排污权交易基准价定价机制探讨

构建科学合理的基准价定价机制是推动排污权交易的基础性工作,本文以政策、管理、技术三个方面作为立足点,探讨了基准价定价机制,构建了工作框架。研究认为现阶段基准价定价采取成本定价法是合适的,并对基准价定价技术难点进行了剖析,提出了建议。     

农村污水设施车载式剩余污泥脱水技术与设备研究

日益增长的农村污水设施剩余污泥已成为农村污水治理工作开展面临的新难题,农村剩余污泥适合采用多台污水设施共用车载式剩余污泥脱水设备进行脱水后收运集中处理,而农村道路的宽度和限高以及污水设施与道路间的距离等是主要的限制因素,因此急需研发适合农村作业环境的小型车载式剩余污泥脱水关键技术与设备.本研究的车载式剩余污泥脱水通过主要脱水设备负压运行方式,有效减小设备的尺寸,设备外观尺寸为5.995 m×1.905 m×2.56 m,吸污管道50 m.结果表明：可适应农村的作业环境,满足90%以上的农村小型污水处理设施使用.该设备行驶油耗7.2 L·h^-1,工作油耗1.88 L·h^-1;脱水后的污泥含水率80%左右.模拟案例表明,车载式剩余污泥脱水设备脱水收运方式比不脱水直接收运方式每台户用小型设施每年可节省污泥收运费103.3元,在一个安装了4400台小型污水设施的农村区域,每年可节省污泥收运费约45.5万元.     

人工强化生态滤床滤料性能研究

为了给人工强化生态滤床在工程应用选择滤料提供参考,利用室内模拟试验装置,考察了沸石、砾石、火山岩、陶环、碳环5种滤料在孔隙率、挂膜速度、机械强度、不同进水流量条件下COD、氨氮去除效果等方面的性能.结果表明,陶环和碳环孔隙率远大于其他3种滤料,陶环、碳环.火山岩.沸石和砾石的孔隙率分别为77％,75％,47％,38％和35％.当水力负荷为8mL/min时,在第11d,砾石滤料和火山岩滤料的COD去除率稳定,分别达到40.8％和41.6％,而其他3种滤料去除率仍处于上升阶段.这说明砾石与火山岩挂膜速度大于其他3种滤料.当系统稳定运行后,在水力负荷为3.75 mL/min时,碳环和火山岩滤料的COD去除率高于其他3种滤科.当水力负荷保持3.75mL/min时,进水COD升高,火山岩滤料COD去除率降低,小于其他3种滤料.这说明火山岩滤料与其他滤料相比具有更好的抗COD负荷冲击能力.沸石抗氨氮负荷冲击能力高于其他滤料.陶环和碳环强度差于其他3种滤料.研究表明,5种滤料各具特点,在实际工程滤料选择过程中应充分考虑施工和造价等因素.对于大型工程,如果工程当地不具备火出岩和沸石矿资源,应优先选择砾石滤料.     

Hydrodechlorination of polychlorinated biphenyls in contaminated soil from an e-waste recycling area,using nanoscale zerovalent iron and Pd/Fe bimetallic nanoparticles

Soil pollution by polychlorinated biphenyls (PCBs) arising from the crude disposal and recycling of electronic and electrical waste (e-waste) is a serious issue, and effective remediation technologies are urgently needed. Nanoscale zerovalent iron (nZVI) and bimetallic systems have been shown to promote successfully the destruction of halogenated organic compounds. In the present study, nZVI and Pd/Fe bimetallic nanoparticles synthesized by chemical deposition were used to remove 2,2′,4,4′,5,5′-hexachlorobiphenyl from deionized water, and then applied to PCBs contaminated soil collected from an e-waste recycling area. The results indicated that the hydrodechlorination of 2,2′,4,4′,5,5′-hexachlorobiphenyl by nZVI and Pd/Fe bimetallic nanoparticles followed pseudo-first-order kinetics and Pd loading was beneficial to the hydrodechlorination process. It was also found that the removal efficiencies of PCBs from soil achieved using Pd/Fe bimetallic nanoparticles were higher than that achieved using nZVI and that PCBs degradation might be affected by the soil properties. Finally, the potential challenges of nZVI application to in situ remediation were explored.     

Response of bacterial communities to short-term pyrene exposure in red soil

Pyrene, a representative polycyclic aromatic hydrocarbon (PAH) compound produced mainly from incomplete combustion of fossil fuels, is hazardous to ecosystem health. However, long-term exposure studies did not detect any significant effects of pyrene on soil microorganism. In this study, short-term microcosm experiments were conducted to identify the immediate effect of pyrene on soil bacterial communities. A freshly-collected pristine red soil was spiked with pyrene at 0, 10, 100, 200, and 500 mg·kg^-1 and incubated for one day and seven days. The bacterial communities in the incubated soils were analyzed using 16S rRNA sequencing and terminal restriction fragment length polymorphism (T-RFLP) methods. The results revealed high bacterial diversity in both unspiked and pyrene-spiked soils. Only at the highest pyrene-spiking rate of 500 mg·kg^-1, two minor bacteria groups of the identified 14 most abundant bacteria groups were completely suppressed. Short-term exposure to pyrene resulted in dominance of Proteobacteria in soil, followed by Acidobacteria, Firmutes, and Bacteroidetes. Our findings showed that bacterial community structure did respond to the presence of pyrene but recovered rapidly from the perturbation. The intensity of impact and the rate of recovery showed some pyrene dosage-dependent trends. Our results revealed that different levels of pyrene may affect the bacterial community structure by suppressing or selecting certain groups of bacteria. It was also found that the bacterial community was most susceptible to pyrene within one day of the chemical addition.     

非质量氧同位素分馏效应研究进展

非质量氧同位素分馏效应(mass independent oxygenisotope fractionation)研究为一些重大地质科学问题的解释开辟了一条新途径。在简要介绍非质量分馏理论后,重点评述了非质量氧同位素分馏效应的研究进展,包括非质量同位素分馏效应的成因机制、氧同位素组成分析方法建立及其在环境地学领域的应用。并对非质量氧同位素分馏领域未来研究趋势作了进一步探讨。     

不同浪高条件下生态浮岛稳定性模拟分析

以辽河干流实际水文资料为依据,在沈阳农业大学水利综合实验基地实验池,通过模拟不同浪高条件,研究不同固定方式生态浮岛的稳定性差异,确定适合于辽河生态浮岛建设的合适类型。结果表明,各位移指标经方差分析和多重比较及均值比较分析,立桩式浮岛稳定性最优,索道式浮岛次之,沉坠式浮岛稳定性较差;绳索张力和沉坠位移指标经比较分析,索道式浮岛较立桩式浮岛稳定,沉坠式浮岛稳定性较差。综合考虑各项分析结果,本研究选择索道式和立桩式作为辽河生态浮岛野外段建设预实验的固定方式,经河流实际水文及其他条件检验后,选择一种最优的固定方式,指导大规模建设。     

硫酸盐还原菌和酸性矿山废水的生物处理

本文论述了硫酸盐还原菌的代谢和所需要的碳源以及硫酸盐还原的影响因素和生物处理酸性矿山废水的研究进展.     

废弃铅锌冶炼厂重金属污染场地的健康风险评价

通过对广西某废弃铅锌冶炼厂区进行布点采样、监测分析,选取Cu、Pb、Zn、Cd、Cr、As六种重金属元素作为评价因子,对污染场地进行健康风险评价.结果显示,指数评价法表明厂区污染状况为废渣＞＞建筑垃圾＞土壤,Cd ＞Zn ＞As ＞Pb ＞Cu＞ Cr,土壤受到中度污染,废渣和建筑垃圾受到重度污染.健康风险评价法表明土壤、废渣和建筑垃圾的危害商分别为2.032、13.891、2.975,非致癌危害废渣＞＞建筑垃圾＞土壤;Cu、Zn、Cr、Cd、As的危害商分别为0.053、0.118、0.184、7.001、11.542,非致癌危害As ＞Cd ＞Cr＞Zn ＞Cu.土壤、废渣和建筑垃圾的致癌风险分别为5.387E-04、7.954E-04、2.455E-04,致癌危害废渣＞土壤＞建筑垃圾;As、Cd、Cr的致癌风险分别为5233E-04、2.400E-05、1.032E-03,致癌危害Cr＞As ＞Cd.综上,人体健康危害废渣＞建筑垃圾＞土壤,主要危害元素为As、Cd、Cr.     

Establishing eutrophication assessment standards for four lake regions, China

The trophic status assessment of lakes in different lake regions may provide important and fundamental information for lake trophic state classification and eutrophication control. In this study, a region-specific lake eutrophication assessment standard was established through a frequency distribution method based on chlorophyll-a concentration. The assessment standards under the oligotrophic state for lakes in the Eastern plain, Yungui Plateau, Northeast Plain and Mountain Mongolia-Xinjiang regions are total phosphorus of 0.068, 0.005, 0.011, 0.005 mg/L; total nitrogen of 1.00, 0.16, 0.37, 0.60 mg/L; Secchi depth of 0.60, 8.00, 1.55, 3.00 m; and CODMn of 2.24, 1.00, 5.1 l, 4.00 mg/L, respectively. Moreover, a region-specific comprehensive trophic level index was developed to provide an understandable assessment method for the public. The results indicated that the frequency distribution analysis based on chlorophyll-a combined with trophic level index provided a useful metric for the assessment of the lake trophic status. In addition, the difference of eutrophication assessment standards in different lake regions was analyzed, which suggested that the sensitivities of algae to nutrients and the assessment standard of trophic status possessed significant regional differences for the four lake ecoregions. Lake eutrophication assessment standards would contribute to maximizing the effectiveness of future management strategies, to control and minimize lake eutrophication problems.