Environmental decentralization,environmental public service,and public health: evidence from 289 cities in China

Environmental Geochemistry and Health - Effective supply of environmental public services (EPS) is important to guarantee the mitigation of residential pollution exposure risk. This study analyzes...     

Recycling sewage sludge into ceramic materials: A review

Environmental Chemistry Letters - Huge amounts of unwanted sewage sludge are generated in the process of wastewater treatment, calling for methods to recycle sewage sludges into value-added...     

Preparation and Characterization of Collagens from the Skin of Northern Snakehead (<Emphasis Type="Italic">Channa argus)</Emphasis>

Channa argus, a type of snakehead fish native to China, is a popular food fish in certain Asian countries but is a known destructive invasive species in the US. In this study, the two collagens, i.e. acid-soluble collagen (ASC) and pepsin-solubilized collagen (PSC), were obtained from C. argus skin. The yield of ASC was 28.0% and that of PSC was 16.8% on the dry bases. The collagens were identified as the collagen of type I by SDS–PAGE patterns. The Tds were approximately 27.0?°C. Similar ultraviolet spectra of both collagens were observed. Fourier Transform infrared spectra indicated PSC structure had a little change due to the loss of terminal domains by pepsin digestion. The results of XRD proved that the two collagens retained their helical structures. The results suggest that the collagens isolated from C. argus can potentially be alternative sources of vertebrate collagens for use in the food and other industries.     

Enhanced debromination of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) by zero-valent zinc with ascorbic acid

• Highly efficient debromination of BDE-47 was achieved in the ZVZ/AA system. • BDE-47 debromination by the ZVZ/AA can be applied to a wide range of pH. • AA inhibits the formation of (hydr)oxide and accelerates the corrosion of ZVZ. • Reduction mechanism of BDE-47 debromination by the ZVZ/AA system was proposed. A new technique of zero-valent zinc coupled with ascorbic acid (ZVZ/AA) was developed and applied to debrominate the 2,2′,4,4′-Tetrabromodiphenyl ether (BDE-47), which achieved high conversion and rapid debromination of BDE-47 to less- or non-toxic forms. The reaction conditions were optimized by the addition of 100 mg/L ZVZ particles and 3 mmol/L AA at original solution pH= 4.00 using the solvent of methanol/H₂O (v:v= 4:6), which could convert approximately 94% of 5 mg/L BDE-47 into lower-brominated diphenyl ethers within a 90 min at the ZVZ/AA system. The high debromination of BDE-47 was mainly attributed to the effect of AA that inhibits the formation of Zn(II)(hydr)oxide passivation layers and promotes the corrosion of ZVZ, which leads to increase the reactivity of ZVZ. Additionally, ion chromatography and gas chromatography mass spectrometry analyses revealed that bromine ion and lower-debromination diphenyl ethers formed during the reduction of BDE-47. Furthermore, based on the generation of the intermediates products, and its concentration changes over time, it was proposed that the dominant pathway for conversion of BDE-47 was sequential debromination and the final products were diphenyl ethers. These results suggested that the ZVZ/AA system has the potential for highly efficient debromination of BDE-47 from wastewater.     

Magnetotactic bacteria: Characteristics and environmental applications

• Magnetotactic bacteria (MTB) synthesize magnetic nanoparticle within magnetosomes. • The morphologic and phylogenetic diversity of MTB were summarized. • Isolation and mass cultivation of MTB deserve extensive research for applications. • MTB can remove heavy metals, radionuclides, and organic pollutants from wastewater. Magnetotactic bacteria (MTB) are a group of Gram-negative prokaryotes that respond to the geomagnetic field. This unique property is attributed to the intracellular magnetosomes, which contains membrane-bound nanocrystals of magnetic iron minerals. This review summarizes the most recent advances in MTB, magnetosomes, and their potential applications especially the environmental pollutant control or remediation. The morphologic and phylogenetic diversity of MTB were first introduced, followed by a critical review of isolation and cultivation methods. Past research has devoted to optimize the factors, such as oxygen, carbon source, nitrogen source, nutrient broth, iron source, and mineral elements for the growth of MTB. Besides the applications of MTB in modern biological and medical fields, little attention was made on the environmental applications of MTB for wastewater treatment, which has been summarized in this review. For example, applications of MTB as adsorbents have resulted in a novel magnetic separation technology for removal of heavy metals or organic pollutants in wastewater. In addition, we summarized the current advance on pathogen removal and detection of endocrine disruptor which can inspire new insights toward sustainable engineering and practices. Finally, the new perspectives and possible directions for future studies are recommended, such as isolation of MTB, genetic modification of MTB for mass production and new environmental applications. The ultimate objective of this review is to promote the applications of MTB and magnetosomes in the environmental fields.     

Prediction of half-life for adsorption kinetics in a batch reactor

Environmental Science and Pollution Research - Besides adsorption rate constant, the half-life was also a basic factor that described the characteristics of adsorption kinetics. However, the direct...     

表面活性剂对焦化污染土壤中多环芳烃淋洗修复研究

异位土壤淋洗是一种高效修复污染土壤技术。以孝义市某焦化厂污染土壤为研究对象,采用批处理实验,探究表面活性剂曲拉通-100(TX-100)、吐温80(TW80)、烷基糖苷(APG)作为淋洗剂对土壤中16种多环芳烃(PAHs)的淋洗效果,并以TW80为代表,考察了淋洗剂浓度、淋洗时间、pH以及淋洗方式对污染土壤中PAHs的去除效果。结果表明,TW80、TX-100和APG对土壤中16种PAHs的总去除率分别为25.67%、18.89%和16.77%。TW80作为淋洗剂,3环PAHs的去除率低于高环(3环)PAHs,主要与焦化污染土壤中以3环PAHs为主有关;高环PAHs随着环数的增加,去除率降低。焦化污染土壤中PAHs的去除在240min达到平衡;大部分PAHs去除率随TW80浓度的增加而增大;pH可不作调整;在TW80用量相同情况下,建议采用单次淋洗。     

呼吸效应对矿井封闭火区氧浓度的影响分析

为避免因火区封闭导致重大安全事故发生，通过采集某矿井1 d内3个不同监测点的大气压力变化情况，建立大气压力波动模型并分析计算，同时建立火区内外压差100，750 Pa情形下的氧浓度模型进而获得火区内侧氧气浓度因呼吸效应，在不同压差、体积大小火区、风阻、瓦斯涌出量、封闭时刻等多因素耦合影响下随时间的变化规律，以评估火区危险性。研究结果表明:井下大气随地面大气周期波动，封闭火区内、外侧之间的气压差因外界大气波动呈现16 h的余弦波动和8 h的线性波动周期变化；密闭质量好的火区具有更好地抗干扰性，内侧氧浓度的降低主要依靠瓦斯稀释；密闭质量差的火区，内侧氧浓度易受到火区涌出瓦斯、外界涌入大气双重影响；火区氧浓度在2%~12%之间波动，以至火区存在发生瓦斯爆炸的可能性；火区内外压差较大时，氧浓度波动变化幅度更大，危险作用持续时间更长。结合火区氧浓度波动模型，可有效地对矿井火区采取安全的防范措施，避免瓦斯爆炸事故发生。     

内窥镜检查在电站锅炉内部检验中的应用

工业内窥镜是电站锅炉内部检验中不可或缺的设备,主要用来对集箱、减温器、受热面管等内部人眼无法观察到的地方进行检验,从而确定承压部件内部是否存在严重影响锅炉安全运行的缺陷.本文通过对锅炉内窥实例进行分析和总结,阐述内窥镜检查在锅炉内检中的重要性并给相关工作人员提供借鉴与参考.     

含锌废物综合利用项目环境影响评价工程探索

工业生产的废物当中包含多种重金属,例如钢铁厂的粉尘当中就含有锌。含锌粉尘不仅会在高炉内循环和富集,影响高炉的运行,还会造成环境污染。基于此,本文主要分析含锌废物综合利用,对该项目进行环境评价,探讨有效的对策,以提高含锌废物综合利用的科学性,提高环境保护等级。