Performance and role of N-acyl-homoserine lactone (AHL)-based quorum sensing (QS) in aerobic granules

The present study investigated the relationship between N-acyl-homoserine lactone（AHL）-based quorum sensing（QS） and the physico-chemical properties of aerobic granules.Stable mature granules were observed in SBR2 and SBR3 with average diameters of 0.96,and1.49 mm,respectively. The sludge densities of aerobic granules in SBR2 and SBR3 were1.0246,and 1.0201 g/mL,respectively,which were higher than that of flocculent sludge in SBR1（1.0065 g/mL）. The results showed that the activity of AHL-based QS in SBR2 and SBR3 amounted to 2.4- and 2.1-fold induction,however,that in SBR1 with flocculent sludge was1.6-fold induction. In addition,the results also showed that the activity of AHL-based QS in the three reactors rose in the feast condition,and then dropped with the consumption of substrate. However,the activity of AHL-based QS in these three reactors recovered again in prolonged starvation. Furthermore,the results showed that the enhancement of AHL-based QS favored the extracellular polymeric substance production of microorganisms in activated sludge. Thus,it could be concluded that aerobic granules showed higher AHL-based QS than flocculent sludge,which resulted from the higher sludge density of aerobic granules than flocculent sludge. AHL-based QS was related to the metabolism energy in the feast condition; however,in prolonged starvation,microorganisms would emit more AHL-like molecules to protect themselves to resist starvation. Moreover,the enhancement of AHL-based QS favored the EPS component productivity of the microorganisms in activated sludge,which contributed to maintain the aerobic granular structure.     

我国雾霾成因及防控策略研究

针对近年来我国雾霾频发的现象,通过对我国雾霾现状、污染物来源分析,阐明雾霾成因及危害,并从监测、评价、控制等角度阐述我国雾霾防控策略。     

基于系统动力学模型的清河流域产业结构优化研究

基于清河流域近年的"经济-社会"现状特点与发展趋势,以2010年为水平基准年,建立清河流域产业结构优化SD模型,将整个系统分为人口及生活子系统、经济子系统、用水子系统和污染物子系统。设置四种情景方案进行模拟,模拟时间为2010年到2020年,通过各个方案结果对比分析选出方案四为最优方案。并根据最优方案提出清河流域产业结构优化的建议,从而为清河流域经济的健康可持续发展提供科学的决策依据。     

基于禀赋与压力的城市环境综合分区理论与方法研究

环境综合分区是城市环境总体规划的主要任务和落实资源合理利用与生态环境保护空间约束的重要手段.基于资源环境禀赋和压力的环境综合分区理论与方法,在生态功能分区和大气环境、水环境、水资源、土地资源分区基础上,提出城市环境综合分区二级区划方案,以大连市为例进行实证研究.根据综合分区方案,针对资源环境问题和发展现状,细化生态保护红线及产业空间准入线,引导城市资源利用与环境保护,更好地指导城市建设与产业发展.     

城市生态红线体系构建及其与管理制度衔接的研究

生态红线对构建科学合理的城镇化格局,保障国家区域生态安全具有重要意义。本文重点解析了生态红线的六大内涵与特征,基于结构的敏感性、过程的脆弱性、功能的重要性,研究提出包括五大领域、四大分区的生态红线体系框架。生态红线只有实现真正的"落地",并配套以完善的管控措施,才能真正实现生态红线维护城市空间格局底线的目的。生态红线可与现有的城市环境管理制度、手段等相结合,为城市环境的精细化、系统化管理提供平台。     

生物技术在挥发性有机化合物处理中的应用研究

介绍了生物技术在挥发性有机化合物处理方面的研究现状和进展,对生物技术的优缺点、分类、影响因素、动力学模型做了详细的说明,并结合近年来的研究状况和存在的问题做出展望。     

纳米银诱导细胞自噬的分子机制和生物效应

细胞自噬对维持细胞的生长代谢以及细胞内环境稳态具有重要意义。近年来,纳米银(silver nanoparticles, AgNPs)与细胞自噬的关系逐渐被揭示。深入了解AgNPs诱导的细胞自噬效应有助于其在医药领域的进一步应用,也能为全面评估AgNPs的纳米毒性提供科学依据。本文重点介绍AgNPs诱导细胞自噬的机制及其涉及的主要信号通路,通过探讨不同理化性质的AgNPs诱导自噬的不同结果及机制,归纳总结AgNPs诱导细胞自噬的生物效应,以期为全面认识AgNPs的自噬效应提供科学依据。     

Spatiotemporal differentiation and the obstacle factors influencing the coupling coordination between economic development and water pollution control capability in the Yangtze River Economic Belt

The Yangtze River Economic Belt (YREB) is a highly influential economic belt and an innovative demonstration belt for the protection and restoration of ecological and environmental systems. The dynamic coordination between economic development system (EDs) and water pollution control capability system (WPCCs) is a critical issue to be solved for regional sustainable development. However, this topic has not been adequately addressed in previous studies. To bridge this gap, this paper analyzed the spatiotemporal differentiation and obstacle factors influencing the coupling coordination between EDs and WPCCs in the Chinese Five-Year Plan based on coupling coordination degree model and obstacle degree model. The main results suggest that (1) the comprehensive level of the comprehensive level of water pollution control capability presents an upward trend with the increase of economic development. A J-shaped relationship existed between the EDs and WPCCs. (2) The regions with rapid economic growth are mainly distributed in the Shanghai, Zhejiang, Jiangsu, Chongqing, and Sichuan. Moreover, water pollution control capability system shows this pattern, eastern regions?>?western regions?>?central regions. (3) The coupling coordination level of each region in the YREB has improved from a moderately unbalanced development level to a superiorly balanced development level from 2006 to 2019. (4) Per capita gross domestic product, gross product of tertiary industry, total volume of waste water treated, and per daily volume treated of sewage treatment facilities are the major indexes influencing the coordinated development of the EDs and WPCCs. These findings are conductive to formulating reasonable strategies for water environment protection and sustainable development and providing a direction for urban planning.

     

企业环境行为管理研究——以H省为例

有效防治工业污染、改善环境是工业企业的基本责任。以能够反映企业环境行为的信息为基础,通过建立科学的百分制量化评价体系,对H省具有代表性和典型性的重点排污工业企业的环境守法行为、企业污染控制行为、环境信息公开行为等环境行为进行评价。分析结果表明,该省企业环境行为有较大提升空间,重污染行业形势令人担忧,由此明确企业改善环境行为的关键因素和影响机制,并从企业、政府、社会三个角度提出措施改善企业环境行为的建议。     

Adsorption of microcystins by carbon nanotubes

The production of cyanobacterial toxins microcystins (MCs) by cyanobacterial bloom which may promote the growth of tumor in human liver is a growing environmental problem worldwide. In this paper, the adsorption of MC-RR and LR, which were extracted from cyanobacterial cells in Dianchi Lake in China, by carbon nanotubes (CNTs), wood-based activated carbon (ACs) and clays were investigated. Compared with ACs and clay materials of sepiolite, kaolinite and talc tested, CNTs were found to have a strong ability in the adsorption of MCs. At the concentrations of 21.5 mg l(-1) MC-RR and 9.6 mg l(-1) MC-LR in 50 mmol phosphate buffer solution (pH 7.0), the adsorption amounts of MCs by CNTs with the range of outside diameter from 2 to 10nm were 14.8 and 5.9 mg g(-1), which were about four times higher than those by other adsorbents tested. It was shown that with the decrease of CNTs outside diameters from 60 to 2 nm, the adsorption amount of MCs was apparently increased, however the size of CNTs particles formed in solution declined. This result implies that the size of CNTs tube pore that is fit for the molecular dimension of MCs plays a dominant role. Furthermore the specific surface area of CNTs was also found to be a factor in the adsorption of MCs. The results suggested that the selection of suitable size of CNTs as a kind of adsorbent is very important in the efficient eliminating MCs from drinking water in future.