MANAGING POLLUTION FROM SSI<Emphasis Type="SmallCaps">s</Emphasis> – DESIGNING FOR A SUSTAINABLE INSTITUTION

The common effluent treatment plants (CETPs) are being propagated as the policy response to circumvent the pollution problem from the small-scale industries (SSIs), which abound in developing countries. The formation of the CETPs has been hailed as a collective action or co-operative solution to a common problem involving all the agents responsible for pollution. This paper investigated the desired criteria for designing an institution aimed at solving a common resource problem and factors ensuring the smooth functioning or sustainability of the institution. The design criteria and factors are then tested on a CETP set up in the Indian state of Haryana. The CETP, which was commissioned in 1997 had to be converted to a sewage treatment plant (STP) as the collective arrangement collapsed. The criteria used in the present analysis are that of Ostrom’s [Governing the Commons. Cambridge, UK, Cambridge University Press, 1990] design principles, whereas the factors considered for sustainability are the one suggested by Rawls [A Theory of Justice. USA, Harvard University Press, 1971]. The analysis indicates that the Kundli CETP failed in both counts as neither all the design principles were met nor did the institution fulfil different sustainability criteria. The paper concludes with the lessons that can be learnt from Kundli’s failure. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

酒精废水EIC处理技术及综合利用

介绍了旋流内循环（EIC）厌氧反应器处理高浓度酒精废水的方法及效果，用EIC反应器代替UASB处理工艺，具有污染物去除率高、沼气产生量大等优点，产生的沼气用于发电供热，取得了良好的经济效益、环境效益和社会效益。     

Computer aided injection moulding process analysis of polyvinyl alcohol-starch green biodegradable polymer compound

This study aims to investigate the injection moulding processability of polyvinyl alcohol (PVOH) blending with starch as biodegradable polymer compound. The PVOH-starch polymer compound can be used to produce environmental friendly plastic products. In this study, the injection moulding processability of PVOH-starch compound was computational analyzed by Moldflow^® software. A name tag article design was chosen to determine the appropriate processing parameters of PVOH blending with 50 wt.% (PPV55) and 60 wt.% (PPV46) of starch. The processing behaviour for both compositions of PVOH-starch compounds was characterized according to injection temperature and pressure, volumetric shrinkage and frozen layer fraction. Moldflow^® simulation outcomes exhibited that PPV55 required a higher injection pressure than PPV46. Meanwhile, the simulation outcomes also showed that the volumetric shrinkage of PPV55 is higher than PPV46. Both PPV46 and PPV55 require at least 20 s holding time to achieve stable production.     

Detection of dioxygenase genes present in various activated sludge

GOAL, SCOPE AND BACKGROUND: Activated sludge from refineries contains various microorganisms that could utilize aromatics under aerobic conditions due to the oxygenase enzymes. Dioxygenase enzymes are oxygenases, which are involved in the ring cleavage step of aromatic hydrocarbons. In this study, the selected catabolic loci involved in ring cleavage have been monitored in the activated sludge samples at different time intervals. The investigation of the dioxygenase genes in the Effluent Treatment Plants (ETPs) and evaluation of their presence at different time points provides a clue for the aromatic utilizing potential of the inherent microbial flora. METHODS: The catabolic gene loci pheB, xylE, tod-isp, bed and nahG responsible for the enzymes catechol 1,2-dioxygenase, catechol 2,3-dioxygenase, toluene dioxygenase-iron-sulphur protein component, benzene dioxygenase and naphthalene dioxygenase were used respectively. The time dependent change in eubacterial population was demonstrated by the amplification of 16S rDNA product, followed by restriction digestion. The template DNA was obtained from the activated sludge collected from ETPs. The supporting physiological data for the overall performance of sludge was developed using respirometric analysis. The on-site COD and MLSS analysis for ETP was used in final evaluation. The study was carried out with samples collected from three different ETPs and also from a selected ETP at different time intervals. RESULTS AND DISCUSSION: The respirometric studies were carried out with phenol, catechol, toluene, and naphthalene to arrive at the target genotypes for further study by PCR protocol. The respirometric analysis coupled with the COD and MLSS analysis represented the physiological capacity of the various sludges. Initially, the tracking protocol was optimized by using different sludge samples, which were collected from refineries. The selected genotypes were amplified and their presence has been confirmed using Southern analysis. The gene loci tod-isp, bed and xylE were commonly observed at various time intervals of the sludge from the same source. The gene loci pheB and nahG were found to be relatively rare. CONCLUSION: The 16S rDNA PCR products after restriction digestion produced different DNA fingerprint patterns, suggesting that the microbial community composition was diverse in the three sources. Similarly, the presence of the catechol 2,3-dioxygenase, benzene dioxygenase and toluene dioxygenase genes confirmed the aromatic degrading potential in the various sludges. The probes could not pick the nahG and pheB genes. However, the respirometeric assay suggested that the oxidative capacity to use naphthalene as a substrate exists. RECOMMENDATION AND PERSPECTIVE: Our study of the diversity at various time points from the ETP provided an overview of the shifts of the catabolic composition of the sludge. This also depends on the influential parameters like the incoming pollutant level and the environmental conditions that are prevailing and often changing from time to time. The results of direct DNA extraction and PCR amplification do reflect the relative abundance of a particular catabolic genotype, which could be used to monitor the efficiency of treatment.     

折流旋转床吹脱含氨废水实验研究

应用折流式旋转床吹脱高浓度含氨废水,研究了在不同的工艺条件下,各工艺参数,如气液比、旋转填料床转速、温度等对含氨废水氨去除率的影响.研究表明:折流旋转填料床具有压降小、高传质性能,用于处理含氨废水能有效地提高氨去除率;在温度为23℃、pH为11左右,液体流量为60L/h、气体流量为160m2/h、转鼓转速为800 r/min的条件下,用旋转填料床处理含氨5 000mg/L废水的单程吹脱率可达82%;单元传质高度为36mm.     

重金属废水处理的方案比较研究

针对重金属废水,着重讨论了中和沉淀法、硫化物沉淀法、铁氧体法3种化学沉淀处理方法,从处理工艺、处理效果等多方面比较了它们的优缺点,得出目前采用石灰中和沉淀是一种最可行及有效的工艺方法.     

红球菌J-5菌株降解聚乙烯醇的研究

从土壤样品中分离到一株能以聚乙烯醇(PVA)为唯一碳源、能源生长的纯菌株,经生理生化鉴定和16S rRNA基因序列分析,该菌株属于红球菌属(Rhodococcus sp.),对该菌株降解PVA的特性进行了研究.结果表明,该菌株降解PVA的适宜条件为10000mg/L PVA,25℃,摇床培养;此外,添加0.1%的酵母膏可以明显促进PVA的降解.在该条件下通气培养7d,可以降解58%的PVA,通过红外光谱分析PVA的代谢产物,说明PVA降解的中间产物带有羰基.     

制革工业废水处理技术之硫化物生物毒性研究及工程实践

制革废水中S^2-对生物的毒性较大,由此对处理系统产生不良影响,使制革废水处理达标成为难题。本文研究了硫化物生物毒性,得到了硫化物生物毒性相对临界浓度（200mg/l）,并在第一时间内运用于示范工程实践,取得了良好的效果,从而为制革工业废水处理技术的进一步发展打下了良好的基础。     

有限信息下对排污者进行管理的一种激励机制

管理者和排污者之间的信息不对称是环境管理的一大障碍 .应用激励机制设计理论设计了有限信息下应用排污收费对排污者进行管理的一种激励机制 .这种机制将起到激励真实信息的作用 ,利于减少管理成本 .     

利用文蛤生物标志物评价尾水-海水混合体系污染水平

采用不同浓度（体积比0%～40%,经天然海水稀释而成）的市政污水处理厂（MSTP）尾水对文蛤（Meretrix meretrix）连续培养9d,通过测定9种生化因子水平评价污染暴露对双壳类的生物学效应包括：内脏中的超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GPx）、谷胱甘肽还原酶（GR）、谷胱甘肽（GSH）、乙酰胆碱酯酶（AChE）、金属硫蛋白（MTs）、硫代巴比妥酸反应物（TBARs）以及血细胞的溶酶体膜稳定性（LMS）.SOD、CAT除外的所有生化因子均能对尾水污染产生敏感响应,其中,GPx、MTs、AChE和LMS的响应与尾水浓度呈显著相关（P<0.05或P<0.01）,适于作为尾水污染的生物标志物;依据这些生物标志物计算的综合生物标志物响应指数值（IBR_v2=0.61～2.65）随尾水浓度上升而增大,且两者间存在显著相关性（P<0.01）.研究结果表明,基于生物标志物响应值计算IBR指数的方法适于MSTPs尾水-海水混合体系的综合污染评价.