Characterization of the e ective cellulose degrading strain CTL-6

An e cient cellulose degrading bacteria exists in the thermophilic wheat straw-degrading community, WDC2. However, this strain cannot be isolated and cultured using conventional separation techniques under strict anaerobic conditions. We successfully isolated a strain of e ective cellulose degrading bacteria CTL-6 using a wash, heat shock, and solid-liquid alternating process. Analysis of its properties revealed that, although the community containing the strain CTL-6 grew under aerobic conditions, the purified strain CTL-6 only grew under anaerobic culture conditions. The strain CTL-6 had a striking capability of degrading cellulose (80.9% weight loss after 9 days of culture). The highest e ciency value of the endocellulase (CMCase activity) was 0.404 mol/(min mL), cellulose degradation e ciency by CTL-6 was remarkably high at 50–65°C with the highest degradation e ciency observed at 60°C. The 16S rRNA gene sequence analysis indicated that the closest relative to strain CTL-6 belonged to the genus Clostridium thermocellum. Strain CTL-6 was capable of utilizing cellulose, cellobiose, and glucose. Strain CTL-6 also grew with Sorbitol as the sole carbon source, whereas C. thermocellum is unable to do so.     

Denitrification of coking wastewater with micro-electrolysis

The denitrification for the coking wastewater was conducted by means of original battery principle with Fe-C micro-electrolysis. Fe-C serves as positive and negative electrodes, by which N0₂^?-N and TN were reduced to nitrogen, and then the purpose of denitrifieation for coking wastewater was realized. The influences of pH value, carbon particle size, Fe/C ratio (mass ratio), reaction time and coagulation pH value on removal rate of N0₂^?-N and TN were investigated. Coking wastewater originated from Jiamusi Coal Chemistry Engineering Company. The optimum conditions of treatment were as follows: the initial pH was 3.0, the dosage of Fe 73.5 g/L, reaction time 70 min, mass ratio of Fe/C ratio 1.0:1.3, coagulation pH 9.0 and sedimentation time 40 min. Under those conditions, nitrogen removal efficiencies of N0₂^?-N and TN were beyond 50% and 45%, respectively.     

新时期环境影响评价公众参与有效性研究

简要回顾了中国环境影响评价（EIA）公众参与的历程,以十大经典案例引出公众参与存在的问题,然后从EIA公众参与的程序和过程对这些问题进行了系统的分析,进而提出了一些有针对性的措施。认为建立起一套基于环境信息公开透明基础上的各方对话沟通与利益协调机制是提升中国EIA＆众参与水平的有效措施。需要指出的是：EIA＆众参与有效性的提高,并不仅是技术或者态度的问题,它是一项系统工程,牵涉面广,需要解决好各环节的问题,包括深层次的问题。     

Recent advances on porous organic frameworks for the adsorptive removal of hazardous materials

Environmental pollution is one of the most serious problems facing mankind today,and has attracted widespread attention worldwide. The burgeoning class of crystalline porous organic framework materials, metal–organic frameworks and covalent organic frameworks present promising application potential in areas related to pollution control due to their interesting surface properties. In this review, the literature of the past five years on the adsorptive removal of various hazardous materials, mainly including heavy metal ions, harmful gases, organic dyes, pharmaceutical and personal care products, and radionuclides from the environment by using COFs and MOFs, is summarized. The adsorption mechanisms are also discussed to help understand their adsorption performance and selectivity. Additionally, some insightful suggestions are given to enhance the performance of MOFs and COFs in the adsorptive removal of various hazardous materials.     

渗滤液中溶解性荧光有机物与铅的作用

采用荧光光谱和猝灭滴定实验,结合二维相关分析和区域体积积分分析,研究了生活垃圾渗滤液不同处理阶段样品中溶解性荧光有机物(DFOM)络合Pb(Ⅱ)的特性.结果显示:渗滤液中无机阴离子对Pb(Ⅱ)猝灭DFOM荧光影响较大,它们的存在致使Pb(Ⅱ)对DFOM的荧光猝灭效果不明显.在渗滤液DFOM的各种荧光基团中,Pb(Ⅱ)对类蛋白类物质的荧光猝灭效率高,而对类腐殖质物质的荧光猝灭效率低,这种猝灭特征不随渗滤液处理进行而改变;但Pb(Ⅱ)对调节池和厌氧处理中可溶性微生物降解副产物的荧光猝灭效率低而对氧化沟和MBR出水中DFOM的荧光猝灭效率高.分析结果表明,渗滤液DFOM中类蛋白物质络合Pb(Ⅱ)能力大于类腐殖质物质,经好氧生物处理后,可溶性微生物降解副产物络合Pb(Ⅱ)的能力有所提高.     

Synergistic effect of N- and F-codoping on the structure and photocatalytic performance of TiO2

Three types of TiO₂ nanostructures were synthesized via a facile hydrolysis method at 195 °C. Effects of the preparation method and doping with N and F on the crystal structure and photocatalytic performance of TiO₂ were investigated. The nanomaterials were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller porosimetry, ultraviolet–visible diffuse reflectance spectroscopy and fluorescent emission spectra. Their photo-catalytic activity was examined by the photodegradation of methylene blue in aqueous solution under both ultra-violet and visible light irradiation. The results show that nitrogen and fluorine co-doped anatase TiO₂ had the characteristics of a smaller crystalline size, broader light absorption spectrum and lower charge recombination than pure TiO₂. Most importantly, more efficient photocatalytic activity under both ultra-violet and visible light was observed. The obtained N–F-TiO₂ nanomaterial shows considerable potential for water treatment under sunlight irradiation.     

Development,hotspots and trend directions of groundwater salinization research in both coastal and inland areas: a bibliometric and visualization analysis from 1970 to 2021

Environmental Science and Pollution Research - As a global concern, the issue of groundwater salinization refers to the phenomenon of an increase in the overall chemical content over background...     

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.

     

The association between heavy metal soil pollution and stomach cancer: a case study in Hangzhou City,China

Stomach cancer (SC) is a severe health burden, with nearly half of the world’s cases found in China. Noticeably, the emissions of heavy metals into the environment have increased alongside rapid urbanization and industrialization in China. However, as regards carcinogenic associations, the relationship between heavy metals and SC is yet unclear. Based on 9378 newly diagnosed SC cases in Hangzhou City from 2009 to 2012, this work is concerned with the quantitative characterization of the spatial distribution pattern of SC incidence and its geographical association with soil heavy metals by means of a novel geographical model. The results show that (a) Cd is one of the severe soil pollutants in Hangzhou; (b) higher SC incidence clusters are in central Hangzhou, whereas lower clusters are found in the northeast and southwest with a male to female incidence ratio about 2.2:1; (c) although when considered separately, the heavy metals in this work do not have a considerable impact on the distribution of SC incidence in Hangzhou City, nevertheless, the joint effects of multiple heavy metals have significant impacts on SC risk. The present work calls for a rigorous quantitative assessment of the integrated heavy metal soil pollution and its effects on SC incidence.     

利用重质稠油生产沥青的VOCs排放特征

沥青生产是重要的石化行业子行业之一,目前尚缺乏针对该行业VOCs排放的相关研究.为探明沥青生产行业VOCs的排放特征,选取以重质稠油为原料生产沥青的某典型企业,主要采集有组织和无组织排放工序环节的样品,通过GC-MS定量检测了65种VOCs.结果表明,该企业沥青生产的VOCs排放浓度为37.28~7528.00 μg·m^-3,无组织排放和有组织排放VOCs均以烷烃为主,浓度占比超过50%,而有组织排放废气经末端治理设施处理后芳香烃贡献增加.乙烷、丙烷、正丁烷、异丁烷、正戊烷、异戊烷、环戊烷、正己烷、甲基环戊烷、环己烷、甲基环己烷、乙烯、1-丁烯、苯、甲苯、间二甲苯、邻二甲苯为该企业沥青生产过程的特征VOCs组分.沥青生产行业VOCs排放主要来自无组织排放,其中,95%的VOCs无组织排放来源于储罐区的呼吸损耗,为161.65 t·a^-1,其次为装卸平台,挥发量为9.42 t·a^-1.对无组织排放环节的管控应该成为沥青生产行业的管控重点.