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101.
为解决水环境污染问题,提升水污染源自动监控系统的运行效率,介绍了水污染源自动监控系统的基本情况,指出了其中存在的问题,提出了提升水污染源监控系统运行效果的对策:社会各方形成合力,共同展开源头保障工作,建设水污染源监控系统,规范化推广,提高运营效率,采取统一的业务专业化培训方式,严格规范相关设备的使用,定期进行业务考评,... 相似文献
102.
103.
Assessment of spatial distribution of soil loss over the upper basin of Miyun reservoir in China based on RS and GIS techniques 总被引:2,自引:0,他引:2
Chen T Niu RQ Wang Y Li PX Zhang LP Du B 《Environmental monitoring and assessment》2011,179(1-4):605-617
Soil conservation planning often requires estimates of the spatial distribution of soil erosion at a catchment or regional scale. This paper applied the Revised Universal Soil Loss Equation (RUSLE) to investigate the spatial distribution of annual soil loss over the upper basin of Miyun reservoir in China. Among the soil erosion factors, which are rainfall erosivity (R), soil erodibility (K), slope length (L), slope steepness (S), vegetation cover (C), and support practice factor (P), the vegetative cover or C factor, which represents the effects of vegetation canopy and ground covers in reducing soil loss, has been one of the most difficult to estimate over broad geographic areas. In this paper, the C factor was estimated based on back propagation neural network and the results were compared with the values measured in the field. The correlation coefficient (r) obtained was 0.929. Then the C factor and the other factors were used as the input to RUSLE model. By integrating the six factor maps in geographical information system (GIS) through pixel-based computing, the spatial distribution of soil loss over the upper basin of Miyun reservoir was obtained. The results showed that the annual average soil loss for the upper basin of Miyun reservoir was 9.86 t ha(-1) ya(-1) in 2005, and the area of 46.61 km(2) (0.3%) experiences extremely severe erosion risk, which needs suitable conservation measures to be adopted on a priority basis. The spatial distribution of erosion risk classes was 66.9% very low, 21.89% low, 6.18% moderate, 2.89% severe, and 1.84% very severe. Thus, by using RUSLE in a GIS environment, the spatial distribution of water erosion can be obtained and the regions which susceptible to water erosion and need immediate soil conservation planning and application over the upper watershed of Miyun reservoir in China can be identified. 相似文献
104.
Jingjing Jiang Jiaying Gao Shu Niu Xingyue Wang Tianren Li Shengda Liu Yanhong Lin Tengfeng Xie Shuangshi Dong 《环境科学学报(英文版)》2021,33(8):147-160
The extensive use of tetracycline hydrochloride (TCH) poses a threat to human health and the aquatic environment. Here, magnetic p-n Bi2WO6/CuFe2O4 catalyst was fabricated to efficiently remove TCH. The obtained Bi2WO6/CuFe2O4 exhibited 92.1% TCH degradation efficiency and 50.7% and 35.1% mineralization performance for TCH and raw secondary effluent from a wastewater treatment plant in a photo-Fenton-like system, respectively. The remarkable performance was attributed to the fact that photogenerated electrons accelerated the Fe(III)/Fe(II) and Cu(II)/Cu(I) conversion for the Fenton-like reaction between Fe(II)/Cu(I) and H2O2, thereby generating abundant ?OH for pollutant oxidation. Various environmental factors including H2O2 concentration, initial pH, catalyst dosage, TCH concentration and inorganic ions were explored. The reactive oxidation species (ROS) quenching results and electron spin resonance (ESR) spectra confirmed that ?O2? and ?OH were responsible for the dark and photo-Fenton-like systems, respectively. The degradation mechanisms and pathways of TCH were proposed, and the toxicity of products was evaluated. This work contributes a highly efficient and environmentally friendly catalyst and provides a clear mechanistic explanation for the removal of antibiotic pollutants in environmental remediation. 相似文献
105.
Jin Xie Xiao-Dong Niu Jiao-Jiao Xie Kai-Qiang He Meng-Dan Shi Su-Juan Yu Chun-Gang Yuan Jing-Fu Liu 《环境科学学报(英文版)》2021,33(10):1-7
The distribution and chemical speciation of arsenic (As) in different sized atmospheric particulate matters (PMs), including total suspended particles (TSP), PM10, and PM2.5, collected from Baoding, China were analyzed. The average total mass concentrations of As in TSP, PM10, and PM2.5 were 31.5, 35.3, and 54.1 µg/g, respectively, with an order of PM2.5 >PM 10 > TSP, revealing that As is prone to accumulate on fine particles. Due to the divergent toxicities of different As species, speciation analysis of As in PMs is further conducted. Most of previous studies mainly focused on inorganic arsenite (iAsIII), inorganic arsenate (iAsV), monomethylarsonate (MMA), and dimethylarsinate (DMA) in PMs, while the identification and sensitive quantification of trimethylarsine oxide (TMAO) were rarely reported. In this study, a high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry system was optimized for As speciation including TMAO in PMs. An anion exchange column was used to separate MMA, DMA and iAsV, while a cation exchange column to separate TMAO and iAsIII. Results showed that iAsV was the dominate component in all the samples, corresponding to a portion of 79.2% ± 9.3% of the total extractable species, while iAsIII, TMAO and DMA made up the remaining 21%. Our study demonstrated that iAsIII accounted for about 14.4% ± 11.4% of the total extracted species, with an average concentration of 1.7 ± 1.6 ng/m3. It is worth noting that TMAO was widely present in the samples (84 out of 97 samples), which supported the assumption that TMAO was ubiquitous in atmospheric particles. 相似文献
106.
Junling Li Hong Li Xuezhong Wang Weigang Wang Maofa Ge Hao Zhang Xin Zhang Kun Li Yan Chen Zhenhai Wu Fahe Chai Fan Meng Yujing Mu Abdelwahid Mellouki Fang Bi Yujie Zhang Lingyan Wu Yongchun Liu 《环境科学学报(英文版)》2021,33(4):185-197
Understanding the formation mechanisms of secondary air pollution is very important for the formulation of air pollution control countermeasures in China. Thus, a large-scale outdoor atmospheric simulation smog chamber was constructed at Chinese Research Academy of Environmental Sciences (the CRAES Chamber), which was designed for simulating the atmospheric photochemical processes under the conditions close to the real atmospheric environment. The chamber consisted of a 56-m3 fluorinated ethylene propylene (FEP) Teflon film reactor, an electrically-driven stainless steel alloy shield, an auxiliary system, and multiple detection instrumentations. By performing a series of characterization experiments, we obtained basic parameters of the CRAES chamber, such as the mixing ability, the background reactivity, and the wall loss rates of gaseous compounds (propene, NO, NO2, ozone) and aerosols (ammonium sulfate). Oxidation experiments were also performed to study the formation of ozone and secondary organic aerosol (SOA), including α-pinene ozonolysis, propene and 1,3,5-trimethylbenzene photooxidation. Temperature and seed effects on the vapor wall loss and SOA yields were obtained in this work: higher temperature and the presence of seed could reduce the vapor wall loss; SOA yield was found to depend inversely on temperature, and the presence of seed could increase SOA yield. The seed was suggested to be used in the chamber to reduce the interaction between the gas phase and chamber walls. The results above showed that the CRAES chamber was reliable and could meet the demands for investigating tropospheric chemistry. 相似文献
107.
Cai Yujie Zhang Xinhua Xue Ruiying Wang Ming Deng Qing 《Environmental Fluid Mechanics》2022,22(4):839-863
Environmental Fluid Mechanics - Based on the mechanism of landslide dam failure caused by overtopping, a simplified mathematical model for simulating dam breach overtopping flow processes was... 相似文献
108.
应用1958~1995年38a6月份陕西省关中、陕南地区24站的降水资料,研究了关中、陕南6月份的降水特点;选取其中12站作为资料站,计算出关中、陕南6月份的降水指数f,研究了关中、陕南初夏(6月份)的干旱特点;就初夏干旱发生的高空500hPa环流形势与历年平均状况进行了对比分析,并对初夏干旱作了预测。 相似文献
109.
斜坡变形与失稳活动是黄土高原突出的地质地貌现象.它有较强的致灾性。本文通过陕西铜川斜坡变形的现场实际调查,研究了该地斜坡的形态、物质组成、变形形式以及作用因素等。本研究对厚层黄土区斜坡变形灾害的防治有较重要意义。 相似文献
110.
针对制糖生产用水存在的问题,提出了制糖生产零取水零排放的技术方案及工艺组成。其核心技术经试验和工程实践证明是合理、有效的,具有技术先进性和推广性。 相似文献