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11.
高负荷人工土层地下渗滤系统处理生活污水中试工程的研究 总被引:3,自引:0,他引:3
对传统的地下渗滤系统进行改进,采用多层过渡结构的人工土层来增大对颗粒有机物的接触氧化表面积,同时设置曝气装置保证好氧过程的氧气供应,可以大大提高污水地下处理系统的水力负荷.以中国南方典型的红壤土、河沙和砾石为填充材料,处理广州地化所小区的生活污水,水力负荷达40 cm/d,远大于类似系统.试验结果表明,改进后的系统能创造良好的好氧/厌氧环境,对污染物去除效果良好,COD、BOD5、TN、NH 4-N、TP和SS去除率分别达到了76.7%~89.1%、83.3%~92.5%、50.3%~66.1%、65.2%~79.6%、75.4%~90.1%和77.0%~91.3%,出水主要污染物达到了《污水综合排放标准》(GB 8978-1996)一级排放标准或二级排放标准. 相似文献
12.
地铁盾构施工风险评估与风险规避研究 总被引:1,自引:1,他引:1
牛康 《中国安全生产科学技术》2011,7(5):42-46
深圳地铁二号线2202标段包括科苑站—红树湾站—世界之窗站,大部分采用盾构法施工。盾构隧道处于砂质粘性土地层填海地层,下穿4栋高尔夫别墅,存在基岩隆起、孤石和易出现施工扰动等情况。对2202标盾构施工进行安全评估,指出盾构机选型、盾构机进出洞及盾构施工过程中的风险源,如始发方向失控、盾尾卡死、洞口土体坍塌、地面建筑物出现不均匀沉降等,进而强调在施工过程中要正确辨识风险源,并根据地质、水文和周围环境条件研究采取适当的规避风险措施。 相似文献
13.
谭华荣;林跃胜;马康;王飞;方凤满;刘曦博 《环境科学学报》2023,43(10):143-154
水体金属污染对人体健康构成严重威胁,建立金属污染源与健康风险间的关联对金属污染的精准治理至关重要.在安徽省庐江县采集177个地表水样品并测定14种金属元素浓度,采用绝对主成分得分-多元线性回归(APCS-MLR)和基于蒙特卡罗模拟(Monte Carlo simulation)的健康风险评估模型识别地表水中金属的污染源并评估其健康风险.结果表明,庐江县地表水中Al、Be、Co、Cr、Cu、Fe、Mg、Mn、Ni、Pb、Sn和Zn的平均浓度北高南低,Sr呈相反的空间分布特征,而As的空间差异不明显.Be、Fe、Mn和Ni的平均浓度超过《地表水环境质量标准》(GB3838-2002)中的Ⅲ类水质类别限值.APCS-MLR确定了3个污染源,包括交通源、自然源以及农业与矿业混合源,方差贡献率分别为41.94%、18.06%、11.23%.交通源对所有人群造成致癌与非致癌风险的概率均超过80%,对健康风险的贡献率也高于50%.摄入率(IR)和体重(BW)是控制婴儿和儿童健康风险的最敏感参数,Ni和Be浓度分别是导致其他年龄段居民高致癌和非致癌风险的关键元素. 相似文献
14.
Min-Gu Lee Dongwoo Kang Hoyong Jo Jinwon Park 《Journal of Material Cycles and Waste Management》2016,18(3):407-412
In this study, we propose a process making calcium carbonate and calcium sulfate and recovering absorbent using ammonia absorbent, carbon dioxide, and industrial waste. The main objective of this study is to confirm the possibility of carbon capture and utilization based on waste materials. We assumed desulfurization gypsum and construction waste (ready mixed concrete washing water, waste concrete, etc.) are CaSO4, Ca(OH)2, respectively. And concentration of simulated carbon dioxide gas was 15 vol% similar to flue gas. Calcium carbonate was produced by combination reaction between ionic CO2 in absorbent and metal ion in the solid waste. Experiments were conducted at normal temperature and pressure. Furthermore, the generated products were characterized by X-ray diffraction, and scanning electron microscope. 相似文献
15.
Yuling Zhang Hanxiao Wei Yijian Jiang Shaoxin Kang Zhiguang Hu Jilong Wang 《Journal of Polymers and the Environment》2018,26(1):116-121
Poly(aspartic acid-itaconic acid) copolymers (PAI) is a new scale inhibitor for water treatment. Thus, it is necessary to investigate its biodegradability. The biodegradability of PAI was investigated through CO2 evolution tests under different conditions based on determination of carbon dioxide production. The investigation results showed that the degradation rate of PAI on day 10 and day 28 were respectively 38.7 and 79.5%, indicating that PAI was one kind of easily biodegradable scale inhibitors. With the increase in the content of itaconic acid in copolymerization process, the biodegradability of PAI was significantly reduced. In addition, the high biodegradability might be attributed to the existence of C–N bone-structure and more –COO–. Finally, Cu2+ could decrease the degradation percentage and the enzyme inhibition effect of Cu2+ was not the linear effect, but the “low-dosage effect”. 相似文献
16.
17.
Vegetation and carbon sequestration and their relation to water resources in an inland river basin of Northwest China 总被引:1,自引:0,他引:1
In the Heihe River Basin in the arid inland area of northwest China, the distribution of water resources in vegetation landscape zones controls the ecosystems. The carbon sequestration capacity of vegetation is analyzed in relation to water resources and vegetation growing conditions. During the last 20 years, the vegetation ecosystems have degenerated in the Heihe River Basin. Simulation using the C-FIX model indicates that, at present, the total amount of NPP of vegetation accounts for about 18.16 TgC, and the average value is 106 gC/m(2)/yr over the whole basin. NPP has generally the highest value in the upperstream mountain area, middlestream artificial oases area, downstream river bank area, alluvial fan and the terminal lake depression where vegetation grows relatively well. The lowest value is found in the vast downstream desert and Gobi area. Protection of vegetation ecosystems and enhancement of carbon sequestration require such inland river basins as the Heihe River Basin to be brought under management in a comprehensive way, taking water as a key, to carry out a rational and efficient allocation and utilization of water resources. 相似文献
18.
Tony Prato Choongkwan Kang 《Journal of the American Water Resources Association》1998,34(6):1465-1472
ABSTRACT: Nitrogen (N) fertilizer rates for achieving optimum crop yields often vary within a field due to spatial variability in soil moisture and nitrogen content and other crop growth factors. When there is substantial within-field variability in these factors, uniform application of N (UAN) may not be economically efficient in terms of maximizing net return because N is likely to be over-applied in some areas and under-applied in other areas of the field. In addition, over-application can adversely affect water quality. A sample of fields in a Midwestern agricultural watershed is used to test for statistically significant differences in N application rates, crop yields, surface and ground water quality and net returns between UAN and variable application of N (VAN) for four cropping systems. Profitability and water quality benefits of VAN are sensitive to the distribution of soil types within a field. Water quality effects and profitability of UAN and VAN vary with cropping systems. VAN is not uniformly superior to UAN in terms of increasing net returns and improving water quality for the farming systems and watershed evaluated in this study. 相似文献
19.
以丙烯腈生产废水中的丙烯腈低聚物为原料制备聚丙烯酰胺。通过正交实验考察了水解反应条件和交联反应条件对反应的影响。FTIR表征结果显示,丙烯腈低聚物中的氰基已完全水解为酰胺基,产物聚丙烯酰胺中含有酰胺基和羧基。实验结果表明,在自来水加入量100 m L、水解反应温度95℃、m(Na OH)∶m(丙烯腈低聚物)=2.0、水解反应时间3 h的最佳水解反应条件,交联反应温度60℃、质量分数37%~40%的甲醛加入量6 m L、交联反应时间2 h的最佳交联反应条件下,处理20 g丙烯腈低聚物,可得到产物聚丙烯酰胺14.50 g,聚丙烯酰胺的水解度为21.1%、相对分子质量为2.7×106。产品性能满足Q/SH 0046—2007《钻井液用聚丙烯酰胺技术要求》中部分水解聚丙烯酰胺的性能要求。 相似文献
20.
Dongjin Lee Jisu Bae Jungu Kang Kiheon Kim 《Journal of Material Cycles and Waste Management》2016,18(3):445-454
This study was to find out potential of methane yield on food waste and food waste leachate as biomass in Korea. The seven biogasification facilities were selected for comparison of theoretical methane yield and actual methane yield. The theoretical methane yield was calculated based on organic constituents (carbohydrate, protein, fat) and based on element analysis. The actual methane yield was investigated based on volatile solids and CODcr. Theoretical methane yields by organic constituents were 0.52 Sm3CH4/kg VS and 0.35 Sm3CH4/kg CODcr and these by element analysis were 0.53 Sm3CH4/kg VS and 0.36 Sm3CH4/kg CODcr. Actual methane yields were 0.36 Sm3CH4/kg VSin and 0.26 Sm3CH4/kg CODcrin. Considering the average removal efficiency of organic materials of seven FWL biogasification facilities, actual methane yields were 0.48 Sm3CH4/kg VSrem and 0.33 Sm3CH4/kg CODcrrem. Methane yield by organic constituents is very similar to that by element analysis and actual methane yields of volatile solids and CODcr were similar to theoretical value. The actual methane yield in this study showed approximated boundary values with previous other references which conducted in lab-scale or biochemical methane potential (BMP) tests. In conclusion, Korean food waste and food waste leachate have sufficient potential of methane yield in the ongoing biogasification facilities. 相似文献