Cui Rong, Jahng Deokjin
Department of Environmental Engineering and Biotechnology, Myongji University, 449-728, Yongin, Kyunggido, Republic of Korea.
Biotechnol Lett. 2006 Apr;28(8):531-8. doi: 10.1007/s10529-006-0012-9.
To improve biogas yield and methane content in anaerobic digestion of excess sludge from the wastewater treatment plant, the sludge was disintegrated by using various methods (sonication, alkaline and thermal treatments). Since disintegrated sludge contains a high concentration of soluble proteins, the resulting metabolite, ammonia, may inhibit methane generation. Therefore, the effects of protein removal from disintegrated sludge on methane production were also studied. As a result, an obvious enhancement of biogas generation was observed by digesting disintegrated sludge (biogas yield increased from 15 to 36 ml/g COD(added).day for the raw excess sludge and the sonicated sludge, respectively). The quality of biogas was also improved by removing proteins from the disintegrated sludge. About 50% (w/w) of soluble proteins were removed from the suspension of disintegrated sludge by salting out using 35 g MgCl(2) x 6H(2)O/l and also by isoelectric point precipitation at pH 3.3. For deproteinized sludge, methane production increased by 19%, and its yield increased from 145 ml/g COD(removed) to 325 ml/g COD(removed). Therefore, the yield and quality of biogas produced from digestion of excess sludge can be enhanced by disintegrating the sludge and subsequent protein removal.
为提高污水处理厂剩余污泥厌氧消化过程中的沼气产量和甲烷含量，采用了多种方法（超声处理、碱处理和热处理）对污泥进行破解。由于破解后的污泥含有高浓度的可溶性蛋白质，其产生的代谢产物氨可能会抑制甲烷生成。因此，还研究了从破解后的污泥中去除蛋白质对甲烷产生的影响。结果表明，消化破解后的污泥时，沼气产量有明显提高（原剩余污泥和超声处理后的污泥的沼气产量分别从15毫升/克化学需氧量（添加量）·天增加到36毫升/克化学需氧量（添加量）·天）。通过从破解后的污泥中去除蛋白质，沼气质量也得到了改善。使用35克六水合氯化镁/升进行盐析以及在pH值为3.3时进行等电点沉淀，可从破解后的污泥悬浮液中去除约50%（重量/重量）的可溶性蛋白质。对于脱蛋白污泥，甲烷产量提高了19%，其产率从145毫升/克化学需氧量（去除量）增加到325毫升/克化学需氧量（去除量）。因此，通过破解污泥并随后去除蛋白质，可以提高剩余污泥消化产生的沼气的产量和质量。
