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191.
以某酶制品厂的废水为研究对象,确定了絮凝-SBR-Fenton高级氧化的试验方法.结果表明,在絮凝阶段,当聚合氯化铝(PAC)投加量为0.6g/L,搅拌6 min,絮凝70min的条件下,预处理的出水CODCr效果最好,去除率为44.6%;再经过SBR工艺处理,停留时间为14 h时,CODCr去除率达到了89.2%;之后再进行Fenton高级氧化,氧化的最佳条件是:ρ(FeSO4·7H2O)为3 g/L,ρ(H2O2)为0.8g/L,反应时间2 h.最终出水达到了GB 8978-1996<污水综合排放标准>中二级排放标准. 相似文献
192.
水中总氮测定相关问题的实验探讨 总被引:1,自引:0,他引:1
通过对国家标准测定方法《碱性过硫酸钾消解紫外分光光度法》进行水样中总氮的测定,进一步理解在220nm、275nm波长处进行吸光度测定的重要性。并提出:在已经知道水样中没有氨氮、亚硝酸盐氮,只有硝酸盐氮的情况下.就能通过快速的方法一即不加氧化剂、不加压,可以进行总无机氮的测定。快速测定无机总氮对于工程应用来说很有意义。因为国标的方法需要半天时间测定。而用此方法则仅需几分钟就可完成测定。、另外对于有机物对于测定结果的影响,参考吸光度比值(A275/A220×100%)应小于20%,越小越好,超过时应予鉴别。 相似文献
193.
194.
结合环境监测仪器设备的特点,着重阐述了从设备分类、量值溯源、维修维护等几方面环境监测设备的常规管理方法,并对其现代化的管理进行了探索。 相似文献
195.
196.
建立了结构-TMD振动方程,推导了无控结构和带TMD受控结构基于功率表达的运动方程,分别解释并给出了各种功率表达参数的物理意义,推导了随机激励下结构耗能功率流均值的随机表达式,对比分析了基于功率法的结构-TMD优化方法与其他优化方法的优化分析结果,并对其减震控制效果进行了对比分析。结果表明,结构-TMD系统的参数可以通过耗能功率流随机分析方法所得均值进行优化,且通过功率法优化后,结构在减震效果上优于其他传统方法得到的结果,从耗能功率均值的随机分析和时程功率分析角度证明了TMD控制的有效性;TMD做功功率为负时对结构有控制效果,起吸收转移能量的作用,且功率幅值越大控制效果越好,做功功率为正时则相反。 相似文献
197.
Pinpin Lu Xiaojian Zhang Chiqian Zhang Zhangbin Niu Shuguang Xie Chao Chen 《环境科学学报(英文版)》2014,26(2):323-331
This study investigated the bacterial regrowth in drinking water distribution systems receiving finished water from an advanced drinking water treatment plant in one city in southem China. Thirteen nodes in two water supply zones with different aged pipelines were selected to monitor water temperature, dissolved oxygen (DO), chloramine residual, assimilable organic carbon (AOC), and heterotrophic plate counts (HPC). Regression and principal component analyses indicated that HPC had a strong correlation with chloramine residual. Based on Chick-Watson's Law and the Monod equation, biostability curves under different conditions were developed to achieve the goal of HPC 100 CFU/mL. The biostability curves could interpret the scenario under various AOC concentrations and predict the required chloramine residual concentration under the condition of high AOC level. The simulation was also carded out to predict the scenario with a stricter HPC goal (≤50 CFU/mL) and determine the required chloramine residual. The biological regrowth control strategy was assessed using biostability curve analysis. The results indicated that maintaining high chloramine residual concentration was the most practical way to achieve the goal of HPC ≤ 100 CFU/mL. Biostability curves could be a very useful tool for biostability control in distribution systems. This work could provide some new insights towards biostability control in real distribution systems. 相似文献
198.
Photocatalytic ozonation of phenol and oxalic acid (OA) was conducted with a Ag^+/TiO2 catalyst and different pathways were found for the degradation of different compounds. Ag^+ greatly promoted the photocatalytic degradation of contaminants due to its role as an electron scavenger. It also accelerated the removal rate of OA in ozonation and the simultaneous process for its complex reaction with oxalate. Phenol could be degraded both in direct ozonation and photolysis, but the TOC removal rates were much higher in the simultaneous processes due to the oxidation of hydroxyl radicals resulting from synergetic effects. The sequence of photo-illumination and ozone exposure in the combined process showed quite different effects in phenol degradation and TOC removal. The synergetic effects in different combined processes were found to be highly related to the properties of the target pollutants. The color change of the solution and TEM result confirmed that Ag+ was easily reduced and deposited on the surface of Tit2 under photo-illumination, and dissolved again into solution in the presence of ozone. This simple cycle of enrichment and distribution of Ag^+ can greatly benefit the design of advanced oxidation processes, in which the sequences of ozone and photo-illumination can be varied according to the needs for catalyst recycling and the different properties of pollutants. 相似文献
199.
Removal of noxious dyes is gaining public and technological attention. Herein grafting polymerization was employed to produce a novel adsorbent using acrylic acid and carboxymethyl cellulose for dye removal. Scanning electron microscopy and Fourier-transform infrared spectroscopy verified the adsorbent formed under optimized reaction conditions. The removal ratio of adsorbent to Methyl Orange, Disperse Blue 2BLN and malachite green chloride reached to 84.2%, 79.6% and 99.9%, respectively. The greater agreement between the calculated and experimental results suggested that pseudo second-order kinetic model better represents the kinetic adsorption data. Equilibrium adsorptions of dyes were better explained by the Temkin isotherm. The results implied that this new cellulose-based absorbent had the universaiity for removal of dyes through the chemical adsorption mechanism. 相似文献
200.