活性污泥吸附废水中的铍

探讨了活性污泥吸附处理含铍废水的吸附动力学特性及吸附模型,研究了吸附后铍在活性污泥上的存在形态。实验结果表明,铍离子在活性污泥上的吸附行为遵循二级动力学规律,活性污泥在溶液中的分散性非常好,污泥微孔内扩散效应不是吸附过程的主要控制步骤,扩散速率主要由液相向固相的传质速率所控制,铍在污泥上的吸附主要为快速的表面吸附。铍在活性污泥上的吸附数据既可用Freundlich方程描述,也符合Langmuir吸附规律,Langmuir曲线的相关性还较Freundlich曲线高,吸附过程受温度影响不大,通过对处理后污泥的连续提取实验研究可知,处理后的活性污泥中铍的主要存在形态为有机结合态、残渣态和交换态。     

《国家危险废物名录》在危险废物管理中的存在的问题

本文介绍了我国危险废物名录目前的现状,分析了危险废物名录在危险废物监管中存在的问题,对危险废物的监管提出了建设鉴定机构、严格鉴定程序、豁免制度等建议。     

Chemical composition and source apportionment of PM10 and PM2.5 in different functional areas of Lanzhou, China

To elucidate the air pollution characteristics of northern China, airborne PM_10(atmospheric dynamic equivalent diameter ≤ 10 μm) and PM_(2.5)(atmospheric dynamic equivalent diameter ≤ 2.5 μm) were sampled in three different functional areas(Yuzhong County,Xigu District and Chengguan District) of Lanzhou, and their chemical composition(elements, ions, carbonaceous species) was analyzed. The results demonstrated that the highest seasonal mean concentrations of PM_10(369.48 μg/m~3) and PM_(2.5)(295.42 μg/m~3) were detected in Xigu District in the winter, the lowest concentration of PM_(2.5)(53.15 μg/m~3) was observed in Yuzhong District in the fall and PM_10(89.60 μg/m~3) in Xigu District in the fall.The overall average OC/EC(organic carbon/elemental carbon) value was close to the representative OC/EC ratio for coal consumption, implying that the pollution of Lanzhou could be attributed to the burning of coal. The content of SNA(the sum of sulfate, nitrate,ammonium, SNA) in PM_(2.5)in Yuzhong County was generally lower than that at other sites in all seasons. The content of SNA in PM_(2.5)and PM_10 in Yuzhong County was generally lower than that at other sites in all seasons(0.24–0.38), indicating that the conversion ratios from precursors to secondary aerosols in the low concentration area was slower than in the area with high and intense pollutants. Six primary particulate matter sources were chosen based on positive matrix factorization(PMF) analysis, and emissions from dust, secondary aerosols, and coal burning were identified to be the primary sources responsible for the particle pollution in Lanzhou.     

Self-feedback LSTM regression model for real-time particle source apportionment

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