本文關鍵詞：嗜酸性硫桿菌的分離純化及其應用研究　出處：《南京理工大學》2015年碩士論文　論文類型：學位論文

  更多相關文章： 酸洗污泥 嗜酸性硫桿菌 重金屬 生物浸出 黃鉀鐵礬

【摘要】：針對酸洗污泥的減量化與資源化問題,現(xiàn)有的火法、濕法和固化等處置方法存在著二次污染、經(jīng)濟性差、有效資源無法回收利用等問題。本研究富集培養(yǎng)嗜酸性硫桿菌,探究生物法在酸洗廢棄物處理領域的可行性。對江蘇省重點地區(qū)的不銹鋼企業(yè)進行采樣分析,得出酸洗廢水進水的pH在2-3左右,經(jīng)石灰和堿液中和沉淀后,出水的pH在6-7左右。酸洗污泥的pH基本呈堿性,在8-9左右,含水率大約在70%～80%。酸洗廢水和酸洗污泥中Fe、Ca含量最高,平均含量分別為13.63%和27.57%；重金屬Ni、Cr的含量突出,平均含量分別為2.26%和2.77%；酸根離子含量最高的為F,平均含量達到23.57%。從南京市城東污水處理廠的二沉池中富集培養(yǎng)菌株作為實驗菌株,經(jīng)分離鑒定為嗜酸性硫桿菌,命名為Acidithiobacillus ferrivorans NJUST22。分別討論初始pH、亞鐵濃度和溫度對菌株活性的影響,確定最佳運行參數(shù),即菌株可以利用亞鐵作為能源,最適pH為2.5,溫度為30℃。由于酸洗廢水和酸洗污泥中含有一定量的重金屬和酸根離子,會對菌株產(chǎn)生潛在的毒害作用,需研究對其的耐受性。結果表明：菌株可耐受600mg/L的重金屬離子Cr3+和Ni2+; NO3-、Cl-、SO42-、PO43-要達到0.3mol/L時才會出現(xiàn)強烈的抑制作用；而F-僅需0.01mol/L就會對菌株活性造成強烈的抑制。嗜酸性硫桿菌在培養(yǎng)過程中,使整個培養(yǎng)基pH降低,以達到浸出污泥中重金屬的目的。但由于酸洗污泥pH過高和氟離子濃度過高兩個原因,會一定程度抑制菌株的活性,導致整個培養(yǎng)基pH下降緩慢,重金屬離子的浸出率較低。當初始亞鐵濃度為5.0g/L時,重金屬Cr3+和Ni2+的浸出率分別達到34.87%和85.37%,過高的初始亞鐵濃度反而會導致浸出率的下降�？疾斐跏紁H、亞鐵濃度和溫度對生物法合成黃鉀鐵礬的影響,對黃鉀鐵礬進行物相分析,并探究其對廢水中重金屬離子的去除效果。結果表明：菌株的活性決定了黃鉀鐵礬的生成量,但初始pH低于2.0、溫度低于20℃以及培養(yǎng)基中的亞鐵濃度過低時都不利于黃鉀鐵礬的生成。黃鉀鐵礬樣品由形狀不規(guī)則的小顆粒膠連在一起組成,分散性好。樣品的平均粒徑為17.74μm,分布較均勻。生物法合成黃鉀鐵礬時,酸洗廢水(出水)中Cr3+的去除率較高,最高可達到87.02%,Ni2+的去除率相對較低,最高可達到55.30%。
[Abstract]:Aiming at the problem of reduction and reuse of acid sludge, the existing fire, wet and solidification disposal methods have two problems, such as pollution, poor economy, and effective resources can not be recycled. This study enriched and cultured eosinophilic bacilli, and explored the feasibility of biological method in the field of acid washing waste treatment. Sampling and analyzing the stainless steel enterprises in key areas of Jiangsu Province, it is concluded that the pH of the pickling waste water is about 2-3, and the pH of the effluent is about 6-7 after neutralization and precipitation by lime and alkali. The pH of the pickling sludge is basically alkaline, at about 8-9, and the water content is about 70% ~ 80%. The contents of Fe and Ca in acid pickling wastewater and acid washed sludge were the highest, the average contents were 13.63% and 27.57% respectively. The contents of heavy metals Ni and Cr were outstanding, the average contents were 2.26% and 2.77% respectively, and the highest content of acid ion was F, with an average content of 23.57%. From the two sink of Chengdong wastewater treatment plant in Nanjing, the strain was selected as an experimental strain and identified as acidophilic Thiobacillus, named Acidithiobacillus ferrivorans NJUST22. The effects of initial pH, ferrous concentration and temperature on the activity of bacteria were discussed respectively, and the best operation parameters were determined. That is, strain can use ferrous as energy source, the optimum pH is 2.5, and the temperature is 30 C. Because of a certain amount of heavy metals and acid ion in pickling and pickling sludge, it will have potential toxicity to the strain, and it is necessary to study its tolerance. The results showed that the strain could tolerate heavy metal ions Cr3+ and Ni2+ of 600mg/L, while NO3-, Cl-, SO42- and PO43- had strong inhibition when 0.3mol/L reached 0.3mol/L, while F- only needed 0.01mol/L, which strongly inhibited the activity of strain. In the process of culture, Thiobacillus eosinophilia reduces the whole medium pH to achieve the purpose of Leaching Heavy Metals in sludge. However, due to two reasons of high pH and high fluoride concentration, the activity of the strain will be inhibited to a certain extent, resulting in a slow decline of pH in the whole culture medium and a low leaching rate of heavy metal ions. When the initial ferrous concentration is 5.0g/L, the leaching rates of heavy metals Cr3+ and Ni2+ reach 34.87% and 85.37% respectively. The higher initial ferrous concentration will lead to the decrease of leaching rate. The effects of initial pH, ferrous concentration and temperature on biotic synthesis of jarosite were investigated. Phase analysis of jarosite was carried out and its removal effect on heavy metal ions in wastewater was explored. The results showed that the activity of the strain determined the production of jarosite. However, when the initial pH was below 2, the temperature was below 20 C, and the ferrous concentration in the medium was too low, it was not conducive to the generation of jarosite. The samples of potassium ferric alum are made up of small particles with irregular shape, and have good dispersibility. The average particle size of the sample is 17.74 m, and the distribution is more uniform. In the process of biological synthesis of jarosite, the removal rate of Cr3+ in acid washing wastewater (effluent) is high, the highest can reach 87.02%, and the removal rate of Ni2+ is relatively low, up to 55.30%.
【學位授予單位】：南京理工大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：X703;X172

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相關期刊論文 前1條

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本文編號：1339115