引滦水中不同形态天然有机物的卤代活性

用过滤、ＸＡＤ树脂吸附和阴离子树脂吸附等方法将引滦水中的天然有机物分离为悬浮态、憎水化合物、腐殖酸类化合物、非腐殖酸类阴离子化合物和其它亲水化合物。分别对不同形态有机物进行氯化处理，测定了产物中的挥发性卤代烃。结果表明，引滦水中天然有机物的主要氯化产物是氯仿和一溴二氯甲烷，此外还生成少量二溴一氯甲烷。悬浮态有机物和溶解态腐殖酸是生成氯仿的最重要母体，一溴二氯甲烷和二溴一氯甲烷则大多来源于溶解态腐殖     

若干典型岩性区域沉积物金属元素地球化学特征比较研究

研究了４种成片分布的典型岩性（页岩、石灰岩、花岗岩、黄土）区域沉积物金属元素（Ｌｉ、Ｎａ、Ｋ、Ｃａ、Ｓｒ、Ｂａ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕ、Ｚｎ、Ａｌ等共１６种）总量与形态特征．结果表明：这４种岩性区域沉积物金属元素含量与形态均有显著的差别．与其它岩性相比，黄土地区易迁移元素含量高，而重金属含量显著较低；其金属元素残渣态含量高，而有机态、铁锰氧化物态和可交换态含量低．石灰岩地区重金属含量较高，而易迁移元素如Ｎａ，Ｓｒ等含量则较低；其重金属元素残渣态含量不偏低，表明经风化作用释放出来的重金属参与了次生矿物的形成过程而得以富集．花岗岩地区重金属含量居中，而Ｆｅ和Ａｌ含量较高；其金属元素残渣态含量不偏高则与风化作用较强有关．页岩地区元素含量与形态均居中，代表了各种岩性的平均水平．     

水库沉积物贫营养型好氧反硝化菌(Pseudomonas sp.)分离及其对微污染水体脱氮效率分析

为探究深水水库沉积物微生物功能特征及利用价值,于2019年在实验室对小湾水库表层沉积物微生物进行了驯化分离,并分析了其中一株细菌的脱氮效率.结果表明,分离出的细菌XW731经鉴定属于假单胞菌属（Pseudomonas sp.）,是一种贫营养型好氧反硝化菌;在分别以NH₄⁺-N、NO₃^--N和NO₂^--N为唯一氮源时,该菌对NH₄⁺-N、NO₃^--N和NO₂^--N去除率分别为33.6%、68.5%和9.1%;以NH₄⁺-N和NO₃^--N为氮源时,对NH₄⁺-N和NO₃^--N去除率分别为66.4%、89.6%,同步硝化反硝化能力更强.将该菌投加到两种城市微污染水体后测试表明,该菌对城市河道水体的NH₄⁺-N和NO₃^--N去除率分别为38.3%和42.4%,对城市降雨水体的NH₄⁺-N和NO₃^--N去除率分别为22.2%和7.7%.     

Extraction of heavy metals from e-waste contaminated soils using EDDS

Environmental contamination due to uncontrolled e-waste recycling activities is drawing increasing attention in the world. Extraction of these metals with biodegradable chelant [S,S]-ethylenediaminedisuccinic acid (EDDS) and the factors influencing extraction efficacy were investigated in the present study. Results showed that the addition of EDDS at low pH (5.5) produced higher metal extraction than that at high pH (8.0) solution. Metal speciation analysis indicated that Cu was completely complexed with EDDS at different pH conditions with various amounts of EDDS applied. For Pb and Zn, at low EDDS dose of 0.304 mol/kg soil, they were present as Pb- and Zn-EDDS. However, at high EDDS dose of 1.26 mol/kg soil, most of Pb was bound with dissolved organic matter. Ca and Al were found to be strong competitors for trace metals to EDDS at low application dose and low pH condition.     

生物过滤法净化垃圾填埋场温室气体甲烷的研究进展

生物过滤法是一种低费用、无二次污染的减少垃圾填埋场温室气体甲烷排放的方式,是垃圾填埋气净化的一种很好的选择.介绍了净化垃圾填埋场甲烷的生物过滤器类型及甲烷氧化微生物,概述了生物过滤器氧化甲烷的影响因素、操作条件,并分析了其发展趋势.     

Quantification of the Exposure–Lag–Response Association Between Air Pollution and Respiratory Disease Morbidity in Chongqing City,China

Environmental Modeling & Assessment - The health effects of air pollution on respiratory disease morbidity and mortality commonly vary with air pollutants’ intensity and latency after...     

Up-regulation of contractile endothelin receptors by airborne fine particulate matter in rat mesenteric arteries via activation of MAPK pathway

Fine particle matters (PM_2.5) is a well-known risk factor for cardiovascular diseases. However, the underlying molecular mechanisms are largely unknown. Vascular hyper-reactivity plays an important roles in the pathogenesis of cardiovascular diseases. The present study was designed to investigate a hypothesis that PM_2.5 up-regulated endothelin receptors in mesenteric artery and the potential underlying mechanisms. Rat mesenteric arteries were cultured with PM_2.5. The artery contractile responses were recorded by a sensitive myograph. ET_B and ET_A receptor expressions of mRNA and protein were assessed by quantitative real-time PCR, Western blotting, and immunohistochemistry, respectively. Results showed that ET_B receptor agonist, sarafotoxin 6c induced a negligible contraction in fresh artery segments, while ET_A receptor agonist, ET-1 induced an obvious contraction. After organ culture, the contraction curve mediated by ET_B and ET_A receptors were shifted toward the left. PM_2.5 1.0 μg/ml cultured for 16 h further enhanced ET_B and ET_A receptor-mediated contractile responses with a markedly increased maximal contraction. The organ culture enhanced ET_B and ET_A receptor mRNA and protein levels from fresh arteries, which were further increased by PM_2.5. The U0126 (MEK/ERK1/2 inhibitor) and SB203580 (p38 inhibitor) significantly attenuated both organ cultured-induced and PM_2.5-induced up-regulation of ET_B receptor. U0126 also suppressed organ culture-increased and PM_2.5-increased expressions of ET_A receptor. SB203580 only suppressed PM_2.5-induced enhanced expressions of ET_A receptor In conclusion, airborne PM_2.5 up-regulates ET_B and ET_A receptors of mesenteric artery via p38 MAPK and MEK/ERK1/2 MAPK pathways.

     

Effects of fuel types and fuel sulfur content on the characteristics of particulate emissions in marine low-speed diesel engine

Environmental Science and Pollution Research - The emission of particulate matter from ships does great harm to human health and atmospheric environment. Sulfur emission regulations also affect...     

Characterizing interactions of socioeconomic development and environmental impact at a watershed scale

Environmental Science and Pollution Research - Worldwide socioeconomic development has resulted in huge irretrievable environmental problems in various ecosystems. This study employed seven coastal...     

A living mechanical file: the burrowing mechanism of the coral-boring bivalve Lithophaga nigra

The burrowing mechanism of a coral borer, Lithophaga nigra, from Penhu island was studied from 1984–1985. Chemical analysis, behavioral observation, anatomy, functional morphology and electronmicroscopic data revealed that this organism is not a chemical borer, as previously believed, but a mechanical borer with a very specially modified internal organ and an external shell configuration that enables it to function as an extremely efficient regenerative mechanical file.