摘要:

Ozone inactivation ofGiardia muriscysts was investigated in laboratory phosphate buffer (pH 6.7; 22°C) at bench-scale using four ozone dose levels and two contact times. The C3H/HeN mouse model was used to assess the infectivity of ozone treated cysts. This model was found to be a sensitive measure of cyst inactivation to 99.99% inactivation and beyond. It was also observed that ozone rapidly inactivatedG. murisand that ozone concentration appeared to be the most important parameter for predicting ozone inactivation ofG. muriscysts.

ISSN:0191-9512    

DOI:10.1080/01919519208552314

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The design engineer and owner have multiple issues to address when planning to use an ozone process in a water or wastewater treatment plant. Considerations include feed-gas properties and equipment, ozone generator features and size, ozone contactor type and configuration, and methods of off-gas ozone destruction. Many successful ozone systems are in use today.Where performance has suffered, deficient feed-gas treatment often is the problem. The feed-gas to the ozone generator must be oil-free, particulate-free, and dry. In this paper, the factors involved in selecting and operating feed-gas equipment are presented.

ISSN:0191-9512    

DOI:10.1080/01919519208552315

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The decomposition of ozone in basic aqueous solutions was simulated on the basis of two previously reported detailed mechanisms. According to the calculations, the mechanism given by Tomiyasu, Fukutomi and Gordon5is an appropriate model for the ozone decomposition, both in the presence and the absence of hydrogen peroxide and/or carbonate ion in basic solution. On the basis of this mechanism the main chain carrier is the ozonide ion radical.

ISSN:0191-9512    

DOI:10.1080/01919519208552316

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Experiments were performed to evaluate disinfection by-products in model humic acid solutions which were ozonated at three different ozone to carbon levels and then chlorinated. These experiments were conducted in order to help understand whether the ozone/post-chlorination process alters the amount and type of mutagenic by-products formed, from those produced by chlorination of humic acid alone. Disinfection by-products were identified by gas chromatography/mass spectrometry (GC/MS). Samples of clarified and sand-filtered Mississippi River water at a pilotscale drinking water treatment plant in Jefferson Parish, Louisiana, that were ozonated and post-disinfected with chlorine, also were analyzed by GC/MS. A comparison of the by-products in the pilot plant study versus those in our laboratory study showed that similar compounds were produced. The effect of bromide ion in the pilot plant water on by-product formation also is discussed.

ISSN:0191-9512    

DOI:10.1080/01919519208552317

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

PEROXONE is an advanced oxidation process for water treatment which is generated by combining ozone and hydrogen peroxide. In this study, surface water supplies were seeded with viableGiardia muriscysts and disinfected by ozone and PEROXONE in the pretreatment columns of a 22.7 L/min pilot plant. Inactivation was examined in two source waters under conditions of varying applied ozone doses (0.5–4.0 mg/L), with and without the addition of hydrogen peroxide; at increasing contact times (3, 6, 9, and 12 min); and with and without added high turbidity (10 and 50 NTU). Approximately 108viableG. muriscysts were injected into the ozone contactor-column influent. The cysts were collected at the ozone contactor-column effluent and concentrated, and viability was then determined usingin vitroexcystation.

ISSN:0191-9512    

DOI:10.1080/01919519208552318

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0191-9512    

DOI:10.1080/01919519208552313

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor