Environmental risk assessment of selected organic chemicals based on TOC test and QSAR estimation models

Environmental risks of organic chemicals have been greatly determined by their persistence,bioaccumulation, and toxicity(PBT) and physicochemical properties. Major regulations in different countries and regions identify chemicals according to their bioconcentration factor(BCF) and octanol–water partition coefficient(Kow), which frequently displays a substantial correlation with the sediment sorption coefficient(Koc). Half-life or degradability is crucial for the persistence evaluation of chemicals. Quantitative structure activity relationship(QSAR) estimation models are indispensable for predicting environmental fate and health effects in the absence of field-or laboratory-based data. In this study, 39 chemicals of high concern were chosen for half-life testing based on total organic carbon(TOC) degradation,and two widely accepted and highly used QSAR estimation models(i.e., EPI Suite and PBT Profiler) were adopted for environmental risk evaluation. The experimental results and estimated data, as well as the two model-based results were compared, based on the water solubility, Kow, Koc, BCF and half-life. Environmental risk assessment of the selected compounds was achieved by combining experimental data and estimation models. It was concluded that both EPI Suite and PBT Profiler were fairly accurate in measuring the physicochemical properties and degradation half-lives for water, soil, and sediment.However, the half-lives between the experimental and the estimated results were still not absolutely consistent. This suggests deficiencies of the prediction models in some ways, and the necessity to combine the experimental data and predicted results for the evaluation of environmental fate and risks of pollutants.     

麻疯树胚乳愈伤组织诱导及其污染消除

经过比较分析各种消毒方法,获得了较为理想的麻疯树(Jatrophacurcas)胚乳愈伤组织,并动态观察其类型、形态特征、增殖速率和形态发生能力,为麻疯树胚乳植株再生及愈伤组织和细胞培养生产药用成分奠定了基础.以麻疯树成熟胚乳为外植体进行愈伤组织的诱导,测试0.4mg/L的分裂素(BA、KT与TDZ)与2.0mg/L的生长素(IAA、IBA、NAA与2,4D)搭配组合的诱导效果.结果表明,对胚乳愈伤诱导效果而言,2.0mg/L的2,4D效果最好,NAA的效果次之,IBA又次之,IAA的效果最差.BA和KT诱导效果差异不显著,TDZ的添加可促进胚乳愈伤组织的诱导.选择适宜的消毒剂(种类、浓度)和消毒(处理)时间对胚乳外植体的接种成功具有至关重要的作用.在本试验所采取的灭菌方式中,用70%酒精处理30s,然后用10%NaClO处理25min,灭菌效果最佳,同时对胚乳外植体的生长影响最小.图3表1参23     

河流-地下水渗流系统对城市污水的净化作用及机理

通过野外试验与理论分析，研究了河流－地下水渗流系统对城市污水的净化作用及机理，结果表明：河流－地下水渗流系统对城市污水的COD，重金属，氮等具有很好的净化作用，对COD的去除主要是好氧微生物降解，其次为厌氧微生物降解，重金属与挥发酚主要是土壤吸附作用，而氮的去除是好氧环境中的硝化作用与厌氧环境中的反硝化作用的联合作用的结果，其中硝化作用是氮净化效率的限制因子。     

轮窑烧砖烟气元二次污染治理工艺研究

对轮窑志烟气处理的石灰乳水溶液吸收过程和百渣的固化过程进行了理论分析，探讨了该系统的工艺条件和设施。结果表明，采用喷射鼓泡瓜器自理含氟、含烟气，氟化物平均浓度从９４．７ｍｇ／ｍ＾３降至７．２ｍｇ／ｍ＾３，二氧化硫从６２５．５ｍｇ／ｍ＾３降至１１５．８ｍｇ／ｍ＾３，平均去除率氟化物为９２．４％，二氧化硫为８１．５％；吸收排渣可固化于主产品内而又不影响产品质量，消除了二次污染。     

"电能替代"是治理城市雾霾的重要途径探讨

城市雾霾已经严重影响城市居民的正常生活与工作.研究表明,传统化石燃料在城市及其周边地区终端用户中直接使用是产生城市雾霾的主要原因.为了治理城市雾霾,国家和地方各级政府以及有关单位出台了一系列政策和行动方案.其中,利用绿色能源电能,在生产和生活中,代替传统化石能源,这一方案在城市终端用户中都可以大面积使用电能替代,是阻止城市雾霾的重要举措,电能替代不仅可以有效缓解城市雾霾,还可以提高城市智能化水平,是未来城市发展的重要趋势.     

Progress in research and development of particle electrodes for three-dimensional electrochemical treatment of wastewater: a review

Environmental Science and Pollution Research - A three-dimensional (3D) electrochemical technology is regarded as a very effective industrial wastewater treatment method as it has high treatment...     

Removal of Methylene Blue from Water by Peach Gum Based Composite Aerogels

Journal of Polymers and the Environment - In this study, novel composite aerogels of peach gum/activated carbon (PGAC) and peach gum/graphene oxide (PGGO) were synthesized by freeze-drying method...     

Correction to: Facile synthesis of the magnetic metal–organic framework Fe3O4/Cu3(BTC)2 for efficient dye removal

Environmental Chemistry Letters - Dyeing wastewaters present high hazards for the environment and human health. Advanced dye removal may be achieved by magnetic metal–organic frameworks...     

PPCPs and heavy metals from hydrothermal sewage sludge-derived biochar: migration in wheat and physiological response

Environmental Science and Pollution Research - Once the sludge was directly used in the farmland, it will have a negative impact on human health through the food chain because sludge contains...     

Distribution patterns of lead in urban soil and dust in Shenyang city, Northeast China

We investigated the spatial distribution of Pb in soil and dust samples collected from 54 sites in Shenyang city, Liaoning province, Northeast China. Soil background Pb concentration was 22 mg kg⁻¹ and control values from non-industrial areas were 33 mg kg⁻¹ for soil and 38 mg kg⁻¹ for dust. Soil Pb concentrations varied widely, ranging from 26 to 2911 mg kg⁻¹, with a mean concentration of 200 mg kg⁻¹, 9 times the background value and 6 times the control value. There was great variation in soil Pb, with a coefficient of variation (CV) of 1.06 and a standard deviation (SD) of 212 mg kg⁻¹. Dust Pb concentrations fluctuated from 20 to 2810 mg kg⁻¹, with a mean value of 220 mg kg⁻¹, almost 6 times the control value. No significant differences in distribution were observed between soil Pb and dust Pb. The highest Pb concentration was observed in Tiexi district in an industrial area. Soil Pb concentration decreased with depth and with distance from the pollution source. Lead concentrations initially changed little but then decreased with distance from the roadside, and were generally higher on the east side of roads than on the west. Lead contents in different categories of urban area differed substantially with dust and soil Pb concentrations decreasing in the sequence: industrial >business >mixed (residential, culture and education)> reference areas.