菌劑的最佳脫氮條件,結(jié)果表明在碳源為琥珀酸鈉,pH為7.0,溫度為30℃,搖床轉(zhuǎn)速為150rpm,C/N為12條件下菌劑的脫氮效果最好,氨氮去除率達(dá)到91.18%。當(dāng)海藻酸鈉為1%,聚乙烯醇為8%,活性炭為2%時(shí),包埋固定化小球在穩(wěn)定性,成球性和傳質(zhì)性能上都有較好的表現(xiàn)。固定化過程中使用的化學(xué)藥劑會(huì)對(duì)微生物活性會(huì)產(chǎn)生一定的影響,但經(jīng)過活性恢復(fù)實(shí)驗(yàn)后,固定化小球的脫氮性能與游離菌劑相當(dāng)。當(dāng)固定化小球投加量為20%時(shí),氨氮去除率達(dá)到89.78%。固定化小球在模擬廢水氨氮濃度低于500mg/L時(shí),20h內(nèi)氨氮去除率均能達(dá)到最大,且能維持在85%左右;當(dāng)模擬廢水氨氮濃度達(dá)到1000mg/L時(shí),需要28h才能達(dá)到最大氨氮去除率81.7%。
[Abstract]:With the improvement of industry, agriculture and people's living standards, nitrogen pollution has become a major environmental problem in the world, which has aroused widespread concern from all walks of life and promoted the rapid development of biological nitrogen removal technology. New biological denitrification techniques are also emerging. The appearance of heterotrophic nitrification-aerobic denitrifying bacteria made the nitrification process and denitrification process unified in time and space and greatly improved the efficiency of nitrogen removal. The emergence of microorganism immobilization technology overcomes the problems such as the difficulty of preservation and transportation of microorganisms and the serious loss after addition. In this study, three strains of heterotrophic nitrification-aerobic denitrifying bacteria (WN1,WN3) and DN02,3 strains (WN1,WN3 and DN02,3) were screened from the sludge of secondary sedimentation tank and a lake sediment of Nanchang University. The ammonia nitrogen removal rates of WN1,WN3 and DN02,3 strains were 68.9, respectively. 71.7% and 66.2%. The results of mixed culture experiment showed that three strains of bacteria could be cultured symbiotically, and the optimum mixture ratio of three strains of bacteria was found to be WN1:WN3:DN02=0.935:0.965:1.100, by mixing design. Under the optimum compound ratio, the removal rate of ammonia-nitrogen reached 90.37% and the maximum concentration of N was 7.58 mg / L no _ 2--N, and the concentration of N was always 0.58 mg 路L ~ (-1) 路L ~ (-1) ~ (-1). The optimum denitrification conditions were further studied. The results showed that the best denitrification effect was obtained when the carbon source was sodium succinate, the pH was 7.0, the temperature was 30 鈩，

本文編號(hào)：2383725