聚乙烯及其废料油化技术中催化剂的研制与性能研究

本文研究了几种自制催化剂对聚乙烯热解产物的催化改质作用,催化反应温度与催化剂性质对催化改质所得气体收率及组成、汽油收率及辛烷值、柴油收率以及催化剂积碳的影响,探讨了适合聚乙烯及其废料热解产物催化改质的催化剂应具备的特性及热解产物在催化剂上反应的类型,同时探讨了本研究对废塑料油化技术的指导作用。应用此催化剂液体收率可达８０％以上,汽油辛烷值为８２（ＲＯＮ）。     

烷基苯磺酸钠对水生动物的生物效应研究

本文通过洗涤剂的主要成分—烷基苯磺酸钠对大型蚤和鲤鱼的毒性试验,说明烷基苯磺酸钠的毒性属中等。对大型蚤２４ｈＥＣ５０为７．２３ｍｇ／Ｌ,４８ｈＥＣ５０为３．８３ｍｇ／Ｌ;对鲤鱼４８ｈＬＣ５０为３．７４ｍｇ／Ｌ,９６ｈＬＣ５０为２．２３ｍｇ／Ｌ。鲤鱼生活在０．５ｍｇ／Ｌ的烷基苯磺酸钠溶液中,１５ｄ就能引起鳃的损伤。     

小城镇生态监测指标体系及监测方法研究综述

阐述了小城镇开展生态监测的目的和意义,以及小城镇生态监测指标体系的建立原则,介绍了城市生态子系统环境监测指标体系、农村生态子系统环境监测指标体系和自然生态子系统环境监测指标体系的具体内容,以及相关的监测方法与技术。     

苯甲酸生产废水的处理与资源化

为有效地回收甲苯液相氧化法生产苯甲酸的工业废水中的苯甲酸和乙酸,并配合废水生物降解的末端处理技术,研究了20%,30%和50%磷酸三丁酯(TBP)/煤油的混合溶剂、正辛醇和甲苯萃取苯甲酸稀溶液特性,以及对工业废水处理的实验.结果表明,TBP对苯甲酸稀溶液具有良好的萃取作用,而纯溶剂体系与溶剂的极性有关,正辛醇的萃取能力与30%TBP相当;残液中的COD_Cr值由萃取剂在水中的溶解和苯甲酸自身的COD_Cr值组成,其中残液中溶剂溶解导致的COD_Cr值随其中苯甲酸浓度变化不明显,且COD_Cr值的大小为:50%TBP≈30%TBP>正辛醇>20%TBP>甲苯.针对工业废水中主要含有苯甲酸和乙酸的工况,提出了废水资源化的处理工艺流程,即首先采用甲苯进行废水中苯甲酸的回收,之后,再利用三烷基氧磷/煤油为萃取剂回收废水中的醋酸,进一步生产绿色化学品乙酸钙镁盐.     

环境信息系统研究

环境信息系统是提高环境管理水平的重要手段。对国内外环境信息系统研究现状进行综述 ,分析国内外研究存在的问题 ,讨论环境信息系统研究的未来发展趋势     

生态修复:从民事法律责任到行政法律义务

生态修复是救济生态环境损害的方式,或体现为民事法律责任,或体现为行政法律义务.作为民事法律责任的生态修复体现了以环境权为权源通过民事法律规范以司法途径救济生态环境损害的救济方式,作为行政法律义务的生态修复体现了"行政命令+行政处罚+代履行"的生态环境损害救济方式.将生态修复作为民事法律责任是目前的主流做法,但将生态修复...     

Mechanism and characterization of microplastic aging process: A review

● Methods for estimating the aging of environmental micro-plastics were highlighted. ● Aging pathways & characterization methods of microplastics were related and reviewed. ● Possible approaches to reduce the contamination of microplastics were proposed. ● The prospect and deficiency of degradable plastics were analyzed. With the increasing production of petroleum-based plastics, the problem of environmental pollution caused by plastics has aroused widespread concern. Microplastics, which are formed by the fragmentation of macro plastics, are bio-accumulate easily due to their small size and slow degradation under natural conditions. The aging of plastics is an inevitable process for their degradation and enhancement of adsorption performance toward pollutants due to a series of changes in their physiochemical properties, which significantly increase the toxicity and harm of plastics. Therefore, studies should focus on the aging process of microplastics through reasonable characterization methods to promote the aging process and prevent white pollution. This review summarizes the latest progress in natural aging process and characterization methods to determine the natural aging mechanism of microplastics. In addition, recent advances in the artificial aging of microplastic pollutants are reviewed. The degradation status and by-products of biodegradable plastics in the natural environment and whether they can truly solve the plastic pollution problem have been discussed. Findings from the literature pointed out that the aging process of microplastics lacks professional and exclusive characterization methods, which include qualitative and quantitative analyses. To lessen the toxicity of microplastics in the environment, future research directions have been suggested based on existing problems in the current research. This review could provide a systematic reference for in-depth exploration of the aging mechanism and behavior of microplastics in natural and artificial systems.     

Evaluation of activated sludge properties’ changes in industrial-wastewater pre-treatment: role of residual aluminum hydrolyzed species with different polymerization degree

● Medium poly Al salts dominated the PAC residual salts with a rational dosage. ● Settlement flocculation effect under medium poly Al salts showed a better trend. ● Complex of medium poly Al salts and enzymes promoted cell activity. ● Medium poly Al salts were beneficial to the effluent indexes. With the widespread introduction of pre-coagulation prior to the biological unit in various industrial wastewater treatments, it is noteworthy that long-term accumulation of residual coagulants has certains effect on both micro and macro characteristics of activated sludge (AS). In this study, the morphology distributions of residual aluminum salts (RAS) and their effects on the removal efficiency of AS were investigated under different PAC concentrations. The results showed that the dominance of medium polymeric RAS, formed under an appropriate PAC dose of 20 mg/L enhanced the hydrophobicity, flocculation, and sedimentation performances of AS, as well as the enzymatic activity in cells in the sludge system, improving the main pollutants removal efficiency of the treatment system. Comparatively the species composition with monomer and dimer / high polymer RAS as the overwhelming parts under an over-dosed PAC concentration of 55 mg/L resulted in excessive secretion of EPS with loose flocs structure and conspicuous inhibition of cellular activity, leading to the deterioration of physico-chemical and biological properties of AS. Based on these findings, this study can shed light on the role of the RAS hydrolyzed species distributions, closely relevant to Al dosage, in affecting the comprehensive properties of AS and provide a theoretical reference for coagulants dosage precise control in the pretreatment of industrial wastewater.     

Screening of indicator pharmaceuticals and personal care products in landfill leachates: a case study in Shanghai,China

● A systematic framework was developed to identify i-PPCPs for landfill leachate. ● The wide-scope target analysis offered a basis for comprehensive i-PPCP screening. ● Source-specificity and representativeness analysis helped to refine i-PPCPs. ● Erythromycin, gemfibrozil and albendazole were identified as i-PPCPs for leachate. Identifying potential sources of pharmaceuticals and personal care products (PPCPs) in the environment is critical for the effective control of PPCP contamination. Landfill leachate is an important source of PPCPs in water; however, it has barely been involved in source apportionment due to the lack of indicator-PPCPs (i-PPCPs) in landfill leachates. This study provides the first systematic framework for identifying i-PPCPs for landfill leachates based on the wide-scope target monitoring of PPCPs. The number of target PPCPs increased from < 20 in previous studies to 68 in the present study. Fifty-nine PPCPs were detected, with median concentrations in leachate samples ranging from below the method quantification limit (MQL) to 41 μg/L, and 19 of them were rarely reported previously. A total of 29 target compounds were determined to be PPCPs of high concern by principal component analysis according to multiple criteria, including occurrence, exposure potential, and ecological effect. Coupled with source-specificity and representativeness analysis, erythromycin, gemfibrozil, and albendazole showed a significant difference in their occurrence in leachate compared to other potential sources (untreated and treated municipal wastewater and livestock wastewater) and correlated with total PPCP concentrations; these were recommended as i-PPCPs for leachates. Indicator screening procedure can be used to develop a sophisticated source apportionment method to identify sources of PPCPs from adjacent landfills.