Remediation of soil heavily polluted with polychlorinated biphenyls using a low-temperature plasma technique

Polychlorinated biphenyls （PCBs） were removed by low-temperature plasma technique （dielectric barrier discharge） from heavily polluted soil and their intermediate products were analyzed. The removal rate ranged from 40.1 to 84.6% by different treatments, and they were also influenced significantly （P 〈 0.01） by soil particle-size, electric power, gas flow rate and reaction time. The optimal reaction conditions of PCB removal from the soil were obtained experimentally when soil particle-size, electrical power, flow rate and reaction time were 5-10mm, 21w, 120mL. rain and 90rain, respectively. However, decreasing electrical power, flow rate and reaction time to 18 w, 60 mL. min- and 60 min respectively were also acceptable in view of the cost of remediation. This technique was characterized by the additional advantage of thorough oxidation of PCBs in the soil, with no formation of intermediate products after reaction. The technique therefore shows some promise for application in the remediation of soils contaminated with persistent organic pollutants in brown field sites in urban areas.     

潜流-垂直流改进型人工湿地处理河道水的研究

针对微污染河道水C/N比不足和磷浓度低的问题,将传统人工湿地改进后用于处理。改进后的人工湿地包含潜流段和垂直流段,潜流段填充沸石和腐木,其中腐木作为补充碳源,垂直流段填充水泥砖块,并种植美人蕉。试验结果表明:改进型人工湿地脱氮除磷效果良好,氮的去除主要发生在潜流段,氨氮和总氮的去除率达到90%以上,填充的补充碳源不会恶化水质;磷的去除主要发生在垂直流段,水泥砖块具有良好的去除低浓度磷的性能,但其寿命不长,需要及时的更换;美人蕉对湿地脱氮影响非常小。     

黄河三角洲地区冰雹分析及其短时预报

介绍了冰雹的气候特征, 利用黄河三角洲地区１９８８～１９９７ 年的 ７１１ 雷达回波、降雹资料及有关的高空探测资料, 对冰雹云的雷达回波参数和环境场要素进行了统计分析。结果表明：降雹与雷达回波顶温度、回波强度、０～－ ２０℃之间云体的厚度、７００ ｈ Ｐａ 上的比湿及云体的冷暖厚度之比等参数有关。在此基础上, 建立了冰雹的短时预报方程, 并为人工防雹提供可作为依据的简明判据     

Production of activated carbons from pyrolysis of waste tires impregnated with potassium hydroxide

Activated carbons were produced from waste tires using a chemical activation method. The carbon production process consisted of potassium hydroxide (KOH) impregnation followed by pyrolysis in N2 at 600-900 degrees C for 0-2 hr. The activation method can produce carbons with a surface area (SA) and total pore volume as high as 470 m2/g and 0.57 cm3/g, respectively. The influence of different parameters during chemical activation, such as pyrolysis temperature, holding time, and KOH/tire ratio, on the carbon yield and the surface characteristics was explored, and the optimum preparation conditions were recommended. The pore volume of the resulting carbons generally increases with the extent of carbon gasified by KOH and its derivatives, whereas the SA increases with degree of gasification to reach a maximum value, and then decreases upon further gasification.     

基于生命周期评价的清洁生产模式研究

从实现企业可持续发展的目标出发,将生命周期评价引入企业清洁生产,构建了相关模式。该模式基于边界确定、清单分析、数据处理、方案确定、方案实施等5个方面,在对企业生产现状全面调查、分析及研究的基础上,确定企业开展清洁生产审计的对象,分析审计对象的物料和能源损失及污染物产生和排放原因,为寻求清洁生产机会和制定实施清洁生产方案奠定基础。分析了该模式在实际应用中存在的问题,并提出了相关对策建议。     

黑龙江省环境与健康工作探讨

环境污染对于人类健康的危害极大,人类疾病大部分都与环境污染有关。随着人们受到环境污染的影响越来越大,很多未发现的疾病不断出现,而且发病率越来越高。本文通过对近年来黑龙江省环境与健康工作的探讨,指出了目前黑龙江省环境与健康工作的问题与不足,并提出了对策及建议。希望能够给黑龙江省的环境与健康工作提供一些帮助,为全省人民的身体健康做出贡献。     

5083铝合金在模拟淡海水中的电化学行为研究

采用循环极化、动电位极化研究了不同盐度的海水对5083铝合金腐蚀性能的影响。结果表明,自腐蚀电位随着浸泡时间的延长开始迅速负移,60 d后趋于稳定;循环极化显示击破电位随盐度的增加逐渐降低,保护电位随盐度的增加先减小后增大,在盐度为1.5%(质量分数)处达到最小值;腐蚀形貌显示5083铝合金在盐度为1.5%(质量分数)的海水中点蚀最严重;不同盐度下5083铝合金的阴极保护电位区间约在-0.90～-1.05 V之间。     

良好的作业条件是实现矿山本质安全的基础

矿山井下开采是一种工作环境特殊的职业.长期以来,多数矿山的现场作业条件较差,井下工作面场地狭窄,地质条件复杂,水、火、尘、顶板、有毒有害气体等灾害时刻威胁着矿工的人身安全.即使在矿山地表,也多是条件简陋,投入不足.长时间工作或生活在这样的环境中,不仅会对矿工、家属的身体健康造成伤害,而且还会对矿工的心理健康产生不良影响.长期以来人们对良好的作业条件存在片面的认识,不少人简单地认为,良好的作业条件就是生产机具、设备安全性能以及生产场所周围环境等.在生产管理中更是不重视良好的作业条件,只关注一些表面现象.……     

高度分散TiO2催化超声降解乙基紫及与悬浮TiO2催化活性的比较

采用输出功率为50 W,频率为40 kHz的超声波作为激发源激发TiO₂,比较了分散和悬浮2种不同形态TiO₂存在时超声降解乙基紫的情况.结果表明,在高度分散TiO₂存在的条件下,超声降解乙基紫的效果要远远好于悬浮TiO₂,超声照射40 min降解率达到78.45 %,而在悬浮TiO₂存在下降解率只有27.12 %,在单纯超声波作用下同样时间内降解率只有10%.另外还研究了不同因素包括：反应时间、初始浓度、催化剂加入量、超声功率和温度等对TiO₂催化超声降解乙基紫反应的影响,讨论了TiO₂催化超声降解乙基紫可能的反应机理.     

Phytotoxicity in seven higher plant species exposed to di-<Emphasis Type="Italic">n</Emphasis>-butyl phthalate or bis (2-ethylhexyl) phthalate

We investigated phytotoxicity in seven plant species exposed to a range of concentrations (0–500 mg·kg^?1 soil) of di-n-butyl phthalate (DnBP) or bis (2-ethylhexyl) phthalate (DEHP), two representative phthalate esters (PAEs) nominated by USEPA as priority pollutants and known environmental estrogens. We studied seed germination, root elongation, seedling growth, biomass (fresh weight, FW) and malondialdehyde (MDA) content of shoots and roots of wheat (Triticum aestivum L.), alfalfa (Medicago sativa L.), perennial ryegrass (Lolium perenne), radish (Raphanus sativus L.), cucumber (Cucumis sativus L.), oat (Avena sativa) and onion (Allium cepa L.), together with monitoring of plant pigment content (chlorophyll a, b and carotinoids) in alfalfa, radish and onion shoots. Root elongation, seedling growth and biomass of the test species were generally inhibited by DnBP but not by DEHP, indicating a lower level of phytotoxicity of DEHP than of DnBP. MDA contents of four species were promoted by PAE exposure, but not in alfalfa, ryegrass or onion shoots, indicating lower sensitivity of these three species to PAE pollutants. Plant pigment contents were clearly affected under the stress of both pollutants, implying the potential damage to the photosynthetic system of test plants, mainly by decreasing the content of chlorophyll a and b. Results of DnBP and DEHP phytotoxicity to the primary growth of test plants has provided information for the assessment of their environmental risk in the soil and also forms a basis for the further analysis of their toxic effects over the whole growth period of different plant species.