南京市郊农业生态系统建设与发展

南京市处于长江流域下游，是我国重要的农业生产基地，也是全国经济发达地区之一。它既有近郊的蔬菜生产，又有远郊的粮食作物种植，农田生态类型与农、牧、副的复合生态类型多种多样，而且其生产潜力很大。本文对南京市郊生态系统的建设进行分析研究，并着重探讨生态系统建设模式及土地合理利用，为建立合理的南京市郊区农业生态系统提供依据。     

民众环境意识是环境教育的核心与目的

当前“低碳经济”、“低碳生活”等理念在众多媒介有大量的表述和宣传报道。但抽样调查显示，实际上广大公众对于“低碳”的认知却颇有一些不甚清晰明了。概念的模糊性及不确定性，势必影响并阻碍我们积极倡导和实践推进生态文明建设，努力实现清洁发展、安全发展、绿色发展及可持续发展。     

武义萤石矿床矿物包裹体研究

矿物包裹体研究表明,武义萤石矿床是含矿地热水活动的产物。其形成温度为130°±27℃,压力为47.23-426.96×10~5帕。属于低温浅成热液矿床。冷渗流大气降水在深处受地热影响加热活化,发生水—岩化学反应和物质交换,导致含矿地热水的形成。它在构造作用和热力及压力梯度驱动下回返上升,于地表—近地表裂隙带与大气降水混合,温压骤降,加以冷的含CO_2和O_2的大气降水界入,使成矿物质自溶液中沉淀析出。     

化学热洗法处理页岩气开采废钻井液

针对页岩气开采过程中所产生的废钻井液处理,采用化学热洗的方法对废钻井液进行了油、水、固三相分离,并使用5%的清洗剂对废钻井液中的泥砂和岩屑进行除油。结果表明:温度为40℃、搅拌转速为160 r/min、破稳剂浓度为50 g/L、清洗剂的浓度为5%时,废钻井液中油的回收率达到了98%,泥砂与岩屑的含油量均小于2%。     

Microcystis aeruginosa/Pseudomonas pseudoalcaligenes interaction effects on off-flavors in algae/bacteria co-culture system under different temperatures

We conducted an experiment to study the interaction effects of Microcystis aeruginosa and Pseudomonas pseudoalcaligenes on off-flavors in an algae/bacteria co-culture system at three temperatures (24, 28 and 32°C). Gas chromatography–mass spectrometry was applied to measure off-flavor compounds dimethyl sulfide (DMS), dimethyl trisulfide (DMTS), 2-methylisoborneol, geosmin (GEO) and β-cyclocitral. During the lag phase of co-cultured M. aeruginosa (first 15 days), P. pseudoalcaligenes significantly increased the production of DMS, DMTS and β-cyclocitral at all three temperatures. In the exponential phase of co-cultured M. aeruginosa (after 15 days), M. aeruginosa became the main factor on off-flavors in the co-culture system, and β-cyclocitral turned to the highest off-flavor compound. These results also indicated that DMS, DMTS and β-cyclocitral were the main off-flavor compounds in our M. aeruginosa/P. pseudoalcaligenes co-culture system. Univariate analysis was applied to investigate the effects of M. aeruginosa and P. pseudoalcaligenes on the production of off-flavors. The results demonstrated that both M. aeruginosa and P. pseudoalcaligenes could increase the production of DMS and DMTS, while β-cyclocitral was mainly determined by M. aeruginosa. Our results also provide some insights into understanding the relationship between cyanobacteria and heterotrophic bacteria.     

Effect of AlCl3 concentration on nanoparticle removal by coagulation

In recent years, engineered nanoparticles, as a new group of contaminants emerging in natural water, have been given more attention. In order to understand the behavior of nanoparticles in the conventional water treatment process, three kinds of nanoparticle suspensions, namely multi-walled carbon nanotube-humic acid (MWCNT-HA), multi-walled carbon nanotube-N,N-dimethylformamide (MWCNT-DMF) and nanoTiO₂-humic acid (TiO₂-HA) were employed to investigate their coagulation removal efficiencies with varying aluminum chloride (AlCl₃) concentrations. Results showed that nanoparticle removal rate curves had a reverse “U” shape with increasing concentration of aluminum ion (Al^3 +). More than 90% of nanoparticles could be effectively removed by an appropriate Al^3 + concentration. At higher Al^3 + concentration, nanoparticles would be restabilized. The hydrodynamic particle size of nanoparticles was found to be the crucial factor influencing the effective concentration range (ECR) of Al^3 + for nanoparticle removal. The ECR of Al^3 + followed the order MWCNT-DMF > MWCNT-HA > TiO₂-HA, which is the reverse of the nanoparticle size trend. At a given concentration, smaller nanoparticles carry more surface charges, and thus consume more coagulants for neutralization. Therefore, over-saturation occurred at relatively higher Al^3 + concentration and a wider ECR was obtained. The ECR became broader with increasing pH because of the smaller hydrodynamic particle size of nanoparticles at higher pH values. A high ionic strength of NaCl can also widen the ECR due to its strong potential to compress the electric double layer. It was concluded that it is important to adjust the dose of Al^3 + in the ECR for nanoparticle removal in water treatment.     

实施跨界水环境补偿的探讨——对《水污染防治行动计划》中“实施跨界水环境补偿”的解读

针对《水污染防治行动计划》提出"实施跨界水环境补偿"的要求,文章总结分析了国内外已开展的水环境补偿实践情况,表明实施水环境补偿对跨界水质改善具有较好作用;从宏观层面分析了在我国推广跨界水环境补偿面临的主要困境与问题,并从政策、资金等方面提出了相关建议,为下阶段我国推广实施跨界水环境补偿提供参考。     

低温低浊高色水源水处理的进展研究

针对低温低浊高色水源水质特征,对近年低温絮凝剂、低温强化混凝技术、低温膜集成技术研发与应用现状进行了综合论述.通过对低温混凝剂的絮凝机理与效果、各技术低温保持水质达标的应对策略的深入剖析,预测低温低浊高色水处理的发展趋势.研究表明,开发低温专用的高效低耗、质优价廉、无毒无二次污染的载体絮凝水处理剂,探索在不增加甚至减少工程造价条件下对低温期及平常期水处理均有效的工艺,是低温低浊高色水源水处理的关键.