Iron and Manganese Removal with Ozonation in the Presence of Humic Substances

The conditions for the removal of iron and manganese contained in slightly mineralized water, rich in humic substances, were determined in a case where an intermediate oxidation was provided in a conventional potabilization line comprising a coagulationflocculation stage with iron salts.

The experiments were conducted both on a synthetic water, with or without addition of humic substances, and on raw water from the Moulin-Papon dam. While iron was easily removed by simply increasing the pH measurement from 8.2 to 8.5 without intermediate oxidation, ozonation applied to water with a pH of nearly 8.4 did not enable the manganese to be removed with a low ozone dose (about 1 mg/L) unless a significant amount of bicarbonates (120 to 130 mg/L as CaCO₃) were injected prior to the ozonation-filtration stage.

As it removes the manganese from the water, intermediate ozonation also removes the abatement of organics on the filters, and lowers the THM buildup potential.     

New York City's Ozone Demonstration Plant Design

Designand construction specifications of a 3 mgd (12, 187 m³/day) demonstration plant to treat water by ozonation followed by diatomaceous earth (DE) filtration at New York City's Jerome Park Reservoir are described. The primary treatment objectives are to maintain a treated water quality of turbidity below 0.2 NTU, color below 3 color units, and iron and manganese below 0.3 mg/L. Three process trains will be employed, each operating at a maximum of 1 mgd (3,786 m³/day), to test variousmodificationsof theozone/DE process. The demonstration plant is scheduled to operate approximately one year, beginning in April 1986, to provide data for a full-scale plant to be constructed later in the decade.     

Removal of Residual Dissolved Ozone with Manganese Dioxide for Process Control with UV254

Ozonation is one of the most promising options to remove organic micropollutants (OMP) from wastewater treatment plant effluents. For an economic operation and in order to avoid formation of bromate, the ozone dose has to be adjusted in real-time due to the strongly varying effluent quality. The reduction of UV absorption at 254 nm (?UV₂₅₄) is a useful surrogate parameter for OMP removals. Unfortunately dissolved ozone also absorbs UV at 254 nm and therefore might disturb a ?UV₂₅₄-based process control. A fixed bed of manganese dioxide granules was found to efficiently remove residual ozone.     

Pilot Testing Of Trace Metals Removal With Ozone At Snowbird Ski Resort

A pilot study at the Snowbird Ski Resort in Utah evaluated feasibility of ozonation replacing chlorine and sulfur dioxide for oxidation of iron and manganese in groundwater. Ozonation also was tested for the removal of lead and cadmium, occurring at concentrations exceeding drinking water Maximum Contaminant Levels. An ozone dose of 2 mg/L, contacted with the water for 1 minute prior to filtration, was selected as optimum for iron and manganese removal from 0.4 mg/L and 40 μg/L, respectively, to below detection limits. Lead, copper, and arsenic also were removed to below detection limits. The removal of cadmium and zinc improved when ozone was contacted for 10 minutes. With metals removal through ozonation and filtration, taste and odor enhancement also were reported.     

Ozone Cooling Tower Treatment With and Without Mineral Removal

This paper builds on a prior paper by this author, McGrane (1991). In that paper, ozone is used as the sole means of cooling tower water treatment. The paper discusses water conservation by increased cycles of concentration, greatly increased efficiency through extremely low biological populations, and corrosion data which is compared to ozonated and chemically treated towers.

New in this paper are the results from the combination of a low pressure reverse osmosis system with ozone treatment for cooling tower water. Scale formation has continued to plague cooling towers with high concentrations of calcium in the make-up water. The use of a mineral removal system in cases of extremely hard water has made ozone an attractive alternative to traditional chemicals in many areas.     

Advanced Oxidation Treatment of Drinking Water: Part II. Turbidity,Particles and Organics Removal from Lake Huron Water

Pre-coagulation ozonation has been reported to be effective in drinking water treatment processes. Limited data are available on the impact of advanced oxidation processes (AOPs) on Lake Huron water which serves as a primary source of drinking water for many communities around the Great Lakes region. Impact of ozone/hydrogen peroxide based AOP on Lake Huron water was studied. The results show that AOPs can achieve higher particles removal in finished water and deliver improved filtered water turbidity compared to the conventional treatment process. Sharp decline in ultraviolet absorbance at 254 nm (UV₂₅₄) was observed immediately following AOP treatment while only minimal overall decrease in dissolved organic carbon (DOC) was achieved.     

Comparison of Ozone Efficiency for Manganese Oxidation Between Raw and Settled Water

Ozone was tested at the Moores Bridges WTP as a replacement for chlorine for oxidizing dissolved manganese. Two points of ozone application were tested, raw and settled water. Dissolved manganese appeared to be much more readily oxidized with a lower ozone dose when ozone was applied to the settled water than when it was applied the raw water. Apparently the TOC concentration of the water affected ozone's ability to oxidize manganese by exerting an ozone demand which must be overcome. Because of the results of the pilot testing, a decision was made to ozonate settled water rather than raw water to oxidize the manganese.     

A Comparison of Objectives,Level of Development and Energy Consumption of Two New Hungarian Ozonation Plants

Basedon the success of the first Hungarian large capacity drinking water treatment ozonation plant of Budapest that was put into operation in 1984, a similar second plant was put into operation in 1988 in Debrecen with 150,000 inhabitants. This recently built plant solves taste and odor problems and water quality development of a surface water treatment plant with a capacity of 50,000 m³/day that is operative for a longer period of time. The experiences gained at the Budapest ozonizing plant were utilized during both planning and construction. Thus, for example, the method of ozone absorption had been modified.

The in-situ repair of the Frings turbines for ozone contacting placed at the Rackeve plant of the Budapest Waterworks will be introduced, as well as a concept of a newer kind of ozone mixing.     

The Oxidation of Manganese and Disinfection By Ozonation in Water Purification Processing

The surface water of a river has been used as the raw water by the Waterworks Bureau of Osaka City. At present, the manganese contained in the raw water is oxidized by breakpoint chlorination and all oxides are removed by coagulation, sedimentation followed by rapid sand filtration, with chlorine being used as the final disinfectant.

Prechlorination was not conducted in the ongoing pilotplant experiment of an advanced water purification process with ozone and granular activated carbon. It is necessary, therefore, to oxidize manganese by the oxidative effect of ozone instead of prechlorination.

It is important for the treatment of manganese to adjust the ozone dosage because manganese is oxidized up to the soluble septavalent state by the surplus ozone. Since ozone does not continue to exist for very long in water, though its disinfecting power is high, final disinfection by chlorine is required.     

地下水固锰除铁工程设计

地下水固锰除铁工艺中在跌水曝气后过氧化问题一直是该工艺的关键内容,将跌水曝气池、滤池、反冲洗水池合建形成一体化固锰除铁单元,可以根据水量控制曝气强度,防止过曝气,稳定过滤水头,而且可以节约占地,减少滤池面积,并方便运行管理。     

NaOH改性沸石吸附地下水中铁锰效能研究

为了提高沸石对铁锰的吸附性能，利用3种不同改性剂对天然沸石进行改性比较对铁锰的去除效果。通过NaOH改性沸石除铁锰的静态吸附试验研究，考察改性沸石对铁锰的去除效果。结果表明NaOH改性沸石对铁锰的去除效果优于NaCl和HDTMA改性沸石对铁锰的去除效果，NaOH改性沸石的投加量、改性沸石的对铁锰的吸附时间、原水的pH值等因素对铁锰的去除效果有较大的影响，最佳投加量为50g/L，最佳吸附时间为120min，最佳pH值为中性偏酸性或者偏碱性且pH值〈8时，对铁锰的吸附规律较好的符合Langmuir吸附等温式。NaOH改性沸石对铁去除率可达83．09％，对锰的去除率为49．65％。经过改性，沸石对铁锰的去除率和吸附容量都有了较大的提高。     

Applications of Ozone in Japan for Water and Wastewater Treatment

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.     

The Installation of GAC and Ozone Surface Water Treatment Plants In Anglian Water,UK

The surface water treatment plants in Anglian Water are being upgraded in order to more reliably meet the requirements of the EEC Drinking Water Directive. Ozone and additional GAC filtration capacity are being installed at 11 waterworks treating river and reservoir water, with capacities ranging from 11 to 360 ML/d. The installations and reasons for the plant designs are discussed.     

Removal Mechanism of Natural Organic Matter and Organic Acid by Ozone in the Presence of Goethite

The oxidations of natural organic matter (NOM) and a model compound (p-chlorobenzoic acid) were characterized using ozonation and catalytic ozonation processes. In general, the catalytic ozonation showed better performance in the removal of organics tested in the study. The hydrophobic, transphilic, and hydrophilic NOM fractions were isolated using XAD-8 and -4 resins to evaluate the reaction characteristics. The catalytic ozonation in the presence of goethite accomplished the higher removal of NOM with simultaneous reduction of the three fractions than the ozonation which removed the hydrophobic portion only. The analysis of discrete size distributions of NOM revealed that ozonation yielded a removal of >1,000MW and an increase of <1,000MW, whereas all molecular weight fractions reduced after catalytic ozonation. The concentrations of model compound and aqueous and gaseous ozone were monitored during the oxidations, and efficiencies were compared for cases in the absence and presence of iron oxide (FeOOH).     

Studies on the Disinfection and Removal of Biofilms by Ozone Water Using an Artificial Microbial Biofilm System

Inactivation rates of the biofilms of P. fluorescence and P. aeruginosa established on a small slide glass in ozone water (0.9–3.2 mg/L, 1–20 min) were determined in a batch or flow-through system. The effects of ozone water on the biofilm matrices were defined clearly in situ by confocal laser scanning microscopy. These results indicate that ozone is an effective biocide against biofilms and it can remove exopolysaccharides in the biofilm matrices. However, the effective concentration of ozone for disinfection of biofilms varied with the biofilms formed, mainly due to reactions of ozone with constituents of the biofilms.     

地下水生物除铁、锰的影响因素试验研究

目的：研究锰砂滤层去除铁、锰过程中滤速、温度、溶解氧3个因素对去除效果的影响,为生物法除铁、锰的实际运行提供了参考依据。方法：在其他运行条件相同的情况下,只改变其中一项,进行去除率试验对比。结论：（1）当处理只有铁超标的地下水时,滤速可以适当提高,锰超标时,出水中的含锰量是选择过滤速度的主要的控制指标;（2）DO在一定范围内的变化对生物除铁除锰效率的提高无显著影响。从经济性和微生物角度考虑原水DO维持在3mg／L左右既可满足运行要求;（3）当铁锰共存时,最适宜的处理环境温度为20℃。     

The Influence of the Removal of Specific NOM Compounds by Anion Exchange on Ozone Demand,Disinfection Capacity,and Bromate Formation

This research on a pilot scale focuses on the reaction of ozone with natural organic matter (NOM) for three water qualities with different dissolved organic carbon (DOC) concentrations and NOM compositions, obtained after several stages of an anion exchange process. It was shown that for the same ozone dosage per DOC, the ozone demand was higher, less bromate was formed and a lower disinfection capacity was reached for water containing mainly humic substances, than for water where the humic substances were partly removed. It can be concluded that NOM composition, specifically the humic substances, influences the ozone demand, disinfection capacity and bromate formation.     

生物膜技术在饮用水除铁除锰中的研究综述

铁锰是人体重要的组成元素,在维持机体正常的新陈代谢方面具有重要作用,然而过多的铁锰摄取又会引发许多潜在的并发症状。本文针对我部分地区地下水中铁锰含量严重超标的现象,探讨了地下水除铁除锰技术中的生物接触氧化方法,并就其影响因素进行了分析,最后对其未来的发展方向进行了展望。     

Oxidation by UV and Ozone of Organic Contaminants Dissolved in Deionized and Raw Mains Water

Organic contaminants dissolved in deionized pretreated and raw mains water were reacted with ultraviolet light and ozone. Ozone first was used for partial oxidation followed by ozone combined with ultraviolet radiation to produce total oxidation. The reduction of TOC level and direct oxidation of halogenated compounds were measured throughout the treatment process. The rate of TOC reduction was compared for ozone injected upstream and inside the reactor.     

Ozonation at Wiggins Water Purification Works,Durban, South Africa

The post-ozone plant at Wiggins waterworks was commissioned during 1984. The main objective of the post–ozone plant was to ensure proper disinfection, including the elimination of viruses, whenever raw water for the works was pumped from the polluted lower Umgeni River. The main problems experienced with the post–ozone plant were poor ozone transfer efficiency in the contact tank and poisoning of the catalyst in the thermal-catalytic destructor.