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.

Simulation of Low TDS and Biological Units of Fajr Industrial Wastewater Treatment Plant Using Artificial Neural Network and Principal Component Analysis Hybrid Method

Being familiar with characteristics of industrial town effluents from various wastewater treatment units, which have high qualitative and quantitative variations and more uncertainties compared to urban wastewaters, plays very effective role in governing them. With regard to environmental issues, proper operation of wastewater treatment plants is of par- ticular importance that in the case of inappropriate utilization, they will cause serious problems. Processes that exist in environmental systems mostly have two major characteristics: they are dependent on many variables;and there are complex relationships between its components which make them very difficult to analyze. In order to achieve a better and efficient control over the operation of an industrial wastewater treatment plant (WWTP), powerful mathematical tool can be used that is based on recorded data from some basic parameters of wastewater during a period of treatment plant operation. In this study, the treatment plant was divided into two main subsystems including: Low TDS (Total Dissolved Solids) treatment unit and Biological unit (extended aeration). The multilayer perceptron feed forward neural network with a hidden layer and stop training method was used to predict quality parameters of the industrial effluent. Data of this study are related to the Fajr Industrial Wastewater Treatment Plant, located in Mahshahr—Iran that qualita- tive and quantitative characteristics of its units were used for training, calibration and validation of the neural model. Also, Principal Component Analysis (PCA) technique was applied to improve performance of generated models of neural networks. The results of L-TDS unit showed good accuracy of the models in estimating qualitative profile of wastewater but results of biological unit did not have sufficient accuracy to being used. This model facilitates evaluating the performance of each treatment plant units through comparing the results of prediction model with the standard amount of outputs.

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.

Total concentrations and different fractions of heavy metals in sewage sludge from Guangzhou, China

Dewatered municipal sludge samples were collected from five municipal wastewater treatment plants （WWTPs） and one industrial WWTP in Guangzhou, China. A number of agricultural parameters and total metal concentrations in the sludge were determined. Metal speciation was also studied. The results showed that sewage sludge had high organic carbon, and was rich in such nutrients as N and P. The concentrations of Mn, Zn, and Cu were the highest, followed by Ni, Pb, and Cr, Cd had the lowest concentration. In addition, the concentrations of the aforementioned heavy metals in the sludge samples were higher than those recorded in the background data for crop soils. With the exception of Cu and Cd from site S1, and Ni from sites S1, $2, and $5, all other metal concentrations conformed to permissible levels prescribed by the national application standard of acid soil in China （GB 18918--2002）. The results of the BCR sequential extraction showed that the concentrations of Mn and Zn were predominant in acid-soluble/exchangeable and reducible fractions. Cu was principally distributed in oxidizable and residual fractions, whereas Cr was present in oxidizable and residual fractions, Pb was found in the state of residual fractions, and the distribution of Ni and Cd did not show significant characteristics.

污水处理厂温室气体排放特征与减排技术研究

污水处理厂是温室气体的重要排放源,必须探索和应用有效的减排技术,提升温室气体减排能力。深入分析污水处理厂温室气体排放特征,有助于更好地应用减排技术。直接排放与间接排放是污水处理厂温室气体的两种主要排放形式。结合污水处理厂温室气体的来源,以山东省某污水处理厂为例,核算2018-2020年温室气体直接排放量与间接排放量,然后根据污水处理厂温室气体排放特征,分析污水处理厂温室气体的减排措施。总体来说,要科学选择污水处理工艺,合理调节工艺运行参数,有效减少温室气体排放量。

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。

基于BiLSTM深度学习模型的污水处理厂水质预测

针对污水处理厂部分水质指标难以实时测定的问题,本研究利用BiLSTM神经网络建立软测量模型,获取预测数据。实验表明,该模型对出水COD与出水TN的预测均有较高的准确度。预测数据可为污水处理厂运营者的维护与管理提供科学依据,并且可以提前预知水质异常等状况。

啤酒废水资源化利用研究

为探索研究啤酒废水不经预处理直接进市政污水处理厂的影响和效果,实现碳废物综合利用、变废为宝,文章以青岛啤酒(随州)有限公司为例,通过对企业产生的综合废水和随州市污水处理厂上一年运行数据进行分析,预测啤酒废水资源化利用将对污水处理厂的影响。在项目实施后,对运行一年的数据进行了分析总结评价。结果表明:预测值和实际结果基本一致,啤酒废水资源化利用后污水处理厂进水COD浓度增加了18.93%,污水运行中碳环境得到改善,运行更加稳定,出水TN浓度由9.50~20.77 mg/L降为8.78~12.7 mg/L,且90%运行时间低于10.0 mg/L,去除率提高了16.78个百分点,CO_(2)排放减少2816 t/a,节约成本111.12万元/a。

进一步改善城市网-厂-水体污水系统升级改造和运行效率的四点看法

2022年,《深入打好城市黑臭水体治理攻坚战实施方案》发布,要求努力解决河流雨后黑臭和雨季河流断面水质下降问题,力争到2025年,进水BOD浓度高于100毫克/升的城市生活污水处理厂规模占比达90%以上,城市生活污水集中收集率达到70%以上。水行业正面临着防止雨后河流返黑和改善雨季河流水质等新任务。因此,结合近年来成绩、实践和欧美的经验教训,提出和讨论了与进一步改善网-厂-水体城市污水系统升级改造及运行效率相关的四个问题:分流制管网有没有外(雨)水入侵和溢流、污水处理厂的进水浓度应多高、为什么部分污水处理厂需局部扩容、为什么污水管道中流速低于自净流速,并在此基础上,对相关工作提出了建议。

乳制品废水作为污水处理厂碳源的可行性评估

我国污水处理厂普遍存在进水碳源不足的问题。污水处理厂为了应对高排放标准带来的挑战,需要在处理过程中投加碳源,增加了污水处理的运行成本和温室气体排放。污水处理厂的碳排放是我国碳排放的重要组成部分,其减排目标的完成对于我国实现双碳目标具有重要作用。国家支持具有良好可生化性的食品加工废水作为碳源供污水处理厂生物脱氮使用。文章分析了某乳制品加工企业的生产废水作为污水处理厂替代碳源的可行性。结果表明,乳制品废水具有高碳、低碳的水质特点,可以在保证出水达标的前提下替代商业碳源。乳制品废水作为污水处理厂碳源既降低了污水处理的运行成本,也减少了温室气体的排放,具有经济、环境双重效益。

山东省小城镇典型污水处理厂设计

小城镇污水来源复杂,不仅涉及居民生活污水,还有商业、轻工业、公共服务业产生的污水,水质与水量波动较大。本文以山东省某城镇污水处理厂为例,结合设计处理规模及进出水水质,合理设计污水处理工艺,并分析主要构筑物的设计参数,以减少污水处理厂的用地、能耗及运行费用,为类似小城镇污水处理厂设计提供参考。

机器学习用于城镇污水处理厂进水预测的实践研究

通过分析比较不同的污水处理厂进水预测方法,并对影响进水情况的有关因素进行相关性分析,采用基于机器学习的BP神经网络模型来预测污水处理厂的日进水量及化学需氧量。利用位于国内南方和北方的两个典型污水处理厂的实际运行数据进行试验,结果显示该模型预测精度良好,与实际数据偏差保持在5%以内。

印染废水处理工艺设计与分析

以某工业园区污水处理厂为例,对印染废水的水质和水量特点进行分析,提出解决方案,并进一步进行工艺设计。经实际运行后发现,该污水处理厂出水水质可以稳定达标,取得良好的经济效益。

芯片工业园区废水处理工程实例

针对芯片工业废水成分复杂、氟离子浓度高且含有多种有害物质等水质特征,采用化学沉淀-水解酸化-AO/MBR-RO工艺进行处理,RO浓水通过臭氧催化氧化-AO(MBBR)/MBR组合工艺进行处理,同时辅助设计Fenton高级氧化及除氟树脂。出水稳定达到GB 3838—2002《地表水环境质量标准》中Ⅲ类排放标准(ρ(TN)≤15mg/L),满足废水回用要求。详细介绍了污水处理厂各工艺单元的设计参数及主要设备配置,并对工艺特点进行了总结分析。

煤制甲醇污水深度处理工艺应用实践

针对兖州煤业榆林能化有限公司甲醇厂在煤制甲醇生产过程中,产生废水量大、传统物理处理和生物处理时工艺能耗大、成本高以及中水利用率低等技术难题,通过技术研究根据当前煤制甲醇废水处理现状,对废水处理工艺进行优化,提出IMC污水处理工艺,并采用双膜法深度处理循环水系统进行污水排放。通过实际应用效果:污水处理系统优化后污水排放量由原来的187 t/h减少至32 t/h,污水循环利用率提高了92.4%,污水处理费用减少了107.9万元/年,取得了显著应用成效。

污水处理场CO废气治理设施运行技术分析

随着环保排口及现场异味管控的要求逐步提高,炼油企业污水处理场需持续加强高浓度废气设施的运行管理。该文结合某炼油企业污水处理场CO(Catalytic Oxidation)设施处理炼油污水产生的废气实例展开分析,通过剖析CO设施处理尾气过程中存在的问题,如上游来气浓度及气量波动、阻火器流通量下降以及余热回收换热器堵塞等,提出精细管控上游各路来水、加强污水处理过程工艺控制、管线材质升级以及余热换热器高压清洗等建议,保障CO尾气治理设施平稳高效运行。实践表明,该污水处理场CO废气设施排口控制更加稳定,取得了较好的经济效益与环境效益。

南方某工业镇污水处理系统厂网改扩建设计思路

文章主要针对南方某工业镇现有污水处理系统存在的问题进行分析,基于现状污水厂的处理能力提出管网分流改造的思路,并通过实施智能分流技术、工业废水监测控制系统,提高管网的运维管理水平;对新建污水站采用优化预处理和生化处理工艺等措施,较好地解决了工业废水的处理问题。

净水厂工程废水处理技术及其综合评价方法研究

当前,净水厂废水处理问题日益严峻,对环保及可持续发展构成重大挑战。本研究针对此问题,深入探讨了废水处理的相关技术和综合评价方法。通过化学沉淀、微生物处理、物理吸附等技术手段,有效减少了废水对环境的影响。同时,采用多指标评价方法,结合实际情况调整权重,全面评估处理效果。研究结果显示,综合处理技术显著提升了废水质量,COD、BOD等指标均得到明显改善,优于单一处理技术,为净水厂的废水处理提供了有效的解决方案。本研究构建的综合评价方法能够准确、全面地评价净水厂工程废水的处理效果,从而为决策者提供参考并指导后续处理流程的优化。

Short-term prediction of the influent quantity time series of wastewater treatment plant based on a chaos neural network model

By predicting influent quantity,a wastewater treatment plant(WWTP)can be well controlled.The non-linear dynamic characteristic of WWTP influent quantity time series was analyzed,with the assumption that the series was predictable.Based on this,a short-term forecasting chaos neural network model of WWTP influent quantity was built by phase space reconstruction.Reasonable forecasting results were achieved using this method.

改良A/A/O+MBR工艺在全地埋式城市污水处理厂的应用

兰州市盐场污水厂扩建工程是黄河(兰州段)水污染治理项目的重要组成部分,设计规模10×104m^(3)/d(近期设备安装规模7.5×104m^(3)/d),采用“环境友好、土地集约、资源利用”的全地埋式污水厂建设理念,地下箱体结构为污水处理设施,地面上为景观公园。污水处理主体工艺采用改良A/A/O+MBR工艺,出水经UV消毒加次氯酸钠消毒后外排或回用,污泥采用离心脱水机脱水后外运处置。工程投入运营后,出水指标稳定达到《城镇污水处理厂污染物排放标准》(GB18918-2002)一级A标准。该工程的建成投运为黄河流域兰州段水质改善提供了基础保障,对改善黄河兰州段水系生态环境,推动黄河流域生态保护和高质量发展起到重要作用。