丽江市古城区污水处理厂扩建工程的启动调试及运行

丽江市污水处理厂扩建工程处理规模为1万m3/d,采用了改良型ICEAS工艺。该污水处理系统的启动调试内容,包括调试前的准备工作以及活性污泥的培养与驯化。活性污泥培养驯化历时50 d左右,活性污泥絮体基本形成,生物相基本稳定,处理效果显著,出水各项指标达标。在进水BOD低营养源不足的不利条件下,成功完成了该污水处理厂的启动调试和活性污泥培养驯化,对指导污水厂的调试运行有着重要的意义。     

Preparation of a titanium dioxide photocatalyst codoped with cerium and iodine and its performance in the degradation of oxalic acid

A novel class of visible light-activated photocatalysts was prepared by codoping TiO(2) with cerium and iodine (Ce-I-TiO(2)). The particles were characterized using the Brunauer-Emmett-Teller method, X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and UV-Visible light absorption. Particles of Ce-I-TiO(2) had greater photoabsorption in the 400-800 nm wavelength range than iodine-doped TiO(2) (I-TiO(2)). The effects on the photocatalytic degradation of oxalic acid under visible light or UV-Visible light irradiation were investigated. The photocatalytic activity of Ce-I-TiO(2) calcined at 673 K was significantly higher than that of Ce-I-TiO(2) calcined at 773 K and I-TiO(2) calcined at 673 K in aqueous oxalic acid solution under visible light or UV-Visible light irradiation. Under visible light irradiation, oxalic acid was first adsorbed on the surface of the catalysts rather than reacted with free radicals in the bulk solution, and then oxidized by (·)OH(ads) to CO(2), which was verified by studying the effects of nitrogen purging and scavengers, as well as by gas chromatography/mass spectrometry.     

活性碳纤维负载纳米TiO_2光催化材料的制备

采用浸渍液中添加环氧树脂黏结剂并高温热处理的方法,制备出活性碳纤维(ACF)负载纳米TiO2光催化材料。对光催化材料的表面形貌和TiO2晶相进行了表征,发现所制备的光催化材料很好地保持了m(锐钛矿型)∶m(金红石型)为79∶21的混晶结构。评价了光催化材料对亚甲基蓝溶液的光催化降解性能。结果表明,当浸渍液中黏结剂质量浓度为5g/L时,ACF负载纳米TiO2光催化材料失重率较低,表明TiO2的负载强度较高。浸渍液中黏结剂质量浓度为15g/L时,ACF上TiO2负载率最高,为65%。当浸渍液中黏结剂质量浓度为25g/L时,ACF负载纳米TiO2光催化材料对亚甲基蓝的降解率最高,反应120min时,亚甲基蓝降解率均接近100%。     

华中地区种植业生产碳排放驱动因素分析

农业是温室气体排放的第二大人为因素源,探寻农业生产碳排影响因素,对实现农业节能减排有重要意义。以中国粮食主产区华中地区为背景,综合运用IPCC(2006)推荐的方法估算华中地区1994~2013年种植业生产的碳排放量,基于Kaya恒等式、灰色关联模型对华中地区种植业生产的碳排放驱动因素进行识别并探讨主要影响因素的贡献。结果显示:(1)华中地区1994~2013年种植业生产碳排放呈上升趋势,2013年达到了11 257.63万t CO2-eq。其中,河南省、湖北省、湖南省的种植业生产碳排放增幅分别为101.29%、24.88%、21.73%;(2)在过去的20 a中,种植业生产效率、种植业结构、农业劳动力规模对农业生产碳排放具有一定抑制作用,而农业经济发展则促进了种植业生产碳排,具有一定的推动作用;(3)近20 a的农业发展过程中,华中地区种植业生产碳排放最主要的贡献因子是种植业结构,其次是农业从业人口、种植业产值、人均农用物资消耗量。     

半干法脱硫技术的应用与分析

NID半干法脱硫技术结构简单,具有较高的脱硫率.通过在NID脱硫技术实施中的调试和运行,分析其工艺特点和工艺控制要点,并提出了存在的问题和对策.     

长江水系河流与水库中鲤鱼的元素含量特征

针对长江三峡水库蓄水后引起水库汞活化效应对生态与环境的影响问题,系统地分析了长江水系水库与河流鲤鱼肌肉的Ａｓ,Ｃｄ,Ｃｕ,Ｆｅ,Ｈｇ,Ｍｎ,Ｐｂ,Ｓｅ,Ｎａ,Ｍｇ等元素含量的分布特征。并以丹江口水库－汉江,陈村水库－青戈江为例,用多元分析证明水库与河流的鲤肌肉中Ａｓ,Ｓｅ,Ｈｇ,Ｃｄ等元素含量存在显著差异,同时指出水库汞活化效应引起的鱼体汞含量增加是该元素的一种生物地球化学现象,并利用同一水系水库     

Tissue-dependent distribution and accumulation of chlorobenzenes by vegetables in urban area

Five seasonal vegetables from three growing sites in Hangzhou city, Zhejiang Province, were studied for the levels of four chlorobenzenes(CBs): o-dichlorobenzene (o-DCB), p-dichlorobenzene (p-DCB), m-dichlorobenzene (m-DCB), and 1,2,4-trichlorobenzene (1,2,4-TCB). Samples of each vegetable from each site were subdivided into leaves, stems, and roots, and these subsamples were analyzed separately for the levels of accumulated CBs. Relations between the levels of CBs in vegetables with the total organic carbon (TOC) of the soil, the lipid content of the vegetable, and the physicochemical properties of CBs were established. Results showed that o-DCB, p-DCB, m-DCB, 1,2,4-TCB were present in all vegetables analyzed. For spinaches (Spinacia oleracea), Chinese cabbages (Brassica rapa var. pekinensis), and celery (Apium graveolens var. dulce), the highest level of CBs was with roots, followed by leaves. While for radishes (Raphanus sativus), and carrots (Daucus carota subsp. sativus), the highest level was with leaves, followed by stems. The accumulation of CBs was found to have a good correlation with the plant-tissue lipid content, the contaminant air-water Henry's coefficient (H), the contaminant octanol-water partition coefficient (K(ow)), and the physiological characteristics of the vegetables.     

基于车站设施服务水平累积时间的地铁换乘车站风险分析

为研究地铁换乘车站风险,制定客流组织方案,基于Fruin设施服务水平划分标准,提出通过比较各级服务水平累积时间,对地铁换乘车站风险进行分析。以北京地铁1,5号线换乘站-东单站为研究对象,对单向换乘及双向换乘2种方案下,早高峰1 h的客流疏运过程进行模拟。研究结果表明：采用双向换乘方案时,客流平均密度高峰值对应区域发生变化,站台北端上行扶梯入口的E,F服务水平累积时间共增加68.5倍,站厅北端楼扶梯附近E,F服务水平累积时间共增加4.9倍,成为新的客流风险点,早高峰期间在该区域应加强客流疏导。