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161.
类Fenton氧化技术去除榨菜生产废水COD的研究   总被引:1,自引:0,他引:1  
研究了紫外光照射下类Fenton试剂对榨菜生产废水COD的去除,考察了光照时间、初始pH值、过氧化氢用量、FeCl3·6H2O用量等因素对榨菜废水中COD去除率的影响。结果表明,光照时间60 min,初始pH值3,H2O2(30%)的用量为理论值的120%,c0(H2O2)∶c0[Fe(Ⅲ)]=11.6∶1.0时,COD去除率效果为最佳,达到79%。当H2O2投加总量不变时,去除率随着投加次数的增多而增大。  相似文献   
162.
总结了近5年来再入飞行力热环境预测与试验技术的研究进展.针对高速绕流流场引起的宽频声振环境和瞬态热环境,调研了国内外在上述环境的数值模拟预测、等效模拟试验和试验观测方面的最新研究情况和目前仍面临的难点问题.重点介绍了中物院总体所围绕再入飞行力热环境预测与试验方面开展的研究工作和已取得的部分研究成果.提出了后续研究方向和...  相似文献   
163.
Surface sediment samples from 12 sites of the three selected rivers in Daliaohe River watershed (Hunhe River, Taizihe River and Daliaohe River) were analyzed with the objective of establishing sources and hazard of the organochlorinae pesticides (OCPs) and polychlorinated biphenyl (PCBs) in surface sediments. The total concentrations of OCPs varied from 3.06 to 23.24 ng g−1. ∑HCH (α-HCH, β-HCH, δ-HCH, γ-HCH), ∑DDT (p, p′-DDE, p, p′-DDD, o, p′-DDT, p, p′-DDT) and ∑Cyclodiene (Heptachlor, Aldrin, Heptachlor epoxide, Dieldrin, Endrin) ranged from 1.86 to 21.48, 0.5 to 2.81 and 0.56 to 1.53 ng g−1, respectively. Results of OCPs also illustrate that the most dominant pollutants among the OCPs was ∑HCH, and γ-HCH was the most dominant isomer in HCH, which was evidence of recent input of lindane. It possibly came from the runoff of polluted soils and long-scale transportation. Total PCB concentrations ranged between 1.88 and 16.88 ng g−1. The peak concentrations of PCBs were found in sediments from station T5 and D3, which are in the vicinity of industrial areas and ferry, respectively. These data show a moderate level of OCPs and PCBs contaminations compared to that in other countries.  相似文献   
164.
2003年夏秋季大气环流异常对西北地区降水的影响   总被引:4,自引:2,他引:4  
林纾  赵建华  瞿汶 《灾害学》2004,19(3):62-67
根据2003年6~10月西北地区118站逐日降水资料,对该地区、该时段的大气环流及其对该地区降水的影响进行了分析研究.  相似文献   
165.
Adsorption-desorption characteristics of mercury in paddy soils of China   总被引:1,自引:0,他引:1  
Mercury (Hg) has received considerable attention because of its association with various human health problems. Adsorption-desorption behavior of Hg at contaminated levels in two paddy soils was investigated. The two representative soils for rice production in China, locally referred to as a yellowish red soil (YRS) and silty loam soil (SLS) and classified as Gleyi-Stagnic Anthrosols in FAO/UNESCO nomenclature, were respectively collected from Jiaxin County and Xiasha District of Hangzhou City, Zhejiang Province. The YRS adsorbed more Hg(2+) than the SLS. The characteristics of Hg adsorption could be described by the simple Langmuir adsorption equation (r2 = 0.999 and 0.999, P < 0.01, respectively, for the SLS and YRS). The maximum adsorption values (Xm) that were obtained from the simple Langmuir model were 111 and 213 mg Hg(2+) kg(-1) soil, respectively, for the SLS and YRS. Adsorption of Hg(2+) decreased soil pH by 0.75 unit for the SLS soil and 0.91 unit for the YRS soil at the highest loading. The distribution coefficient (kd) of Hg in the soil decreased exponentially with increasing Hg(2+) loading. After five successive desorptions with 0.01 mol L(-1) KCl solution (pH 5.4), 0 to 24.4% of the total adsorbed Hg(2+) in the SLS soil was desorbed and the corresponding value of the YRS soil was 0 to 14.4%, indicating that the SLS soil had a lower affinity for Hg(2+) than the YRS soil at the same Hg(2+) loading. Different mechanisms are likely involved in Hg(2+) adsorption-desorption at different levels of Hg(2+) loading and between the two soils.  相似文献   
166.
建设绿色企业文化是秦皇岛港实现绿色发展的前提,对港口的发展有深远的意义和重要作用.秦皇岛港应从强化领导意识、提高职工素质、完善绿色制度体系、构建绿色企业形象等方面入手建设港口绿色企业文化.  相似文献   
167.
图书馆藏书大多存在实物与财产登记不符的状况,如情况较为严重则会影响到图书馆流通、采访等项工作的开展,因此适时进行书库清点具有重要意义。本文以中国环境管理干部学院图书馆的清点为实例,初步探讨了将条码作为清点切入点的书库清点工作的方法、步骤和注意事项。  相似文献   
168.
Water level response to hydropower development in the upper Mekong River   总被引:3,自引:0,他引:3  
Li S  He D 《Ambio》2008,37(3):170-177
Environmental changes and their transboundary influences on the Mekong watercourse system have been an international research focus in recent years, but the opinions and results related to the impacts of upper Mekong River dams are quite different. In this paper, based on the records of water levels from 1960 to 2003 at three mainstream sites in the upper Mekong River, a quantitative examination has been undertaken into characteristics of the mainstream water-level process at multiple timescales and its response to cascade development. The major results are: i) Annual mean, wet period mean, and the mean water levels during the period between March and April (PBMA period) exhibit a significant increasing trend at Jiuzhou and Yunjinghong sites, which are influenced by large-scale factors such as climate change and solar activity. ii) The interdecadal and interannual variations of annual mean, annual maximum, and wet period mean water levels at three sites show similar features during the dam construction period. iii) The interdecadal variations of PBMA period water level show a gradual increase at Gajiu and Yunjinghong sites but a falling trend at Jiuzhou; these trends confirm that there is some regulation on the flow in the dry season caused by the two existing dams. iv) The downstream effects of the present dams on water levels are very limited at the annual mean and wet season mean levels, not apparent at the monthly and yearly timescales, and relatively significant at daily and hourly timescales.  相似文献   
169.
Anaerobic degradation behavior of nonylphenol polyethoxylates in sludge   总被引:1,自引:0,他引:1  
Lu J  Jin Q  He Y  Wu J  Zhang W  Zhao J 《Chemosphere》2008,71(2):345-351
Anaerobic biodegradation behavior of nonylphenol polyethoxylates (NPEOs) was investigated. Results showed that terminal electron acceptors, organic matters, initial concentration, and temperature had great influence on the anaerobic biodegradation of NPEOs. Anaerobic biodegradation of NPEOs could be enhanced by adding sulfate or nitrate while this process could be inhibited by adding organic matters. The maximum removal rate increased 1.24 microM d(-1) for each ten micromoles increase in initial concentration. The decrease in temperature caused a sharp decrease in the removal efficiency of NPEOs. The temperature coefficient (PHI) for the anaerobic biodegradation of NPEOs was 0.01 degrees C(-1). Nonylphenol (NP), the typical intermediate of NPEOs, could inhibit the anaerobic biodegradation of NPEOs only at high concentration. However, these environmental factors had no effect on the anaerobic biodegradation pathway of NPEOs. The accumulation of NP and short-chain NPEOs during NPEO biodegradation led to a significant increase in the estrogenic activity during the biodegradation period.  相似文献   
170.
The effects of various pretreatment methods, including thermo-acid, thermo-alkaline, ultrasonic-alkaline and ultrasonic-acid, on solubilization and subsequent acidification efficiency of waste activated sludge (WAS) were investigated. The results showed that both thermo-alkaline and ultrasonic-alkaline significantly improved the solubilization of WAS at a high concentration (7.4% of total solids). Solubilization of volatile solids (VS) and crude protein was 60.2-61.6% and 66.8-67.5%, respectively. Thermo-alkaline or ultrasonic-alkaline pretreatment also enhanced the efficiency of subsequent WAS acidification. Experimental results showed that they had similar effects on the acidification of WAS. The conversion ratio from VS to total volatile fatty acids (TVFAs) was 0.230 in the case of the ultrasonic-alkaline pretreatment. Through this pretreatment, the level of TVFAs was 68% more than the untreated WAS after 252 h of fermentation. The mechanism of TVFAs production under different pretreatment methods was further investigated and the results indicated that soluble protein was the main substrate for TVFAs production from the WAS after the thermo-alkaline or ultrasonic-alkaline pretreatment.  相似文献   
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