Optimized production of a novel bioflocculant M-C11 by Klebsiella sp. and its application in sludge dewatering

The optimized production of a novel bioflocculant M-C11 produced by Klebsiella sp. and its application in sludge dewatering were investigated. The optimal medium carbon source,nitrogen source, metal ion, initial pH and culture temperature for the bioflocculant production were glucose, NaNO3, MgSO4, and pH 7.0 and 25°C, respectively. A compositional analysis indicated that the purified M-C11 consisted of 91.2% sugar, 4.6% protein and 3.9% nucleic acids（m/m）. A Fourier transform infrared spectrum confirmed the presence of carboxyl, hydroxyl,methoxyl and amino groups. The microbial flocculant exhibited excellent pH and thermal stability in a kaolin suspension over a pH range of 4.0 to 8.0 and a temperature range of 20 to 60°C.The optimum bioflocculating activity was observed as 92.37% for 2.56 mL M-C11 and 0.37 g/L CaCl2 dosages using response surface methodology. The sludge resistance in filtration（SRF）decreased from 11.6 × 1012 to 4.7 × 1012m/kg, which indicated that the sludge dewaterability was remarkably enhanced by the bioflocculant conditioning. The sludge dewatering performance conditioned by M-C11 was more efficient than that of inorganic flocculating reagents,such as aluminum sulfate and polymeric aluminum chloride. The bioflocculant has advantages over traditional sludge conditioners due to its lower cost, benign biodegradability and negligible secondary pollution. In addition, the bioflocculant was favorably adapted to the specific sludge pH and salinity.     

生态文明建设的先锋——瑶里

瑶里镇地处景德镇市东北端,是江西景德镇陶瓷发祥地,古名＂窑里＂。远在唐代中叶,这里就有生产陶瓷的手工作坊。这里的高岭是中国古代著名的瓷用原料产区,是国际黏土矿物学通用术语——＂高岭土＂的命名地。     

Fenton试剂在处理高岭土选矿废水中的应用研究

介绍了Fenton试剂处理难降解有机废水的作用机理,初步探讨了H2O2投加量、硫酸亚铁用量及反应时间对水样处理效果的影响.结果表明:仅H2O2作用时,色度去除率达到98%以上,处理后水样色度小于5;在硫酸亚铁投加量为150mg/L时,氧化后废水的COD质量浓度只有29.62 mg/L;水样甲醛在反应10min时去除率超过99%,反应2 h后无机离子浓度大大降低.     

煤系高岭土开发利用中存在的问题与对策

煤炭行业开发利用煤系高岭土具有许多有利的条件,但也存在一些问题。作者针对目前煤系高岭土开发利用中存在的问题提出了相应的对策,以供有关决策部门参考。