污灌土壤中多环芳烃自净的微生物效应

本文研究了不同污灌区各个季节表土和底土中多环芳烃(PAH)含量和微生物生态变化。研究结果表明,PAH总量是表土高于底土,灌水期(7月)高于翻耕前和停灌后。经鉴定的9种PAH以苯并(a)芘、苯并(e)芘和1,2一苯丙蒽含量最低,联苯、萤蒽、芘、苊、菲、蒽较高。其迁移规律是随石油废水中油的输入而吸附于电厂粉煤灰和土壤表层,大量累积于灌渠渠首和附近田块中。污灌区的微生物生态特征是以细菌为主,真菌和放线菌较少。细菌的活性(活细胞数)是表土高于底土,灌水期7月高于4月和9月。细菌的优势种群为芽胞杆菌和假单胞杆菌等。PAH因土壤中的理化和生物因子的作用而消减,并未随灌溉的时间而变化。为了防止PAH累积于农田,在渠首设立吸附过滤沉降池。     

Characterizing the antibiotic resistance genes in a river catchment: Influence of anthropogenic activities

Previous studies on environmental antibiotics resistance genes(ARGs) have focused on the pollution sources such as wastewater treatment plants, aquaculture and livestock farms,etc. Few of them had addressed this issue in a regional scale such as river catchment. Hence,the occurrence and abundances of 23 ARGs were investigated in surface water samples collected from 38 sites which located from the river source to estuary of the Beijiang River.Among them, 11 ARGs were frequently detected in this region and 5 ARGs(sul I, sul II, tet B,tet C, and tet W) were selected for their distribution pattern analysis. The abundances of the selected ARGs were higher in the upstream(8.70 × 10~6 copies/ng DNA) and downstream areas(3.17 × 10~6 copies/ng DNA) than those in the midstream areas(1.23 × 10~6 copies/ng DNA), which was positively correlated to the population density and number of pollution sources. Pollution sources of ARGs along the Beijiang River not only had a great impact on the abundances and diversity, but also on the distribution of specific ARGs in the water samples. Both sul I and sul II were likely originated from aquaculture farms and animal farms,tet W gene was possibly associated with the mining/metal melting industry and the electric waste disposal and tet C gene was commonly found in the area with multiple pollution sources.However, the abundance of tet B was not particularly related to anthropogenic impacts. These findings highlight the influence of pollution sources and density of population on the distribution and dissemination of ARGs at a regional scale.     

层次分析法在规划环评中的应用--以太仓市沿江地区规划为例

综合分析了层次分析法(AHP法)的特点及应用于规划环评的优势,并以太仓市沿江地区规划为例,综合考虑社会、经济和环境资源的因素,建立了评价体系,对太仓市沿江地区规划的4个替代方案进行了比选,最后对拟定规划方案给出了修正建议。     

3种酰胺类除草剂对斑马鱼不同生长阶段的急性毒性效应

为探明酰胺类除草剂对鱼类不同生长阶段的毒性效应,分别以斑马鱼胚胎、8日龄仔鱼、55日龄幼鱼和3月龄成鱼为受试对象,研究3种酰胺类除草剂乙草胺、丙草胺和丁草胺对斑马鱼(Danio rerio)不同生长阶段的毒性效应。研究发现,高浓度乙草胺、丙草胺和丁草胺均可抑制斑马鱼胚胎的孵化。乙草胺对斑马鱼胚胎、仔鱼、幼鱼和成鱼的96 h-LC50值分别为5.82、1.34、3.00、1.44 mg·L-1,毒性从高到低顺序依次为:仔鱼成鱼幼鱼胚胎。丙草胺对斑马鱼胚胎、仔鱼、幼鱼和成鱼的96 hLC50值分别为2.79、2.02、2.26、2.01 mg·L-1,毒性从高到低顺序依次为:仔鱼、成鱼幼鱼胚胎。丁草胺对斑马鱼胚胎、仔鱼、幼鱼和成鱼的96 h-LC50值分别为1.73、0.919、3.37、1.19 mg·L-1,毒性从高到低顺序依次为:仔鱼成鱼胚胎幼鱼。研究结果表明,酰胺类除草剂对斑马鱼4个典型生长阶段的毒性差异较大,仔鱼阶段对酰胺类除草剂最敏感,成鱼其次。     

Cationic content effects of biodegradable amphoteric chitosan-based flocculants on the flocculation properties

A series of biodegradable amphoteric chitosan-based flocculants (3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CTA) modified carboxymethyl chitosan, denoted as CMC-CTA) with different substitution degrees of CTA were prepared successfully. The content of carboxymethyl groups in each CMC-CTA sample was kept almost constant. The solubility of the various flocculants showed that, higher cationic content of flocculants caused a better solubility. The flocculation experiments using kaolin suspension as synthetic water at the laboratory scale indicated that the substitution degree of CTA was one of the key factors for the flocculation properties. With the increase of cationic content, the flocculants were demonstrated better flocculation performance and lower dosage requirement. Flocculation kinetics model of particles collisions combining zeta potential and turbidity measurements was employed to investigate the effects of the cationic content of the flocculants on the flocculation properties from the viewpoint of flocculation mechanism in detail. Furthermore, flocculation performance using raw water from Zhenjiang part of Yangtze River at the pilot scale showed the similar effects to those at the laboratory scale.     

系统性生物多样性保护法律体系的定位与构建

随着国家政策导向提出实现生物多样性整体性、系统性保护的要求,新时期背景下的生物多样性保护除了注重实现生物多样性在自然生态系统、生物物种、遗传资源(基因)三方面的协同性整体性保护以外,还强调了实现自然生态系统平衡、维护国家安全等总体性目标。在此背景下,本文建议,生物多样性保护法律体系也应当在推动立法实践、提升国家安全治理能力、整合现有立法资源等方面发挥其应有价值。从系统性的角度出发,明确法律体系贯彻生物多样性整体性保护理念、执行国家战略部署以及平衡多元化利益的应有定位,并在此基础上从整体性目标的树立、网格联动性的体系构建、合理配置现行法律制度等方面探寻系统性法律体系的构建路径,将有效发挥我国生物多样性保护法律体系在服务社会需求、回应国家政策导向等方面的制度支撑价值。     

浙江省生态功能区划研究

在浙江省生态环境现状调查的基础上,运用GIS等先进技术,采用定性与定量相结合的方法,对浙江省生态环境现状、生态环境敏感性和生态服务功能重要性进行评价,形成浙江省生态功能区划方案,将浙江省划分为6个生态区、15个生态亚区、47个生态功能区,并确定了具有重要生态系统服务功能的5个重要生态功能区域.区划成果为浙江生态省建设规划的实施、资源的合理利用和工农业生产合理布局提供了科学依据.     

超重力旋转填料床中柠檬酸钠法烟气脱硫

采用柠檬酸-柠檬酸钠缓冲溶液作为吸收液,在超重力旋转填料床(简称填料床)中进行模拟烟气中SO2的吸收和解吸实验,考察了吸收液组成及各操作参数对SO2吸收率及解吸率的影响.实验结果表明:吸收过程中吸收液的柠檬酸浓度越高、吸收液初始pH 越高,SO2吸收率越高;填料床转速增大、液气比增大,SO2 吸收率下降速率增大;解吸过...     

Chemisorption and Physical Adsorption Roles in Cadmium Biosorption by Chlamydomonas Reinhardtii

Abstract

The aim of this study was to investigate the mechanism of cadmium (Cd) adsorbed by microalgae Chlamydomonas reinhardtii (C.reinhardtii). The kinetic and adsorption isotherm of the process could be well described by mathematical models. Chemical modification experiments and Fourier transform infrared spectra indicated that carboxyl and amine groups were the important functional groups for adsorption of Cd. The maximum contribution of physical adsorption in the overall adsorption process was evaluated as 5.5%. These results indicated that chemisorption was the dominating mechanism of Cd biosorption by C.reinhardtii.