Asn57 N-glycosylation promotes the degradation of hemicellulose by β-1,3–1,4-glucanase from Rhizopus homothallicus

Environmental Science and Pollution Research - N-glycosylation alters the properties of different enzymes in different ways. Rhizopus homothallicus was first described as an environmental isolate...     

污水处理厂出水中常见抗生素光降解去除规律研究进展

残留的抗生素和新产生的抗生素代谢产物会通过不同的途径进入到环境中,污染环境,诱导产生一些耐药和变异的超级细菌,严重危害人类健康.梳理分析了污水处理厂出水中常见的抗生素种类,阐述了光降解抗生素的反应机理和影响抗生素光降解的因素,并从高效光转化材料的制备、光降解产物的精准识别和降解产物的生物毒性评估角度提出开展后续研究的建...     

Effect of placement angles on wireless electrocoagulation for bipolar aluminum electrodes

A new electrocoagulation process based on bipolar aluminum electrode is proposed. The placement angles of bipolar electrode are key parameter. The numerical simulations support the experimental results. We in our previous study reported the wireless electrocoagulation (WEC) based on bipolar electrochemistry for water purification. One of the most important advantages of WEC is the omission of ohmic connection between bipolar electrode (BPE) and power supply, and thus the electrochemical reactions on BPE are driven by electric field in solution induced by driving electrodes. In this study, the impact of placement angle of bipolar aluminum electrode on WEC was investigated to provide a detailed analysis on the correlations between the bipolar electrode placement angle and bipolar electrocoagulation reactions. The results showed that the WEC cell with a horizontal BPE placed at 0° produced the maximum dissolved aluminum coagulant, accounting for 71.6 % higher than that with a vertical one placed at 90°. Moreover, the finite element simulations of current and potential distribution were carried out along the surface of BPE at different placement angles, revealing the mechanism of different BPE placement angles on aluminum dissolution rates in WEC system.     

两种改良型A~2/O工艺处理城市污水的运行实例

以广东省佛山市甲、乙两间污水处理厂为例,从工艺特征、工艺参数、水质特点、存在问题及相应措施几个方面介绍了两种改良型A2/O工艺在不同进水条件下的运行情况。     

Does leakage exist in China’s typical protected areas? Evidence from 13 national nature reserves

Environmental Science and Pollution Research - There is profound interest in knowing the degree to which the effectiveness of China’s nature reserves, and whether leakage is common around the...     

Research progress on distribution,sources, identification,toxicity, and biodegradation of microplastics in the ocean,freshwater, and soil environment

• Microplastics are widely found in both aquatic and terrestrial environments. • Cleaning products and discarded plastic waste are primary sources of microplastics. • Microplastics have apparent toxic effects on the growth of fish and soil plants. • Multiple strains of biodegradable microplastics have been isolated. Microplastics (MPs) are distributed in the oceans, freshwater, and soil environment and have become major pollutants. MPs are generally referred to as plastic particles less than 5 mm in diameter. They consist of primary microplastics synthesized in microscopic size manufactured production and secondary microplastics generated by physical and environmental degradation. Plastic particles are long-lived pollutants that are highly resistant to environmental degradation. In this review, the distribution and possible sources of MPs in aquatic and terrestrial environments are described. Moreover, the adverse effects of MPs on natural creatures due to ingestion have been discussed. We also have summarized identification methods based on MPs particle size and chemical bond. To control the pollution of MPs, the biodegradation of MPs under the action of different microbes has also been reviewed in this work. This review will contribute to a better understanding of MPs pollution in the environment, as well as their identification, toxicity, and biodegradation in the ocean, freshwater, and soil, and the assessment and control of microplastics exposure.     

纳米二氧化铈的潜在生态风险及毒性作用机制研究进展

作为重要的纳米稀土化合物,纳米二氧化铈(CeO2 )被广泛应用于工、农、医学等领域,随之而来的是大量的纳米CeO2 在其生产使用和处理处置等过程中被释放进入到环境中,进而导致其生物安全性受到越来越多的关注.本文从纳米CeO2 对细胞、组织器官、植物、水生生物和土壤生物产生的毒性效应入手,系统综述了纳米CeO2 的潜在环...     

垃圾填埋场稳定化及其研究现状

文章对直埋场稳定化过程进行了初步描述,并从填埋气、渗滤液、垃圾组成和沉降等４个方面总结了填埋场稳定化的研究现状。     

Antibiotic resistance and plasmid profiling of <Emphasis Type="Italic">Vibrio</Emphasis> spp. in tropical waters of Peninsular Malaysia

Vibrio species isolated from four different sampling stations in the west coast of Peninsular Malaysia were screened for their antimicrobial resistance and plasmid profiles. A total of 138 isolates belonging to 15 different species were identified. Vibrio campbellii, V. parahaemolyticus, V. harveyi, and V. tubiashii were found to predominance species at all stations. High incidence of erythromycin, ampicillin, and mecillinam resistance was observed among the Vibrio isolates. In contrast, resistance against aztreonam, cefepime, streptomycin, sulfamethoxazole, and sulfonamides was low. All the Vibrio isolates in this study were found to be susceptible to imipenem, norfloxacin, ofloxacin, chloramphenicol, trimethoprim/sulfamethoxazole, and oxytetracycline. Ninety-five percent of the Vibrio isolates were resistant to one or more different classes of antibiotic, and 20 different resistance antibiograms were identified. Thirty-two distinct plasmid profiles with molecular weight ranging from 2.2 to 24.8 kb were detected among the resistance isolates. This study showed that multidrug-resistant Vibrio spp. were common in the aquatic environments of west coast of Peninsular Malaysia.     

Chemical techniques for assessing bioavailability of sediment-associated contaminants: SPME versus Tenax extraction

The traditional approach for predicting the risk of hydrophobic organic contaminants (HOCs) in sediment is to relate organic carbon normalized sediment concentrations to body residues or toxic effects to organisms. However, due to the multiple variables controlling bioavailability, this method has limitations. A matrix independent method of predicting bioavailability needs to be used in order to be universally applicable. Both chemical activity (freely dissolved chemical concentrations) measured by solid-phase microextraction (SPME) and bioaccessibility (rapidly desorbing fraction) estimated by Tenax extraction have been developed to predict bioavailability of sediment-associated HOCs. The objectives of this review are to summarize a number of studies using matrix-SPME or Tenax extraction to estimate bioavailability and/or toxicity of different classes of HOCs and evaluate the strengths and weakness of these two techniques. Although the two chemical techniques assess different components of the matrix, estimates obtained from both techniques have been correlated to organism body residues. The advantages of SPME fibers are their applicability for use in situ and their potential usage for a wide array of contaminants by selection of appropriate coatings. Single time-point Tenax extraction, however, is more time- and labor-effective. Tenax extraction also has lower detection limits, making it more applicable for highly toxic contaminants. This review also calls for additional research to evaluate the role of sequestrated contaminants and ingestion of sediment particles by organisms on HOC bioavailability. The use of performance reference compounds to reduce SPME sampling time and linking chemical based bioavailability estimates to toxicological endpoints are essential to expand the applications of these methods.