不同填埋龄垃圾甲烷和恶臭物质产生潜势

针对甲烷和恶臭物质产生潜势与垃圾填埋龄的关系,利用全自动甲烷潜能测试系统进行厌氧发酵实验,监测累积产甲烷量和速率,使用气相色谱/质谱联用仪分析恶臭物质种类和浓度.结果表明：填埋龄较短的垃圾产气量高于填埋龄较长的垃圾,填埋龄3a的垃圾产气量最大,单位质量垃圾甲烷累计产生量为29.81mL/g,填埋龄7a的垃圾产气量最小,为6.16mL/g,填埋龄3a的垃圾产甲烷速率最大,最高值达112.3mL/d;共检出40种恶臭物质,芳香族和脂肪烃种类最多、浓度最高,芳香族、卤代烃和含硫化合物浓度比例随垃圾填埋龄增加而增加;脂肪烃浓度比例随垃圾填埋龄增加而减小.     

1979~2016年中国城市生活垃圾产生和处理时空特征

改革开放以来,随着我国社会经济发展、居民生活水平提高,城市生活垃圾与日俱增,其妥善处理是我国各级政府面临的重要环境管理问题之一.本文通过系统收集和整理1979~2016年我国城市生活垃圾产生和处理的政府统计及相关中英文文献数据,分析了我国城市生活垃圾产生和处理的时空演变特征,建立了全国与各地区城市生活垃圾物理组分数据清单.研究结果表明：1979~2016年我国城市生活垃圾产生量显著增长至2016年的2.04亿t,以厨余类为主要成分.全国城市生活垃圾无害化处理率达到96.6%,无害化处理方式逐渐转向为焚烧为主、填埋补充的技术格局.我国各地区城市生活垃圾产生量、产生量增速、物理组分、无害化处理率和处理能力等存在时空差异,各地区应因地制宜,结合国家专项规划,提高生活垃圾减量化和资源化水平,弥补无害化处理缺口.     

长三角地区气溶胶光学性质与新粒子生成观测

2019年5月27日～6月27日对江苏省常州市的气溶胶光学性质参数、颗粒物数浓度和PM_(2.5)组分进行观测,联用扫描电迁移率粒径谱仪(SMPS)、黑碳仪(AE33)、腔衰减相移式单次反照率监测仪(CAPS)、在线离子色谱分析仪(MARGA)和RT-4型有机碳/元素碳(OC/EC)分析仪分析:①新粒子生成期间化学组分与光学参数的变化;②IMPROVE、 MIE理论重建消光系数与实测值的闭合性对比.观测期间共有两次明显的新粒子生成事件,粒子粒径从4 nm持续增长到64 nm,在新粒子生成初期硫酸盐贡献较大,生成过程中实测平均消光系数为95.40 Mm~(-1),IMPROVE模型重建平均消光系数为140.20 Mm~(-1),MIE理论模型计算平均消光系数为93.54 Mm~(-1),低于我国城市气溶胶消光系数均值300 Mm~(-1).本次观测采用多仪器联用的方式从颗粒物数浓度粒径谱、化学组分谱等不同的方面更好地对气溶胶理化性质进行表征.     

EDDS强化Fe0-Al0体系降解废水中4-氯酚的性能和机理

采用乙二胺二琥珀酸（EDDS）强化Fe⁰-Al⁰体系还原水溶液中的O₂产生H₂O₂和·OH等活性氧（ROS）的绿色高级氧化工艺,以4-氯酚（4-CP）模拟废水为研究对象,考察了溶液的初始pH值、铁铝的质量比、EDDS投加量和4-CP的初始浓度等因素对4-CP降解的影响.采用电子自旋共振（ESR）法、苯甲酸捕捉法以及4-CP的降解产物等证实了ROS的产生及4-CP的降解机制.结果表明：EDDS强化Fe⁰-Al⁰/O₂体系对4-CP的去除率随溶液初始pH的升高而降低,但在pH=2.5～9范围内,始终具有较好的4-CP去除率;随Fe⁰：Al⁰质量比增加4-CP的去除率先增大后减小,最佳质量比为4：1;随EDDS投加量和4-CP初始浓度增加,4-CP的去除率增大;EDDS可使体系的高级氧化能力提高9倍,在初始pH=2.5、Fe⁰=8g/L、Al⁰=2g/L、EDDS=1.5mmol/L条件下,反应3h后100mg/L 4-CP的去除率和脱氯率均达到近100%..     

Rates of environmental problem generation: Thoughts on a new research direction

Environmental scientists are continually discovering new and emerging environmental problems. There have been many studies of how a particular environmental problem has occurred, its costs to society, and its (potential) resolution. However, to date there have been few studies of the rate at which new environmental problems are generated by human technological innovations. In this note, I present a conceptual framework that will help quantify how many now-unknown problems we may expect to occur in a given sector. Two brief case studies illustrate the difficulty of finding appropriate dataset for fitting the full model, however. Policy implications of the conceptual framework are discussed, with different kinds of economic sectors requiring different approaches.     

深圳玉龙坑垃圾填埋场填埋气体产生量预测研究

通过综合垃圾填埋量、垃圾组分、以及气候特点等因素，采用二阶段复合产气速率模型对玉龙坑填埋场封场前后填埋气体产生量情况进行了预测。预测结果表明玉龙坑填埋场在封场后10年内仍有较大量的填埋气体产生，若不加以妥善处理将会产生安全隐患，若加以利用会产生经济效益。该模型的应用可为垃圾填埋场进行填埋气体产生量预测及收集处理系统的设计、管理提供合理的依据。     

Municipal Solid Waste Management in the Accra Metropolitan Area, Ghana

Municipal solid waste management in Accra, Ghana, is at present delivered in an unsustainable manner. Due to uncontrolled urbanisation, large quantities of waste are generated daily in Accra, and this exerts much pressure on an over strained solid waste management system. Coupled with weak institutional capacity, and lack of resources, both human and capital, the city authorities face difficulties in ensuring that all the waste generated in the city is collected for disposal. Home collection of waste is limited to high and, some middle income areas while the poor are left to contend with the problem on their own. This leads to indiscriminate disposal of waste in surface drains, canals and streams, creating unsanitary, and unsightly environments in many parts of the city.     

Acid-forming capacity of lead–zinc mine tailings and its implications for mine rehabilitation

Acid mine drainage problems were experienced in a Pb–Zn mine operation at Lechang, in the northern part of Guangdong Province, People's Republic of China. Geochemical and acid generation evaluations were made on fresh tailings including tailings fine, tailings sand and high sulphide tailings, and oxidised tailings with the aim of providing information on mine rehabilitation. All fresh tailings had a pH higher than 7 while the oxidised tailings had a pH of 4.9 (range 1.6 to 7.4). Only samples with pH < 3 had an electrical conductivity (EC) > 4 dS m-1. Total S contents of all tailings samples were very high with the high sulphide fraction having a mean S content of 38%. All fresh tailings had a high acid neutralisation capacity (ANC) while half of the oxidised tailings had an ANC less than zero. The results from the acid–base account and the net acid generation test indicated that all fresh and oxidised tailings samples were acid-forming except for the sand fraction samples. All tailings samples contained high total concentrations of Cd, Cu, Fe, Pb and Zn but low concentrations of total nitrogen and phosphorus. The preliminary results demonstrated that the tailings were all acid-forming especially the high sulphide fraction which should be kept permanently unexposed under impermeable cap or water.     

Control effects of pε and pH on the generation and stability of chlorine dioxide

IntroductionDuetotheformationofsomepotentiallyhazardousby productsfromchlorinedisinfectionindrinkingwater,chlorinedioxide(ClO2 ) ,asanalternativedisinfectantandaneffectiveoxidant,formedfewerhalogenatedDBPsthanchlorine(Richardson ,1 994;2 0 0 0 ;Bryant,1 992 ) .InvestigationsofthegenerationandstabilityofClO2 havealreadypromoteditsapplication .However,previousstudiespaynoattentiontothefactorofelectronactivity (pε)thatactuallyaffectsthegenerationandstabilityofClO2 Theignoranceofpεappearan…     

Comparison of masking agents for antimony speciation analysis using hydride generation atomic fluorescence spectrometry

A sensitive atomic spectrometric method for the redox speciation analysis of Sb in water is described. The proposed method is based on the selective generation of stibine from Sb(III) in a continuous flow system using non-dispersive atomic fluorescence spectrometry for detection. The effects of the HCl concentration on the fluorescence intensities of Sb(III) and Sb(V) were investigated. The results indicated that atomic fluorescence emission due to Sb(V) can constructively interfere with the determination of Sb(III). For the determination of Sb(III), four compounds were tested as masking agents to inhibit the generation of stibine from Sb(V). The effects of the concentrations of the masking agents and of HCl on the fluorescence signals from Sb(III) and Sb(V) were studied. The results indicated that citric acid and NaF can successfully suppress hydride generation from Sb(V). To evaluate the developed methodology and the influence of the matrix, the recovery of Sb(III) from natural water that was spiked with different Sb(III) and Sb(V) concentrations was tested.