Levels and distributions of polychlorinated biphenyls in sewage sludge of urban wastewater treatment plants

Concentrations of polychlorinated biphenyls （PCBs） have been measured in sewage sludge samples from 8 urban wastewater treatment plants in Beijing, China. The PCB congeners were analyzed by isotope dilution high resolution gas chromatography/high resolution mass spectrometry method. The concentration of PCBs ranged from 65.6 to 157 ng/g dry weight （dw）, with a mean value of 101 ng/g dw. The dioxin-like PCB WHO-TEQs （World Health Organization-Toxic Equivalents） of the sludge were lower than 1 pg /g dw. Consequently, all the concentrations of PCBs in sludge samples were below the upper limit for land application according to the Chinese legislation law for agriculture use. The PCB homologue profiles in sludge samples were dominated by tri-CBs and tetra- CBs. Similar distributions have been found in one of the Chinese PCB commercial products. The patterns of dioxin-like and indicator congeners observed in this study were quite similar in all samples. The predominant congener for dioxin-like and indicator PCBs were PCB-118 and PCB-28, respectively, while PCB-126 had the highest TEQ value.

Current Seasonal Variations in Physicochemical and Heavy Metals Parameters of Sewage Treatment Plant Effluent and Suitability for Irrigation

The study aims to investigate the current extent of physicochemical parameters and heavy metal contamination in the effluent of the Jaganpur sewage treatment plant (STP), Dayalbagh, Agra India. Majority of the nearby farmers have access to use of STP effluent in irrigation purposes for growing major edible crops. The problems of using STP effluent for irrigation purpose, continuous water quality analysis required. To check the quality of irrigation water, substantial physicochemical parameters accordance to Indian Standards (IS-Reaffirmed 2002/2003) analysed to calculate Sodium absorption ratio (SAR) and Residual sodium carbonate (RSC). To estimate the heavy metal pollution index (HPI) and metal quality index (MQI), toxic Heavy metals such as As, Cr, Mn, Fe, Ni, Cu, Zn, Pd, Cd, Co, and B also determined in the STP effluent with an AAS and results verified with ICP-OES against certified standards. The high value of SAR (range 13 to 20) and RSC (range -10 to 11) in STP effluent exceeded the permissible limit for irrigation purpose. On the other hand, HPI and MQI values (1692.4 and 58.1, respectively) show that high metal contamination mainly due to industrial and domestic wastewater does not treat appropriately in the sewage treatment plant. Thus it is suggested that further studies are carried out on the STP effluents to improve the water quality through proper treatment. Treated wastewater used for irrigation purposes needs to analyse the contamination like heavy metals and pinpoint the pollution sources.

Discussion on the Problems and Developing Trend of Construction of Sewage Treatment Plants in Small Towns

Existing problems of sewage treatment plants in small towns were summarized firstly,and then the developing trend of construction of sewage treatment plants in small towns was discussed from the aspects of project decision,site selection,design,processing technology and construction financing models. Finally,outlooks for its future development were proposed to provide reference for the construction of sewage treatment plants in small towns in future.

Behavior of Antibiotic-Resistant Fecal Coliforms in the Stream of a Sewage Treatment Plant in Tokyo

We are confronting a new threat in the prevalence of antibiotic-resistant bacteria followed by epidemic spread in aquatic environments in metropolitan areas because damage from river floods is increasing remarkably in Japan due to global extreme weather. The sewer penetration rate is about 100% in Tokyo and reclaimed water from sewage treatment plants accounts for over 50% of all water in both the down- and mid-stream areas of local rivers. The water quality of these rivers, which contain microflora, seems to be seriously affected by reclaimed water. In this study, we collected water samples on July 17, 2018 and examined the behavior of antibiotic-resistant fecal coliforms in the stream of a sewage treatment plant in Tokyo. Extended-spectrum β-lactamase (ESBL)-producing fecal coliforms with encoding genes were found;the CTX-M-1, CTX-M-9, TEM, and SHV groups were found to have survived in the final effluent to the river after sterilization with sodium hypochlorite.

Advances in Research of Characteristics and Removal of Microplastics in Sewage Treatment Plants

Microplastic pollution has become a worldwide issue.The discharge of sewage treatment plants(STPs)or wastewater treatment plant(WWTPs)is an important way for microplastics to enter the environment.This study reviewed the sources and occurrence characteristics(type,size,color and components)of microplastics in domestic and foreign sewage plants.It elaborated the removal principles of microplastics by primary,secondary and tertiary treatments.In addition,the removal effects of various treatment units and different processes on microplastics were summarized.In the future,the removal mechanism of microplastics in sewage treatment plants should be discussed in more depth,so as to further improve the removal rate of microplastics by optimizing and transforming traditional sewage treatment processes.Therefore,it is necessary to develop new technologies/processes specifically for the removal of microplastics and promote them to practical applications.

Water Analyses, Eco-Balance and Socio-Demographic Analyses as Prerequisites for Solutions of the Sewage Treatment Problems in Rural Areas

The implementation of the EU-water framework directive (EU-WFD) demands a financeable and adaptable sewage treatment, creating a need for action especially in rural areas, where the “good ecological status” is often not reached even though the sewage works fulfill the legal minimum requirements. Therefore the construction of new, more efficient wastewater treatment plants is advisable. Due to the precarious financial situation in most rural areas, many municipalities can however not master the necessary funds for an improved waste water infrastructure. A large part of the costs would have to be shouldered by the local population in the form of additional sewage levies, leading to massive socio-economic strain. Hence, different solutions, which are tailored to the socio-economic, demographic and environmental characteristics of rural areas and fulfill the legal requirements, need to be developed. One possible approach is presented in the form of the Dirlammen case study (municipality Lautertal, Hesse, Germany). It consists of 1) biological and physicochemical analyses of the waste waters, 2) a modified eco-balance for the construction of a new sewage works and 3) socio-economic and demographic analyses of the population. It serves as a tool for the assessment of the influencing ecological, socio-economic and demographic factors on the sewage problems in rural areas. These findings can easily be transferred to other rural areas with a similar configuration and thus deliver the basis for a generally applicable approach to these problems. The results of the comprehensive analysis have shown for the municipality Dirlammen/Lautertal that the continued operation of the existing pond sewage plant is, with regards to the ecological, socio-economic and demographic points of view, preferable to the construction of a new waste water treatment plant. With regard to the sustainability principles of the sewage treatment and the objectives of the EU-WFD, existing sewage works should be operated for as long as the sewage treatment is feasible within technical and legal boundaries. With the construction of new facilities on the other hand, the expected improvement of the water quality has to be weighed against the ecological impairments caused by the construction itself. Rural waste water plans have to be developed for the long-term, taking not only the ecology into account but also the demographic change. Possible approaches in this regard could be a shift towards a decentralized waste water treatment concept and–even more important–improvements of the river morphology. But also the reduction of the diffuse pollution from agricultural sources should be considered for the development of strategies for the improvement of the ecological state. Short-term optimization measures in the existing sewage works might also improve the water quality until the long-term development plans can be implemented. In particular the challenges of the demographic change and linked with that the changing requirements for the rural waste water treatment must be addressed by any future plans. Only with the help of such a comprehensive approach the dangers of bad planning and unacceptable socio-economic burdens can be minimized.

Experimental Study on Anaerobic Digestion of Remaining Sludge in Municipal Wastewater Treatment Plant

Along with the development and progress of environmental protection management,it is necessary to pay full attention to the disposal of excess sludge in the process of urban sewage treatment plant management.It is necessary to ensure effective integration of management mechanisms and management paths.To a certain extent,it can improve the actual efficiency of digestion and treatment work and lay a foundation for the optimal operation of environmental protection management.In this paper,the treatment of excess sludge in a sewage treatment plant is studied.The method and results of anaerobic digestion test of excess sludge in a sewage treatment plant are discussed for reference only.

雨污合流制地区溢流污染影响因素及管控建议

雨污合流制地区汛期溢流成为城市河流返黑返臭的重要原因,溢流污染的有效控制,对改善水环境,提升人民幸福感、获得感与安全感有着重要作用。针对雨污合流制地区汛期溢流污染防控,总结了合流制溢流污染的特点、对水环境质量的影响以及合流制溢流污染的影响因素等内容,分析了我国溢流污染严重区域的分布特征并提出管控建议。研究发现,我国合流制溢流污水呈现出成分复杂、水量水质变化大、初期雨水水质差等特点,且合流制溢流污染会导致城市面源污染,加重地表水质恶化程度。通过分析合流制溢流污染的2个主要影响因素(降水量和管网条件),初步识别出我国溢流污染严重区域主要集中在东部、南部地区,且相关性分析结果表明汛期降水量及管网密度与区域水质存在中等相关关系。为加强合流制地区溢流污染防控,提出要因地制宜制订汛期雨污溢流污染排放管控标准、开展溢流污染控制技术更新行动、加强汛期雨污溢流污染的全过程管理、加强汛期雨污溢流污染治理成效考核等具体建议,以期为有效控制合流制溢流污染,推动水环境质量持续改善提供参考。

城镇污水厂各工序段对微塑料去除率差异特性分析

污水处理厂被认为是微塑料的主要排放与储存场所.为探究城镇污水处理厂不同处理工序段对污水中微塑料的去除效率差异特性,以内蒙古某污水处理厂为研究对象,通过采用体式显微镜观察,并借助LAS X软件统计分析的方法展开研究,结果表明:污水厂中微塑料的主要存在形态以纤维状为主(61.8%),其次为碎片状与薄膜状,微塑料的尺寸主要集中在0.25-0.50mm(32.9%).一级处理工序中对微塑料去除效果最好的构筑物分别是:粗格栅、细格栅和初沉池,尤其对尺寸小于0.25mm微塑料颗粒的去除效果最好.旋流沉砂池对纤维、碎片和薄膜状微塑料均没有起到积极的去除效果,二级处理工序中的二沉池对微塑料的去除起到了关键作用,其次为纤维生物转盘,其对尺寸介于0.50~1.00mm的微塑料去除效率最高.一级处理工序对3种形状微塑料的去除效率均为正值,且去除效率与微塑料尺寸呈负相关关系.一级处理工序中的构筑物对小尺寸微塑料的去除效率比较稳定,而对大尺寸微塑料的去除效率波动较大,对不同形状微塑料的去除率随污水在各处理构筑物流动方向沿程呈下降趋势.二级处理工序对3种形状微塑料的去除率均呈现为负值,而仅对尺寸小于0.50mm的微塑料去除率为正值.本研究旨在为污水厂提升微塑料去除率的运行管理提供理论指导作用.

基于减污降碳和水质目标约束下的黄河干流兰州段城区污水处理厂出水排放限值研究

为科学合理地提出黄河干流兰州段城区污水处理厂出水排放限值,实施精准科学治污,持续改善黄河干流兰州段水环境质量,本文以兰州市城区四座有代表性的污水处理厂(西固、七里河安宁、盐场和雁儿湾污水处理厂)为研究对象,统计四座污水处理厂主要污染物排放浓度、中水回用率、主要污染物去除率及减排效果,分析四座污水处理厂入河排污对黄河干流兰州段水质的影响,梳理污水处理厂运行阶段的碳排放情况.结果表明:(1)兰州市城区四座污水处理厂中水回用率低,介于0.86%~4.66%之间.(2)四座污水处理厂主要污染物的去除率高于国内污水处理厂主要污染物去除率的平均水平,COD、NH_(3)-N年均减排量分别为114584.1、8234.6 t,减排效果明显.(3)在黄河枯水期上游来水水量小、水质接近或超出GB 3838-2002《地表水环境质量标准》Ⅱ类水质目标限值的条件下,叠加区间其他入河排污口的影响,兰州市城区四座污水处理厂均按照设计规模及设计出水水质排污会对下游河段水质造成影响.因此,不能一味地追求出水水质,盲目提标改造,要综合考虑污水处理厂运行过程中的碳排放,在满足受纳水体水质目标前提下,统筹考虑减污降碳.

佛山市某污水厂技改工程实例

介绍了佛山某污水处理厂技改工程的工艺流程和设计参数。在用地紧张的条件下,改造原有构筑物,新建“深度处理+超滤反渗透+浓水处理”为主体工艺的中水回用系统。实际运行结果表明,技改后满足扩容减排的政策要求,出水水质稳定达标排放,为类似污水处理厂的技改提供了相关设计经验。

城镇污水系统碳核算方法研究及典型工艺减碳路径分析

梳理了现有污水处理碳核算体系,提出了针对不同应用场景的核算方式和边界范围,选取长沙市8座典型污水处理厂进行碳核算分析,发现污水处理厂站工程中电耗和生化单元中的N_(2)O为主要碳排热点,其分别贡献了53.28%和23.56%的碳排放量,同时化石源CO_(2)排放也是污水处理厂运行过程中不可忽视的重要排放源。通过典型工艺核算分析,发现AAO-MBR工艺各项碳排放强度指标均处于最高水平。通过碳排影响因素相关分析,研究发现进水TN、BOD_(5)浓度与各项碳排放强度呈现一定的负相关关系。案例污水处理厂通过一系列替碳措施形成在厂界范围内实现了一定规模的碳减排,但距污水处理行业碳中和目标还相差甚远,基于此,提出了源、网、厂、端全流程碳减排路径。

振动式MBR处理城镇生活污水中试研究

以城镇居民生活污水为原水,构建五段式Bardenpho-rMBR工艺进行中试研究,考察了中试系统对COD、TP、TN、氨氮、硝态氮、SS等污染物的去除效果,以及运行过程中的跨膜压差变化、产水通量、能耗和药耗。并将中试系统与污水处理厂原系统,以及中试膜处理与深度处理进行对比,以期分析rMBR工艺特性。结果表明,出水COD、TP、TN、氨氮浓度平均值分别为11、0.16、5.26、0.583 mg/L,平均去除率分别为92.4%、96.9%、79.5%、97.2%。出水指标能稳定达到《城镇污水处理厂污染物排放标准》(GB 18918—2002)的一级A标准。

基于碳减排的厌氧氨氧化脱氮工艺应用及强化调控进展

随着我国“双碳”目标的提出和水处理行业提标改造的重点落在生物脱氮,污水处理厂从关注满足排放许可限制转向实现碳中和、能量自给及资源回收。厌氧氨氧化(Anammox)技术凭借无需外加有机碳源、占地面积小、污泥产量少以及脱氮效率高等节能降耗与碳减排优势,代表着未来污水生物脱氮的发展方向。基于已有研究成果,梳理对比了传统脱氮与Anammox反应的发展历程;重点综述了新兴短程硝化耦合Anammox(PN-A)工艺、短程反硝化耦合Anammox(PD-A)工艺和甲烷型反硝化耦合Anammox(DAMO-Anammox)工艺在城市主流工况的应用进展;详细探讨了主流Anammox工艺面临低温、进水负荷不均和光照等环境因素冲击时,可施行的“侧流污泥补充至主流”“侧流污水间歇性补充至主流”“驯化生物膜颗粒”等内源性以及外源性的强化调控策略及内在机制;最后围绕分子生物学技术、材料科学、数字信息技术和管理政策,对加快Anammox生物脱氮技术的创新发展与推广应用进行了展望。

炼化企业智慧污水场建设实践与探索

炼化企业污水处理场承接上游生产装置排污水,是炼化企业重要的环保装置。目前炼化企业污水处理场的管控较为粗放,相对于生产装置,缺少完善的智慧管控系统,多数污水场对于智慧化理解程度不足,目前仅实现生产数据的集中显示和操作的远程化等常规控制,同时污水处理主要以环保达标为主,处理成本较高。随着数字化发展,智慧污水场建设是未来发展的必然趋势。污水处理场智慧化建设中,主要问题是污水处理场缺乏有效数据,以及数据精确性、及时度和同步性等问题,同时缺少对数据的筛选,未能做好数据的统一、分类和分层。通过探索智慧污水场建设,基于感知层采集、物联网技术,人工智能技术,结合污水场运行规律,建设智慧管控平台。通过系统智慧化建设及运行优化分析,提升水厂的精细化管理水平,降低污水处理成本,具有重要的指导意义。

长江大保护试点城市某污水处理厂尾水湿地净化效果研究

为探寻污水处理厂配套尾水湿地净化效果,以长江大保护试点城市某污水处理厂尾水湿地为例,通过现场调查与采样,分析湿地出水水质特征,探讨影响湿地污染物去除效率因素。结果表明:尾水湿地出水COD、NH_(3)-N及TP浓度满足设计目标,潜流湿地对COD去除率较高,表流湿地对氨氮及磷的去除率较高,优于涵养塘;湿地实际运行水力负荷、水力停留时间和污染物负荷与设计值不符,影响污染物去除效果;据此提出湿地运行优化建议,促进湿地深度脱氮除磷,提升尾水湿地效能;运行优化可提高潜流湿地污染物去除率,同时污水处理厂减少碳排放94.74 gCO_(2)m^(3)。研究结果可为该尾水湿地运行管理及长江大保护试点城市系列污水处理厂配套尾水湿地设计与运维提供参考。

Stable Isotopic Signatures of NO3 in Waste Water Effluent and Los Angeles River

A metropolitan city such as Los Angeles (LA) is an ideal study site with a very high population density, and it houses at least 3 treatment plants where sewage is treated preliminarily and then progressing to tertiary treatment before discharging into the LA River. We will gain a better understanding of the water quality in the LA River and the nitrate load in the watershed system by examining the influence of waste water treatment plants (WWTPs). The goal of this study is to pinpoint the exact source of nitrate in the LA River using the isotope signatures. We have selected sampling locations both upstream and downstream of the WWTP. This serves to monitor nitrate levels, aiding in the assessment of treatment plant effectiveness, pinpointing nitrate pollution sources, and ensuring compliance with environmental regulations. The research explores the isotopic composition of NO3 in relation to atmospheric nitrogen and Vienna Standard Mean Ocean Water, shedding light on the contributions from various sources such as manure, sewage, soil organic nitrogen, and nitrogen fertilizers. Specifically, there is a change in the δ15NAir value between the dry and wet seasons. The isotope values in the Tillman WWTP sample changed between dry and wet seasons. Notably, the presence of nitrate originating from manure and sewage is consistent across seasons, emphasizing the significant impact of anthropogenic and agricultural activities on water quality. This investigation contributes to the broader understanding of nitrogen cycling in urban water bodies, particularly in the context of wastewater effluent discharge. The findings hold implications for water quality management and highlight the need for targeted interventions to mitigate the impact of nitrogen-containing compounds on aquatic ecosystems. Overall, the study provides a valuable framework for future research and environmental stewardship efforts aimed at preserving the health and sustainability of urban water resources. This data informs decisions regarding additional treatment or mitigation actions to safeguard downstream water quality and ecosystem health.

某化工企业污水处理场生化污泥固废属性鉴别研究

采用热泵低温干化技术,将某化工企业污水处理场污泥含水率从80%降至30%,实现污泥的减量化、稳定化。对干化后的生化污泥进行危险属性鉴定,以便达成最优的处理处置方式。结果表明,该生化污泥不属于危险废物,可按照一般固废进行处置。本研究结果为生化污泥的鉴定提供思路和参考,为企业日常管理提供依据。

小城镇污水处理厂的选址管理

针对小城镇污水处理厂的存在问题,从选址管理的角度,以衡阳市某处小城镇污水处理厂为例,从规划底线管控,建设规模和用地规模,为配套管网建设创造条件,为先进工艺提供用地保障、自然资源、卫生防护距离、交通条件、安全性等方面对小城镇污水处理厂的选址要素进行分析,为同类型项目在规划选址及审批管理上提供参考。

污水处理厂智慧管控平台的设计要点概述

通过研究分析污水处理厂的运行情况,为污水处理厂提供一个可行的智慧水务管理技术方案,全方位提高水厂的管理水平。帮助污水处理厂实现了电子化的生产运行数据记录、信息化的数据查询共享方式、规范化的生产运行管理体系、智能化的数据汇总和统计、高度灵活的报表配置和导出、图形化的数据统计分析结果展现,从而提高生产运行数据的准确性,减少管理人员数据统计分析的工作量,提高生产运行管理效率。并对污水处理系统进行全面检视、改进、优化,提高污水厂运行的自动化、信息化、智能化水平,减少污水厂的能耗、药耗,降低运维人工成本,提升污水厂的经济、环境、社会效益。