重金属复合污染农田土壤的微生物群落遗传多样性研究

采集了浙江省富阳市环山乡某冶炼厂小高炉附近受铜、锌、铅、镉不同程度复合污染的4个农田土壤样品，首先扩增土壤总DNA中的16S rDNA，然后进行变性梯度凝胶电泳(Denaturing Gradient Gel Electrophoresis)，分析了长期受重金属复合污染的农田土壤的微生物群落遗传多样性变化．结果表明，不同程度的重金属复合污染明显改变了农田土壤的微生物群落遗传多样性，但与多样性的改变不是简单的负相关关系，最大的多样性指数出现在中等污染程度的土壤中．     

皮革废水有机污染物生物降解特性研究

选取二萘磺酸钠、单宁酸及杨梅栲胶3种皮革鞣剂,接种皮革废水处理厂的活性污泥,在批式试验中研究了好氧及厌氧降解特性及降解动力学.以实际皮革废水为研究对象,同样采用批式试验考察了好氧及厌氧降解过程COD变化规律.结果表明,对于皮革鞣剂的去除及矿化,好氧降解优于厌氧降解.好氧降解二萘磺酸钠、单宁酸及杨梅栲胶的去除率分别为>90%、>90%、50%～75%;厌氧降解的去除率分别为10%～40%、>95%、20%～30%;好氧及厌氧降解单宁酸的COD去除率分别为>75%、<75%.好氧降解单宁酸及杨梅栲胶的一级动力学速率常数k值受初始浓度影响较小,而好氧降解二萘磺酸钠的k值受到初始浓度显著影响,二萘磺酸钠≥70 mg·L-1对微生物产生毒性作用,k值明显下降.皮革废水生物降解具有明显阶段性特征,快速及慢速降解期内COD浓度与反应时间呈现很好的线性关系,好氧最大比降解速率是厌氧最大比降解速率的11.6倍.     

烟酰胺降解菌的筛选及其降解特性

采用HPLC对某烟酰胺生产废水的主要成分进行分析,并模拟废水中的主要成分烟酰胺(nicotinamide)的浓度,对以烟酰胺为唯一碳源配制的培养基进行降解实验,获得有较佳降解率和生长能力的菌株YSI-1和YSI-2.结果表明,YSI菌株的混合菌降解效果优于单株菌,混合菌在初始OD600值为0.4,pH为7.0时,对浓度为2000 mg/L的烟酰胺降解2 d的降解率可达32.8%.延长处理时间或提高菌种的初始OD600值,烟酰胺的去除率均有较大的增加.     

锑污染土壤固化-稳定化的影响因素

通过比较不同稳定剂、固化剂、土壤pH条件下土壤中重金属锑的修复效果,研究了锑的固化-稳定化影响因素并探讨了相关稳定化机理.实验结果表明:铁基稳定剂的效果明显优于磷酸二氢钾和腐殖酸钠,而零价铁的稳定化效果更优于硫酸铁和硫酸亚铁,较适宜的稳定剂投加量为5％(w);水泥做固化剂对锑的稳定化效果优于氧化钙,最佳投加量为5％(w...     

改性聚偏氟乙烯中空纤维超滤膜处理乳化液废水

应用改性聚偏氟乙烯中空纤维超滤膜处理乳化液废水(COD浓度100~300 g/L、含油量30~100 g/L),考察了在不同压力、温度及流速条件下,膜处理能力的变化,并研究了清洗方法对膜性能的恢复效果。结果表明,在组合预处理条件下,乳化液废水的COD去除率可达95%以上,油去除率可达99%以上,采用金属清洗剂可使膜的透过量恢复率达97%以上。该项研究为膜处理技术用于乳化液废水处理奠定了基础。     

废水同步生物处理与生物燃料电池发电研究

利用厌氧活性污泥作为接种体成功地启动了空气阴极生物燃料电池(ACMFC),110h的接种产生了0.24V的电压;以乙酸钠和葡萄糖作底物分别产生了0.38V和0.41V电压(外电阻1 000Ω),最大功率密度分别达到146.56 mW/m²和192.04mW/m²,表明有机废水可以用来发电;同时,乙酸钠和葡萄糖的去除率分别为99%和87%,表明燃料电池可以处理废水.二者的电子回收率均在10%左右,主要是由于阴极对氧气分子的透过作用引起的微生物好氧呼吸导致电子损失.     

Decomposition kinetics of dimethyl methylphospate(chemical agent simulant) by supercritical water oxidation

Supercritical water oxidation （SCWO） has been drawing much attention due to effectively destroy a large variety of high-risk wastes resulting from munitions demilitarization and complex industrial chemical. An important design consideration in the development of supercritical water oxidation is the information of decomposition rate. In this paper, the decomposition rate of dimethyl methylphosphonate（DMMP）, which is similar to the nerve agent VX and GB（Sarin） in its structure, was investigated under SCWO conditions. The experiments were performed in an isothermal tubular reactor with a H2O2 as an oxidant. The reaction temperatures were ranged from 398 to 633℃ at a fixed pressure of 24 MPa. The conversion of DMMP was monitored by analyzing total organic carbon （TOC） on the liquid effluent samples. It is found that the oxidative decomposition of DMMP proceeded rapidly and a high TOC decomposition up to 99.99% was obtained within 11 s at 555℃. On the basis of data derived from experiments, a global kinetic equation for the decomposition of DMMP was developed. The model predictions agreed well with the experimental data.     

Monitoring impact of mefenacet treatment on soil microbial communities by PCR-DGGE fingerprinting and conventional testing procedures

The effect of acetanilide herbicide mefenacet on soil microbial communities was studied using paddy soil samples with different short-term treatments. The culturable bacteria （plate counts）, dehydrogenase activity and changes in community structure （denaturing gradient gel electrophoresis （DGGE） analysis） were used for biological community assessments. Mefenacet was a significant stimulus to cultural aerobic bacteria and dehydrogenase activity while Sphingobacterium multivorum Y1, a bacterium efficiently degrading the mefenacet, only induced the increasing colony-forming unit （CFU） of bacteria but little effect on dehydrogenase activity during the whole experiment. The degree of similarity between the 16S rDNA profiles of the communities was quantified by numerically analyzing the DGGE band patterns. Similarity dendrograms showed that the microbial community structures of the mefenacet-treated and non-treated soils were not significantly different. But supplement of S. multivorum Y1 could increase the diversity of the microbial community in the mefenacet-polluted paddy soil. This work is a new attempt to apply the S. multivorum Y1 for remediation of the mefenacet-polluted environments.     

Effect of components in activated sludge liquor on membrane fouling in a submerged membrane bioreactor

Introduction The membrane bioreactors (MBRs) have shown many advantages over conventional activated sludge processes, which apply membrane modules instead of the secondary settle tank to make a better separation of the solids and liquid and have been grea…     

小型污水处理系统设计建议

针对小型污水处理系统的特点,着眼于提高处理效率、降低能耗、减少产泥、方便管理、节省占地等原则,对其构筑物、设备及工艺的设计经验和发展趋势进行了较为全面的总结,并提出了相应的具体设计建议.