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Vertical and temporal distributions of N and P in soil solution in aquatic-terrestrial ecotone (ATE) of Taihu Lake were investigated, and the relations among N, P, ORP (oxidation reduction potential), TOC, root system biomass and microorganism were studied. As a whole, significant declines in TN, NO3^--N, DON (dissolved organic nitrogen) and TP concentration in soil solution have occurred with increase of the depth, and reached their minima at 60 cm depth, except for NH4^+-N, which increased with depth. The concentration of TP increased gradually from spring to winter in the topsoil, the maximum 0.08 mg/L presented in the winter while the minimum 0.03 mg/L in spring. In the deeper layer, the concentration value of TP fluctuated little. As for the NO3^--N, its seasonal variation was significant at 20 cm depth, its concentration increased gradually from spring to autumn, and decreased markedly in winter. Vertical and temporal distribution of DON is contrary to that of NO3^--N. The results also show that the variation of N and P in the percolate between adjacent layers is obviously different. The vertical variation ofTN, TP, NO3^--N, NH4^+-N and DON is significant, of which the variation coefficient of NO3^--N along the depth reaches 100.23%, the highest; while the variation coefficient of DON is 41.14%, the smallest. The results of correlation analysis show that the concentration of nitrogen and phosphorus correlate significantly with TOC, ORP, root biomass and counts of nitrifying bacteria. Most nutrients altered much from 20 to 40 cm along the depth. However, DON changed more between 60 and 80 cm. Results show that soil of 0-60 cm depth is active rhizoplane, with strong capability to remove the nitrogen and phosphorus in ATE. It may suggest that there exists the optimum ecological efficiency in the depth of above 60 cm in reed wetland. This will be very significant for ecological restoration and reestablishment. 相似文献
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Sludge concentration dynamic distribution and its impact on the performance of UNITANK 总被引:2,自引:0,他引:2
UNITANK is a biological wastewater treatment process that combines the advantages of traditional activated sludge process and sequencing batch reactor, which is divided into Tank A, B and C. In this study, the sludge distribution and its impact on performance of UNITANK were carried out in Liede Wastewater Plant (WWTP) of Guangzhou, China. Results showed that there was a strong affiliation between Tank A and B of the system in sludge concentration distribution. The initial sludge concentration in Tank A could present the sludge distribution of the whole system. The sludge distribution was mainly influenced by hydraulic condition. Unsteady sludge distribution had an impact on variations of substrates in reactors, especially in decisive reactor, and this could lead to failure of system. Settler could partially remove substrates such as COD and NO3-N, but there was adventure of sludge deterioration. The rational initial sludge concentration in Tank A should be 4000-6000 mg/L MLSS. 相似文献
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目前,由于人类污染源每年向大气排汞量日益增长,使国际上对汞排放的控制研究成为热点,本文通过理论计算及工程实例说明了循环流化床干法烟气脱硫除尘一体化工艺系统可以有效地控制燃煤电厂汞的排放。 相似文献
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昆钢滇中铁合金厂6000KVA电炉烟尘治理 总被引:1,自引:0,他引:1
昆钢滇中铁合金厂6000KVA电炉采用干法袋式除尘工艺处理烟气,通过改变滤袋材质、控制在线过滤风速、延长清灰静止沉降时间等措施,使整套装置除尘效率达到99.5%。 相似文献
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污水化学除磷技术的现状和进展 总被引:8,自引:0,他引:8
综述了化学除磷的各种方法,原理,特点及其在使用过程中的不足之处。在此基础上,提出了一种新的化学除磷技术—固定化活性氧化镧的化学—吸附除磷技术。通过将其和一般的化学除磷技术进行对比,介绍了该技术所具备的开发潜质。 相似文献
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给水中藻类的影响及其去除方法概述 总被引:9,自引:0,他引:9
富营养化水体中的藻类对自来水制水企业正常生产的影响日益严重。系统地介绍了藻类的成因、分类,对自来水企业运行带来的不利影响,以及现行的去除藻类方法,此外还探讨了今后藻类左除研究的发展方向。 相似文献
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本实验研究了湿式振动纤维栅的一种新型过滤材质——扁平形金属丝带。根据影响除尘性能的因素,分别研究了风速和过滤片数对金属丝带纤维栅的除尘效率和过滤阻力的影响,并从理论上解释了金属丝带纤维栅的过滤阻力增加的原因,提出了一种新型结构的金属丝带纤维栅。矩形金属纤维栅实验结果说明:在一定风速下,随着过滤片数的增加,除尘效率增加。当风速为3.3m/s,过滤片为6片时,全粉尘的除尘效率达99%;呼吸性粉尘的分级效率大于94%,达到了与化学纤维栅相同的水平。过滤阻力随着速度和过滤片数的增加近似呈线性增加。当湿式振动矩形金属纤维栅为6片,风速为3.3m/s时,纤维栅在当量直径为0.074mm和0.109mm时的最大过滤阻力分别为488Pa和500Pa。 相似文献
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WANG Jian-li ZHONG Jun-bo GONG Mao-chu LIU Zhi-min ZHAO Ming CHEN Yao-qiang 《环境科学学报(英文版)》2007,19(6):644-646
Five monolithic catalysts with low noble metal content were prepared by irnmerge method (Pt/γ=Al2O3, Pt/La-Al2O3, Pt/YSZ-AI203, Pt+Pd/La-Al2O3 and Pd/La-Al2O3) and their activity measurements were carried out in a conventional fixed-bed flow reactor. The results show that La-Al2O3 can promote activity of the prepared catalysts and can decrease the complete conversion temperature of cooking fume. The Pt/La-Al2O3 catalyst has the highest activity and can be applied in wide range of gas hourly space velocity (GHSV). Some characterizations (XRD, TPR) were carried out with the objective to explain differences in catalytic behaviors. The prepared catalyst showed a great potential for application. 相似文献
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