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1.
Results of a pilot (100 m3/h) investigation on ozone disinfection of municipal tertiary effluents for reuse in agriculture carried out at West Bari (S. Italy) treatment plant are presented. Among dosages, contact times and advanced treatment schemes investigated it was demonstrated that ozone disinfection results in the achievement of the WHO microbial guideline (1,000 CFU/100ml for Fecal Coliforms) for unrestricted wastewater reuse in agriculture of both clarified and clarified-filtered municipal secondary effluents; it is very effective towards Pseudomonas aeruginosa, rather effective towards Giardia lamblia and substantially ineffective towards Cryptosporidium parvum and it forms limited amount of DBP (approx. 350 ppb of total aldehydes). O&M costs amount to 37 Euro/1000m3. 相似文献
2.
Oxidation kinetics of selected pharmaceutical compounds and their degradation during ozonation of secondary treated municipal wastewater effluent (MWWE) was investigated. The apparent second-order rate constants for the reaction between chlorotetracycline (CTC), enrofloxacin (ENR), gemfibrozil (GEM) and ozone ranged between 6.82 – 52.7 × 104 M?1s?1. The measured second-order hydroxyl radical rate constants were several orders of magnitude higher at 8.4 × 109 – 13.1 × 109 M?1s?1 with a reactivity sequence of GEM > CTC > ENR. Overall degradation of CTC, ENR and GEM in secondary treated municipal wastewater effluent was >76 % at ozone doses of 0.33 mg O3/mg DOC or higher. 相似文献
3.
Lewis Debevec Jr. 《臭氧:科学与工程》1990,12(2):95-105
In previous years, the start-up and operation of ozone systems at U.S. municipal water and wastewater treatment facilities has resulted in numerous problems. Some of these problems were of such a magnitude that the operating agency decided to abandon the ozone system. In other cases, the system is operating and the problems are resolved. An investigation of 11 U.S. facilities was conducted to determine what problems were experienced and how the problems were resolved. 相似文献
4.
The transformation of 41 target emerging contaminants in secondary treated municipal wastewater effluent in Canada was examined at pilot-scale, at transferred ozone doses of 2.8 mg/L (0.46 O3/mg DOC) and 4.4 mg/L (0.72 mg O3/mg DOC). In general, transformation efficiencies of CECs either increased or were retained at the higher ozone dose. The higher ozone dose of 0.72 mg O3/mg DOC (Zspec = 0.6 mg O3/mg DOC) was sufficient to transform 21 of the 31 detected CECs by over 80% as well as achieving the disinfection target of < 200 MPN E. coli per 100 mL. 相似文献
5.
Wastewater disinfection by ozone was investigated at pilot scale on different effluents. The organic matter (COD and TOC) was shown to have the biggest influence on the ozone demand of the effluents. Disinfection of fecal indicators could be modeled as the reaction on a double population. The presence of more resistant microorganisms results in the need for higher treatment doses and a tertiary filtration when the effluent has to meet the stringent Title 22 standard. Eventually, the high virucidal power of ozone makes it very attractive when viruses are targeted. 相似文献
6.
Effluent from the Pa?aköy Wastewater Treatment Plant was oxidized by using O3 and O3/H2O2. DOC, COD, UV254, total coliform, dissolved ozone and some endocrine disrupting compounds were monitored during oxidation. Results showed that O3 provided superior disinfection, however, lower reductions in DOC, COD and endocrine disrupting compounds were exhibited compared to O3/H2O2. The highest removal efficiency of DOC, COD and endocrine disrupting compounds were achieved at 0.5 molar ratio of O3/H2O2. The benefit of H2O2 addition for advanced oxidation reduced significantly when the mole ratio was increased to 2. Therefore, the mole ratio of H2O2 to O3 is a critical parameter for the design of wastewater oxidation by O3/H2O2. 相似文献
7.
Hydroxyl radical (HO?) production during ozonation of municipal wastewater was investigated with and without liquid or solid-phase promoters. For liquid-phase promoters, an “ozone dose threshold” was observed, below which addition of H2O2 yielded no discernible increase in the rate of HO? production. This threshold occurs because ozonation of bulk organics in wastewater promotes HO? due to the presence of ambient promoters. Although solid-phase catalysts are reported to promote oxidation of contaminants, ozonation of effluent over TiO2 or GAC was no more effective on trace organic removal than over inert surfaces. 相似文献
8.
Maria Quero-Pastor Carmen Garrido-Perez Asuncion Acevedo Merino Jose M. Quiroga Alonso 《臭氧:科学与工程》2016,38(6):425-433
This article presents the results of the degradation of clofibric acid by ozonation. Furthermore, results of the toxic effect of clofibric acid and its intermediate compound, 4-chlorophene generated during the oxidation process, to alga Selenastrum capricornium, are also discussed. The degradation and mineralization of the compound are studied according to the optimized operating conditions. These variables include pH, conductivity, hydraulic retention time and the use of a mixing maze. All the trials are conducted in a purpose-built pilot-scale reactor. Working under the optimal operating conditions (pH = 9, HRT = 12.5 min and ozone dose = 14 ± 2 gN/m3), a degradation value of 98% was obtained, although mineralization of the compound did not occur. Results show that clofibric acid and its intermediate are toxic during the first 10 min of treatment for concentrations equal to or greater than 1 mg/L. Under optimal conditions toxicity is not observed for any concentrations. 相似文献
9.
Many fruit and vegetable processing operations are examining technologies to reduce effluent volume and encourage water recovery and reuse. Implementing technologies and programs to promote in-plant reuse and recycling of discharge water is cost-effective and may improve processing efficiency. The efficacy of ozonation of defrost water has been investigated to determine the appropriate treatment level for in-plant reuse at a fruit processing plant in Clovis, California. Treatments of 0.5 ppm and 1.0 ppm of aqueous ozone achieved water quality acceptable for in-plant reuse, while an ozone treatment of 1.0 ppm was needed to significantly (P < 0.05) reduced the microbial load of flume wash effluent. 相似文献
10.
臭氧/活性炭处理炼油废水的初步研究 总被引:2,自引:0,他引:2
考察了可能在实际水处理过程中影响O3 活性炭催化氧化工艺处理效果的因素 ,结果表明该工艺将臭氧的强氧化能力与活性炭的吸附、催化能力有机的结合到了一起 ,利用活性炭的催化作用来提高臭氧化的能力 ,使废水的处理效果大为改观 ,该工艺具有一定的可行性 相似文献
11.
In Japan, ozone is used for potable water treatment, night soil and industrial wastewater treatment, and for offensive gas treatment at sewage and night soil treatment plants. This paper describes its implementation, and presents experimental findings of the combined ozone and ultraviolet radiation as a new ozone utilization technology. 相似文献
12.
This paper summarizes the potential options applying ozone for the improvement of effluents from wastewater treatment plants. A specific focus will be on the technical aspects of how to integrate ozone technique in existing or new conventional treatment plants. Additionally some large scale projects will be illustrated, where this technique is now in operation. The following aspects are of interest and are discussed: necessary ozone dose range (depends on application, water matrix and contaminants); required components of ozone systems (ozone generator, gas supply, reaction system, off-gas handling); process control, online measurement; potential parameters to be used for process control; design guidelines for the integration of ozone systems; and cost calculations. 相似文献
13.
Shane A. Snyder Eric C. Wert David J. Rexing Ronald E. Zegers Douglas D. Drury 《臭氧:科学与工程》2006,28(6):445-460
The oxidative removal of a diverse group of trace organic contaminants from surface water and wastewater was evaluated using ozone (O3) and O3 combined with hydrogen peroxide (O3/H2O2). Target compounds included estrogenic and androgenic steroids, pharmaceuticals, pesticides, and industrial chemicals. Bench- and pilot- scale experiments were conducted with surface water spiked with the target compounds and wastewater effluent containing ambient concentrations of target compounds. Full-scale water treatment plants were sampled before and after ozonation to determine if bench- and pilot-scale results accurately predict full-scale removal. In both drinking water and wastewater experiments, the majority of target compounds were removed by greater than 90% at O3 exposures commonly used for disinfection. Atrazine, iopromide, meprobamate, and tris-chloroethylphosphate (TCEP) were the most recalcitrant compounds to oxidize using O3, with removals generally less than 50%. The addition of H2O2 for advanced oxidation was of little benefit for contaminant removal as compared to O3 alone. O3/H2O2 provided a marginal increase in the removal of dilantin, diazepam, DEET, iopromide, and meprobamate, while decreasing the removal efficacy of pentoxifylline, caffeine, testosterone, progesterone, and androstenedione. In wastewater experiments, O3 and O3/H2O2 were shown to remove in vitro estrogenicity. Collectively, these data provide evidence that O3 is a highly effective oxidant for removing the majority of trace organic contaminants from water. 相似文献
14.
M. T. Orta de Velásquez A. E. Campos-Reales-Pineda I. Monje-Ramirez I. Yáñez Noguez 《臭氧:科学与工程》2010,32(5):323-328
The aim of this work was to determine the effect of ozone on dissolved organic matter (DOM) during wastewater coagulation using alum. Adding ozone to the coagulation treatment (O3ECT) enhanced the quality of the final effluent in comparison to conventional coagulation treatment (CT). Final effluents were analyzed by Fourier transform infrared Spectroscopy (FTIR) and UV-Vis spectroscopy. The hydrophilic polar fraction was separated from the hydrophobic fraction using fractionation resins XAD-8 and XAD-4. Wastewater hydrophilic DOM was characterized by molecular weight distribution (MWD), and, BOD5, TOC and DOC parameters. Results show that FTIR spectra for both effluents were very similar in the frequency range 7000 to 1400 cm?1; however, some differences occurred in the O3ECT effluent in the range 1100 to 700 cm?1, which indicated that amines and aromatics groups were affected. In the same way, the UV-Vis spectra showed that there was an increase in absorbance within the wavelength range 285 to 300 nm for the O3ECT effluent (when compared with CT) while the absorbance decreased in the range 210 to 455 nm, particularly at 380 nm. With regards to the hydrophilic polar compounds of DOM, the most abundant fraction in raw wastewater was found in the 3–10 kDa range. After CT, the effluents fraction concentrations decreased in all cases, but for O3ECT the 10–30 kDa range exhibited a marked increase while the smaller (<3 kDa, 3–10 kDa) and larger fractions (>30 kDa) decreased. The ozone application during coagulation slightly increased TOC and DOC percentage removals, 84.4% to 89.1% and 80% to 82.5%, respectively. This suggests that the small dose of ozone transferred (1.47 mg/L) caused only minor changes in DOM. Finally, the O3ECT effluent exhibits 10 mg/L more of biological oxygen demand (BOD5) than a single CT. 相似文献
15.
Wastewater containing indigenous bacteria and enteric viruses was ozonated in a contact column with counter-current circulation of ozonated air and water. The mean slope of the inactivation curve for indigenous viruses is about half that observed for E. coli and fecal streptococci. For 3 rag osub3;/l, in the presence of residual ozone and a contact time of 19 min, inactivation of 1 log for the viral population and 2 logs for the fecal bacteria are observed. A negative correlation exists between inactivation and organic content. 相似文献
16.
Textile wastewaters are known to be highly resistant to biodegradation under both natural and wastewater treatment plant conditions. However, ozonation can be used to increase the biodegradability of the biologically resistant compounds. The combined method of ozonation and subsequent biodegradation of both synthetic and real textile wastes was explored in laboratory-scale studies. Two kinds of industrial wastes were simulated for effluents from dyehouse and washing machines. Upon determining the ozonation conditions of synthetic wastes, the real industrial wastes were investigated. The real textile wastewater was taken from textile factories, located in ód? , Poland, from subsequent stages of textile processing; dyeing, washing, rinsing and from an equalizer tank. Ozonation was carried out in a lab-scale bubble column sparged reactor, while the biological degradation proceeded in a trickle bed biofilter. 相似文献
17.
Thalita Marques Passos Lívia Helena Moreira da Silva Leonardo Marmo Moreira Renato Amaro Zângaro Roberto da Silva Santos Fernanda Barrinha Fernandes 《臭氧:科学与工程》2014,36(2):138-143
Giardia spp. is a flagellate protozoan that presents two evolution forms, cysts and trophozoites. Cysts are resistant to chlorine, the most employed disinfectant agent in the treatment of water. For this reason, new techniques for the disinfection of waters that contain this parasite are necessary. This work evaluated the efficiency of the disinfection by ozone and ultrasound individually and simultaneously upon wastewater. The data obtained showed that after application, ozone, ultrasound, and combined techniques induced a significant elimination of Giardia spp. cysts. Furthermore, this effect was more accentuated when the two techniques were applied simultaneously. 相似文献
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19.
Tracer and disinfection tests were performed with the ozone bubble-diffuser contactors at the Belmont and Southport Advanced Wastewater Treatment Plants operated by the City of Indianapolis, Department of Public Works. The objective of the study was to develop a better understanding for the role of hydrodynamics and contactor design on the disinfection efficiency achieved in these contactors. Tracer tests were performed at varying gas and wastewater flow rates. The results indicated that high backmixing occurred within each chamber of the over-under ozone bubble-diffuser contactor trains. The addition of three baffles to one of the contactor trains resulted in a decrease in overall contactor backmixing. Low contactor backmixing was observed at high wastewater flow rates combined with high or medium gas flow rates for both the modified and original trains. Monitoring of effluent fecal coliform concentrations for both the original and modified contactor trains revealed lower average concentrations in the modified train effluent as compared to the original train. 相似文献
20.
A research program was undertaken to examine the dose-response of Escherichia coli ATCC 11775 in ozone demand-free phosphate buffer solution and in a high quality secondary wastewater effluent with a total organic carbon content of 8 mg/L and a chemical oxygen demand of 26 mg/L. The studies were conducted in benchscale batch reactors for both water types. In addition, studies using secondary effluent also were conducted in a pilot-scale, semi-batch reactor to evaluate scale-up effects. It was found that the ozone dose was the most important design parameter in both types of water. Contact time was of some importance in the ozone demand-free water and had no detectable effect in the secondary effluent.
Pilot-scale data confirmed the results obtained at bench-scale for the secondary effluent. Regression analysis of the logarithm of the E. coli response on the logarithm of the utilized ozone dose revealed that there was lack-of-fit using the model form which has been used frequently for the design of wastewater disinfection systems. This occurred as a result of a marked tailing effect of the log-log plot as the ozone dose increased and the kill increased. It was postulated that this was caused by some unknown physiological differences within the E. coli population due to age or another factor. 相似文献