微生物絮凝法处理养鱼污水

以枯草杆菌为絮凝产生菌,优化养鱼污水对其培养条件,探讨其降解污水有机物效果及增殖变化,并讨论分析絮凝活性分布、成分组成。结果表明：pH 6.7～7.8、碳氮比20～40、COD≥85 mg/L养鱼污水（灭菌）培养该菌36 h,其培养液（2 mL投量）对高岭土悬液的絮凝率达39.5%,养鱼污水COD去除率达47.2%,絮凝菌生长良好;该絮凝菌其絮凝活性物质是菌体分泌物,成分主要为多糖。     

室外条件下蚯蚓协同微生物直接处理鲜鸡粪

选用赤子爱胜蚓(Eisenia fetida)协同EM菌和硝化细菌直接进行室外条件下的鲜鸡粪处理实验,以菌剂接种量、缓冲层厚度、投放密度等为主要筛选参数,并对经蚯蚓消化处理前后的鸡粪冲淋水中氮磷的变化进行了取样检测.实验结果表明,室外条件下蚯蚓借助于微生物的协同作用可直接处理鲜鸡粪.当鲜鸡粪负荷为15 g/d时,在接种EM菌剂和硝化菌剂各10 mL,铺设4 cm厚度凹土缓冲层,蚯蚓投放密度为12条的条件下,鲜鸡粪被降解的效果最好.经过蚯蚓消化降解后的鸡粪水中TN浓度降低了20.34％,TN中无机氮含量增多,NH4+-N和N03--N所占TN比例分别增加了18.79％和37.96％;TP浓度降低了14.40％.     

石灰投加与搅拌对生态厕所的灭菌效果

以发展中国家农村地区的卫生条件改善为目的,开展了简易生态厕所的粪便堆肥处理实验。在投加石灰作为抑菌剂的条件下,研究了搅拌混合对杀灭致病微生物的影响,以及使堆肥终产物达到可接受风险值所需的最佳搅拌条件。实验确定了石灰的投加量,并应用Beta-Possion模型对堆肥处置过程中致病微生物对暴露人群的健康风险进行评价,从而从健康风险控制的角度确定了最佳的搅拌次数。研究结果表明,石灰投加量约占堆肥干重1.5%,手动搅拌50次,经搅拌后放置12 h能达到可接受的风险值(3.2×10-5)。     

稠油降解微生物的筛选鉴定及其降解特性

从二连油田原油和油层水中筛选驯化出3株能够降解稠油的细菌DS1、DS2和DS3,通过16S rRNA基因序列比对发现DS1、DS2和DS3分别与溶血不动杆菌(Acinetobacter haemolyticus)、鹑鸡肠球菌(Enterococcus gallinarum)和耳炎短杆菌(Brevibacterium otitidis)相似度最高,分别为99%、99%和98%。研究结果表明,DS1对温度和pH有较强耐受性,DS3对盐度的适应性较好,2株菌最适的降解条件为温度35~40℃、盐度2%~5%(W/V)、pH为7~10。在5%的原油浓度下,复合菌对原油的30 d降解率达89.2%。经GC-MS分析,微生物降解作用后,除C29其他烃类几乎被全部降解。3株菌在7d内对500 g/L粘度为1 746 mPa·s(50℃)的稠油降粘率分别为49.1%、46.6%和49.0%,而复合菌对稠油的降粘效果高于单一菌株,其降粘率达到57.0%。     

浓度波扩散模型在玉米秸秆厌氧干发酵中的应用及验证

将Vavilin的浓度波扩散模型引入到玉米秸秆厌氧干发酵中,使用MATLAB7.0软件运用最小二乘法,计算初始含水量为70%的中温玉米秸秆干发酵过程中Ds、DB和ρm等相关模型系数,并通过不同初始含水量(75%、80%和85%)实验来进行验证,结果表明,所得模型系数在含水量70%~80%时预测效果较好,能较为准确地反映发酵过程中的传质过程。     

混合菌种的共固定化技术在污染治理中的应用

对混合菌种固定化技术所用的载体和改进方法作了介绍,以及在污染治理中的应用进行了综述,治理的污染物主要包括酚类、卤化烃、氮和磷及其芳香族化合物。对该技术在污染治理中的应用前景作了评述。     

纳米零价铁在水处理中的应用研究综述

纳米零价铁(nZVI)作为最常用的纳米颗粒之一,在去除环境水体中的污染物方面开展了大量的研究.本篇综述通过系统全面地总结nZVI的相关进展,介绍nZVI的各个方面进而指导其发展方向.其中,研究内容主要包括制备方法、改性方式、去除不同水中污染物的作用机理和催化机理、在场地研究中的应用以及毒性作用机制.本文发现,纳米零价铁仍存在缺少综合评价方法、应用受限、各项研究不同步等问题.nZVI未来的发展,应具备考虑反应性、稳定性、迁移性、毒性的评价方法,避免同一改性材料在不同研究方向的时间差异性,让nZVI的应用更好地适用实地研究.     

Zeolite powder addition to improve the performance of submerged gravitation-filtration membrane bioreactor

In this study, the effect of zeolite powder addition on submerged membrane bioreactor （SMBR） on membrane permeability, and the removals for COD, NH3-N, TN were investigated. Through the parallel operation of control and test systems, it was found that the zeolite powder addition could alleviate the ultra-filtration membrane fouling and enhance the membrane permeability. On the basis of experimental investigations, a concept of ＂protection coating layer＂ was proposed to illustrate the phenomenon of UF membrane fouling. In addition, the removal for COD in test system was more stable, a little higher compared to the control system. Due to the combination of nitrification and ion exchange, a more excellent removal for NH3-N in test system was obtained regardless of influent NH3-N loading rate. It was also found that a mean 25% higher TN removal took place in the test system, and ion exchange and simultaneous nitrification and de-nitrification were analyzed to be main factors. During the stable operation period, the SOURs of test zeolite powder added sludge and control activated sludge were measured to be 75 mgO2/（gMLVSS, h） and 24 mgO2/（gMLVSS, h） respectively, it meant that the zeolite powder addition could enhance the microorganism activity significantly.     

Biodegradation of 2,6-ditert-butylphenol by immobilized microorganism strains

2,6-Ditert-butylphenol （2,6-DTBP） is a major organic contaminant presenting in acrylic fiber manufacturing wastewaters. This compound is of high bio-resistance due to its complex structure which consists of one phenol group and two highly branched tert-butyl groups. This research attempted to improve the biodegradation efficiency of 2,6-DTBP through various strain immobilization methods. The stratified immobilization can settle oxygen transmission in the single microorganism immobilization, and can realize two-process reaction in the single device by choosing two symbiotic microorganisms. Two effective strains, named F-1-4 and F-3-4, which were screened out in our previous work, were used to degrade 2,6-DTBP after being immobilized in calcium alginate gel. Results indicate that the substrate removal efficiency of various immobilization methods follows the order： stratified 〉 single F-3-4 〉 mixed ≈single F-1-4. The immobilized biodegradation capacity was higher than the free one. After an incubation time of 12 d, 91% of 2,6-DTBP could be degraded by the stratified immobilization method, compared to 79% achieved by the mixed immobilization method with an initial 2,6-DTBP concentration of 100 mg/L. The stratified immobilization satisfies the oxygen demand nature of the aerobic F-3-4 and the facultative F-1-4, thus yielding the highest degradation efficiency. Both the outer layer strain F-3-4 and the inner layer strain F-1-4 can grow actively on the substrate of 2,6-DTBP, as illustrated by SEM images. This study shows that the highly bio-refractory compound, 2,6-DTBP, can be effectively degraded using appropriately inunobilized microorganism strains.     

改性秸秆制备固定化微生物及对钻井泥浆的处理

将小麦秸秆改性后制备改性秸秆固定化微生物,用于处理钻井泥浆。考察了改性时间、改性剂浓度、改性剂配比对秸秆吸附微生物效果的影响,以及改性秸秆固定化微生物对钻井泥浆的处理效果。实验结果表明:在改性时间为60 min、氢氧化钠溶液浓度为0.1 mol/L、过氧化氢溶液浓度为1.0 mol/L、氢氧化钠溶液与过氧化氢溶液体积比为3∶1的最佳改性条件下,改性秸秆的BET比表面积增大了36.27%,Langmuir比表面积增加了37.63%,微生物吸附量增加了200.77%;在钻井泥浆处理量为1 000 g、改性秸秆固定化微生物加入量为2 g、土壤加入量为1 000 g、处理时间为15 d的条件下,钻井泥浆COD、可溶性盐、石油烃的去除率分别为84.9%,71.6%,90.1%。