The combination of chemical,structural, and functional indicators to evaluate the anthropogenic impacts on agricultural stream ecosystems

Environmental Science and Pollution Research - Freshwater contamination by pesticides in agricultural landscapes is of increasing concern worldwide, with strong pesticide impacts on biodiversity,...     

Monitoring and evaluation of antibiotic resistance genes in three rivers in northeast China

Environmental Science and Pollution Research - Antibiotic resistance genes (ARGs) have become an important public health problem. In this study, we used metagenomic sequencing to analyze the...     

纺织印染厂废水的深度处理中试及工程应用

采用曝气生物滤池(BAF)-臭氧-曝气生物滤池工艺对广东某大型纺织印染厂的常规水解酸化-接触生物氧化处理出水进行深度处理回用中试,在中试研究成功的基础上,设计了每小时处理5 t的工业化试验装置。试验运行结果表明:进水COD为100~150 mg/L,色度约80倍,浊度约10 NTU,在前BAF水力停留时间3 h,中间化学氧化池中臭氧投加量40 mg/L,后BAF水力停留时间2 h的情况下,经组合工艺处理后出水COD约30 mg/L,色度2倍,浊度<1 NTU,该工艺处理后的出水,可直接回用于对电解质浓度要求不高的生产工艺中,也可作为反渗透或纳滤膜的预处理工序。     

环氧化合物分子结构与致变活性的关系

由化学物质毒性效应登录(RTECS)1998年光盘系统检索获得86种环氧化合物对鼠沙门氏菌致变活性数据.应用主成分分析法从11种分子描述符中选择出5种对致变活性有明显影响的描述符:碳原子数,苯环数,氢原子数,烷基数和氧原子数.通过样本学习集训练并优化神经网络结构,建模分类预报:对于86个样本,低和高2类活性,正确分类率达到92%.结果表明:3～4个骈接苯环的环氧化物的特殊结构具有很强的致变活性.     

100年来东湖富营养化发生的沉积学记录

在210Pb计年的基础上,运用水生生物遗存、色素、有机碳同位素和磁化率分析了东湖钻孔沉积物中的生物与环境信息,重建了东湖100多年来湖泊营养与环境演化历史.研究发现东湖100多年来在人类活动不断增强的背景下,指示重金属污染的磁化率和指示湖泊富营养化的色素指标如蓝藻叶黄素(Myx)、颤藻黄素(Osc)快速上升,相应的水生生物如介形虫、腹足类、水生高等植物等表现明显的组合和变化阶段,同时有机碳同位素偏正与湖泊生产力升高和藻类繁盛有关.沉积记录表明东湖生态系统近代发生了深刻变化,湖泊营养演化自早至晚呈现四阶段性:贫营养阶段(1900-1966AD)色素水平低、拥有较丰富的水生高等植物和腹足类;中营养阶段(1966-1983AD)色素含量增高、水生高等植物和腹足类减少;富营养化阶段(1983-1989AD)色素含量快速增高、水生高等植物消失;超富营养化阶段(1989AD－至今)色素含量稳定居高、某些耐污染的介形类较繁盛.结果对于认识湖泊生态环境演化与人类活动的关系、以及如何治理湖泊环境具有现实的意义.     

新型异养氨氧化菌的分离鉴定及氨氧化特性

从青岛海岸采集淤泥．通过富集培养,以硅胶平板点种分离．经纯化得到一株氨氧化菌H9菌株。该菌可以在营养培养基中生长,是一株异养氨氧化菌,经形态、生理生化特性、16SrRNA序列分析等初步鉴定该菌属于假诺卡氏菌属（Pseudonocardia sp．H9）。该菌株具有将氨氧化为硝酸的能力,明显不同于自养型的硝化作用过程需要亚硝化细菌和硝化细菌的密切协作才能把氨氧化成硝酸的特点。此外,该菌可以在无有机碳的培养基或在有机碳C／N达7或更高的培养基中氧化氨至硝酸;在亚硝化培养基与LB的混合培养基中,在LB占15％以下时,LB越高越有利于氨的氧化和菌的生长。该菌株的生长和氧化氨的最适温度为30℃;pH5．0～10．0,最适为8．0;氨离子摩尔浓度1～40mmol／L,最适为8mmol／L;氯化钠质量分数为0％～8％,最适为3．5％。由于该菌株具有以上的特性和优点．在污水的脱氮处理以及养殖海水的氨氮处理中有较高的应用前景,同时也是研究氨的生物氧化机制的理想菌株。     

有机离子载入-复焙烧失法制备新型净水材料

探索了一种制备介孔复合净水材料的新方法——载入有机离子一复焙烧失法。通过实验得到的最佳工艺参数为：有机载入剂为CTMAB,有机载入剂(质量浓度5g/L)加入量4mL／g,有机离子交换反应时间2h,反应温度40℃,复焙烧失温度230℃,复焙烧失时间1．5h。在最佳工艺条件下制备的净水材料对色度为7400倍、COD为3040mg／L的染料废水的脱色率为98．9％,略优于杏壳活性炭的脱色率(98．2％);COD去除率为91．3％,与杏壳活性炭的COD去除率91．7％相差无几。净水材料的染料吸附量是添加剂升温烧蚀后产品的近85倍,是酸洗刻蚀后产品的近590倍,是原材料的900多倍,其对染料废水的净化能力整体优于杏壳活性炭。     

冷却-高压静电一体化技术在高温定型机油烟废气净化中的应用

采用冷却-高压静电一体化技术处理印染企业的高温定型机油烟废气,将蒸发冷却、间接水冷、高压静电法集成一体.弥补了传统水喷淋技术与湿法静电技术存在二次污染的不足.通过优化参数,提高了污染物去除率和废油,余热的回收率,白坯布高温定型机每天每台可回收废油188 kg.     

Rhodobacter sp. NP25b菌株缺氧降解壬基酚聚氧乙烯醚的研究

从城市污水处理厂活性污泥中分离得到一株能够在缺氧条件下以壬基酚聚氧乙烯醚(NPEOs)为惟一碳源和能源生长的菌株NP25b.经生理生化鉴定和16S rRNA基因序列分析,该菌株属于红细菌属(Rhodobacter sp.),对该菌株降解NPEOs的特性进行了研究.结果表明,在缺氧条件下,菌株NP25b在7 d内对初始底物浓度为400 mg/L NPEOs的降解率可达84%.利用液相色谱-质谱(LC-MS)和气相色谱-质谱(GC-MS)对NPEOs降解中间产物进行了分析,结果表明,主要降解产物为短链NPEOs和壬基酚聚氧乙烯醚乙酸(NPECs),其中包括具有较强内分泌干扰效应的NP1EO.该菌株能够代谢含有疏水基团的聚氧乙烯醚类表面活性剂,例如辛基酚聚氧乙烯醚和脂肪醇聚氧乙烯醚.推测菌株NP25b降解NPEOs是通过乙氧基(EO)链末端氧化后逐步切割完成的.     

Diffusion pollution from livestock and poultry rearing in the Yangtze Delta,China

BACKGROUND: The Yangtze Delta is one of the most developed regions in China and includes Shanghai, eight cities in Jiangsu province and eight cities in Zhejiang province. Meat consumption in this region has increased with economic growth, and most of the consumed meat is produced locally. The water quality of surface waters has deteriorated in recent years. An example was the huge blue-green algae bloom in Tai Lake in late May 2007, which affected millions of people's daily drinking water. However, animal husbandry is considered to be one of the main pollution sources. METHODS: Pollutants (NH3-N, total phosphorus (TP), and total nitrogen (TN)) excreted by livestock and poultry, and the resultant COD (chemical oxygen demand) and BOD (biochemical oxygen demand), were estimated using two different methods based on different data sets. RESULTS: The number of livestock and poultry has remained stable in the Yangtze Delta over the four years from 1999 to 2002, with the average number of pigs, cattle, sheep and poultry being 21.1 M, 0.4 M, 7.7 M and 597.6 M, respectively. Pollutants in livestock and poultry excreta estimated by Method I were: 0.12 Mt NH3-N, 0.11 Mt TP and 0.29 Mt TN, resulting in COD and BOD of 1.34 Mt and 1.30 Mt, respectively, while the estimations based on Method II were: 0.18 Mt NH3-N, 0.15 Mt TP and 0.40 Mt TN, resulting in COD and BOD of 1.95 Mt and 1.80 Mt, respectively. DISCUSSION: Pollutants excreted annually by livestock and poultry in the Yangtze Delta are estimated to be: 0.17 Mt NH3-N, 0.16 Mt TP and 0.42 Mt TN, giving rise to a COD of 1.86 Mt and a BOD of 1.72 Mt. Approximately 25% of this pollution was estimated to enter water bodies, which means that the annual pollutant load is 43,700 t NH3-N, 39,400 tTP, 104,600t TN with a COD of 465,000 tand a BOD of 430,100 t. Pollutants from animal husbandry were similar in magnitude to those from industrial wastewater. Pigs produced the most pollution, followed by poultry, cattle and sheep. The pollution load from animal husbandry in the Yangtze Delta is about twice the average level of the whole of China. CONCLUSIONS: Domestic wastewater was the main pollution source in the Yangtze Delta, followed by pollution from raising livestock and poultry and from industrial wastewater. The pollution load in Shanghai and Jiaxing were the greatest, followed by 7 cities of Jiangsu province (except Suzhou) and other cities of Zhejiang province and Suzhou. Pigs and poultry produced about 90% of the total pollutants from animal husbandry. RECOMMENDATIONS AND PERSPECTIVES: The local governments, especially in Shanghai and Jiaxing, should focus their attention on the pollution produced by livestock and poulrry. Controlling pollution from pigs and poultry will have the greatest impact in this region. Control of pollution will be facilitated by the development of large-scale livestock and poultry farming units and a shift away from small scale husbandry.