长江三峡地区坡地发育初步研究

坡地发育是地貌学研究的基本问题之一。三峡地区坡地发育的研究对三峡库岸稳定性的评估和三峡移民的土地开发具有十分重要的意义。首先从概括坡地发育的研究进展，阐述科学家们对坡地发育的不同看法入手，引出三峡地区坡地发育的特殊性。初步研究三峡地区的坡地发育具有分段式分进的特点，包括中山峰陡坡的剥蚀后退过程，山顶缓坡的风化剥蚀夷平的过程，上段斜坡的片流坡地侵蚀过程，下段陡坡的剥坡后退过程，山麓堆积缓坡的剥蚀过程等。通过分析三峡地区坡地的五种坡段的成因、现状、发展趋势以及它们对三峡库区的稳定性和三峡移民的土地开发的影响，预测未来的三峡库岸，大部分为剥蚀陡坡，部分为崩塌滑坡陡坡，三峡沿岸城镇开发建设的重点将是库岸有坡地的防护工程。     

Contamination of Canadian and European bottled waters with antimony from PET containers

Using clean lab methods and protocols developed for measuring Sb in polar snow and ice, we report the abundance of Sb in fifteen brands of bottled water from Canada and forty-eight from Europe. Comparison with the natural abundance of Sb in pristine groundwaters, water bottled commercially in polypropylene, analyses of source waters prior to bottling, and addition of uncontaminated groundwater to PET bottles, provides unambiguous evidence of Sb leaching from the containers. In contrast to the pristine groundwater in Ontario, Canada containing 2.2 +/- 1.2 ng l(-1) Sb, 12 brands of bottled natural waters from Canada contained 156 +/- 86 ng l(-1) and 3 brands of deionized water contained 162 +/- 30 ng l(-1); all of these were bottled in PET containers. Natural water from Ontario bottled in polypropylene contained only 8.2 +/- 0.9 ng l(-1). Comparison of three German brands of water available in both glass bottles and PET containers showed that waters bottled in PET contained up to 30 times more Sb. To confirm that the elevated Sb concentrations are due to leaching from the PET containers, water was collected in acid-cleaned LDPE bottles from a commercial source in Germany, prior to bottling; this water was found to contain 3.8 +/- 0.9 ng l(-1) Sb (n = 5), compared with the same brand of water purchased locally in PET bottles containing 359 +/- 54 ng l(-1) (n = 6). This same brand of water in PET bottles, after an additional three months of storage at room temperature, yielded 626 +/- 15 ng l(-1) Sb (n = 3). Other German brands of water in PET bottles contained 253-546 ng l(-1) Sb (n = 5). The median concentration of Sb in thirty-five brands of water bottled in PET from eleven other European countries was 343 ng l(-1) (n = 35). As an independent check of the hypothesis that Sb is leaching from PET, the pristine groundwater from Canada (containing 2.2 +/- 1.2 ng l(-1) Sb) was collected from the source using PET bottles from Germany: this water contained 50 +/- 17 ng l(-1) Sb (n = 2) after only 37 days, even though it was stored in the refrigerator, and 566 ng l(-1) after six months storage at room temperature.     

废水产氢产酸/同型产乙酸耦合产酸条件优化

为了更好地发挥产氢产酸/同型产乙酸耦合系统在废水厌氧发酵生产乙酸方面的优势,有必要寻找一种简单有效的方法以获得该系统产酸的优化条件.利用经过加热处理并活化的厌氧污泥作种泥,以模拟废水中的葡萄糖为底物,针对发酵时间、底物浓度、种泥浓度、初始pH进行4因素10水平均匀设计实验,得到了乙酸生产指标与产酸条件之间关系的回归方程;也得到了以高乙酸产量为主要目标导向同时兼顾高乙酸产率和高乙酸生产强度目标的优化条件;优化条件实验乙酸浓度比均匀设计中最高乙酸浓度提高20%左右.研究表明,将均匀设计应用于废水产氢产酸/同型产乙酸耦合产酸条件优化,可以避免盲目性,迅速获得满意结果.     

Recent biosensing developments in environmental security

Environmental security is one of the fundamental requirements of our well being. However, it still remains a major global challenge. Therefore, in addition to reducing and/or eliminating the amounts of toxic discharges into the environment, there is need to develop techniques that can detect and monitor these environmental pollutants in a sensitive and selective manner to enable effective remediation. Because of their integrated nature, biosensors are ideal for environmental monitoring and detection as they can be portable and provide selective and sensitive rapid responses in real time. In this review we discuss the main concepts behind the development of biosensors that have most relevant applications in the field of environmental monitoring and detection. We also review and document recent trends and challenges in biosensor research and development particularly in the detection of species of environmental significance such as organophosphate nerve agents, heavy metals, organic contaminants, pathogenic microorganisms and their toxins. Special focus will be given to the trends that have the most promising applications in environmental security. We conclude by highlighting the directions towards which future biosensors research in environmental security sector might proceed.     

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.     

水体中钼污染物的迁移转化研究进展

水体的重金属钼污染在中国部分地区已经显现,明确钼迁移转化规律是治理钼污染的基础.在总结水体钼污染形成机制的基础上,综述了水体钼污染物迁移转化的研究进展.其中,在水体胶体对钼的吸附研究方面较深入,酸碱条件和胶体种类是钼迁移转化的主要影响因素.而目前的研究,对尾矿中不同种类原钼矿物迁移转化与环境条件相互作用的关系尚不明确.因此,解决实际钼污染同题还需更深入的系统性探索.     

应用陶粒过滤-陶瓷膜组合对止咳糖浆制药废水深度处理的试验研究

止咳精浆制药废水经生物接触氧化一体化废水处理装置处理后,其出水中COD、BOD和氨氮等主要污染物质均不能达标排放.在实验室中采用陶粒过滤-陶瓷膜组合对经一体化处理装置处理后的制药废水进行深度处理,在陶粒柱反应器选用粒径为1～2 mm的陶粒滤料,陶瓷膜反应器选用孔径为2～3/μm陶瓷膜的条件下对水样进行测试.废水经陶粒过滤-陶瓷膜组合处理后,其BOD、COD、SS和氨氮指标均可稳定达标排放.     

Implications of urine-to-feces ratio in the thermophilic anaerobic digestion of swine waste.

Thermophilic anaerobic digestion of swine manure represents a potential waste treatment technology to address environmental concerns, such as odor emissions and removal of pathogenic microorganisms. However, there are concerns relative to the stability of this process when swine manure is the sole substrate. In this study, the potential of biogas production from swine manure as the sole substrate under thermophilic (50 degrees C) conditions was investigated in the laboratory, to determine whether separation of urine and feces as part of the waste collection process would benefit anaerobic digestion. Effluent from a continuously stirred tank reactor was used as the inoculum for batch tests, in which the substrate contained three different concentrations of urine (urine-free, as-excreted urine-to-feces ratio and double the as-excreted urine-to-feces ratio). Inocula were acclimated to these same urine-to-feces ratios to determine methane production. Results show that both urine-free and as-excreted substrates were not inhibitory to anaerobic inocula. Anaerobic microorganisms can be readily acclimated to substrate with double the as-excreted urine concentration, which contained nitrogen concentrations up to 7.20 g/L. Cumulative methane production reached similar levels in the batch tests, regardless of the substrate urine concentration.