磁性载体生物膜反应器处理生活污水的试验研究

选取天然多孔矿物-浮石、网络状塑料外壳、磁铁为材料,开发出一种新型磁性载体,并将该载体应用于生物膜反应器中进行废水处理试验,结果表明:该磁性载体生物膜反应器在载体的挂膜性能及主要污染物去除功能上均优于非磁性载体生物膜反应器.磁性载体可在5d内完成挂膜,而非磁性载体则需8d,磁性载体生物膜反应器对COD、NH+ 4-N的去除率比非载体生物膜反应器分别高出5%和20%左右.在载体中心磁场强度为200Gs,水中溶解氧DO为2.0~3.5mg/L,水力停留时间HRT为5h的条件下,校园生活污水经磁性载体生物膜反应器处理后,出水中COD稳定在20mg/L左右, NH4+-N在5mg/L以下,两者的去除率均在90%左右,出水总氮为15mg/L,去除率在50%以上.实验结果还表明:连续运行60d后,磁性载体反应器内的生物膜量和悬浮污泥量仅为非磁性载体反应器的70%,说明磁场的存在有利于污泥减量化.磁载体生物膜反应器中载体外表面附着污泥及生物膜的SOUR值均大于非磁载体生物膜反应器,表明一定的磁场强度可以提高微生物活性.     

Employment of passive sampling in monitoring indoor air quality in selected residences in a Tri-city area in Poland

Time-weighted average concentrations of selected volatile compounds were measured in chosen residences in a Tri-City area of Poland by means of passive sampling. The results were compared to those obtained by dynamic technique – sorption tubes filled with Tenax TA sorbent. Results obtained by employing the two techniques were similar. Total volatile organic compound (TVOC) parameters were also determined. An attempt was also made to evaluate the influence of outdoor air pollutants on indoor air quality.     

Urinary level of homovanillic acid and mercury in autistic children

Catecholamines and their metabolites affect children's nervous system. Dopamine is an important neurotransmitter in the brain. In the routine analysis for diagnostics of diseases, the dopamine metabolite homovanillic acid (HVA) is determined. Mercury is a neurotoxic agent and can cause different undesirable effects on the brain. In the present work a putative correlation between HVA, the main metabolite of dopamine, and mercury in urine of healthy and autistic children was studied. The level of HVA was higher in the urine of autistic children (14.5 ± 8.3 mg L^?1) compared to generally healthy children (4.4 ± 0.5 mg L^?1). The level of mercury in the urine of autistic children was lower (0.36 ± 0.24 µg L^?1) than in the urine of healthy children (2.1 ± 1.0 µg L^?1) showing that there is no correlation between HVA and mercury.     

我国原铝冶炼行业温室气体排放模型

我国原铝冶炼行业产业集中度较低,生产水平参差不齐,随着国内原铝产量不断增加,原铝行业碳排放及其计算方法备受关注. 针对我国原铝冶炼过程原料类型、能源结构复杂的特点,对国内外已有碳排放核算框架进行细化,从物料、工序、工艺3个层面构建了复杂的原铝冶炼系统温室气体排放计算模型. 在广泛文献调研的基础上,选取典型原铝冶炼企业开展现场调研及专家咨询,进而形成模型的基础数据库. 利用上述模型对我国2011年原铝冶炼过程碳排放进行核算. 结果表明:综合考虑氧化铝生产工艺结构、电解铝行业分布区域的电网能源结构,我国原铝冶炼系统CO₂排放因子(以铝锭计)为14.70t/t. 电解铝生产过程电耗相关排放占70%,南方电网区域电解铝生产电耗相关CO₂排放分别比华中、华北地区低13%、30%. 原铝冶炼行业可通过优先选用碳排放因子较低的物料、淘汰落后氧化铝工艺、开发引进低温低电压工艺技术等手段,进一步实现物料、工序及工艺的多层次温室气体减排.      

镉对油菜幼苗硫吸收、转运和分布的影响

采用营养液培养-同位素示踪法研究了镉(Cd2+浓度为10μmol.L-1和50μmol.L-1)对油菜幼苗(秦油9号)硫吸收、转运和分布的影响.结果表明,镉处理促进了油菜植株对硫的吸收.10μmol.L-1镉处理96 h油菜植株比对照组吸收的硫增加了36%,而且促进了硫向地上部的转运,有39.4%的硫被转运到植株的地上部,转运速率较对照组增加了50%.相同时间内,50μmol.L-1镉处理的油菜植株中的硫仅比对照组多3%,转运速率显著下降,但仍有25.9%的硫被转运至地上部.     

建筑垃圾资源化处置技术及装备综述

介绍了国内外有关建筑垃圾资源化处置的相关工艺,并从分选除杂、破碎、筛分、整形强化四方面总结了建筑垃圾资源化处置技术与装备,分析其性能特点及应用范围,为我国相关工艺技术及装备的发展提供参考和借鉴。     

锅炉废气流化床污泥干化塔的热力计算与分析

利用锅炉尾部废烟气(120～190℃)干化市政污泥,降低污泥含水率可达到后继合理利用。从三方面对污泥干化进行了分析:1)干燥后污泥含水率与污泥处理量关系;2)入口烟温、流量与污泥处理量关系;3)干燥后烟气相对湿度影响因素分析。结果表明:提高入口烟温、流量,污泥出口含水率都可以提高污泥处理量,高入口烟温、流量下,污泥处理量受含水率的影响更大;污泥出口含水率高时,入口烟温提高使污泥处理量提高增大显著;入口烟气流量愈高,入口烟温提高对污泥处理量的增加愈大。干燥后烟气相对湿度与入口烟温有关,干燥之后的烟气的相对湿度离饱和状态较远,此温度范围内的出口烟气湿度还有较大的余量。     

g 辐照预处理促进剩余污泥发酵产氢的研究

为降低能耗,提高辐照技术的经济性,探讨了在0~9.5kGy范围内,γ辐照剂量对生活污水处理厂二沉池剩余污泥中耗氢菌的抑制效果和对发酵产氢的影响,建立了描述发酵产氢过程及辐照影响的动力学模型.结果表明,γ辐照剂量从0增加至9.5kGy时,污泥溶解率从0增加至4%,上清液中可检测出一定的蛋白质和多糖等物质,其中蛋白质中的氮素占溶出总氮素的90%,表明较低剂量辐照即对污泥菌体造成较明显的破解,这可在一定程度上抑制无法形成芽孢的耗氢菌活性;与之相对应的是污泥发酵产氢能力的明显提升,以葡萄糖为底物(1.0g/L),在35℃和初始pH值为7.0时,当辐射剂量仅为0.5kGy时,累积产氢量即比未辐照时有70%的提升,进一步增加辐照剂量至5kGy,累计产氢量和产氢得率均继续增长且达到最大值,分别为240mL/g葡萄糖和1.93mLH2/mol葡萄糖(发酵液的污泥量达2.0g VSS/L);此后,污泥发酵产氢能力随辐射剂量的增加而降低.修正的Logistic模型能很好地描述本研究中累积产氢量随时间的变化规律,而修正的Han-Levenspiel模型能很好地描述辐照剂量对平均产氢速率的影响.     

Associations between soil lead concentrations and populations by race/ethnicity and income-to-poverty ratio in urban and rural areas

Lead (Pb) is a well-studied environmental contaminant that has many negative health effects, especially for children. Both racial/ethnic and income disparities have been documented with respect to exposure to Pb in soils. The objectives of this study were to assess whether soil Pb concentrations in rural and urban areas of South Carolina USA, previously identified as having clusters of intellectual disabilities (ID) in children, were positively associated with populations of minority and low-income individuals and children (≤6 years of age). Surface soils from two rural and two urban areas with identified clusters of ID were analyzed for Pb and concentrations were spatially interpolated using inverse distance weighted analysis. Population race/ethnicity and income-to-poverty ratio (ITPR) from United States Census 2000 block group data were aerially interpolated by block group within each area. Urban areas had significantly higher concentrations of Pb than rural areas. Significant positive associations between black, non-Hispanic Latino, individuals and children ≤6 years of age and mean estimated Pb concentrations were observed in both urban (r = 0.38, p = 0.0007) and rural (r = 0.53, p = 0.04) areas. Significant positive associations also were observed between individuals and children with an ITPR < 1.00 and Pb concentrations, though primarily in urban areas. Racial/ethnic minorities and low ITPR individuals, including children, may be at elevated risk for exposure to Pb in soils.     

Space-time stick-breaking processes for small area disease cluster estimation

We propose a space-time stick-breaking process for the disease cluster estimation. The dependencies for spatial and temporal effects are introduced by using space-time covariate dependent kernel stick-breaking processes. We compared this model with the space-time standard random effect model by checking each model’s ability in terms of cluster detection of various shapes and sizes. This comparison was made for simulated data where the true risks were known. For the simulated data, we have observed that space-time stick-breaking process performs better in detecting medium- and high-risk clusters. For the real data, county specific low birth weight incidences for the state of South Carolina for the years 1997–2007, we have illustrated how the proposed model can be used to find grouping of counties of higher incidence rate.