二氧化钛颗粒制备及其对水中三价砷的去除

以硫酸氧钛和聚乙烯醇(PVA)为原料,通过冰水浴法制备了二氧化钛(TiO2)颗粒,并研究了其对砷的吸附性能。利用X射线衍射仪(XRD)和扫描电子显微镜(SEM)对TiO2颗粒进行了表征,结果表明,吸附剂为锐钛矿结构,比表面积246 m2/g。TiO2颗粒对模拟地下水中砷(Ⅲ)的吸附动力学研究表明,吸附过程符合准二级动力学。采用Langmuir和Freundlich方程对吸附平衡数据进行了拟合,结果表明,吸附等温线符合Langmuir模型,最大吸附量为22.3 mg/g。TiO2颗粒对三价砷的吸附在pH为9.1时吸附量最大,吸附受CO23-影响较大。将110 g TiO2颗粒装备成过滤滤壶,对山西地下水(总砷含量190μg/L)进行了除砷实验,经过3 600柱体积后,滤液中砷浓度低于10μg/L,符合国家饮用水标准。     

油气长输管道工程生态保护工作要点

在具体分析油气长输管道工程生态保护重要性基础上,从项目前期、施工过程、施工结束后三个阶段介绍了生态保护工作要点。项目前期生态保护包括管道路由选线、项目(预)可研、专项评价、工程设计4个方面,施工期包括保障监管资源、实施合规管理等方面,施工结束后生态恢复包括戈壁、荒漠、沙漠、干旱区绿洲、黄土高原、土石山区、平原、冻土区等方面。     

臭氧光电催化耦合处理炼油反渗透浓水

为控制炼油废水对环境的污染,采用臭氧光电催化氧化耦合工艺对炼油废水反渗透浓水进行了处理研究,主要考察了pH、电流密度、臭氧投加量等因素对该耦合体系废水处理效果的影响。结果表明,臭氧光电催化氧化耦合技术可有效降解炼油废水反渗透浓水;废水中油类及COD的去除率随pH的增大先提高后降低;随电流密度的增大,COD去除率先提高后降低,油类物质先提高然后基本保持恒定;臭氧投加量不断增大,COD及油类物质去除率先提高后趋于稳定。当pH=7.5,臭氧投加量达到8 mg/L,电流密度50 mA/cm2,停留时间30 min,出水达到COD≤50 mg/L,石油类≤0.5 mg/L的排放要求。     

Degradation characteristics and metabolic pathway of 17alpha-ethynylestradiol by Sphingobacterium sp. JCR5

A 17alpha-ethynylestradiol (EE2)-degrading bacterium was isolated from the activated sludge of the wastewater treatment plant (WWTP) of an oral contraceptives producing factory in Beijing, China. On the basis of its morphology, biochemical properties and the 16S rDNA sequence analysis, this strain was identified as Sphingobacterium sp. JCR5. This strain grew on EE2 as sole source of carbon and energy, and metabolized up to 87% of the substrate added (30 mgl-1) within 10 d at 30 degrees C. In addition to EE2 the strain could be cultivated on steroidal estrogens like estrone (E1), 17beta-estradiol (E2), estriol (E3) and mestranol (MeEE2), the intermediates of contraceptive medicine processing and on some aromatic compounds. Mass spectrum analysis of the EE2 degradation showed that in the first step it is oxygenized to E1, 2-hydroxy-2,4-dienevaleric acid and 2-hydroxy-2,4-diene-1,6-dioic acid, which are the main catabolic intermediates. The former was analogous to the pathway of a previously reported testosterone-degrading bacterium Comamonas testosteroni TA441 and the latter is a metabolite with a different cleavage position of 3-hydroxy-4,5-9,10-disecoestrane-1(10),2-diene-5,9,17-trione-4-oic acid from the former.     

Simulating uptake and transport of TNT by plants using STELLA

Understanding the uptake and transport of soil organic contaminants by plants is crucial to a successful application of phytoremediation technique. This study investigated the removal of 2,4,6-trinitrotoluene (TNT) from a contaminated sandy soil by a poplar tree (Populus fastigiata) through the examinations of temporal variations of xylem water potential, leaf water transpiration, and root water and TNT uptake. A dynamic model for Uptake and Translocation of Contaminants from a Soil-Plant ecosystem (UTCSP), developed using the STELLA software package, was modified for the purpose of this study. The model was calibrated using laboratory measurements prior to its application. Simulation results showed that about 25% of TNT was removed from the soil by the poplar tree in 90 days. Simulations further revealed that the rates of water and TNT up taken by roots had a typical diurnal variation pattern: increasing during the day and decreasing during the night, resulting from daily variations of xylem water potentials that were caused by leaf water transpiration. In general, the storage of TNT mass in the roots decreased with time and occurred partially because of the low availability of soil TNT as time elapsed and partially because of the biodegradation of TNT in the plant tissues. This study suggests that the UTCSP model could be a useful tool for estimating phytoremediation of soil TNT by a plant.     

中国1997-2006年可持续发展动态测度分析

利用生态足迹分析法对中国1997-2006年的生态足迹与生态承载力进行核算,从而定量测度近10年来中国的可持续发展状况,根据结果对生态足迹的供给和需求进行分析并提出相应的建议和对策.结果表明:10年来,中国的生态足迹快速增长,由1997年的1.287 hm2增长到2006年的1.941 hm2,人均生态赤字从1997年的0.596 9hm2增长到2006年的1.267 0 hm2,自然生态系统处于不可持续的发展状态; 在生态足迹的构成中,能源和水域的生态赤字最为严重,远未满足供需平衡;此外,万元GDP占用生态足迹从1997年的2.014 8 hm2降低到2006年的1.209 8hm2,说明中国资源利用效率提高较快,经济增长方式在向良性发展.     

Spatial distribution of inorganic nitrogen contents of marsh soils in a river floodplain with different flood frequencies from soil-defrozen period

Contents of inorganic nitrogen (NH4(+)-N and NO3(-)-N) in soil profiles were measured in five typical zones ( including permanently flooded floodplain(B), 1-year floodplain (O), 5-year floodplain (F),10-year floodplain (T), and 100-year floodplain (H) )from Huolin River floodplain in Erbaifangzi, Jilin Province of China, in the soil-defrosted period (Mayof 1999). Contour maps and profile maps were constructed to describe the spatial distributions of NH4(+)-N and NO3(-)-N) in order to identify the influences of flood frequencies on them. Results showed that NH4(+)-N generally increased with depth in soil profiles from the five areas, but NH4(+)-N contents in T or H areas significantly differed from those in other areas. For NO3(-)-N, with the exception that there was a significant cumulative peak (6.77 +/- 0.08 mg kg(-1)) at 15-cm depth (10-20 cm) in B area, no significant difference was observed between NO3(-)-N contents in soil profiles from the other four areas. The horizontal distributions of NH4(+)-N and NO3(-)-N in top soils (0-10 cm) were different in the five areas,which were greatly influenced by flood frequencies. The highest content of NH4(+)-N or NO3(-)-N did not appear in B area but in the floodplain with certain flood frequency. For example, NH4(+)-N content (16.81 mg kg-(1)) in 5-year floodplain wetland was highest, and the highest content of NO3(-)-N(1.69 mg kg(-1)) appeared in 1-year floodplain wetland. In addition, NH4(+)-N contents were significantly correlated with soil pH, and NO3(-)-N contents had significant correlation with inorganic carbon, but there were no significant correlations between inorganic nitrogen and other selected soil properties.     

风景名胜区开发建设项目环境影响评价程序和指标体系——以本溪水洞国家级重点风景名胜区为例

文章以本溪水洞国家级重点风景名胜区为例 ,对山岳型风景资源开发建设项目环境影响评价程序和指标体系进行了研究。评价程序分三个层次进行。规划指标和人为自然灾害指标为第一个层次 ;景观指标和生态指标为第二个层次 ;环境质量和环境感应指标为第三个层次。每个层次和指标体系都赋予了内涵。     

Ce-Mn双金属氧化物深度催化氧化废气中的氯甲苯

采用Ce-Mn双金属氧化物深度催化氧化废气中的氯甲苯。实验结果表明:当n(Ce):n(Mn)为1:5时,CeO_2与MnO_x之间的协同效应最大,对氯甲苯的去除效果最好;在以纯氧为氧化剂、反应温度为360℃、氯甲苯体积分数为0.5%～1.5%、体积空速为12 000～30 000 h~(-1)的条件下,氯甲苯去除率可达100%。     

清洁生产评价专题编制方法探讨

在环境影响评价报告中对清洁生产评价专题的编制不规范,缺少量化指标。以山东万得集团年产亿米高档染织面料项目的清洁生产评价为例,通过指标体系建立、评价方法确定、评价结果分析等,提出一种操作性强、可供借鉴的编制方法。