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11.
Enhanced sludge solubilization by microbubble ozonation 总被引:7,自引:0,他引:7
A microbubble ozonation process for enhancing sludge solubilization was proposed and its performance was evaluated in comparison to a conventional ozone bubble contactor. Microbubbles are defined as bubbles with diameters less than several tens of micrometers. Previous studies have demonstrated that microbubbles could accelerate the formation of hydroxyl radicals and hence improve the ozonation of dyestuff wastewater. The results of this study showed that microbubble ozonation was effective in increasing ozone utilization and improving sludge solubilization. For a contact time of 80 min, an ozone utilization efficiency of more than 99% was obtained using the microbubble system, while it gradually decreased from 94% to 72% for the bubble contactor. The rate of microbial inactivation was obviously faster in the microbubble system. At an ozone dose of 0.02 g O3 g−1 TSS, about 80% of microorganisms were inactivated in the microbubble system, compared with about 50% inactivation for the bubble contactor. Compared to the bubble contactor, more than two times of COD and total nitrogen, and eight times of total phosphorus content were released from the sludge into the supernatant by using the microbubble system at the same ozone dosage. The application of microbubble technology in ozonation processes may provide an effective and low cost approach for sludge reduction. 相似文献
12.
采用非均相催化臭氧氧化工艺深度处理化工废水二级生化出水,探索负载不同活性组分的活性炭催化剂及该工艺处理化工废水的影响因素。结果表明:当进水COD为85~110 mg/L,臭氧投加量为60 mg/L,催化剂投加量为200 mg/L Cr时,臭氧氧化、ACCA-1、ACCA-2和ACCA-3催化臭氧氧化对出水COD的平均去除率分别为22.46%、32.7%、40.5%和35.7%,3种催化剂均可强化臭氧氧化效果。活性炭催化剂能提高臭氧利用率,叔丁醇对ACCA-2抑制效果最明显。 相似文献
13.
Changes in biomass activity and characteristics of activated sludge exposed to low ozone dose 总被引:1,自引:0,他引:1
Libing Chu Jianlong Wang Bo Wang Xin-Hui Xing Sangtian Yan Xulin Sun Benjamin Jurcik 《Chemosphere》2009,77(2):269-272
In this paper, the response mechanism of activated sludge exposed to low-dose ozone at less than 20 mg O3 g−1 total suspended solids (TSS) was studied by analyzing the changes in sludge activity and the evolution of C, N, P and metals from sludge following ozonation. The intracellular ATP concentration was not affected at less than 5 mg O3 g−1 TSS and thereafter decreased rapidly to around 60% when the ozone dose increased to 20 mg O3 g−1 TSS. Similarly, the efficiency of sludge solubilization initially changed a little and then increased rapidly to around 30% at an ozone dose of 20 mg O3 g−1 TSS. However, the activities of superoxide dismutase and protease decreased immediately upon exposure to ozone. These findings indicate that ozone firstly destroys the floc, leading to the disruption of the compact aggregates, which does not affect cells viability but induces a decrease in enzyme activities. Ozone then attacks the bacterial cells of the sludge, causing a decrease in cells viability. During ozonation, the content of carbon, nitrogen and phosphorus in the sludge matrix decreased, while the content of these elements in the micro-solids and supernatant gradually increased. Most of the released metals from the sludge matrix were found in the micro-solids. 相似文献
14.
Linlin Xing Yongbing Xie Daisuke Minakat Hongbin Cao Jiadong Xiao Yi Zhang John C. Crittenden 《环境科学学报(英文版)》2014,26(10):2095-2105
Ozonation of oxalate in aqueous phase was performed with a commercial activated carbon(AC)in this work. The effect of AC dosage and solution pH on the contribution of hydroxyl radicals(HOU) in bulk solution and oxidation on the AC surface to the removal of oxalate was studied. We found that the removal of oxalate was reduced by tert-butyl alcohol(tBA) with low dosages of AC,while it was hardly affected by tBA when the AC dosage was greater than 0.3 g/L. tBA also inhibited ozone decomposition when the AC dosage was no more than 0.05 g/L, but it did not work when the AC dosage was no less than 0.1 g/L. These observations indicate that HOUin bulk solution and oxidation on the AC surface both contribute to the removal of oxalate. HOU oxidation in bulk solution is significant when the dosage of AC is low, whereas surface oxidation is dominant when the dosage of AC is high. The oxalate removal decreased with increasing pH of the solution with an AC dosage of 0.5 g/L. The degradation of oxalate occurs mainly through surface oxidation in acid and neutral solution, but through HOUoxidation in basic bulk solution. A mechanism involving both HOUoxidation in bulk solution and surface oxidation was proposed for AC enhanced ozonation of oxalate. 相似文献
15.
木糖生产废水的脱色研究 总被引:2,自引:0,他引:2
实验表明用臭氧化法进行木糖生产废水的脱色处理效果颇佳。在30分钟内就能达到90%的去除率,反应速度受pH、温度等因素影响较小。实验同时表明,臭氧氧化法对COD的去除效果不理想,需要和其它方法结合处理。 相似文献
16.
垃圾渗滤液生物处理出水臭氧氧化的研究 总被引:3,自引:1,他引:2
对垃圾渗滤液生物处理出水进行了臭氧氧化的研究。研究表明,随着氧化时间的延长,CODCr去除率增大;在碱性条件下进行臭氧氧化。pH越高,CODCr去除效率越高。采用BOD5/CODCr来表征垃圾渗滤液的生物降解性,研究了臭氧氧化前后垃圾渗滤液生物处理出水的生物降解性变化规律,表明臭氧氧化可以提高垃圾渗滤液生物处理出水的生物降解性,但提高的幅度不大。通过色谱-质谱法(GC—MC)对臭氧氧化前后垃圾渗滤液的成分进行分析,结果表明,臭氧氧化前后废水中的主要成分没有发生变化,仍然为难降解物质;臭氧氧化使废水中的部分物质发生了结构上的变化,减少、消失和生成的物质多为可降解物质。 相似文献
17.
Lian Yang Qinxue Wen Zhiqiang Chen Ran Duan Pan Yang 《Frontiers of Environmental Science & Engineering》2019,13(3):32
18.
Xinshu Liu Xiaoman Su Sijie Tian Yue Li Rongfang Yuan 《Frontiers of Environmental Science & Engineering》2021,15(4):75
19.
Zhe Wang Wenjuan Zhang Zhiwei Wang Jing Chang 《Frontiers of Environmental Science & Engineering》2023,17(5):54
20.
Fernando J. Beltrán Juan F. García‐Araya Javier Rivas Pedro M. Álvarez Eva Rodriguez 《Journal of environmental science and health. Part. B》2013,48(4):439-454
Abstract Comparison of the effects and kinetics of UV photolysis and four advanced oxidation systems (ozone, ozone/hydrogen peroxide, ozone/UV radiation and UV radiation/hydrogen peroxide) for the removal of simazine from water has been investigated. At the conditions applied, the order of reactivity was ozone < ozone/hydrogen peroxide < UV radiation < ozone/UV radiation and UV radiation/hydrogen peroxide. Rate constants of the reactions between ozone and simazine and hydroxyl radical and simazine were found to be 8.7 M‐1s‐1 and 2.1x109 M‐1s‐1, respectively. Also, a quantum yield of 0.06 mol.photon‐1 was found for simazine at 254 nm UV radiation. The high value of the quantum yield corroborated the importance of the direct photolysis process. Percentage contributions of direct reaction with ozone, reaction with hydroxyl radicals and direct photolysis were also quantified. 相似文献