流域社会经济的水环境效应评估新方法及在南四湖的应用

针对我国湖泊生态安全评估及“一湖一策”工作的需要,初步提出一种流域社会经济的水环境效应评估新方法,与以往思路不同的是,新方法体现了正向作用和逆向反馈、现状水平和未来演变趋势相结合的认知框架,并系统阐述了指标优选、评估标准确定、等级划分和不确定性评估方法.最后,选择水质良好的湖泊代表——南四湖开展案例解析.结果表明:通过当前水平和未来变化速率更能全面认识评估结果,也有利于确定流域社会经济系统调控战略的必要性及潜力、方向和阈值;南四湖评估指数从2000年的“Ⅳ级:较严重”提升到2010年的“Ⅱ级:较轻”,尤其是在2003年和2007年存在2个“跳跃式”提升,但若维持现状规模和高速发展速度,未来20年很可能呈现逐渐缓慢下降趋势,并长期处于“Ⅲ级:一般”水平;为了确保维持现状等级且稳中小幅度上升的趋势,到2030年,建议南四湖流域社会经济发展速度控制在过去11年平均增长速度的75％左右以下,环境响应措施力度可能需要提升到评估标准的Ⅰ级水平.     

利用稳定同位素202Hg稀释技术判定不同来源有机肥施用对外源汞在土壤中形态分布的影响

有机肥施入土壤后,是否会对土壤重金属的活性及植物吸收造成影响是人们关心的问题.本研究应用稳定同位素²⁰²Hg稀释技术,通过培养实验和改进的Tessier连续提取法,探索不同来源有机肥(秸秆、杨树叶、油枯、酒糟、猪粪、鸡粪)施用对外源汞在天津潮土中形态分布及有效性的影响.结果表明,在连续提取法中结合同位素²⁰²Hg稀释技术,通过同位素比值R_Hg(²⁰²Hg/²⁰⁰Hg)的变化对Hg进行形态分析,相比传统的对Hg形态直接进行含量测定,可以更精确直观地反映出Hg形态分布的变化.在潮土中加入外源²⁰²Hg和有机肥后,同位素比值R_Hg最为显著的变化集中在交换态(含水溶态)、胡敏酸结合态、富里酸结合态及有机质结合态,且不同来源有机肥对Hg形态的影响也主要集中在这部分形态,对碳酸盐结合态、铁锰氧化物结合态和残渣态的影响较小.与未加入有机肥的对照处理相比,猪粪及鸡粪的施用使外源示踪²⁰²Hg显著向活性较强的交换态(含水溶态)、富里酸结合态转移,而在胡敏酸结合态中比例降低,下降幅度约为55%(猪粪)和58%(鸡粪).油枯及酒糟的施用,使外源示踪²⁰²Hg显著向活性较低的胡敏酸结合态转移,其同位素比值R_Hg分别增长了约90%(酒糟)和85%(油枯),而在活性较高的交换态(含水溶态)和富里酸结合态中分布比例降低.秸秆和杨树叶对于污染土壤Hg形态分布的影响并不显著.研究结果表明,不同来源的有机肥对Hg污染潮土中Hg的形态分布有显著影响,因此,在Hg污染农田土壤上施用有机肥料需要格外谨慎.     

全球气候变化对森林生态系统的影响

人类活动所引起的温室效应及由此造成的全球气候变化和对全球生态环境的影响正越来越引起人们的关注。作为全球陆地生态系统一个重要组分的森林对未来气候变化的响应更是人们关注的重点。文中系统地论述了未来气候变化对森林生态系统树种组成、林分结构、分布和生产力的潜在响应,提出了今后需要加强的一些研究领域。     

船舶在航更换压载水方法浅析

介绍了船舶在航更换压载水的各种方法，包括逐一更换法，注入顶出法和稀释法。并将各种方法从对船舶和船员的安全所造成的影响两方面进行了比较。     

Chemical forms of cobalt and nickel extracted by M1, M3 and CaCl2 DTPA

Mehlich 1(M1), mehlich 3(M3) and CaCl₂ DTPA have been used to predict the available micronutrient in soil. However, the forms of micronutrient extractable by these extractants are not known. In the present study, ten soils, collected from five provinces and the capital of China, representing a wide range of chemical and physical properties, were analyzed by sequential extraction to isolate five forms of cobalt and nickel, they are exchangeable, carbonate bound, Fe Mn oxide bound, organically bound and residual forms. The chemical forms extracted by M1, M3 and CaCl₂ DTPA were also investigated. The results show strong correlation between the carbonate bound or organically bound forms of Co or Ni and the amounts of extractable by any of the above three extractants. The main forms extracted by these extractants are carbonate and organically bound forms. The ranking of these three extractants for extraction of Co and Ni are M1>M3=CaCl₂ DTPA and M1=M3>CaCl₂ DTPA, respectively.     

我国食用海洋生物资源的开发及其对策

在概述我国海域主要的资源生物及其开发现状的基础上,指出在70年代中期以前,随捕捞力量的增加,我国海洋总渔获量增长较快;但此后,尽管捕捞力量仍继续增加,总渔获量增长缓慢。作者认为,过度捕捞、污染以及其他不利的环境因素变化是导致总渔获量缓慢增长的主要原因。为合理利用资源,提高渔获量,应在加强海洋生态系研究的基础上,积极开发外海(包括远洋)资源,并着重发展海洋农牧化。     

土壤中铜的形态及其转化

本文报告了使用连续提取方法研究加铜培育的黄棕壤、水稻土、红壤、砖红壤中铜的形态,并初步考察了土壤酸度、氧化还原状况等因素对铜形态的影响,对铜在不同矿物之间结合形态的转化进行了模拟。     

Concentrations and chemical forms of potentially toxic metals in road-deposited sediments from di erent zones of Hangzhou, China

The 25 road-deposited sediments were collected from five di erent land-use zones (industrial, residential, commercial, park, and countryside) in Hangzhou, China. The concentrations of metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in these samples were determined using ICP-AES after digestion with the mixture of HNO3-HF-HCl (aqua regia), and chemically fractionated according to the modified BCR (the European Community Bureau of Reference) sequential extraction procedure. The high metal concentration levels were detected in the sample from industrial zone and commercial zone having heavy tra c. While the low metal levels were noted in the street dust sample from residential zone, park, and countryside zone. The mobility sequence based on the sum of the BCR sequential extraction stages was: Zn (80.28%), Pb (78.68%), Cd (77.66%) > Cu (73.34%) > Mn (67.92%) > Co (41.66%) > Ni (30.36%) > Cr (21.56%), Fe (20.86%). Correlation analysis and principal component analysis were applied to the data matrix to evaluate the analytical results and to identify the possible pollution sources of metals. Factor analysis showed that these areas were mainly contaminated by three sources, namely lithology, tra c, and industry.     

序批式气提生物反应器(SABR)处理氯苯胺类有机废水好氧污泥颗粒化研究

研究了序批式气提生物反应器(SABR)处理氯苯胺类(CAs)有机废水过程中好氧污泥的颗粒化.SABR运行15d后,反应器内出现细小污泥颗粒,通过缩短循环时间与污泥沉降时间,并逐步提高COD与CAs进水负荷,SABR运行48d后污泥颗粒化明显;反应器在循环时间为12h、污泥沉降时间为6min、表面气速为2.4cm.s-1、COD负荷为1.0~3.6kg.m-3.d-1、CAs负荷逐步提升至800g.m-3.d-1的条件下继续运行50d,SABR污泥颗粒化趋于成熟,COD、CAs去除率稳定在90%、99.9%以上.根据污泥形态、最小沉降速率、SVI和目标污染物降解性能的变化,好氧污泥颗粒化过程可分为启动期、颗粒污泥形成期、生长期和成熟期.成熟好氧颗粒污泥粒径为0.9~2.5mm,平均颗粒密度为64g.L-1(以MLVSS计),污泥最小沉降速率为68.4m.h-1,SOUR为167mg.g-1.h-1;颗粒污泥外形为圆形或椭圆形,呈橙黄色,结构较致密,颗粒内外分布有丰富的类球菌、类短杆菌,与胞外多聚物交织共存.