高COD焦化废水的吸附研究

研究了粉末活性炭对焦化废水COD的去除效率.结果表明,在pH值为6左右时,向50 mL焦化废水中投加1 g粉末活性炭,吸附1 h,COD去除率可达98.5%.     

Impact of Bioaugmentation with a Consortium of Bacteria on the Remediation of Wastewater-Containing Hydrocarbons (5 pp)

Goals, Scope and Background It has been observed that hydrocarbon treated wastewaters still contain high COD and a number of intermediates. This suggests that the required catabolic gene pool for further degradation might be absent in the system or, that its titer value is not significant enough. By providing the desired catabolic potential, the overall efficiency of the treatment system can be improved. This study aims to demonstrate this concept by bioaugmentation of a lab-scale reactor treating refinery wastewater with a consortium having the capacity to complement the alkB genotype to the available microbial population. Methods Two reactors were set up using activated biomass collected from a refinery treatment plant and operated at a continuous mode for a period of 8 weeks. The feed to both reactors was kept constant. Crude oil was spiked regularly. One reactor was bioaugmented with a consortium previously described for crude oil spill remediation. The efficiency of the bioaugmented reactor was demonstrated by reduced COD. The changes in the microbial population over a period of time were analyzed by RAPD. Catabolic activity of the biomass in both reactors was monitored by PCR. The presence of the catabolic loci was confirmed by Southern Hybridization. Results and Discussion 52.2% removal of COD was observed in the bioaugmented reactor while only 15.1% reduction of COD was observed in the reactor without bioaugmentation. The change in microbial population can be seen from the 4th week, which also corresponds to improved catabolic activity. The presence of the bedA locus was seen in all samples, which indicates the presence of aromatic degraders, but the appearance of the alkB locus, from the 6th week onwards, which was observed only in the samples from the bioaugmented reactor. The results suggest that the gene pool of the bioaugmented reactor has catabolic loci that can degrade accumulated intermediates, thus improving the efficiency of the system. Conclusions In this study, improvement of efficiency of bioremediation was demonstrated by addition of catabolic loci that are responsible for degradation. Bioaugmentation was carried out in biomass that was collected from an ETP (effluent treatment plant) treating hydrocarbon containing wastewater to study the strategies for improvement of the treatment system. Biostimulation, only marginally improved the efficiency, when compared to bioaugmentation. The improved efficiency was demonstrated by COD removal. The presence of the alkB locus suggests the importance of a catabolic gene pool that acts on accumulated intermediates. It is well documented that straight chain aliphatics and intermediates of aromatic compounds after ring cleavage, accumulate in refinery wastewater systems, thereby hindering further degradation of the wastewater. Supplementation of a catabolic gene pool that treats the lower pathway compounds and alkanes will improve the overall efficiency. In this study, results suggest that the alkB locus can also be used to monitor the degradative mode of the activated biomass. Recommendations and Perspective . Pollution from petroleum and petroleum products around the globe are known to have grave consequences on the environment. Bioremediation, using activated sludge, is one option for the treatment of such wastes. Effluent treatment plants are usually unable to completely degrade the wastewater being treated in the biological unit (the aerator chambers). The efficiency of degradation can be improved by biostimulation and bioaugmentation. This study demonstrates the improved efficiency of a treatment system for wastewater containing hydrocarbons by bioaugmentation of a consortium that supports degradation. Further experiments on a pilot scale are recommended to assess the use of bioaugmentation on a large scale. The use of molecular tools, like DNA probes for alkB, to monitor the system also needs to be explored.     

三峡库区移民贫困致因的精准识别与减贫路径的实证研究

随着我国经济发展和扶贫成效的显现,老区、山区、民族地区和移民库区等集中连片的特殊贫困区已经成为我国当前精准扶贫的主战场。由于面临生产资料匮乏、生态环境恶化和地质灾害频发等恶劣环境,库区移民贫困问题已成为新时期扶贫攻坚最难啃的"硬骨头"。因此,开展库区移民贫困致因的精准识别与减贫路径研究具有重要的现实意义。基于对库区移民贫困现状的扎根理论分析,本文提出了分析农户生计的新框架。在此基础上,本文以三峡库区26个县(区)为研究对象,随机抽取4县(区)796户移民作为样本,首先,采用灰色关联分析法和熵权法对库区移民主要致贫因子进行挖掘;接着,采用PLS-SEM模型分析影响库区移民生计状况的关键因子和关键路径。研究表明:(1)三峡库区移民贫困现象仍很严重,患病、劳动能力弱和失地是移民致贫的三大主因。三峡库区仍有175.94万人生活在贫困线以下,三大致贫原因依次是:因病致贫26.49%、因劳动能力弱致贫22.10%和失地致贫21.65%。(2)心理资本可有效促进移民其他资本效能的发挥,对生计状况存在着显著的直接效应和间接效应。(3)在影响生计状况的四类资本中,人力资本对库区移民生计状况影响最大。基于以上发现,本文提出了实现库区移民精准脱贫的政策建议:(1)国家应高度重视三峡库区移民贫困问题,大力开展精准扶贫;(2)增加心理干预措施以提高移民心理资本存量,帮助移民摆脱心理贫困;(3)开展劳动力技能培训,提高库区移民人力资本水平。     

城市工业COD总量优化分配研究

总量控制是控制污染源发展趋势、改善环境质量、实现经济社会可持续发展的重要途径,如何在适度公平的基础上寻求环境、经济、技术、资源等整体最优是环境科学领域的研究课题。本文以工业城市苏州市为例,研究其工业化学需氧量的排放特征,以基尼系数法分行业对其工业化学需氧量排放量的公平性进行评价,并将总量控制与资源、社会和经济相联系,以行业经济效益最大化和增加治理投资费用最小化为目标,利用多目标行业总量优化分配模型对苏州市的工业化学需氧量排放总量进行优化分配。研究结果表明,纺织业、化学原料及化学制品制造业、能源和水的生产与供应业、造纸及木材加工、医药制造业等行业是苏州市的化学需氧量重点排放行业,经优化分配后,COD排放总量削减了10%,新鲜用水量减少了41.81%,行业年总产值增幅达到214.69%,资源和水环境容量在满足一定的经济增长速度的条件下实现优化配置,总量控制制度在市场经济体制下发挥出尽可能大的环境效益和经济效益。     

总有机碳测定仪的新用途──测气体中CO_2的研究

用ＴＯＣ总有机碳测定仪来鉴定污水和生活用水处理效果及污染指标是它的一项实际应用，而本义介绍的用来测定ＣＯ２则是一项开创性的工作。作者在对进口的ＴＯＣ仪使用的基础上研究了测定气体中总碳、总有机碳尤其是ＣＯ２问题，取得了较好的结果并应用到实际测定中。     

络合萃取法处理工业含酚废水

设计了高效ＱＨ型络合萃取脱酚溶剂,建立了工业含酚废水络合萃取工艺,进行了不同种类含酚废水的络合萃取平衡和错流萃取的实验。结果表明,利用ＱＨ混合型络合萃取剂,通过２－３级错流接触（油水比为１：１）,废水残液中的酚类浓度小于０．５ｍｇ／Ｌ,可以达到国家规定的排放标准。初步研究表明,该法对废水中ＣＯＤ亦有较好的去除效果。     

大辽河水系主要污染物特征分析

对大辽河流域主要污染物CODMn(或CODCr)和氨氮多年时空变化特征进行分析,认为二者浓度在空间上都有从上游到下游显著升高的趋势,年内变化呈现明显的点源特征。     

MERCK公司COD试剂的替代品开发

德国MERCK公司制造的COD测定仪器在我国环保行业、科研院所的水质监测工作中应用广泛,但配套试剂价格昂贵,限制了该仪器的使用。实验设计了高量程(100～1500mg/L)和低量程(25～100mg/L)COD替代试剂的开发方案。通过实验,确定了两个量程下COD替代试剂中K2Cr2O7、H2SO4-Ag2SO4、HgSO4的浓度和投加量以及测试方法。实验结果表明,在高量程和低量程范围内,使用COD替代试剂的测试结果与MERCK公司配套试剂的测试结果比较相符,反应时间也可缩短至30min。     

曝气生物滤池快速启动和活性保持性能研究

研究了两级曝气生物滤池处理生活污水时各级的快速启动和在低负荷下活性保持的能力,考察了出水中主要污染物和生物滤池内生物量随时间的变化情况。结果表明,碳氧化生物滤池从低负荷恢复时,所需要的时间与活性保持时的负荷大小有关,负荷越小,所需要的时间越长。在极端情况下,恢复时间接近一次完全启动的时间,因此碳氧化生物滤池的低负荷维持并没有太大的实际意义。而硝化生物滤池在低负荷下活性保持良好,重新启动仅需要完全启动1/10的时间,这就有可能以低成本实现硝化生物滤池的活性保持。     

不同阳离子和碳氮比对反硝化性能及亚硝酸盐氮积累的影响

在序批式反应器(SBR)中,采用乙酸钠为碳源,通过硝酸钠和硝酸钙的交替投加、微量元素的投加以及碳氮比(COD/NO₃⁻-N)的改变,探究了不同控制条件对反硝化性能及NO₂⁻-N积累的影响,并分析了反应器中微生物种群演替特征。结果表明,在以乙酸钠为碳源的SBR中,Ca²⁺浓度过高会抑制反硝化。以NaNO₃为NO₃⁻-N来源时,硝酸盐氮还原率维持在50%左右;相同条件下,以Ca(NO₃)₂为NO₃⁻-N来源时,硝酸盐氮还原率仅有20%。反应器中补充适量磷元素后,硝酸盐氮还原率提高至62%,同时有少量的亚硝酸盐氮积累。当C/N比提高为4后,硝酸盐氮还原率大于98%,长期运行下亚硝酸盐氮积累率平均为83.8%。高通量测序分析结果表明,变形菌门和拟杆菌门在系统中占主导地位。NO₂⁻-N积累的关键功能菌属是Thauera菌属,其最高占比为17.25%。以Ca(NO₃)₂为NO₃⁻-N来源时,Thauera菌属占比仅为0.14%。以上研究结果为短程反硝化的快速启动和稳定运行提供参考。