微生物法去除水中氯苯类化合物的研究进展

氯苯类化合物是水环境污染中的主要污染物之一, 本文主要介绍了目前国内外微生物法处理水中氯苯类化合物的最新研究成果, 包括氯苯类化合物的微生物好氧降解、厌氧降解、共代谢、生物活性炭以及生物处理工艺等, 并展望了该领域今后的研究方向。     

氯代苯胺类化合物微生物降解的研究进展*

对氯代苯胺类化合物(Chlovoanilines,CAS)好氧微生物降解的研究现状进行了系统的综述,内容包括具有降解氯代苯胺类化合物能力的微生物、氯代苯胺类化合物的代谢途径及相关代谢酶的分析、降解质粒和关键代谢酶的基因克隆和表达,并提出了氯代苯胺类化合物好氧微生物降解研究中存在的问题和尚需进一步研究的方面。     

1,2,4—三氯苯在土壤中的降解

在好氧和厌氧两种条件下研究了１,２,４－三氯苯的降解。结果表明,１,２,４－三氯苯的好氧降解和厌氧降解均遵循一级反应动力学。在同样水分、温度及初始浓度条件下,１,２,４－三氯苯的好氧降解比厌氧降解比厌氧降解迅速,其半衰期分别为１．８９￣５．８６和５．０７￣１９．０８ｄ。土壤中１,２,４－三氯苯的初始浓度对于其降解也有显著影响,在０￣１００μｇ·ｇ＾－１的范围内,浓度增高时,其降解加快,说明污染物浓     

环境激素类有机污染物的微生物降解和药物类化合物的残留问题

合成有机物在环境中的残留和危害已不仅仅局限于其毒性、富集、致畸和致突变,同时还能干扰包括人类在内的生物的内分泌调节作用.近年来发达国家已开始逐渐有了环境方面的条例,限制和控制这类化合物在水及食物链中的含量.现已清楚地知道,部分除草剂和杀虫剂(如阿特拉津、DDT),塑料的添加增塑剂均有内分泌激素活性,从而对生物的正常生长发育造成不良的影响.而这些化合物不但广泛存在于环境中,在特定的环境中其含量更是非常之高.以增塑剂邻苯二甲酸和邻苯二甲酸二甲酯为例,它们在填埋渗出液中的含量可高达10g·L^-1.在我们研究这类化合物的微生物降解时发现,从活性污泥和红树林中富集到的好氧微生物能将这类化合物完全矿化,且反应速度很快.同时也发现,在降解邻苯二甲酸二甲酯时,单一的纯菌不能完全降解这类化合物,而二种或三种组合的纯菌可以在一周内将500mg·L^-1的底物完全矿化.我们已分离、鉴定出中间产物,建立起了降解途径.研究的结果证实,邻苯二甲酸二甲酯类环境激素是能够在排放前通过微生物的作用达到完全矿化的.另一方面,药物类化合物的残留问题也是一个逐渐显现出的环境问题,这方面的研究应引起更多的关注和重视.     

1，2，4－三氯苯在土壤中的降解

在好氧和厌氧两种条件下研究了１,２,４－三氯苯的降解,结果表明,１,２,４－三氯苯的好氧降解和厌氧降解均遵循一级反应动力学在同样水分、温度及初始浓度条件下,１,２,４－三氯苯的好氧降解比厌氧降解迅速,其半衰期分别为１．８９～５．８６和５．０７～１９．０８ｄ土壤中１,２,４－三氯苯的初始浓度对于其降解也有显著影响,在０～１００μｇ·ｇ－１的范围内,浓度增高时,其降解加快,说明污染物浓度对降解的影响;在１０～３０℃范围内,温度增高导致降解过程加快,归因于温度升高对微生物酶活性的激活作用．     

二硝基苯胺类除草剂微生物降解研究进展

二硝基苯胺类除草剂是一类广谱、高效且广泛使用的除草剂,微生物的降解代谢作用是其在环境中消解的最主要因素。分离筛选除草剂的高效降解菌株、分析其降解途径并阐明其微生物降解机制,可为除草剂残留污染的微生物降解修复提供理论依据和优良的降解菌株、降解基因和酶资源。本文简述了二硝基苯胺类除草剂的微生物降解菌株、降解代谢途径和降解基因/酶的研究进展,为进一步研究该类除草剂的微生物降解及其污染生物修复提供理论依据和资源。     

降解芳烃微生物的多样性

芳烃是一类生物异源物质,自然微生物群落利用其对环境的适应性,对这类物质由陌生到适应,微生物群落的遗传背景发生了变化,降解芳烃的微生物呈现出多样性,本文系统介绍了降解芳烃微生物的特性,物种资源,环境适应,遗传背景及演变;介绍了各遗传型物种的功能基因数量,表达及调控方式,指明芳烃环境污染的生物修复主要取决于高效工程构造及代谢过程的控制。     

微生物降解多环芳烃(PAHs)的研究进展

从多环芳烃(PAHs)的降解菌株的筛选、降解机制以及PAHs污染的生物修复等方面介绍了微生物降解PAHs的最新研究进展。     

肠道微生物代谢苷类化合物的研究进展CSCD

肠道微生物对苷类化合物的体内代谢十分重要,可分泌代谢酶进行脱糖基、脱甲基、脱羟基、水解和氧化还原等反应将苷代谢生成次级苷、苷元或其他代谢产物,从而促进苷类药物的吸收并发挥药效。本文论述了肠道微生物及代谢酶对苷类化合物代谢的意义,总结了肠道微生物对不同结构类型的苷类化合物的代谢规律及代谢产物,为了解苷类药物的疗效基础、作用机理及利用微生物转化开发苷类药物提供参考。     

土壤中高环多环芳烃微生物降解的研究进展

微生物修复是去除土壤中多环芳烃(PAHs)的主要措施。本文以微生物修复PAHs污染土壤的理论基础及其难点为主线,全面综述了土壤中高环PAHs的微生物降解机理。近年来,富集分离得到的以高环PAHs为唯一碳源和能源的优势降解菌逐渐增多,其中,主要是代谢降解四环PAHs的单株降解菌,一些降解菌还能以共代谢方式利用五环PAHs。高环PAHs污染土壤修复的一个难点是其低生物可利用性,微生物通过释放生物表面活性剂、形成生物膜以及分泌胞外多糖提高高环PAHs的生物可利用性,从而加速其降解。真菌和细菌联合作用能增强污染土壤实地修复的效果。因此,通过微生物修复技术来去除土壤中PAHs具有环境友好性、经济适用性以及可持续应用性。     

污水生物处理中的噬菌体及其功能研究进展

污水生物处理是一种利用微生物分解污水中的污染物、实现污水净化的方法。噬菌体是侵染细菌的病毒,在污水生物处理系统中广泛存在,它们能够特异性地控制微生物菌群,影响污水处理效果和调控污泥性状。因此,研究污水生物处理中噬菌体的分布及其功能具有重要意义。本文介绍了不同污水生物处理中噬菌体的分布,简要分析了噬菌体分离、培养与鉴定方法及其优缺点,详细总结了噬菌体在污水生物处理中的功能,包括：（1）调节微生物群落结构,影响污水处理效果;（2）作为环境监测的指示生物;（3）控制病原菌、污泥膨胀、污泥发泡和膜污染;（4）减少污泥产量,重点分析了影响噬菌体功能的因素,探讨了污水生物处理中噬菌体功能应用存在的问题及其解决方法,最后对噬菌体未来应用的发展方向进行了展望,以期为污水生物处理技术和工艺的开发与应用提供参考,促进污水处理健康发展。     

塔式生物滤池处理洗涤剂工业废水的模拟试验

本项研究工作表明,塔式生物滤池在处理模拟洗涤剂工业废水时,能够适应和克服一般好氧生化法所不能解决的泡沫问题,并对废水中的LAS和COD具有一定的去除效果。根据实验结果,初步认为塔滤可应用于洗涤剂工业废水的生化处理,并向洗涤剂行业首次推荐这种废水生物学净化方法。从塔滤的生物膜中分离出了优势菌,经鉴定为一种气单胞菌(Aeromonas sp. D-4)。     

Coupled biological and photo-Fenton pretreatment system for the removal of di-(2-ethylhexyl) phthalate (DEHP) from water

The photo-Fenton coupled with a biological system for the removal of di-(2-ethylhexyl) phthalate (DEHP) in wastewater was analyzed. The toxicity of DEHP-containing wastewater was found to be reduced after pretreatment by the photo-Fenton reaction. The effect of different factors, such as DEHP, Fe³⁺ and H₂O₂ concentrations and the reaction time, on degradation efficiency was investigated. The optimal time to stop the pretreatment process and introduce the effluent to the biological system was 60 min. The results show that effluent of DEHP-containing wastewater pretreated by the photo-Fenton method is biodegradable and that mineralization can be completed when the wastewater is subsequently treated in a biological system. The coupled Fenton and biological treatment system for the degradation of DEHP-containing wastewater can be successfully performed in a semi-continuous mode. These results indicate that the coupled photo-biological system is an effective and potential method for the treatment of DEHP-containing wastewater.     

Online nonlinear sequential Bayesian estimation of a biological wastewater treatment process

Online estimation of unknown state variables is a key component in the accurate modelling of biological wastewater treatment processes due to a lack of reliable online measurement systems. The extended Kalman filter (EKF) algorithm has been widely applied for wastewater treatment processes. However, the series approximations in the EKF algorithm are not valid, because biological wastewater treatment processes are highly nonlinear with a time-varying characteristic. This work proposes an alternative online estimation approach using the sequential Monte Carlo (SMC) methods for recursive online state estimation of a biological sequencing batch reactor for wastewater treatment. SMC is an algorithm that makes it possible to recursively construct the posterior probability density of the state variables, with respect to all available measurements, through a random exploration of the states by entities called ‘particle’. In this work, the simplified and modified Activated Sludge Model No. 3 with nonlinear biological kinetic models is used as a process model and formulated in a dynamic state-space model applied to the SMC method. The performance of the SMC method for online state estimation applied to a biological sequencing batch reactor with online and offline measured data is encouraging. The results indicate that the SMC method could emerge as a powerful tool for solving online state and parameter estimation problems without any model linearization or restrictive assumptions pertaining to the type of nonlinear models for biological wastewater treatment processes.     

Attached-growth process engineering in wastewater treatment

In view of the importance of biological treatment, it is the purpose of this work to present an overview of attached-growth biological wastewater treatment, considering the active role the engineers have to play in this field. This paper brings together conventional and advanced problems in the field of aerobic attached-growth (biofilm) wastewater treatment. Such an overview of biological wastewater treatment also precedes comments on some important aspects concerning the microorganisms responsible for wastewater treatment as well as considerations on the key factors governing the kinetic of the biological growth and waste treatment, together with application of fundamentals and kinetics to the analysis of these biological processes. A survey of the development of the attached-growth process and some modifications are given. These include additional details on the bioreactor progress and applications. Finally, some aspects regarding process intensification and bioreactor improvement were included.     

Thermophilic biological nitrogen removal in industrial wastewater treatment

Nitrification is an integral part of biological nitrogen removal processes and usually the limiting step in wastewater treatment systems. Since nitrification is often considered not feasible at temperatures higher than 40 °C, warm industrial effluents (with operating temperatures higher than 40 °C) need to be cooled down prior to biological treatment, which increases the energy and operating costs of the plants for cooling purposes. This study describes the occurrence of thermophilic biological nitrogen removal activity (nitritation, nitratation, and denitrification) at a temperature as high as 50 °C in an activated sludge wastewater treatment plant treating wastewater from an oil refinery. Using a modified two-step nitrification–two-step denitrification mathematical model extended with the incorporation of double Arrhenius equations, the nitrification (nitrititation and nitratation) and denitrification activities were described including the cease in biomass activity at 55 °C. Fluorescence in situ hybridization (FISH) analyses revealed that Nitrosomonas halotolerant and obligatehalophilic and Nitrosomonas oligotropha (known ammonia-oxidizing organisms) and Nitrospira sublineage II (nitrite-oxidizing organism (NOB)) were observed using the FISH probes applied in this study. In particular, this is the first time that Nitrospira sublineage II, a moderatedly thermophilic NOB, is observed in an engineered full-scale (industrial) wastewater treatment system at temperatures as high as 50 °C. These observations suggest that thermophilic biological nitrogen removal can be attained in wastewater treatment systems, which may further contribute to the optimization of the biological nitrogen removal processes in wastewater treatment systems that treat warm wastewater streams.     

微生物处理高盐工业有机废水工艺研究进展

随着我国工业化进程加快,其所造成的水污染现象也越来越严重。含盐有机废水的排放会导致环境进一步恶化,为了合理循环利用水资源,相关废水的有效处理至关重要。本文从微生物角度出发,通过典型案例阐述了目前基于微生物所运行的生物工艺技术在高含盐有机废水领域中的研究进展,综述了微生物在高盐环境中的生存与耐受机制,以及在处理高盐工业有机废水方面的研究与应用情况,进一步提出了目前存在的问题及未来在本领域研究与应用的展望,为高盐工业有机废水的生物处理发展方向提供一定的参考。     

Recent development of advanced biotechnology for wastewater treatment

Abstract

The importance of highly efficient wastewater treatment is evident from aggravated water crises. With the development of green technology, wastewater treatment is required in an eco-friendly manner. Biotechnology is a promising solution to address this problem, including treatment and monitoring processes. The main directions and differences in biotreatment process are related to the surrounding environmental conditions, biological processes, and the type of microorganisms. It is significant to find suitable biotreatment methods to meet the specific requirements for practical situations. In this review, we first provide a comprehensive overview of optimized biotreatment processes for treating wastewater during different conditions. Both the advantages and disadvantages of these biotechnologies are discussed at length, along with their application scope. Then, we elaborated on recent developments of advanced biosensors (i.e. optical, electrochemical, and other biosensors) for monitoring processes. Finally, we discuss the limitations and perspectives of biological methods and biosensors applied in wastewater treatment. Overall, this review aims to project a rapid developmental path showing a broad vision of recent biotechnologies, applications, challenges, and opportunities for scholars in biotechnological fields for “green” wastewater treatment.