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Polyaluminum chloride (PAC) was used as coagulant and suspended particles in kaolin water. Online instruments including turbidimeter and particle counter were used to monitor the flocculation process. An evaluation model for demonstrating the impact on the flocculation effect was established based on the multiple linear regression analysis method. The parameter of the index weight of channels quantitatively described how the variation of floc particle population in different size ranges cause the decrement of turbidity. The study showed that the floc particles in different size ranges contributed differently to the decrement of turbidity and that the index weight of channel could excellently indicate the impact degree of floc particles dynamic distribution on flocculation effect. Therefore, the parameter may significantly benefit the development of coagulation and sedimentation techniques as well as the optimal coagulant selection. 相似文献
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Coagulation efficiency and flocs characteristics of recycling sludge during treatment of low temperature and micro-polluted water 总被引:1,自引:0,他引:1
Drinking water treatment sludge, characterized as accumulated suspended solids and organic and inorganic matter, is produced in large quantities during the coagulation process. The proper disposal, regeneration or reuse of sludge is, therefore, a significant environmental issue. Reused sludge at low temperatures is an alternative method to enhance traditional coagulation efficiency. In the present study, the recycling mass of mixed sludge and properties of raw water (such as pH and turbidity) were systematically investigated to optimize coagulation efficiency. We determined that the appropriate dosage of mixed sludge was 60 mL/L, effective initial turbidity ranges were below 45.0 NTU, and optimal pH for DOMs and turbidity removal was 6.5--7.0 and 8.0, respectively. Furthermore, by comparing the flocs characteristics with and without recycling sludge, we found that floc structures with sludge were more irregular with average size growth to 64.7 μupm from 48.1 μupm. Recycling sludge was a feasible and successful method for enhancing pollutants removal, and the more irregular flocs structure after recycling might be caused by breakage of reused flocs and incorporation of powdered activated carbon into larger flocs structure. Applied during the coagulation process, recycling sludge could be significant for the treatment of low temperature and micro-polluted source water. 相似文献
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An Ding Yingxue Zhao Zhongsen Yan Langming Bai Haiyang Yang Heng Liang Guibai Li Nanqi Ren 《Frontiers of Environmental Science & Engineering》2020,14(4):59
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为了考察膜生物反应器(MBR)净化受污染地表水自然启动过程中功能菌群的成熟规律及碱度对MBR去除水中氨氮的影响,通过构建小试规模的MBR,考察了MBR处理受污染地表水的自然启动和稳定运行除污染特性。结果表明,MBR在自然启动过程中不会出现异养菌成熟的标志,系统对进水DOC、UV254和CODMn的平均去除率分别仅为(14.5±5.1)%、(12.6±5.6)%和(31.2±7.4)%,应考虑将其他工艺与MBR联用以提高系统的有机物去除能力。启动23天后,MBR中的亚硝化细菌成熟,NH3-N去除率达到80%以上;启动31 d后,MBR中的硝化细菌成熟,出水NO2--N稳定在0.05mg/L以下。碱度对MBR去除NH3-N效能影响较大,向进水中投加30 mg/L的NaHCO3能使MBR对NH3-N的去除率由(86.1±3.7)%提高至(98.0±1.6)%。在连续曝气、10 L/(m2.h)通量、每10 min反洗15 s运行模式下,MBR的膜污染较为严重,平均TMP增长速率为0.45 kPa/d,需进一步优化相关参数以实现MBR的长期稳定运行。 相似文献
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颗粒物粒径和有机物分子量对超滤膜污染的影响 总被引:1,自引:0,他引:1
采用不同孔径和截留分子量的膜对原水进行预过滤,研究不同粒径的颗粒物和不同分子量的有机物对膜污染的影响。结果表明,随着预过滤膜孔径或截留分子量的减小,原水中浊度、CODMn、DOC和UV254的去除率逐渐提高,超滤膜运行的跨膜压力(TMP)比直接过滤原水时降低;经孔径为1.2μm和0.45μm的膜预过滤后,超滤膜运行的TMP仍上升较快,而经过截留分子量为100 kDa及以下膜预过滤后,膜污染比较缓慢。对膜阻力构成分析的结果表明,随着预过滤膜孔径或截留分子量的减小,超滤膜运行过程中的表面饼层阻力逐渐减小,堵孔阻力也有明显降低,但预膜滤不能有效降低膜的吸附阻力。超滤膜表面的扫描电镜观察结果表明,经过截留分子量在100 kDa及以下的膜预过滤后,超滤膜表面比较干净,此时的膜过滤阻力主要来源于吸附和堵孔阻力。 相似文献
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Ruiping Liu Yanling Yang Guibai Li Wenjie He Hongda Han 《Frontiers of Environmental Science & Engineering》2007,1(2):240-245
This study focused on the adsorptive behaviors of humic acid onto freshly prepared hydrous MnO2(s) (δMnO2), and investigated the feasibility of employing δMnO2 for humic acid removal from drinking water. Effects of such parameters as molecular mass of humic acid, kinds of divalent cations on adsorptive behaviors and possible mechanisms involved were investigated. This study indicated that humic acid with higher molecular mass exhibited more tendency of adsorbing onto δMnO2 than that with lower molecular mass. Ca2+ facilitated more humic acid adsorption than Mg2+; UV-Vis spectra analysis indicated higher capabilities of Ca2+ coordinating with acidic functional groups of humic acid than that of Mg2+. Additionally, ζ potential characterization indicated that Ca2+ showed higher potential of increasing gz potential of δMnO2 than Mg2+. Ca2+ of 1.0 mmol/L increased ζ potential of δMnO2 from ?37 mV (pH 7.9) to +7 mV (pH 7.2), while 1.0 mmol/L Mg2+ increased to lower value as ?9 mV (pH 6.5), correspondingly. Fourier transform infrared (FTIR) spectra demonstrated the adsorption of humic acid onto δMnO2, showing the important roles of-COO? functional groups and surface Mn-OH in the adsorption of humic acid onto δMnO2. 相似文献
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作者认为,高浓度泥水沉淀(浓缩)池的模型律,应建立在以下过程相似的基础上:(1)池内浑水异重流发生相似;(2)池内泥水的沉淀浓缩过程相似。文中讨论了原泥水或配制泥水进行试验、试验为正常负荷或超负荷、采用正态模型或变态模型等各种情况下的模型律以及不能满足相似条件的情况。文中介绍了在两个几何相似的模型中对模型律进行试验检验的结果。 相似文献
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Liu Ruiping Yang Yanling Li Guibai He Wenjie Han Hongda 《Frontiers of Environmental Science & Engineering in China》2007,1(2):240-245
This study focused on the adsorptive behaviors of humic acid onto freshly prepared hydrous MnO2(s) (δMnO2), and investigated the feasibility of employing δMnO2 for humic acid removal from drinking water. Effects of such parameters as molecular mass of humic acid, kinds of divalent
cations on adsorptive behaviors and possible mechanisms involved were investigated. This study indicated that humic acid with
higher molecular mass exhibited more tendency of adsorbing onto δMnO2 than that with lower molecular mass. Ca2+ facilitated more humic acid adsorption than Mg2+; UV-Vis spectra analysis indicated higher capabilities of Ca2+ coordinating with acidic functional groups of humic acid than that of Mg2+. Additionally, ζ potential characterization indicated that Ca2+ showed higher potential of increasing gz potential of δMnO2 than Mg2+. Ca2+ of 1.0 mmol/L increased ζ potential of δMnO2 from −37 mV (pH 7.9) to +7 mV (pH 7.2), while 1.0 mmol/L Mg2+ increased to lower value as −9 mV (pH 6.5), correspondingly. Fourier transform infrared (FTIR) spectra demonstrated the adsorption
of humic acid onto δMnO2, showing the important roles of-COO− functional groups and surface Mn-OH in the adsorption of humic acid onto δMnO2.
Translated from Acta Scientiae Circumstantiae, 2005, 25(3): 351–355 [译自: 环境科学学报] 相似文献