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561.
562.
电导率温度校正计算方法的改进 总被引:2,自引:0,他引:2
通过实验,用分段函数较精确的表示出温度校正系数与温度的关系,对现行电导率温度校正公式进行了改进,可以简化测量过程,提高计算精度。 相似文献
563.
Polyaluminium chlorides with sulfate ion(PACS) were prepared by using AlCl3· 6H2O, Al(SO4 )3· 18H2O and Na2CO3 as raw materials. The effects of basicity (r), Al3 +/SO42- molar ratio and aging time on the morphology of PACS were observed by transmission electrical microscope. The influence of aging time on charge neutralization and coagulation effect of PACS was studied.The effects of basicity (r), Al3+/SO42- molar ratio and aging time on the electrical conductivity of PACS solution were also investigated. The experimental results show that the degree of polymerization of polyaluminium chloride(PAC) increases when SO42-ion is added. The higher the basicity(r) and the longer the aging time, the larger the size of polymer PACS. The ability of PACS neutralizing the charge on Kaolinite decreases with the increase of aging time. The electrical conductivity of PACS solution (the concentration of Al3+ ion is 0.18 mol/L) with different aging time is the function of the basicity and Al3 +/SO42- molar ratios and has its maximum at r = 0.5 and Al3+/SO42- = 12. 相似文献
564.
In this study, tracer tests and organic removal tests were conducted on three different ponds in the purpose of evaluating the influence of the flow velocity and dispersion on the hydraulic efficiency of the pond. The authors have compared the hydraulic flow patterns among ponds with different configurations. Experimental and theoretical analyses were performed. This study indicated that the flow characteristics of square ponds are different from that of baffled ponds; the flow velocity and dispersion are equally important factors which affect the pond hydraulics; the number of inserting baffles can be optimized; and the hydraulic efficiency of multistage ponds is superior to that of baffled ponds. 相似文献
565.
566.
内循环上流式厌氧污泥床启动研究 总被引:4,自引:0,他引:4
介绍了内循环上流式厌氧污泥床工艺及生产性实验启动的研究情况 ,就启动过程中发现的问题进行讨论 ,总结启动过程中应注意的事项 相似文献
567.
生物膜系统同时硝化和反硝化的实验研究 总被引:1,自引:5,他引:1
实验采用人工配水,对生物膜系统中COD和氮的去除进行了研究。实验中pH控制在7.0~7.5左右,温度为20℃~28℃。本实验研究了不同溶解氧、水力停留时间和碳氮比对总氮去除率的影响。实验结果表明,生物膜系统中同时硝化和反硝化具有一定的可行性。在C/N比为8∶1,水力停留时间6h时,溶解氧为0.5~1.0mg/L时,总氮的去除率达53.6%。 相似文献
568.
污水排海工程的扩散器水力设计与模型试验研究 总被引:1,自引:1,他引:1
通过SZ36-1油田二期终端污水排海工程扩散器的水力设计,比较了扩散器的水力设计的两种计算方法,对水力计算中有关参数及局部阻力系数进行了选用,并通过模型试验进行了验证。表明所用计算方法及其结果是可信的,阻力系数的选取是合适的。 相似文献
569.
对于沙壤土柱实验,用TDR(时间域反射计)结合土壤抽提液的溶质分析,研究了在非饱和灌溉条件下的硝化和NO-3的迁移.测得的土壤体电导率与土壤抽提液的电导率之比和土壤含水量成线性关系,籍此用TDR可以确定非饱和灌溉条件下土壤中溶质浓度的变化规律;硝化过程是在土壤表层的不连通的小孔隙中进行的,几乎不受水分运动的影响;由示踪剂Br-的入渗及土壤表层的NO-3(相当于TDR测得的电导率值)入渗分布得出,入渗是按活塞推移作用进行的,借此方法可以研究非饱和入渗的机理. 相似文献
570.
Hydraulic constraints on the performance of a groundwater denitrification wall for nitrate removal from shallow groundwater 总被引:2,自引:0,他引:2
Schipper LA Barkle GF Hadfield JC Vojvodic-Vukovic M Burgess CP 《Journal of contaminant hydrology》2004,69(3-4):263-279
Denitrification walls are a practical approach for decreasing non-point source pollution of surface waters. They are constructed by digging a trench perpendicular to groundwater flow and mixing the aquifer material with organic matter, such as sawdust, which acts as a carbon source to stimulate denitrification. For efficient functioning, walls need to be permeable to groundwater flow. We examined the functioning of a denitrification wall constructed in an aquifer consisting of coarse sands. Wells were monitored for changes in nitrate concentration as groundwater passed through the wall and soil samples were taken to measure microbial parameters inside the wall. Nitrate concentrations upstream of the wall ranged from 21 to 39 g N m(-3), in the wall from 0 to 2 g N m(-3) and downstream from 19 to 44 g N m(-3). An initial groundwater flow investigation using a salt tracer dilution technique showed that the flow through the wall was less than 4% of the flow occurring in the aquifer. Natural gradient tracer tests using bromide and Rhodamine-WT confirmed groundwater bypass under the wall. Hydraulic conductivity of 0.48 m day(-1) was measured inside the wall, whereas the surrounding aquifer had a hydraulic conductivity of 65.4 m day(-1). This indicated that during construction of the wall, hydraulic conductivity of the aquifer had been greatly reduced, so that most of the groundwater flowed under rather than through the wall. Denitrification rates measured in the center of the wall ranged from 0.020 to 0.13 g N m(-3) day(-1), which did not account for the rates of nitrate removal (0.16-0.29 g N m(-3) day(-1)) calculated from monitoring of groundwater nitrate concentrations. This suggested that the rate of denitrification was greater at the upstream face of the wall than in its center where it was limited by low nitrate concentrations. While denitrification walls can be an inexpensive tool for removing nitrate from groundwater, they may not be suitable in aquifers with coarse textured subsoils where simple inexpensive construction techniques result in major decreases in hydraulic conductivity. 相似文献