Occurrence, distribution, and potential influencing factors of sewage sludge components derived from nine full-scale wastewater treatment plants of Beijing, China

Millions of tons of waste activated sludge (WAS) produced from biological wastewater treatment processes cause severe adverse environmental consequences. A better understanding of WAS composition is thus very critical for sustainable sludge management. In this work, the occurrence and distribution of several fundamental sludge constituents were explored in WAS samples from nine full-scale wastewater treatment plants (WWTPs) of Beijing, China. Among all the components investigated, active heterotrophic biomass was dominant in the samples (up to 9478 mg/L), followed by endogenous residues (6736 mg/L), extracellular polymeric substances (2088 mg/L), and intracellular storage products (464 mg/L) among others. Moreover, significant differences (p < 0.05) were observed in composition profiles of sludge samples among the studied WWTPs. To identify the potential parameters affecting the variable fractions of sludge components, wastewater source as well as design and operational parameters of WWTPs were studied using statistical methods. The findings indicated that the component fraction of sewage sludge depends more on wastewater treatment alternatives than on wastewater characteristics among other parameters. A principal component analysis was conducted, which further indicated that there was a greater proportion of residual inert biomass in the sludge produced by the combined system of the conventional anaerobic/anoxic/oxic process and a membrane bioreactor. Additionally, a much longer solids retention time was also found to influence the sludge composition and induce an increase in both endogenous inert residues and extracellular polymeric substances in the sludge.     

Sulfate reducing bacterial community and in situ activity in mature fine tailings analyzed by real time qPCR and microsensor

Sulfate reducing bacteria(SRB) play significant roles in anaerobic environments in oil sands mature fine tailings(MFTs). Hydrogen sulfide(H2S) is produced during the biological sulfate reduction process. The production of toxic H_2S is one of the concerns because it may hinder the landscape remediation efficiency of oil sands tailing ponds. In present study, the in situ activity and the community structure of SRB in MFT and gypsum amended MFT in two settling columns were investigated. Combined techniques of H_2S microsensor and dissimilatory sulfite reductase β-subunit(dsrB) genes-based real time quantitative polymerase chain reaction(qPCR) were applied to detect the in situ H_2S and the abundance of SRB. A higher diversity of SRB and more H_2S were observed in gypsum amended MFT than that in MFT, indicating a higher sulfate reduction activity in gypsum amended MFT; in addition, the activity of SRB varied as depth in both MFT and gypsum amended MFT: the deeper the more H_2S produced. Long-term plans for tailings management can be assessed more wisely with the information provided in this study.     

电解铝行业清洁生产实践

概述了电解铝行业清洁生产实践,分析说明企业实施清洁生产后,能够达到污染减排、节能降耗、提高企业经济效益的目的。     

堆肥处理对污泥腐殖物质组成和光谱学特征的影响

采用凝胶(Sephadex G-75)色谱、荧光光谱和红外光谱法研究了污泥堆肥的HA和FA在堆制前后的组成与结构特征变化．凝胶色谱分析表明,污泥经过63d堆腐后,HA中大分子组分含量明显提高;而FA则由不同分子量物质组成,其中小分子量物质占主要部分,在堆腐以后,FA中大分子物质含量下降30％,小分子量物质含量则相对增加．同时,荧光光谱、红外光谱的结果表明：随着污泥堆肥的进行,HA中有机物不饱和结构的多聚化或联合程度增大,芳香结构物质含量增加;但经过堆制的FA具有更多的结构简单的低分子量物质和更低的芳构化水平．     

Sorption of Perfluorooctane sulfonate（PFOS） including its isomers on hydrargillite as a function of pH,humic substances and Na2SO4

Perfluorooctane sulfonate（PFOS） is a persistent organic pollutant（POP） and emergent contaminant that are widespread in the environment. Understanding the mechanisms controlling the distribution of PFOS and its isomers between hydrargillite and the water phase is important in order to study their redistribution and mobility in the environment. This study investigated the effects of pH, humic acid, fulvic acid and Na₂SO₄ on sorption of PFOS isomers to hydrargillite. A mixture...     

胞外聚合物结合磷效能的研究

以实验SBR反应器的活性污泥为研究对象,探讨了超声波-树脂法提取EPS的方法与程序;以5种不同来源的活性污泥为研究对象,考察了EPS结合磷的效能.结果表明,超声波-树脂法分离EPS和细菌细胞的较优程序为：采用21kHz、40W超声波作用60mL污泥2min（VSS约为8000mg·L-1）;然后,投加80g·g-1（以...     

硫酸盐还原过程中乙酸型代谢方式的形成及其稳定性

通过产酸脱硫反应器处理高浓度硫酸盐废水的连续流试验,考察了不同试验阶段硫酸盐去除率和产气量稳定期,液相末端产物中挥发酸组成的变化、乙酸的分布特征、微生物种群组成和种群间关系.试验结果表明,各试验阶段液相末端产物中乙酸的分布比例高达50%～82%,微生物群体呈现特定的乙酸型代谢方式.乙酸型代谢方式本质上是产酸相反应器处理硫酸盐废水过程中,硫酸盐还原菌(SRB)与产酸菌(AB)建立起生物链式协同代谢关系,并通过非完全氧化型方式分解有机物,从而在末端产物中积累大量乙酸.乙酸型代谢方式的形成取决于利用乙酸的硫酸盐还原菌(ASRB)的竞争能力和它对乙酸的利用能力.乙酸型代谢方式可以为后续产甲烷相反应器提供适宜的底物,对提高硫酸盐废水处理系统的效率和运行稳定性具有重要意义.     

腐植质与有机污染物作用研究进展

综述了腐殖质的结构特性、与有机污染物的结合性质以及腐殖质对有机污染物毒性和生物可利用率的影响。已有的研究表明:腐殖质与有机污染物的结合能力受到下列因素的影响———腐殖质的结构、腐殖质的分子量和浓度、有机物的结构、水环境条件以及光化学降解作用等;腐殖质的存在通常降低了有机污染物的毒性,但在少数情况下例外,其推测性的机理还有待于实验进一步验证;有机污染物的生物可利用率不仅与腐殖质的浓度和组成有关,还受水体PH值的影响。本文同时对腐殖质的结构和多样性的研究、腐殖质对极性有机污染物的迁移、毒性和生物可利用率的研究、腐殖质增强某些有机物毒性的机理的研究进行了展望。     

Dissimilatory reduction of FeIII (EDTA) with microorganisms in the system of nitric oxide removal from the flue gas by metal chelate absorption

In the system of nitric oxide removal from the flue gas by metal chelate absorption, it is an obstacle that ferrous absorbents are easily oxidized by oxygen in the flue gas to ferric counterparts, which are not capable of binding NO. By adding iron metal or electrochemical method, Fe^Ⅲ (EDTA) can be reduced to Fe^Ⅱ(EDTA).However, there are various drawbacks associated with these techniques. The dissimilatory reduction of Fe^Ⅲ(EDTA) with microorganisms in the system of nitric oxide removal by metal chelate absorption was investigated. Ammonium salt instead of nitrate was used as the nitrogen source, as nitrates inhibited the reduction of Fe^Ⅲ due to the competition between the two electron acceptors. Supplemental glucose and lactate stimulated the formation of Fe^Ⅱ more than ethanol as the carbon sources. The microorganisms cultured at 50~C were not very sensitive to the other experimental temperature, the reduction percentage of Fe^Ⅲ varied little with the temperature range of 30-50℃.Concentrated Na2 CO3 solution was added to adjust the solution pH to an optimal pH range of 6-7. The overall results revealed that the dissimilatory ferric reducing microorganisms present in the mix-culture are probably neutrophilic, moderately thermophiUc Fe^Ⅲ reducers.     

稠油热采注汽锅炉节能减排措施实践

提高注汽锅炉系统热率是节能降耗、降本增效的主要挖潜方向。为此开展了一系列节能技术的研究,先后开展了热管空气换热器、高温辐射涂料的节能、硬度在线检测、对流段翅片管硬垢清洗技术的推广应用,通过这些技术的实施应用,取得一定的社会效益和经济效益。