Performance Parameters:Demobilization Antibiotic Resistant Bacteria(ARB)and Carrying Genes(ARG)in Wastewater Disinfection

The UV irradiation is used for removing Antibiotic Resistant Bacteria(ARB)and Antibiotic Resistance Genes(ARG)from wastewater treatment.Bacteriophages are viruses that infect within bacteria,are recognized for bacterial control.The influence of some parameters in quantification and performance influencing of pathogen demobilization could be considered in disinfection of wastewater.The comparison of Polyvalent phage(NE1)versus Coliphage(NE4)in suppressing a bacterium Escherichia coli(NDM-1:b-lactam-resistant)with UV irradiation was observed the efficacy in reduction of cells in the disinfection and parameter process.The results with the effect of UV-C irradiation on NDM-1 infected with 1%of NE4 showed a decrease of cells from 8×10^(6)to 2×10^(5)in 60 min with UV-C dose.The NDM1(E.coli)was infected with 1%of NE4(Polyvalent Phage)under magnetic stirring for 1 h,the cells count was 8×10^(6).After 1 h in UV-C e×posure,the cells number reached 3×10^(5).The NDM1 that was e×posed in 1 h of UV-C irradiation and then was infected with 1%of NE4.Cells counting were done 24 h after this procedure.These cells were e×posed in UV-C and showed a reduction in the number of cells from 1×10^(8)to 4×10^(5)after 60 min.The results indicate that bacteriophages can mitigate bacteria species,and combined the conventional water disinfection technologies that can support the microbial safety control strategies.

Removal efficiencies of natural and synthetic progesterones in hospital wastewater treated by different disinfection processes

Progesterones are ubiquitous in hospital wastewater(HWW)with concentrations much higher than those of estrogens and androgens.To ensure that these water systems are safe to use,disinfection is crucial during HWW treatment by providing"front line"defense against biological contaminations.Here,five disinfection processes,namely,chlorine(Cl_(2)),chlorine dioxide(ClO_(2)),ozone(O_(3)),ultraviolet(UV)),and UV/chlorine(UV/Cl_(2)),were selected to investigate their removal efficiencies for progesterones in primary filtration and secondary biological treatment effluents.There were 61 natural and synthetic progesterones detected in HWW,with the natural progesterones being the main components with a concentration of 845.51 ng/L and contributing to 75.08%of the total proge-sterones.The primary filtration treatment presented insignificant removal effects on the progesterones,while the secondary biological treatment significantly reduced the progesterone content by biode-gradation.The order of removal efficiencies of total progesterones by different disinfection processes was UV/Cl_(2)>Cl_(2)>O_(3)>ClO_(2)>UV.UV/Cl_(2)showed the highest removal efficiency against progesterones mainly due to the activation of Cl_(2)by ultraviolet(UV)photolysis,which helps open the heterocyclic,aromatic,and phenolic rings,thus accelerating progesterone degradation.In addition,the removal efficiencies of natural progesterones in the five disinfection processes were higher than those of synthetic progesterones(progesterone derivatives,19-nortestosterone derivatives,and 17α-hydroxyprogesterone derivatives).

Study of Wastewater Advanced Treatment and Reclaimed Water Reuse for a Large General Hospital

A combined process of biological aerated filter,fiber ball filter and chlorine dioxide disinfection was used to treat effluent of primary hospital wastewater in Jinan.Its treatment capacity was designed as 400m^3/d based on the reclaimed water demand of the large general hospital.The quality of the effluent can meet the requirements of the Reuse of Urban Recycling Water——Water Quality Standard for Urban Miscellaneous Water Consumption(GB/T18920-2002).The project has less site area,low investment and operation cost and high automatic control level,so it can provide scientific references for design and operation of similar projects.

Disinfection of Primary Municipal Wastewater Effluents Using Continuous UV and Ozone Treatment

UV radiation and ozonation were investigated as disinfection alternatives for the wastewater treatment plant. The inactivation of total and fecal coliforms using ozone and ultraviolet radiation as separate treatments was evaluated. Different ozone concentrations (3 to 40 mg O3/L) were applied and UV fluencies ranging from 8.5 to 12 mJ/cm2 at different pH values (from 5 to 9) were tested. Best results were obtained for ozone doses near 20 mg/min with removals of 72% and 78% of fecal and total coliforms, respectively. The ozone also was capable of oxidizing organic matter in the effluent measured as COD (the highest removal obtained was 36% for 20 mg O3/min). Maximum bacterial resistance was observed at pH 7 in both cases. The UV light offered a high bacterial inactivation (over 80%) and the lowest bacterial inactivation was observed at pH 7. Finally, we obtained the electric energy per order (EEO, kWh/m3/order), defined as the electric energy (kW-h) required to degrade a contaminant by one order of magnitude in a unit volume of contaminated water, being noteworthy that EEO values for the UV process resulted were lower than those determined for the process with ozone in all the water flow tested.

Field investigation of antibiotic removal efficacies in different hospital wastewater treatment processes in Thailand

The removal efficacies of 19 antibiotics in different hospital wastewater treatment processes(WWTP)were investigated at various sizes of 60 hospitals across Thailand.The results showed slight differences in the total antibiotic removals(79e84%)among WWTP sizes.High antibiotics loading to all WWTP were amoxicillin,ciprofloxacin,tetracycline ampicillin,and norfloxacin,respectively.Amoxicillin and ampicillin were eliminated highly(90e99%)in every size of WWTP,while various efficacies showed for other antibiotics(0e93%).According to process comparison,activated sludge(CAS),oxidation ditch(OD),and sequencing batch reactor(SBR)systems showed similar removals of overall antibiotics(P>0.05).The attached growth systems such as submerged aerated fixed-film(SAFF)demonstrated relatively lower antibiotic removals.The natural processes such as aerated lagoon(AL),facultative pond(FP),and constructed wetland(CW)presented substantial biodegradation of some recalcitrant antibiotics such as fluoroquinolones,sulfamethoxazole,and trimethoprim.Post-chlorination provided additional elimination of some antibiotics such as amoxicillin and ampicillin.Finally,the top-five of antibiotics released into the water environment via discharged effluent are amoxicillin,tetracycline,ampicillin,ciprofloxacin,and imipenem,respectively,which mainly from the suspended growth systems.

The Role of Wastewater Treatment Plants in the Environmental Dissemination of Antibiotic Resistant Bacteria (ARB) and Resistance Genes (ARG)

This study was conducted to evaluate the influence of wastewater treatment processes on the prevalence of antibiotic resistance fecal coliform (FC) and antibiotic resistance genes (ARGs) of FC. In addition, the occurrence of antibiotic resistant bacteria (ARB) and antibiotic resistant genes (ARGs) in surface waters receiving wastewater was evaluated. Greater resistance against penicillin (P), colisitin (CT) and ampicillin (AMP) were observed for FC isolated from effluent disinfected by chlorine (71%), than that disinfected by UV (45%). The greatest resistance against six antibiotics was recorded for FC isolates from effluent disinfected by chlorine. The prevalence of tetB and blaSHV was lowest in isolates from chlorine-disinfected effluents. The occurrence of ARG blaSHV was highest in FC isolated from effluent disinfected by UV. A significant correlation was recorded between FC levels in surface waters and the level of bacterial resistance to ampicillin (P SHV in effluents and in surface waters. TetA and tetC were highly prevalent in surface water compared to tetB. The results of the study demonstrate the widespread prevalence of ARB and ARG in wastewater and receiving water bodies. The result indicates that the source of ARB and ARG in surface waters originate from wastewater. Released ARB and ARG may serve as the source of ARG to pathogenic bacteria in surface waters. Disinfection processes may influence the selection of antibiotic resistant patterns of bacteria.

Destruction of <i>Escherichia coli</i>and Broad-Host-Range Plasmid DNA in Treated Wastewater by Dissolved Ozone Disinfection under Laboratory and Field Conditions

Broad-host-range plasmids are frequently associated with antibiotic resistance genes and can quickly spread antibiotic resistant phenotypes among diverse bacterial populations. Wastewater treatment plants have been identified as reservoirs for broad-host-range plasmids carrying resistance genes. The threat of broad-host-range plasmids released into the environment from wastewater treatment plants has identified the need for disinfection protocols to target broad-host- range plasmid destruction. Here we evaluate the efficacy of dissolved ozone at 2 and 8 mg·L–1 as a primary means for the destruction of broad-host-range plasmid and chromosomal DNA in simulated effluent. Pilot-scale tests using an experimental unit were carried out in municipal wastewater treatment plant effluent and compared with ultraviolet (UV)-irradiation and chlorination methodologies. Genes specific to Escherichia coli (uidA) and IncP broad-host-range plasmids (trfA) were monitored using real-time quantitative polymerase chain reaction (qPCR), and total DNA was monitored using absorbance spectroscopy. In wastewater treatment plant experiments, E. coli qPCR results were compared to a recognized culture-based method (Colilert?) for E. coli. In laboratory experiments, dissolved ozone at 8 mg·L–1 significantly destroyed 93% total, 98% E. coli, and 99% of broad-host-range plasmid DNA. Ozonation, UV-irradiation, and chlorination significantly reduced DNA concentrations and culturable E. coli in wastewater treat- ment plant effluent. Chlorination and UV disinfection resulted in 3-log decreases in culture-based E. coli concentrations in wastewater treatment plant effluent while changes were not significant when measured with qPCR. Only ozonation significantly decreased the IncP broad-host-range plasmid trfA gene, although concentrations of 2.2 × 105 copies trfA·L–1 remained in effluent. Disinfection processes utilizing high dissolved ozone concentrations for the destruction of emerging contaminants such as broad-host-range plasmid and total DNA may have utility as methods to ensure downstream environmental health and safe water reuse become more important.

Review of advanced oxidation processes for treating hospital sewage to achieve decontamination and disinfection

Hospital sewage contains various harmful pharmaceutical contaminants(e.g.,antibiotics,anti-inflammatory agents,and painkillers)and pathogens(e.g.,bacteria,viruses,and parasites),whose direct discharge into the environment will induce diseases and pose a powerful threat to human health and safety,and environmental ecology.In recent years,advanced oxidation processes(AOPs),particularly photocatalysis,electrocatalysis,and ozone catalysis have been developed as widespread and effective techniques for hospital sewage treatments.However,there is a lack of systematic comparison and review of the prior studies on hospital sewage treatment using AOPs systems.This review elaborates on the mechanisms,removal efficiencies,and advantages/disadvantages of these AOPs systems for hospital wastewater decontamination and disinfection.Meanwhile,some novel and potential technologies such as photo-electrocatalysis,electro-peroxone,Fenton/Fenton-like,and piezoelectric catalysis are also included and summarized.Moreover,we further summarize and compare the capacity of these AOPs to treat the actual hospital wastewater under the impact of the water matrix and pH,and estimate the economic cost of these technologies for practical application.Finally,the future development directions of AOPs for hospital wastewater decontamination and disinfection have been prospected.Overall,this study provides a comparison and overview of these AOP systems in an attempt to raise extensive concerns about hospital wastewater decontamination and disinfection technologies and guide researchers to discover the future directions of technologies optimization,which would be a crucial step forward in the field of hospital sewage treatment.

医院污水处理技术研究进展

医院污水来源及成分复杂,含有病原微生物、药物及其代谢产物、重金属、造影剂及抗性基因等。在国内新冠肺炎疫情反复的特殊时期,医院病人数快速增加,污水中相应的各类治疗药物、消毒药剂、病原微生物等大幅增加,如果不对污水进行有效处理,切断病原微生物和有毒有害物质进入环境的途径,将产生二次污染风险。从医院污水主要成分和特征出发,结合国家和省级相关政策和技术规范要求,分析现阶段国内医院污水处理现状和存在的问题,梳理现有医院污水常规和前沿治理技术,并提出相关对策和建议,以期为我国医院污水治理提供一定技术参考。

高级氧化技术在医院污水低碳无害化处理中的研究与应用

医院污水中存在抗生素、内分泌干扰物等新污染物,这些污染物很难通过常规的生化处理方法有效去除。同时,在重点传染病频发的情况下,对医院污水中病原微生物的消杀能力也有待提高。近年来,国内外学者采用高级氧化技术有效降解医院污水中的抗生素等药物类污染物,同时灭活病原体。然而,高级氧化技术成本高、能耗大和可能产生有毒有害副产物的缺点,限制了其在实际工程中的广泛应用。本文对国内外关于高级氧化技术处理医院污水的研究现状进行了综述。首先介绍了芬顿氧化、活化过硫酸盐、过氧乙酸氧化、臭氧氧化和电化学等高级氧化技术的原理和应用。此外,还对基于电化学的协同催化氧化技术进行了介绍,针对实际医院污水的低碳无害化高级氧化处理工艺与装备进行了总结。最后,对我国目前医院污水低碳无害化处理过程中存在的问题进行了分析,并展望了未来的研究方向。

污水处理厂过氧乙酸消毒特性及应用进展

消毒是污水处理的必要环节,氯是常用化学消毒剂,但消毒过程会产生有害副产物,对人类健康和生态环境造成威胁。过氧乙酸(PAA)是具有氧化性的有机过氧酸,是替代氯的新型绿色消毒剂。本综述系统介绍了PAA消毒剂的结构特征、消毒特性、副产物生成特性以及生物毒性。随后介绍了PAA在污水处理过程中的消毒效果,探讨了PAA和UV耦合工艺在污水消毒中的增效作用,分析了PAA消毒过程中的综合影响因素。进一步总结了PAA在污水消毒领域的具体应用,并介绍了北美、欧洲国家相关典型工程应用案例,以及我国污水处理厂中试研究进展。最后,对PAA在未来污水处理消毒领域的发展方向进行了展望,提出了改进和优化PAA消毒技术的策略和方向,以促进PAA绿色消毒技术在我国污水处理厂的推广应用。

医院污水处理的新趋势

通过文献检索,分析了医院污水处理方面的研究热点;从污水处理要求、工程项目建设、污水处理原则、污水处理工艺、消毒方法等方面总结了目前医院污水处理的现状及趋势;对未来的研究方向进行了展望。

上海某方舱医院污水处理系统分析

文章介绍了上海某方舱医院处理量达500 m^(3)/d的污水处理系统,主要包括污水处理系统的工艺设计流程、工艺原理等内容,并对系统的运行效果进行了分析。来自方舱的混合污水通过专门管道收集后经预处理系统、一体式生化系统及最后的末端消毒系统进行处理。结果显示,经过该系统处理后出水余氯质量浓度稳定在6.5~10.0 mg/L,且上午、下午不同时间段成有规律的相关性,pH值稳定在6~9,余氯值和pH均能够满足规定的污水排放标准。说明该处理系统对于此类污水具有较好的处理效果,为类似项目的污水处理提供了一定的参考。

一种新型的污水脱氮技术氯化-紫外联合工艺研究

采用氯化-紫外联合处理工艺进行处理氨氮废水,研究了不同因素对于氨氮废水的脱除效果。研究结果显示,氨氮的脱除率与水中氯氮的质量比、辐照的剂量、水体酸碱度等相关程度较大,为主要的影响因素。当氯氮的质量比为2.9∶1,254 nm紫外光辐照强度为120 mJ/cm^(2)·60 s,酸碱度为8.0的条件下,氨氮的脱除率达到78.15%,且产生的消毒污染物为相同浓度下折点氯化法的35.5%。

城镇污水处理厂消毒处理技术的探讨

2020年2月1日,生态环境部印发《关于做好新型冠状病毒感染的肺炎疫情医疗污水和城镇污水监管工作的通知》(环办水体函[2020]52号),其中特别指出“地方生态环境部门要督促城镇污水处理厂切实加强消毒工作,确保出水粪大肠菌群数指标达到《城镇污水处理厂污染物排放标准》(GB 18918-2002)要求”。目前我国城镇污水处理厂所采用的消毒处理技术主要包括紫外、臭氧、次氯酸钠、二氧化氯,以及这些处理方式的组合。其中次氯酸钠消毒是目前污水处理厂应用最多的消毒处理方式,然而对于次氯酸钠消毒的工艺参数和运行效果尚缺乏统一的认识,在次氯酸钠投加量、消毒接触时间等关键参数上均存在问题,综述了次氯酸钠投加量,消毒接触时间,水温,氧化还原电位(ORP),氨氮浓度等参数对次氯酸钠消毒效果影响的研究,以期为城镇污水处理厂消毒杀菌提供理论指导。

紫外线消毒技术在污水处理中的应用

介绍了紫外消毒的机理、影响紫外消毒的因素以及紫外消毒装置的基本结构形式。阐述了紫外消毒的现状和应用前景 ,提出紫外消毒可能取代传统的化学消毒法 ,在污水处理 ,特别是回用水的处理中得到广泛的应用。

氯胺消毒及高锰酸钾氯胺联用消毒

以城市污水处理厂二级出水为试验水样,观察了氯、氯胺单独消毒工艺以及高锰酸钾与氯胺协同消毒工艺的消毒效能,同时比较了投药总量相同条件下单独氯胺消毒工艺及高锰酸钾与氯胺协同消毒工艺的消毒效能以及对THMs生成的影响。结果表明,对于污染严重,尤其是耗氯物质含量较高的污水,氯消毒效果受到极大影响,氯胺消毒的效果要略好于氯消毒的效果,而高锰酸钾与氯胺协同消毒工艺的消毒性能明显优于单独氯胺消毒工艺,并且能够进一步降低THMs的生成量。因此,高锰酸钾与氯胺协同消毒工艺可以使处理后水质从微生物安全性到化学安全性两方面均得到提高。

医院典型废水处理工艺单元的抗生素去除效果与评价

采用固相萃取-高效液相色谱法同时检测了医院废水中2种喹诺酮类（氧氟沙星、环丙沙星）和4种磺胺类（磺胺嘧啶、磺胺甲基嘧啶、磺胺二甲基嘧啶、磺胺甲叶恶唑）抗生素,并对医院废水处理工艺的抗生素去除能力进行了评价。结果表明,现行医院废水处理工艺对抗生素的去除能力介于36.3%~100%,废水处理工艺对医院废水中抗生素的去除能力由大到小为：＂厌氧池→好氧池→沉淀池→加氯＂〉＂化粪池→加氯＂〉＂好氧池→沉淀池→加氯＂;＂厌氧池→好氧池→沉淀池→加氯＂工艺对磺胺嘧啶和磺胺甲叶恶唑去除率达到100%,氧氟沙星和环丙沙星的去除率分别为92.5%和95.6%,磺胺甲基嘧啶的去除率为45.8%;＂化粪池→加氯＂工艺对磺胺甲基嘧啶和磺胺甲叶恶唑去除率达到100%,氧氟沙星的去除率达到97.4%,环丙沙星、磺胺嘧啶和磺胺二甲基嘧啶的去除率分别为75.0%、57.9%、36.3%;＂好氧池→沉淀池→加氯＂工艺对磺胺甲基嘧啶去除率达到100%,氧氟沙星、环丙沙星和磺胺甲叶恶唑的去除率分别为59.5%、10.9%和53.8%;厌氧单元对氧氟沙星去除效果较差,对磺胺嘧啶去除效果较好;纯氧曝气好氧单元对环丙沙星、磺胺甲基嘧啶、磺胺二甲基嘧啶、磺胺甲叶恶唑和氧氟沙星的去除率分别为76.0%、62.5%、77.3%、68.4%和13.9%;加氯消毒单元对磺胺二甲基嘧啶的去除效果较差,对磺胺甲叶恶唑的去除效果较好,对其他4种抗生素的去除率也能达到50%以上。

罗氏沼虾育苗废水处理方法与工艺

运用物理、化学及生物法对罗氏沼虾育苗废水进行处理。结果表明:育苗废水经物理法(沉淀、过滤)处理后,水质状况得到改善。浑浊度平均下降68.1%,NH3-Nt、CODMn平均下降24.2%与14.4%;细菌总数、弧菌数下降68.6%和75.4%。24 h后二氧化氯3.0 mg/L为最佳消毒浓度;24 h后溴氯海因3.0 mg/L为最佳消毒浓度;48 h后百杀迪1.5mg/L为最佳消毒浓度。废水经臭氧消毒14h后对细菌的杀灭率达到92.7%,对弧菌的杀灭率在5 h的时候便达到了100%,氧化还原电位提高了约18.6%。消毒剂净化废水的能力依次为臭氧>百杀迪>溴氯海因>二氧化氯。到一定时间当生物膜成熟后,生物滤器对水质净化有良好的效果,系统可较好保持NH3-Nt低值,而保持NO2--N低值不易。