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851.
强化一级处理与SBR工艺处理油脂精炼加工废水 总被引:1,自引:0,他引:1
介绍了规模为200 m^3/d的油脂精炼加工废水处理工程的设计与运行.先经强化一级处理工艺预处理,再经SBR工艺处理,出水的有关指标能达到设计的排放标准,工艺运行稳定. 相似文献
852.
总氮测定中的注意事项 总被引:1,自引:0,他引:1
碱性过硫酸钾消解紫外分光光度法测定总氮中,对空白值偏高的影响因素进行了实验和分析,提出了几点建议及改进措施。 相似文献
853.
854.
柱生物曝气法吸附处理含铬废水 总被引:7,自引:0,他引:7
利用复合生物吸附剂FY01与活性污泥作为吸附材料,探讨了柱式生物曝气法对高浓度含铬电镀废水的生物吸附效果。研究结果表明,FY01性能稳定,耐进水pH冲击能力较强。当进水pH=2—5、流速为500mL/h时,10gFY01和5g活性污泥联合处理60.4mg/L含铬电镀废水2h后,铬的去除率达78%以上;在4℃冰箱和23—28℃实验室保存50d的FY01对铬的去除分别在78%~83%和77%-84%之间。柱式生物曝气吸附法对含铬废水的处理效果理想,运行稳定。串联处理2000mL总Cr、Cu^2+和COD浓度分别为60.4、4.51和48.2mg/L的电镀废水2h后,去除率分别高达92.1%、99.2%和71.4%。 相似文献
855.
Chlorinated and polycyclic aromatic hydrocarbons in riverine and estuarine sediments from Pearl River Delta, China 总被引:53,自引:0,他引:53
Mai BX Fu JM Sheng GY Kang YH Lin Z Zhang G Min YS Zeng EY 《Environmental pollution (Barking, Essex : 1987)》2002,117(3):457-474
Spatial distribution of chlorinated hydrocarbons [chlorinated pesticides (CPs) and polychlorinated biphenyls (PCBs)] and polycyclic aromatic hydrocarbons (PAHs) was measured in riverine and estuarine sediment samples from Pearl River Delta, China, collected in 1997. Concentrations of CPs of the riverine sediment samples range from 12 to 158 ng/g, dry weight, while those of PCBs range from 11 to 486 ng/g. The CPs concentrations of the estuarine sediment samples are in the range 6-1658 ng/g, while concentrations of PCBs are in the range 10-339 ng/g. Total PAH concentration ranges from 1168 to 21,329 ng/g in the riverine sediment samples, whereas the PAH concentration ranges from 323 to 14,812 ng/g in the sediment samples of the Estuary. Sediment samples of the Zhujiang River and Macao harbor around the Estuary show the highest concentrations of CPs, PCBs, and PAHs. Possible factors affecting the distribution patterns are also discussed based on the usage history of the chemicals, hydrologic condition, and land erosion due to urbanization processes. The composition of PAHs is investigated and used to assess petrogenic, combustion and naturally derived PAHs of the sediment samples of the Pearl River Delta. In addition, the concentrations of a number of organic compounds of the Pearl River Delta samples indicate that sediments of the Zhujiang river and Macao harbor are most likely to pose biological impairment. 相似文献
856.
This work evaluated the flushing efficiency of tetrachloroethylene (PCE) using the co-surfactant of non-ionic ethoxylated sorbitan ester (Tween) and oilphilic sorbitan monooleate (Span 80), which formed more hydrophobic micelles than Tween alone. The flushing efficiency was evaluated with laboratory columns filled with silica and aquifer sand. Results from column flushing were also compared to those of batch solubility experiments to study the removal mechanism by the co-surfactant solution. Compared to Tween 80 alone, the molar solubilization ratio and the affinity between the micelles and PCE increased 84% and 90%, respectively, by the co-surfactant solution of Tween 80 and Span 80 mixed at a 4:1 ratio. Flushing with 1% Tween 80 solution yielded a steady PCE recovery of 7% for both silica and aquifer sand in each pore volume (PV). Flushing with co-surfactant of 1% Tween 80 + Span 80 (4:1) further increased PCE recovery to 10% for silica sand and 13% for aquifer sand per PV. A comparison of results from column flushing and batch solubility tests indicated that the primary flushing mechanism of PCE using the co-surfactant solution of Tween 80 + Span 80 (4:1) was micellar solubilization. 相似文献
857.
K R Anderson E L Avol S A Edwards D A Shamoo R C Peng W S Linn J D Hackney 《Journal of the Air & Waste Management Association》1992,42(6):770-776
Respirable carbon or fly ash particles are suspected to increase the respiratory toxicity of coexisting acidic air pollutants, by concentrating acid on their surfaces and so delivering it efficiently to the lower respiratory tract. To investigate this issue, we exposed 15 healthy and 15 asthmatic volunteers in a controlled-environment chamber (21 degrees C, 50 percent relative humidity) to four test atmospheres: (i) clean air; (ii) 0.5-microns H2SO4 aerosol at approximately 100 micrograms/m3, generated from water solution; (iii) 0.5-microns carbon aerosol at approximately 250 micrograms/m3, generated from highly pure carbon black with specific surface area comparable to ambient pollution particles; and (iv) carbon as in (iii) plus approximately 100 micrograms/m3 of ultrafine H2SO4 aerosol generated from fuming sulfuric acid. Electron microscopy showed that nearly all acid in (iv) became attached to carbon particle surfaces, and that most particles remained in the sub-micron size range. Exposures were performed double-blind, 1 week apart. They lasted 1 hr each, with alternate 10-min periods of heavy exercise (ventilation approximately 50 L/min) and rest. Subjects gargled citrus juice before exposure to suppress airway ammonia. Lung function and symptoms were measured pre-exposure, after initial exercise, and at end-exposure. Bronchial reactivity to methacholine was measured after exposure. Statistical analyses tested for effects of H2SO4 or carbon, separate or interactive, on health measures. Group data showed no more than small equivocal effects of any exposure on any health measure.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
858.
运用空气质量模型CMAQ模拟评估民用燃煤减排政策对京津冀大气中BaP污染状况的改进效果,模拟包括作为基准情景的2014年和低消减和高消减2个减排情景.模拟结果表明:基准情景下,京津冀BaP年均浓度为2.54ng/m3,超过国家空气质量标准(1ng/m3),呈现1月 > 4月 > 10月 > 7月的季节变化特点,反映出冬季供暖燃煤的影响;京津冀南部BaP浓度高于北部,推测原因是南部BaP排放量较高.1月削减民用燃煤排放量对降低该地区BaP浓度和沉降量效果最显著,低削减和高削减下,北京、保定、廊坊BaP浓度分别比基准情景降低30%和40%以上;4、7、10月削减民用燃煤排放量对该地区BaP浓度和沉降量的变化影响不大.京津冀民用燃煤联防联控能更加有效地降低该地区BaP浓度. 相似文献
859.
光谱纯度是积分路径差分吸收激光雷达最重要的系统参数之一,光谱纯度直接影响CO2数据的探测精度.在模式研究中要求输入观测的CO2数据误差小于1×10-6,对激光器光谱纯度参数设计提出很高要求.本文采用有效吸收截面分析探测反演误差的方法,研究了由光谱纯度带来的CO2柱浓度探测误差,并基于窄带滤波器对光谱不纯能量的抑制作用,对不同带宽的窄带滤波器进行选择和分析,从而达到降低对光谱纯度的要求,提升探测精度的目的,最后讨论了由于窄带滤波器造成的能量衰减所对随机误差的影响.结果表明:当光谱纯度为99.9%,窄带滤波器带宽1GHz,透射率为0.86,脉冲能量为100mJ时CO2探测的系统误差小于0.084×10-6,随机误差小于0.02×10-6,满足探测精度要求. 相似文献
860.