Advanced Treatment of Wastewater Treatment Plant Effluent by Using Biofilms on Filamentous Bamboo

[ Objective ] The study aimed at treating wastewater treatment plant （WWTP） effluent by using bio-film reactor with filamentous bamboo as bio-carrier. [ Method] With the aid of a continuous flow reactor, a bio-film reactor using filamentous bamboo as bio-carrier was used to treat WWTP effluent with low C/N ratio, and the removal effects of CODc,, TN （total nitrogen）, and NO3--N in the wastewater were analyzed.[ Result ] The average removal rates of CODcr, TN, and NO3- -N reached 47.7%, 23.6% and 34.5% when the C/N ratio of influent was around 2. In addi- tion, a stable bio-film was formed very well in the secondary effluent with low C/N ratio and hardly degradable organic pollutants. The pollutants could be removed effectively because of the excellent surface characteristics and compositions of filamentous bamboo. [ Conclusion] The research provides a new method to treat WWTP effluent with low C/N ratio.

Occurrences of Glucocorticoids in Aquatic Environment and Their Removal during Wastewater Treatment

Glucocorticoids(GCs) are a group of endocrine-disrupting compounds(EDCs) frequently prescribed against various medical conditions.Recently,GCs have been shown to be effective in managing septic shock in patients infected with the 2019 novel coronavirus(COVID-19).Due to colossal consumption and potential risks to aquatic organisms,GCs have immensely attracted the focus of the scientific research community as a water pollutant.Therefore,the aim of this paper is to review the current knowledge on the occurrence of various GCs in the aquatic environment and their removal during wastewater treatment.A variety of GCs are ubiquitous in surface water,hospital wastewater,and sewage water worldwide.And the minimum concentration in volume is below 0.01 ng/L,and the maximum one is 10 000 ng/L,and enter the environment through hospital and urban wastewater discharging.Compared with natural GCs,higher risks to aquatic environments could be induced by synthetic GCs.The current activated sludge processes used in wastewater treatment plants(WWTPs) are not fully effective in eliminating GCs,some of which may further increase the risk of GC in the environment.In comparison with the aerobic process in WWTPs,the anaerobic and anoxic processes were found to be more efficient for GC degradation.Of the studied GCs,fluticasone propionate,clobetasol propionate,fluocinolone acetonide,and triamcinolone acetonide need more attention due to their low removal efficiencies and strong toxicity.Among the advanced treatment processes,reverse osmosis,ultraviolet irradiation,CaO_(2),and plasma could achieve significant GC activity removal while micro/ultra-filtration,chlorination,and ozonation were less efficient.

Impact of wastewater treatment plant effluent discharge on the antibiotic resistome in downstream aquatic environments:a mini review

Antimicrobial resistance(AMR)has emerged as a significant challenge in human health.Wastewater treatment plants(WWTPs),acting as a link between human activities and the environment,create ideal conditions for the selection and spread of antibiotic resistance genes(ARGs)and antibioticresistant bacteria(ARB).Unfortunately,current treatment processes are ineffective in removing ARGs,resulting in the release of large quantities of ARB and ARGs into the aquatic environment through WWTP effluents.This,in turn,leads to their dispersion and potential transmission to human through water and the food chain.To safeguard human and environmental health,it is crucial to comprehend the mechanisms by which WWTP effluent discharge influences the distribution and diffusion of ARGs in downstream waterbodies.In this study,we examine the latest researches on the antibiotic resistome in various waterbodies that have been exposed to WWTP effluent,highlighting the key influencing mechanisms.Furthermore,recommendations for future research and management strategies to control the dissemination of ARGs from WWTPs to the environment are provided,with the aim to achieve the“One Health”objective.

A global perspective on microbial risk factors in effluents of wastewater treatment plants

Effective monitoring and management of microbial risk factors in wastewater treatment plants(WWTPs)effluents require a comprehensive investigation of these risks.A global survey on microbial risk factors in WWTP effluents could reveal important insights into their risk features.This study aims to explore the abundance and types of antibiotic resistance genes(ARGs),virulence factor genes(VFGs),the vector of ARG/VFG,and dominant pathogens in global WWTP effluents.We collected 113 metagenomes of WWTP effluents from the Sequence Read Archive of the National Center for Biotechnology Information and characterized the microbial risk factors.Our results showed that multidrug resistance was the dominant ARG type,while offensive virulence factors were the most abundant type of VFGs.The most dominant types of ARGs in the vector of plasmid and phage were both aminoglycoside resistance,which is concerning as aminoglycosides are often a last resort for treating multi-resistant infections.Acinetobacter baumannii was the most dominant pathogen,rather than Escherichia coli,and a weak negative correlation between Escherichia coli and two other dominant pathogens(Acinetobacter baumannii and Bacteroides uniformis)suggests that using Escherichia coli as a biological indicator for all pathogens in WWTP effluents may not be appropriate.The Getah virus was the most dominant virus found in global WWTP effluents.Our study presents a comprehensive global-scale investigation of microbial risk factors in WWTP effluents,providing valuable insights into the potential risks associated with WWTP effluents and contributing to the monitoring and control of these risks.

Community analysis of ammonia-oxidizing bacteria in activated sludge of eight wastewater treatment systems

We investigated the communities of ammonia-oxidizing bacteria （AOB） in activated sludge collected from eight wastewater treatment systems using polymerase chain reaction （PCR） followed by terminal restriction fragment length polymorphism （T-RFLP）, cloning, and sequencing of the α-subunit of the ammonia monooxygenase gene （amoA）. The T-RFLP fingerprint analyses showed that different wastewater treatment systems harbored distinct AOB communities. However, there was no remarkable difference among the AOB T- RFLP profiles from different parts of the same system. The T-RFLP fingerprints showed that a full-scale wastewater treatment plant （WWTP） contained a larger number of dominant AOB species than a pilot-scale reactor. The source of influent affected the AOB community, and the WWTPs treating domestic wastewater contained a higher AOB diversity than those receiving mixed domestic and industrial wastewater. However, the AOB community structure was little affected by the treatment process in this study. Phylogenetic analysis of the cloned amoA genes clearly indicated that all the dominant AOB in the systems was closely related to Nitrosomonas spp. not to Nitrosospira spp. Members of the Nitrosomonas oligotropha and Nitrosomonas communis clusters were found in all samples, while members of Nitrosomonas europaea cluster occurred in some systems.

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.

Mitigating microbiological risks of potential pathogens carrying antibiotic resistance genes and virulence factors in receiving rivers:benefits of wastewater treatment plant upgrade

Wastewater treatment plants(WWTPs)with additional tertiary ultrafiltration membranes and ozonation treatment can improve water quality in receiving rivers.However,the impacts of WWTP upgrade(WWTP-UP)on pathogens carrying antibiotic resistance genes(ARGs)and virulence factors(VFs)in rivers remain poorly understood.In this study,ARGs,VFs,and their pathogenic hosts were investigated in three rivers impacted by large-scale WWTP-UP.A five-year sampling campaign covered the periods before and after WWTP-UP.Results showed that the abundance of total metagenome-assembled genomes(MAGs)containing both ARGs and VFs in receiving rivers did not decrease substantially after WWTP-UP,but the abundance of MAGs belonging to pathogenic genera that contain both ARGs and VFs(abbreviated as PAVs)declined markedly.'Genome-resolved metagenomics further revealed that WWTP-UP not only reduced most types of VFs and ARGs in PAVs,but also effectively eliminated efflux pump and nutritional VFs carried by PAVs in receiving rivers.WWTP-UP narrowed the pathogenic host ranges of ARGs and VFs and mitigated the cooccurrence of ARGs and VFs in receiving rivers.These findings underline the importance of WWTPUP for the alleviation of pathogens containing both ARGs and VFs in receiving rivers。

Why Should We Bother on Measurement in Wastewater Treatment Operation?

The question of wastewater treatment and control is reflected from a very specific viewpoint: the low priority given to accurate and useful measurements within wastewater treatment. The matter is discussed from four various perspectives, that may be labelled “Legal understanding”;“Needs for accurate measurement results already in the planning and design stage”;“The measurement problem and human behaviour”;“The understanding of the short term and long term dynamics and changes in pollution and flow loads on a wastewater treatment plant (WWTP)”. All these aspects bring about much improved needs for an accurate and frequent measurement scheme both for pollutants and flows entering a WWTP. The conclusion is stated as follows: A far more and well elaborated on-line measurement system at the plants would become a needed tool for improved water environment protection at lower costs.

Full scale application of combined SBF-AS process for municipal wastewater treatment in small towns and cities in China

The combined submerged biofilm （SBF）-activated sludge （AS） process for treatment of municipal wastewater in a small city in China is described in this paper. The process exhibited high removal efficiencies for carbonaceous substances, nitrogen and phosphorus which mainly took place in the combined SBF-AS bioreactor. The SBF-AS bioreactor was divided into pre-anoxic, anaerobic, anoxic and aerobic zones from inlet to outlet, in which fixed biofilm carriers were packed. Excellent performance had been obtained under normal operating conditions in more than one year of operation in Dong’e municipal WWTP, Shandong province, with mean removal efficiencies of BOD5 934%, COD 88%, SS 92%, NH+4-N 821%, TP 75% and TN 667%, and quite high effluent quality such as BOD5 6 to 10 mg/L, COD 20 to 40 mg/L, SS 5 to 10 mg/L, TN 10 to 20 mg/L, NH+4-N 4 to 8 mg/L and TP 06 to 10 mg/L. The effluent was reused multi-purposely, such as toilet flushing, green belt watering and artificial lake pounding. Simultaneous nitrification and denitrification took place due to the DO gradient in biofilm in aerobic zone of the SBF-AS bioreactor, which made TN removal efficiency improved remarkably in system. Some activated sludge was returned from final clarifiers to the bioreactor for phosphorus removal. The process had the advantages of low investment and low operational/maintenance （O/M） costs, low sludge yield and was preferably employed in small towns and cities.

深圳沙河水质净化厂及3#调蓄池工艺设计要点及特点

沙河水质净化厂设计规模为旱季10万m^(3)/d,雨季额外处理10万m^(3)/d初期雨水,3#调蓄池设计规模为15.3万m^(3)。污水及初期雨水处理采用预处理+多段厌氧-好氧(AO)+二沉池+磁混凝高效沉淀池+精密过滤+紫外消毒的工艺,出水水质执行深圳市地方标准《水质净化厂出水水质规范》(DB 4403/T 64—2020)B级标准,其中总氮(TN)≤8 mg/L。污泥处理采用离心浓缩+低温热干化工艺,处理后含水率≤40%。作为国内首个将水质净化厂与初期雨水调蓄池深度融合的全地下式水污染治理综合体,项目采用多段AO耦合“3W法”(Wet-Weather-Wastewater法),并以此为核心提出了一种实现大规模污水及初期雨水高标准协同处理的系统解决方案,且无需大幅度增加污水处理设施体量、投资和运行成本。

污水处理厂中典型肠道病毒的分布与检测方法及其风险评估

新冠肺炎威胁了全球经济和公众健康,其在粪便和污水中的检出表明了存在粪口传播的可能性。污水在城市污水处理系统中来源广泛,是水传播病毒的重要途径。为进一步开展污水处理设施中病毒的相关研究工作,文中分析了污水处理系统中典型肠道病毒的定量分布现状,总结了污水处理流程中病毒的灭活机制,并对国内外污水处理厂的肠道病毒研究进展进行归纳。此外,梳理了污水处理厂样本中典型肠道病毒的浓缩及检测方法,最后结合定量微生物风险评价(quantitative microbial risk assessment,QMRA)分析方法,讨论了病毒的浓度、感染概率及其潜在的健康风险。研究对国内病毒排放标准和风险评价体系的建立进行了探讨,为实现污水处理厂肠道病毒全过程风险管理和后续处理处置相关规范的制定提供参考和理论支撑。

城镇污水处理厂抗生素抗性基因的环境传播途径与机制

城镇污水处理厂是抗生素抗性基因(ARGs)发生转移、传播的重要场所,同时也是环境中ARGs污染的主要来源。对城镇污水处理厂中ARGs向环境介质中的传播途径、影响因素与传播机制进行了综述。结果表明,ARGs可通过出水排放、污泥土地施用、再生水灌溉、气溶胶逸散等途径迁移至环境介质(如受纳水体、土壤、空气)中;ARGs在环境介质中的扩散和存留行为受介质理化性质影响;ARGs在环境介质中主要通过可移动遗传元件(MGEs)介导的水平基因转移(HGT)传播耐药性。

不同负荷梯度对污水厂活性污泥的产酸性能分析

活性污泥发酵产酸有利于实现污泥资源化利用。文中以污水厂活性污泥为研究对象,在污水厂现场采用半连续碱性发酵方法,探究了先低梯度再高梯度长周期提负荷过程中污泥的产酸性能。结果表明:低梯度提负荷运行阶段,第112 d污泥的酸化率达到最大值,且乙酸占比为71.67%,游离氨(FA)质量浓度为(208±39)mg/L,低于250 mg/L,对微生物无抑制性。在高梯度提负荷阶段,第192 d污泥的水解率提高至41%,丁酸与戊酸的占比增加,FA质量浓度逐渐升高至450 mg/L时产酸性能下降。低梯度的优势菌Guggenheimella(24.88%)演变为高梯度的unclassified_Clostridiales(37.08%)。此外,当负荷为3250 mg TSS/(L·d)时,挥发性脂肪酸(VFAs)达到最大值(3339 mg COD_(Cr)/L)。经过50 d的稳定运行,污泥的产酸率为(606±30)mg COD_(Cr)/(g VSS)。合适的负荷梯度有助于污泥中有机物在碱性条件下(pH值=10.0±0.05)长期稳定连续生成VFAs。

超薄玻璃基板深加工项目生产废水预处理工程设计

某废水处理工程建设规模为17800 m^(3)/d,文中介绍了该处理工程的概况、工艺流程以及主要构筑物的工艺设计。工程预计进水组成中,工业废水占有相当的比例,主要以电子废水为主。为解决废水可生化性较差、污水处理难度较大的问题,预处理采用高效水解工艺,降低工业废水毒性,改善废水可生化性,确保二级处理系统稳定运行。污水处理主体工艺推荐采用较长泥龄延时曝气,强化脱氮两级AO工艺,提高难降解有机物去除率。绝大部分进水都具有强酸性或者强碱性,且酸碱性波动范围较大,容易对污水处理流程造成冲击,对污水处理建构筑物造成较大腐蚀。此外,在废水处理站进水端设置较长停留时间的调节池,对来水进行均质调节,在一定程度上可以使废水的pH处在较为稳定的范围内;在废水处理站设置监测排放池,尾水排放前仍有应急调节pH的可能,确保尾水达标排放。通过技术经济比较论证,本次扩能工程拟采用不同类污水分质组合处理的工艺技术路线,提高处理效率,降低建设及运行成本。采用先进的上流式水解污泥床水解反应池池型,并加盖除臭、景观绿化,收集和处理构筑物内的臭气。调试运行结果表明,项目工艺流程及参数设置能够满足各类废水处理排放要求。

工业园区混合废水处理厂工程设计与探讨:以福建某化工废水处理厂为例

福建某工业园区污水处理厂二期设计规模为2.0万m^(3)/d,工业园内的废水主要为石化工业废水。经过对工业园废水水质等特点的充分分析,该工程确定了“企业分类收集池+细格栅及曝气沉砂池+调节池(合建事故池)+水解酸化池+初沉池+生物反应池+二沉池+芬顿高级氧化+三沉池+反硝化深床滤池+加氯消毒”的工艺路线。该工程设计出水水质执行《城镇污水处理厂污染物排放标准》(GB 18918—2002)中的一级A标准,污水厂部分概算工程费用为27906.73万元。该项目结合先进工艺和精细化设计,探讨了工业园区混合污水处理厂的部分设计要点,为国内类似工业污水厂提供一定思路和案例参考。

污水处理过程中双酚A的环境健康风险分析综述

双酚A(BPA)是市政污水处理厂常见的内分泌干扰物。作为一种新污染物,BPA具有低剂量、较高毒性的特征,对生态环境及人类健康存在潜在影响。文章系统总结了污水处理厂中BPA常见去除方法及其特点,通过分析部分污水处理厂再生水中BPA残留现状,得出BPA的主要去除途径为污泥吸附和生物降解,且其处理效果受设备参数、操作条件等综合因素影响。文章同时对不同工艺流程中BPA去除效果进行对比分析,指出了深度处理工艺对提高BPA去除效果的重要性。环境健康风险评价表明,现阶段污水处理过程中的BPA对人类健康风险较低,处于可接受范围,但其潜在风险仍值得人们关注,亟需探究科学合理的去除手段和完善的风险评价方法。最后,文章针对污水处理过程中BPA环境健康风险分析方面研究提出了合理化建议。

纯膜MBBR+磁混凝沉淀工艺在广东省某城市污水厂提标改造中的应用

广东省某城市污水处理厂于2003年建成并投入运营,该污水处理厂原工艺为“厌氧UASB+高负荷生物滤池+固体接触池+生物絮凝沉淀池”,随着污水排放标准的不断提升,该污水处理厂提标改造工作迫在眉睫。经过对多种工艺综合比选,确定将原工艺提标改造为“纯膜MBBR+磁混凝沉淀”,对提标改造工程开展工程设计,剖析提标改造后污水处理厂的运行效果。结果表明:以“纯膜MBBR+磁混凝沉淀”为主体的提标改造工艺优势显著,可节省面积约为2600 m^(2),提标改造后污水处理厂能够连续稳定运行,出水水质满足《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级A标准和《水污染物排放限值》(DB 44/26—2001)第二时段一级标准的较严值。

疫情影响下长沙市某污水处理厂水量水质统计分析

为保障城市污水处理厂的安全运行和达标排放,文中选取长沙市某污水处理厂近6年进水水量和进出水水质数据进行统计和分析。结果表明:该污水处理厂的日均进水量在2018年—2023年3月近6年期间,于2020年达到最低,主要是受2020年年初新冠疫情所采取的封控措施影响;当年的进水水质受疫情和降雨量的双重影响,除2022年外,2020年BOD_(5)、COD_(Cr)和SS浓度较其他年份均大幅下降,而氨氮、TN和TP浓度降低相对较小。2022年进水BOD_(5)和SS低于其他年份可能是受2022年相对严重的疫情和干旱天气的影响,管道中污染物沉积进行厌氧水解导致。以疫情初始的2020年数据为研究对象,该年内各水质指标的进水浓度波动范围较大,总体上在冬季相对较高,在1月底—2月底和夏季偏低。实测出水水质浓度均达到设计出水水质标准,其中SS的去除率最高,而TN的去除率最低,改良式序列间歇反应器(MSBR)能够去除大部分的TN和氨氮。进水BOD_(5)/COD_(Cr)、BOD_(5)/TN和BOD_(5)/TP的平均值分别为0.58、4.95和46.34,1月底—2月底受疫情影响出现短暂的急剧变化,但总体进水可生化性较好、碳源充足,可采用生物除磷工艺。在碳源不足时,为保证出水达标,可考虑化学辅助除磷。研究结果可为疫情影响下类似污水处理厂的设计和运行提供参考。

城市污水处理厂运行决策支持系统(WWTP ODSS~)的介绍和应用

介绍了基于经验知识和活性污泥数学模型ASMs的城市污水处理厂运行决策支持系统(WWTP ODSS)的开发历程、主要结构功能以及应用情况,重点介绍了ODSS中专家系统和模拟系统在北京市清河污水处理厂的应用实例。ODSS系统集预警、故障诊断、过程模拟和预测等多种功能于一体,通过系统内置的溶解氧、回流比和排泥量等单元控制模块实现了前馈-反馈控制策略,为污水处理厂的运行和控制提供有力的指导和支持。

污水处理厂扩建工程设计及运行实例

北方某城市污水处理厂设计总规模18.0×10^(4)m^(3)/d,其中扩建工程设计规模8.0×10^(4)m^(3)/d,出水执行《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级A标准。根据进水水质和排放要求,设计采用“初沉池-多级AO生化池-高速气浮池-反硝化深床滤池”工艺。介绍了扩建工程的工艺流程、主要构筑物设计参数、设计特点,并对运行效果进行分析。实际运行数据表明,出水各项指标均能稳定达标,COD、SS、NH_(3)-N、TN、TP平均去除率分别达到88.90%、96.24%、97.31%、78.00%、92.87%。