臭氧/活性炭联合工艺深度处理焦化废水

采用臭氧/活性炭联合工艺对焦化废水A2/O出水进行深度处理。考察了溶液初始pH值、臭氧投加量、活性炭投加量及使用次数、反应时间对焦化废水处理效果的影响。实验结果表明,活性炭的使用可显著提高臭氧对焦化废水COD的去除率,在溶液初始pH值为10.25、臭氧投加量为7.5 mg/min、活性炭投加量50 g/L、反应时间为30 min条件下,COD去除率达到73.51%。同时,在活性炭重复使用10次时,COD去除率为70.85%,仅降低了2.66%。     

重庆市煤炭资源流动及其未来流量估测

从流量和流向两方面，评估探讨了重庆市煤炭资源流动平衡现状及其面临的问题，并根据对重庆市未来5年外省煤炭输入量的预测值，给出相应的建议。结果表明：（1）重庆市煤炭资源产消失衡，自给率逐年下降，需要大量调入外省煤炭弥补其缺口；重庆市煤炭资源流动比率不断上升，煤炭资源流入强度不断加大，对外依赖性不断加强。（2）经济的快速发展导致重庆市煤炭产需失衡，成为其煤炭资源流动持续增强的根本原因，煤炭资源势差是周边煤炭资源流入重庆的主要因素，距离成本、交通成本和价格差影响着重庆市煤炭供应源的具体选择，从而使距离近、交通通达性较好的四川和贵州成为重庆市主要的两个煤炭供应源。（3）在重庆市外部的煤炭产区中，宁夏、陕西、新疆有望成为重庆市煤炭供应的重要来源，加快陕煤南下以及疆煤入川、渝铁路通道建设是保障重庆乃至整个大西南地区能源供应稳定的重大举措。（4）根据未来5年重庆市外省煤炭输入量的预测结果，指出适当提高公路和水路煤炭运能等措施可解决短时期重庆煤炭紧张的问题。此外，发挥长江黄金水道作用和重庆港口优势，加强储煤基地、煤炭中转码头建设，是保障重庆市未来煤炭供应稳定和能源安全的有效举措     

Response of bacterial communities to mining activity in the alpine area of the Tianshan Mountain region,China

Environmental Science and Pollution Research - Anthropogenic activities, such as mining, influence soil bacterial community composition and microbial distributions. In the current study, the...     

Isolation and characterization of hydrophilic dissolved organic matter in waters by ion exchange solid phase extraction followed by high resolution mass spectrometry

Environmental Chemistry Letters - Dissolved organic matter (DOM) is a complex substance occurring in marine and freshwater environments. DOM has many functions that modify physical, chemical and...     

西葫芦对土壤持久性有机氯化物污染的指示性研究

西葫芦(Cucurbita pepo L.)对土壤中持久性有机氯化物的超强吸收能力已被证实,意味其具有指示区域土壤持久性有机氯化物污染状况的潜能。本研究采用农田小区试验,考察了西葫芦不同组织器官(根、过渡茎、茎、叶和果实)在6个生长期对有机氯化物的累积吸收行为;采用同位素稀释高分辨气相色谱-高分辨质谱法,分析了种植土壤及西葫芦各组织器官中的21种有机氯农药(OCPs)和18种多氯联苯(PCBs)。结果表明,西葫芦可将根吸收的OCPs和PCBs传递到过渡茎和茎。不同生长期采集的西葫芦根、过渡茎和茎中的OCPs和PCBs浓度基本稳定,无明显生物稀释效应,且此3个组织器官中OCPs和PCBs的分布模式与土壤中的分布模式基本一致。因此,可以用西葫芦根和茎中持久性有机氯化物的浓度指示土壤中持久性有机氯化物的污染水平,根和茎的采样时间可以不受西葫芦生长期的限制。     

UV/H2O2工艺降解环丙沙星的研究

采用UV/₂O₂工艺去除水体中的喹诺酮类抗生素环丙沙星（CIP）。考察了溶液pH值、₂O₂投加量以及水体基质对环丙沙星降解效率的影响，分析了降解产物的生成情况。研究表明，环丙沙星的降解符合拟一级反应动力学模型。降解速率受溶液pH值的影响，酸性及中性条件，有利于环丙沙星的降解。₂O₂投加量的增大，使得降解速率逐渐增大，但速率增幅逐渐变缓；最佳₂O₂/环丙沙星摩尔比为2 000。实际水体中存在的NOM、NO^-₃，促进了单独UV作用下，环丙沙星的降解。水体中的?OH焠灭剂，抑制了UV/₂O₂联合作用下，环丙沙星的降解；实际水体中的光解速率常数低于超纯水中的光解速率常数。GC-MS分析表明，UV/₂O₂工艺，使环丙沙星氧化降解生成氨基乙酸、丙二酸、丙三醇和对苯二甲酸等小分子有机物。     

Increased urinary 8-hydroxy-2��-deoxyguanosine levels in workers exposed to di-(2-ethylhexyl) phthalate in a waste plastic recycling site in China

Background

Di-(2-ethylhexyl) phthalate (DEHP) is a common plasticizer used in industrial and diverse consumer products. Animal studies indicate DEHP caused developmental, reproductive, and hepatic toxicities. However, human studies of the potential effects of DEHP are limited.

Methods

The exposed site with a history of over 20 years of waste plastic recycling was located in Hunan Province, China. The reference site without known DEHP pollution source was about 50 km far away from the exposed site. In this study, 181 workers working in plastic waste recycling and 160 gender?Cage matched farmers were recruited. DEHP concentrations in water and cultivated soil samples, serum thyroid-stimulating hormone, malondialdehyde (MDA), superoxide dismutase (SOD), urinary 8-hydroxy-2??-deoxyguanosine (8-OHdG), and micronuclei frequency in human capillary blood lymphocytes were analyzed.

Results

Mean levels of DEHP were greater in environment at the recycling site than at reference site (industry wastewater for the exposed: 42.43 ??g/l; well water: 14.20 vs. 0.79 ??g/l, pond water: 135.68 vs. 0.37 ??g/l, cultivated soil: 13.07 vs. 0.81 mg/kg, p?p?p?Conclusions The occupational DEHP exposure might contribute to oxidative deoxyribonucleic acid damage in the male workers.     

新鲜蔬菜和水果中亚硝酸盐测定方法研究

本文研究了消除新鲜蔬菜和水果中抗坏血酸对亚硝酸盐测定原方法，在样品提取时加入醋酸锌和活性炭，以消除抗坏血酸对测定的干扰，提高了测定的灵敏度和准确必     

Decrease in catalase activity of Folsomia candida fed a Bt rice diet

Here we report the effects of three Bt-rice varieties and their non-Bt conventional isolines on biological traits including survival, reproduction, and the activities of three antioxidant enzymes superoxide dismutase, catalase and peroxidase, in the Collembolan, Folsomia candida. The reproduction was significantly lower when fed Kemingdao and Huahui1 than those feeding on their non-GM near-isogenic varieties Xiushui and Minghui63 respectively, this can be explained by the differences of plant compositions depended on variety of rice. The catalase activity of F. candida was significantly lower when fed the Bt-rice variety Kemingdao compared to the near-isogenic non-Bt-rice variety Xiushui. This suggests that some Bt-rice varieties may impose environmental stress to collembolans. We emphasize that changes in activity of antioxidant enzymes of non-target organisms are important in understanding the ecological consequences for organisms inhabiting transgenic Bt-rice plantations.     

Effects of perfluorooctanoic acid and perfluorooctane sulfonate on acute toxicity,superoxide dismutase,and cellulase activity in the earthworm <Emphasis Type="Italic">Eisenia fetida</Emphasis>

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are the two best-known perfluorinated chemicals and have received much attention due to their ubiquity in the environment. In the present study, we evaluated the effects of PFOS and PFOA on acute toxicity, superoxide dismutase (SOD), and cellulase activities in Eisenia fetida. The results of acute toxicity testing using a filter paper contact test and a natural field soil test showed that PFOA and PFOS exhibited acute toxicity in earthworms, and the toxic effect of PFOS was greater than that of PFOA. The results also showed that avoidance behavior is a more sensitive and easy operation biomarker than acute toxicity and will give us information for early diagnosis of soil pollution, well before the lethal effect becomes apparent. Subchronic exposure to PFOA or PFOS resulted in changes in SOD and cellulase activities in E. fetida, and SOD activity was more sensitive than cellulase activity during early exposure. Based on these findings, we suggest that avoidance behavior and SOD activity in earthworms are suitable biomarkers for evaluating the toxicity of PFOA- and PFOS-contaminated soils. These results indicate that exposure to PFOA and PFOS has a potential impact on soil animals and their environment.