Keisuke Ikehata

Degradation of Aqueous Pharmaceuticals by Ozonation and Advanced Oxidation Processes: A Review

A vast number of pharmaceuticals have been detected in surface water and drinking water around the world, which indicates their ineffective removal from water and wastewater using conventional treatment technologies. Concerns have been raised over the potential adverse effects of pharmaceuticals on public health and aquatic environment. Among the different treatment options, ozonation and advanced oxidation processes are likely promising for efficient degradation of pharmaceuticals in water and wastewater. Recent progress of advanced oxidation of aqueous pharmaceuticals is reviewed in this paper. The pharmaceuticals and non-therapeutic medical agent of interest include antibiotics, anticonvulsants, antipyretics, beta-blockers, cytostatic drugs, H2 antagonists, estrogenic hormone and contraceptives, blood lipid regulators, and X-ray contrast media.

Aqueous Pesticide Degradation by Ozonation and Ozone-Based Advanced Oxidation Processes: A Review (Part II)

Pesticides are known to be persistent in surface water and groundwater supplies and as a result, their existence in these water sources has been recognized as a major problem in many countries. The occurrence of these persistent pesticides in water bodies can also cause potential adverse public and environmental health effects. Among many water and wastewater treatment options, ozonation and ozone-based advanced oxidation processes, such as ozone/hydrogen peroxide, ozone/ultraviolet irradiation, and ozone/hydrogen peroxide/ultraviolet irradiation, possess a high potential for degrading and detoxifying these pollutants in water and wastewater. In this paper, ozone based treatment of four major groups of pesticides, namely aniline-based compounds, pyridines and pyrimidines, triazines, and substituted ureas, as well as that of several miscellaneous pesticides are reviewed. Degree of pesticide degradation, reaction kinetics, identity and characteristics of degradation by-products, and possible degradation pathways are covered and discussed.

Ozonation and Advanced Oxidation Treatment of Emerging Organic Pollutants in Water and Wastewater

A vast number of persistent organic pollutants have been found in wastewater effluent, surface water, and drinking water around the world. This indicates their ineffective removal from water and wastewater using conventional treatment technologies. In addition to classical persistent organics such as organochlorine insecticides, solvents, and polychlorinated biphenyls, a growing number of emerging pollutants of both synthetic and natural origins have been identified as major environmental pollutants in recent years. A variety of advanced and conventional treatment options have been suggested for the removal and/or destruction of these persistent organics in water and wastewater, such as chemical oxidation, activated carbon adsorption, and membrane filtration. Of these options, chemical oxidation using ozone, alone or in combination with additional physical/chemical agents (i.e., advanced oxidation), has been proved a highly effective treatment process for a wide spectrum of emerging aqueous organic pollutants, including pesticides, pharmaceuticals, personal care products, surfactants, microbial toxins, and natural fatty acids. In this paper, we discuss the emerging organic pollutants of concern in the aquatic environment and focus on the issues associated with their removal using ozonation and advanced oxidation processes.

Degradation of recalcitrant surfactants in wastewater by ozonation and advanced oxidation processes: A review

ABSTRACT Surfactants are used in varieties of industrial cleansing processes as well as in consumer products. Spent surfactants normally enter domestic or industrial wastewater and are treated biologically. However, some of them are resistant to biodegradation and are released into the environment. Thus, the toxicity and environmental persistence of these surfactants are emerging concerns. Based on extensive review of the literature, ozonation and advanced oxidation using various combinations of ozone, hydrogen peroxide, ultraviolet light irradiation, and iron salts were found effective in degrading recalcitrant surfactants, including linear alkylbenzene sulfonates, alkylphenol ethoxylates, and quaternary ammonium surfactants. Biodegradability of these surfactants was improved after the treatment to some extent in the aqueous solution as well as in real wastewaters.

Screening of Coprinus Species for the Production of Extracellular Peroxidase and Evaluation of the Enzyme for the Treatment of Aqueous Phenol

The production of extracellular peroxidase by twenty-five strains of Coprinus species was investigated for the purpose of its application to the removal of phenolic and other aromatic compounds from industrial waste streams. After initial screening experiments, the production of peroxidase by three superior strains of C. cinereus UAMH 4103, UAMH 7907 and IFO 30116 was monitored over a 15-day period. Peroxidase activity was detected after 3 days of growth and had reached its peak another 6 days later. The peroxidase activity appeared to increase with a corresponding depletion of glucose concentration and rapidly declined immediately after the exhaustion of glucose. The effectiveness of the cultivated C. cinereus peroxidase (CIP) for the removal of aqueous phenol was evaluated in the presence and in the absence of additives including polyethylene glycol (PEG) and chitosan, and compared with those of purified horseradish peroxidase (HRP) and Arthromyces ramosus peroxidase (ARP). The addition of PEG and chitosan enhanced the efficiency of phenol transformation catalyzed by CIP by the factor of 1.5 and 1.3, respectively. Although the efficiency of phenol transformation was higher with CIP than those with purified HRP and ARP in the absence of additives, its superiority diminished in the presence of PEG. This suggests that the by-products of fungal culture in the crude CIP solution, presumably polycarbohydrates and proteins, have protective effects on the enzyme against inactivation during catalytic transformation of phenol, and the addition of PEG provides small effects on further protection.

Kinetics of Estrone Ozone/Hydrogen Peroxide Advanced Oxidation Treatment

Ozone/hydrogen peroxide batch treatment was utilized to study the degradation of the steroidal hormone estrone (E1). The competition kinetics method was used to determine the rate constants of reaction for direct ozone and E1, and for hydroxyl radicals and E1 at three pH levels (4, 7, and 8.5), three different molar O3/H2O2 ratios (1:2, 2:1, and 4:1) and a temperature about 20°C. The average second-order rate constants for direct ozone-E1 reaction were determined as 6.2 × 103 ± 3.2 × 103 M−1s−1, 9.4 × 105 ± 2.7 × 105 M−1s−1, and 2.1 × 107 ± 3.1 × 106 M−1s−1 at pH 4, 7, and 8.5, respectively. It was found that pH had the greatest influence on the reaction rate, whereas O3/H2O2 ratio was found to be slightly statistically significant. For the hydroxyl radical-E1 reaction, apparent rate constants ranged from 1.1 × 1010 M−1s−1 to 7.0 × 1010 M−1s−1 with an average value of 2.6 × 1010 M−1s−1. Overall, O3/H2O2 is shown to be an effective treatment for E1.

Treatment of Groundwater Contaminated with 1,4-Dioxane, Tetrahydrofuran, and Chlorinated Volatile Organic Compounds Using Advanced Oxidation Processes

ABSTRACT Ozonation and four types of advanced oxidation processes, including O3/H2O2, O3/UV, O3/H2O2/UV, and UV/H2O2, were evaluated for the treatment of contaminated groundwater at a Superfund site in Simpsonville, South Carolina using bench-scale, batch ozone and UV apparatuses. Although the contaminants of concern were 1,4-dioxane, 1,1-dichloroethene, and trichloroethene, several other chlorinated organics as well as tetrahydrofuran were found in the groundwater samples. The O3/H2O2 treatment with O3 and H2O2 doses of 6 and 1.5 mg/L, respectively, and the UV/H2O2 treatment with UV and H2O2 doses of 1,000 mJ/cm and 20 mg/L, respectively, were sufficient to degrade 200 µg/L of 1,4-dioxane, 110 µg/L of 1,1-dichloroethene, and 10 µg/L of trichloroethene below their performance standards of 10, 7, and 4 µg/L, respectively. Due to a high bromide concentration (0.35 mg/L) in the groundwater sample, bromate formation was found to be significant in ozone-based treatment, including O3/H2O2.

Soil-Based Treatment of Partially Treated Liquid Swine Manure

A soil-column system was tested for the removal of soluble organics and nutrients from partially treated liquid swine manure. The liquid manure was applied to the 900 mm deep (300 mm of local topsoil and 600 mm of local subsoil) soil columns continuously for an eight-week period, and leachate as well as soil samples were analysed. An effective liquid manure application rate of 17 mm d−1 was determined based on a preliminary liquid manure soil-based treatment experiment. It was found that more than 90% of five-day biochemical oxygen demand, chemical oxygen demand, total Kjeldahl and ammonia nitrogen, and total phosphorus could be effectively removed from the liquid manure by the soil system. Nitrogen contents accumulated in the soil matrix mostly within the 0 to 300 mm depth, while no significant increase was observed in sub soils. Soil analyses indicated the occurrence of nitrification and denitrification in the soil columns. Nitrogen balance showed that about 42% of the applied nitrogen was lost from the system during the liquid manure soil-based treatment experiment, suggesting the emission of ammonia and other gaseous nitrogen generated through nitrification and denitrification. The leachate of the soil treatment system was used to irrigate Bermuda grass. No negative effect of leachate was observed on the plant growth.

ALUM SETTLING AND FILTRATION TREATMENT OF LIQUID SWINE MANURE

A physical/chemical treatment train, which involved preliminary settling for 24 h followed by coagulation/flocculation of supernatant, and filtration, was applied to raw flushed swine manure in bench- and pilot-scale experiments to investigate the effectiveness of the treatment train against the removal of total suspended solids (TSS) and total phosphorus (TP). Alum was used as a coagulant at an average dose of 1600 mg L-1. In the bench-scale experiments, alum treatment was performed using a jar test apparatus, and filtration was achieved by using polycarbonate track-etched membrane filters of pore sizes of 10 and 20 µm. At the pilot plant, coagulation, flocculation, and clarification were achieved in a custom-designed sludge blanket clarifier equipped with inclined plate settlers, followed by media filtration in a set of three patented Martin filter columns containing glass beads of different void sizes ranging from 5 to 25 µm. Overall percent reductions in TSS and TP were 85% (from 9944 to 1470 mg L-1) and 64% (from 449 to 163 mg L-1) in the bench-scale experiments and were 76% (from 3945 to 936 mg L-1) and 75% (from 164 to 40 mg L-1) in the pilot plant treatment, respectively. Preliminary settling was found to be a very effective step, which removed 53% to 56% and 22% to 28% of TSS and TP, respectively, from the raw liquid swine manure. Moderate reduction in chemical oxygen demand was also observed, while the treatment train had little effect on total Kjeldahl nitrogen and dissolved solids. Particle size distribution analysis showed that most of the phosphorus in the liquid manure was associated with particles <10 µm in size and that coagulation and flocculation could enhance the phosphorus removal considerably. At the end of the pilot-scale experiment, approximately 70% and 50% of the initial mass of TSS and TP was removed from the liquid swine manure, respectively, as preliminary settling sludge, whose volume was accounted for approximately 36% of the volume of initial raw manure.

CHAPTER 7:Heavy Metal Pollution in Water Resources in China—Occurrences and Public Health Implications

Because of their serious acute and chronic toxicity, as well as their wide uses and relevance in human activities, heavy metals have been regarded as priority pollutants worldwide. Heavy metal pollution in water resources can affect the public health directly via tainted drinking water consumption and indirectly via food and soil contamination through irrigation using contaminated water, such as contaminated river water, treated and untreated industrial and domestic wastewaters. In addition to their toxicity, heavy metals tend to accumulate in soils, sediments, plants, aquatic organisms, as well as food crops, domestic animals and humans. The Peoples Republic of China (‘China’) is no exception in environmental pollution due to toxic heavy metals, such as mercury, lead, cadmium, chromium and arsenic, and their compounds. In this chapter, the current status of heavy metal pollution in the water resources in China are reported and discussed, with respect to relevant water quality standards in different types of water, as well as data for recent occurrence in the water resources in China. Special attention is given to addressing human health risks associated with heavy metals in contaminated drinking water, contamination of sediments in rivers and lakes, and impacts of industrial effluents and wastewater irrigation.