尾崎 博明

The purpose of this study is to compare retention characteristics of perfluorinated organic compounds (PFCs) and similar-structured non-fluorinated organic compounds (NFCs) by new generation low-pressure reverse osmosis (LPRO) membranes based on physicochemical properties of the compounds and the results of bench-scale membrane efficiency batch tests as the first-step screening. Molecular weight (MW), molecular size, and hydrophobicity of the compounds greatly influence their retentions by loose and low-desalting membranes than those by tight and high-desalting membranes. The retentions in general increased with increasing MW and molecular length (ML). The retentions are explained more reliably by using both MW and molecular width/height parameters. The roles of MW and ML on the retentions could not be differentiated, since MW increases almost linearly with ML. The NFCs are more easily rejected than the PFCs by the membranes most probably due to hydrophobic adsorption of the PFCs to membranes leading to their slippage through membrane pores owing to their slender molecular structures. Though retentions of NFCs and PFCs in their undissociated states are governed by steric/size exclusion mechanism, hydrophobic adsorption to membrane is a major event for PFCs while it is not for NFCs. Unlike NFCs, retentions of PFCs in their dissociated states are greatly enhanced due to overwhelmingly greater efficacy of electrostatic exclusion. This is the first study comparing retentions of NFCs and PFCs by LPRO membranes and is expected to serve as an important reference for further works.

This article aims to elucidate on usefulness of vacuum ultraviolet (VUV) for photoreductive degradation of perfluorooctanoic acid (PFOA), a representative perfluorinated compound (PFC), in water for the first time. Bench-scale tests were conducted on oxidative and reductive (with aquated electron: eaq -) mineralization of PFOA using low-pressure UV (LPUV) lamps and potassium iodide. Unlike with 254 nm wavelength (UVC), the reductive mineralization with VUV was very inefficient compared to the corresponding oxidative mineralization. The inefficiency is attributed to low reactivity of eaq - with PFOA and its fluorinated products than that of 185 nm photons. Direct VUV photolysis of PFOA and its products in reductive reaction conditions was not apparent due to a very big difference in reactivity of 185 and 254 nm photons with iodide. The results demonstrated that highly energetic VUV photons are not suitable for photoreductive degradations of PFCs involving eaq -, but they can be best used for oxidative degradations. These findings should serve as an important reference on VUV usage to decompose refractory micropollutants. © 2013 Islamic Azad University (IAU).

Low pressure reverse osmosis (LPRO) membrane filtration has emerged as the best alternative to ordinary reverse osmosis (RO) membrane filtration due to very low operating pressure involved with the former resulting in low cost. However, behaviors of perfluorinated compounds (PFCs) with LPRO membrane filtration are not known since the compounds as water/wastewater contaminants have only a very short history. Therefore, adsorption and diffusion behaviors of selected perfluoroalkyl carboxylate (PFAC) and perfluoroalkyl sulfonate (PFAS) compounds with a tight and a loose LPRO membranes were tested in laboratory experiments. Distribution coefficient (logK_mw) and diffusion coefficient (D_p) values for the compounds were experimentally determined for the first time. The D_p values were about three orders of magnitude larger than those for pharmaceutical and endocrine disrupting compounds. The compounds exhibited similar behaviors to those of pharmaceutical and endocrine disrupting chemicals reported earlier. Adsorption of PFCs to membranes was directly correlated to molecular weight (MW) and carbon-chain length, while their diffusion through membrane pores showed inverse correlations with the parameters. Similarly, their rejections were directly correlated to their logK_mw values and MW. However, significance of carbon-chain length on diffusion was not well understood, and hence further investigations should be devoted to elucidate on the point.

Oseltamivir and zanamivir are the two most prescribed antiviral drugs against influenza in Japan. Oseltamivir and its metabolite are frequently detected in surface water bodies in Japan during the last few years particularly in seasonal influenza period posing a potential threat of emergence of drug-resistant genes in human pathogens. Despite the second largest use of zanamivir as an antiviral drug in Japan, its presence and fate in environmental waters is unknown until now. Accurate assessment on the presence and fates of these drugs in environmental waters is the very first step in countering the potential negative impact on human health. We have recently developed a novel solid-phase extraction (SPE) method for simultaneous recovery of oseltamivir and zanamivir in environmental waters. These antiviral drugs were quantified in Neya River water and a nearby conventional sewage treatment plant (STP) during the 2010/2011 seasonal influenza using the SPE method in this investigation. Oseltamivir and zanamivir concentrations in the river water and STP water samples are discussed and compared with those of the 2009/2010 pandemic influenza in this article. This successful simultaneous quantitation of zanamivir in wastewater and river water with high recovery ratios paves the way for its monitoring in environmental waters.

Ultraviolet photolysis and ultraviolet and hydrogen peroxide oxidation of fourteen commonly used pharmaceutical compounds and two personal care products in mixed solution using low pressure ultraviolet lamp was investigated in laboratory batch experiments. Removal of the compounds followed the first-order reaction kinetic. Three distinct impacts of hydrogen peroxide on ultraviolet and hydrogen peroxide oxidation of the compounds (positive, negative and no significant effect) were observed. Removal behavior of the several tested compounds in mixed solution varied significantly than their respective behavior in absence of coexisting compounds. Clofibric acid, diclofenac, fenoprofen, isopropylantipyrine, ketoprofen, phenytoin and triclosan were removed very efficiently (&gt 96%) by ultraviolet photolysis alone. Residual hydrogen peroxide during ultraviolet and hydrogen peroxide oxidation was quantitated for the first time. Hydrogen peroxide addition to ultraviolet photolysis was not worthy for majority of the tested compounds as their removal did not increase significantly and very big fractions (&gt 85%) of the added hydrogen peroxide (0.29 ~ 1.47 mM) remained unused presumably due to small fluence of the lamp, very small molar absorption for hydrogen peroxide at 254 nm (27.06 /M.cm) and acidic pH of reaction solution (&lt 5.7). Further exploration on ultraviolet and hydrogen peroxide oxidation with higher fluence lamp and alkaline solution pH will clarify usefulness of the method to treat pharmaceutical contaminated waters. © IRSEN, CEERS, IAU.

Perfluorooctanoic acid (PFOA) is very persistent in the environment and widely detected in the water environment. Only some advanced methods with extreme reaction conditions are shown to be capable of degrading the compound efficiently, and almost all the earlier investigations used very high PFOA concentrations. The compound is detected normally at very low concentrations in the water environment, while mild reaction conditions for its degradation are preferable. This article aimed to elucidate photodegradation of PFOA in dilute aqueous solutions by combined UV wavelengths (185 nm + 254 nm) and 254 nm using a newly designed UV jacket. PFOA degradation was greatly enhanced with the combined wavelengths with almost one hundred percent PFOA removals in four-hour reaction. The removals were well described by the first-order reaction kinetic. The removal efficiencies and rate values significantly decreased with smaller initial PFOA concentrations. But defluorination was greatly enhanced with smaller PFOA concentrations possibly due to accelerated decomposition of fluorinated intermediates of PFOA. Formic acid and acetic acid were two tentatively identified intermediates of PFOA photolysis while the former was a major intermediate predominantly controlling solution pH during the oxidation. The results demonstrated that PFOA photolysis by the combined wavelengths with mild reaction conditions can be greatly enhanced by proper design of UV jacket and reactor system.

The widespread detection of perfluorinated compounds (PFCs) in the water environment has been a concern for the last several years, while effluents from wastewater treatment facilities are the major sources of these compounds. Even advanced oxidation technologies (AOTs) are not useful for mineralization of the compounds due to their very high stability. Photochemical techniques using particularly vacuum UV (VUV) have been found to be very promising in this regard. But the use of VUV in UV-based AOTs has still not progressed much. Moreover, the impact of water quality on PFCs photomineralization is unknown. This investigation aimed to assess photomineralization potentials of perfluorooctanoic acid (PFOA) in ultrapure water (UPW), tap water (TW), surface water and treated wastewater effluent using a reactor setup enabling maximum utilization of VUV emission of low pressure lamp in laboratory batch experiments. Neya River water (NRW) and the Nakahama Wastewater Treatment Plant Effluent (NWWTPE) represented surface water and treated wastewater effluent respectively. Also, tests were carried out in 50% diluted NRW and NWWTPE. PFOA photomineralization in terms of PFOA removal, defluorination and total organic carbon (TOC) removal are discussed. The usefulness of the method for PFOA mineralization in organic-rich wastewaters, and further research needs are also highlighted.

Presence of the antiviral drug oseltamivir in considerable concentrations in surface waters especially in seasonal and pandemic influenza cases has raised concerns on its possible consequences in the environment and human health. This investigation aimed to elucidate concentration levels of the drug in Neya River in Osaka during 2009/2010 seasonal influenza. Oseltamivir phosphate was detected for the first time in Neya River suggesting the presence of the drug in phosphate form in surface waters is significant only in influenza pandemic cases. Oseltamivir carboxylate concentrations in Neya River were as high as 15-fold the concentrations in Yodo River in 2007/2008 and 3-fold the concentrations in a sewage treatment plant effluent in Kyoto in 2008/2009. The highest oseltamivir carboxylate concentration in Neya River was detected at ST-2 (864.8 ng/L) followed by ST-3. This was possibly due to the inefficiency of the treatment plant upstream and low river water flowrate. Based on the limited information available on the possible environmental risks of the drug in surface waters, the detected concentrations in Neya River may not be an immediate threat to the environment. However, detailed risk assessment studies are essential to clarify the potential environmental risk issue.

Widespread detection of pharmaceutical compounds in water environment has been a serious concern recently, while conventional sewage treatments are ineffective for their elimination. But, advanced oxidation techniques are very promising to remove varieties of organic contaminants in water. This research aims to elucidate oxidation potentials of sixteen commonly used pharmaceutical compounds in mixed solutions by seven advanced oxidation techniques in laboratory batch experiments. The removal profiles exhibited four distinct patterns: a) easily degradable by all seven techniques, b) not easily degradable by all seven techniques, c) easily degradable by ozone-based techniques, but not by ultraviolet radiation-based techniques and d) easily degradable by ultraviolet radiation-based techniques, but not by ozone-based techniques. Ozone-based techniques rather than ultraviolet radiation-based techniques were very powerful for simultaneous removal of the compounds efficiently. Moreover, ozonation combined with ultraviolet radiation was the most appropriate technique for simultaneous removal of the tested compounds efficiently. Increased ozone dissolution and decomposition with ozone-based techniques did not always enhance the compounds' removal. Physicochemical properties of the compounds and solution pH also presumably played an important role on the removal which merits further attention. © IRSEN, CEERS, IAU.

Presence of chlorinated organic compounds in water bodies has become a concern among governments, health authorities and general public. Oxidation of organic compounds in water under high temperature and pressure is considered as a promising technique, but usefulness of the technique to mineralize 2,4-dichlorophenoxyacetic acid (2,4-D) is not well understood. This article aimed to elucidate degradation characteristics of 2,4-D in both subcritical and supercritical waters by laboratory batch experiments. 2,4-D degradation, total organic carbon (TOC) removal and dechlorination increased with increasing reaction time and temperature especially in subcritical waters, while dechlorination was a major step. 2,4-dichlorophenol (2,4-DCP) and acetic acid were the main degradation intermediates both in subcritical and supercritical waters. Though 2,4-D disappeared almost completely in subcritical waters near critical region (approximate to 99%), significant amounts of TOC and organic chlorine still remained as 2,4-DCP and acetic acid. But TOC removal and dechlorination were significantly enhanced (approximate to 95 and 91% respectively) in supercritical waters. Complete mineralization of 2,4-D in subcritical waters required a considerably longer reaction period, while the mineralization was almost complete within a short reaction period in supercritical waters. This is an important information of practical significance for oxidative degradation of chlorinated pesticides similar to 2,4-D.

塩素系農薬（除草剤）として使用される2,4－ジクロロフェノキシ酢酸(2,4－D)の水中での分解を、光触媒繊維を用いる光触媒法とオゾン法との併用法（O3/UV/TiO2）により試み、副生成物の同定を行った。O3/UV/TiO2の併用法によると、オゾン法単独や光触媒法単独の場合よりも、2,4－Dからの脱塩素および2,4－D分解にともなう副生成物である脂肪族化合物の分解を助長することがわかった。したがって、同併用法は副生成物の分解も可能な有望な方法であると言える。

Photocatalytic ozonation (O(3)/UV/TiO(2)) is an emerging oxidation method for recalcitrant organic contaminants in water. However, immobilised TiO(2) catalysts suffer from reduced photonic efficiency. Therefore, TiO(2) catalysts with excellent mechanical and thermal properties and enhanced photonic efficiencies are sought. This paper aimed to elucidate the mineralisation of low concentration 2,4-D (45.0 mu M) by O(3)/UV/TiO(2) using the world's first high-strength TiO(2) fibre in laboratory batch experiments. 2,4-D degradation and TOC removal followed pseudo first-order reaction kinetic. The removal rates for 2,4-D and TOC in O(3)/UV/TiO(2) were 1.5 and 2.4-fold larger than the summation of the values for ozonation (O(3)) and photocatalysis (UV/TiO(2)), respectively. O(3)/UV/TiO(2) was characterised by few aromatic intermediates with low abundance, fast degradations of aliphatic intermediates and dechlorination as a major step. The significantly enhanced 2,4-D mineralisation in O(3)/UV/TiO(2) was attributed to increased ozone dissolution and decomposition, and reduced electron - hole recombination resulting in large number of hydroxyl radical ((center dot)OH) formation from more than one parallel path. The discrepancies in the organic carbon mass budget were attributed to few apparently major unidentified intermediates, while chlorine mass balance was reasonably acceptable. The mineralisation efficiency of O(3)/UV/TiO(2) with the TiO(2) fibre can further be enhanced by optimisation of experimental design parameters. The new TiO(2) fibre is very promising to overcome the problem of reduced efficiency of TiO(2) catalyst in an immobilised state.

This paper aims to elucidate retention characteristics of some pharmaceuticals and personal care products (PPCPs), and endocrine disrupting chemicals (EDCs), by two polyamide low pressure reverse osmosis (LPRO) membranes. Feed solution pH did not have an influence on rejections of undissociated solutes, which was most likely governed by adsorption, size exclusion and diffusion simultaneously. Size exclusion was presumably dominant, especially with tight membranes (UTC-70U). Rejections of the solutes with low dipole moment (< 1.0 debye) decreased with increasing octanol-water partition coefficient (K(ow)). The solutes with large Kow values were most likely adsorbed on membrane and subsequently passed through it resulting in larger diffusion coefficient (D(p)). The rejections decreased with increasing Dp values irrespective of their dipole moments. Rejections of solutes with comparatively larger dipole moments might be dominated by diffusion and/or convection rather than their hydrophobicity. However, rejections of solutes with hydroxyl and carboxyl functional groups by UTC-60 increased with solution pH. More than 80% rejections were obtained for degree of dissociation (alpha) > 0.5. Electrostatic repulsion played a key role for rejection of dissociated solutes, especially by loose LPRO membranes. Therefore, assessing the dissociation degree at desired pH values can be a key step to obtain an insight of rejection mechanisms by polyamide membranes.

近年、水環境中から人畜用の医薬品が検出されており、これらは生理活性を有していることから生態系への影響や上水を経由した場合の人体への暴露影響が懸念されている。本研究では、多孔質セラミックス電極を用いた電気分解処理について16種類の医薬品を対象に検討を行った。多孔質セラミックスろ用いた電極分解処理医薬品を電極内に通水する構造にすることで医薬品を吸着した滞留時間を長くすることで効率よく電気分解を行うことが可能となる新しい水処理法である。

水汚染物質として問題になり始めている各種の医薬品類及び抗菌剤を対象として、水処理技術開発の一環として低圧逆浸透膜による除去を試み、分離特性を明らかにした。比較的塩阻止能が低い低圧逆浸透膜では、非解離性溶質の阻止は溶質分子の大きさが支配因子となり、溶質の解離度が50％以上の場合に80％を超える高い阻止率を示した。塩阻止能が高い低圧逆浸透膜では、溶質の解離性にかかわらず90％程度以上が除去された。また、極性の低い物質では溶質の疎水性(log Kow)が阻止率に影響を及ぼした。

Concentration of 2,4-dichlorophenoxyacetic acid (2,4-D) may affect its degradation kinetics in advanced oxidation systems, and combinations of two or more systems can be more effective for its mineralization at low concentration levels. Degradations and mineralizations of 0.045 mM 2,4-D using O-3, O-3/UV, UV/TiO2 and O-3/UV/TiO2 systems were compared, and influence of reaction temperature on the mineralization in O-3/UV/TiO2 system was investigated. 2,4-D degradations by O-3, O-3/UV and UV/TiO2 systems were similar to the results of earlier investigations with higher 2,4-D concentrations. The degradations and total organic carbon (TOC) removals in the four systems were well described by the first-order reaction kinetics. The degradation and removal were greatly enhanced in O-3/UV/TiO2 system, and further enhancements were observed with larger 03 supplies. The enhancements were attributed to hydroxyl radical ((OH)-O-.) generation from more than one reaction pathway. The degradation and removal in O-3/UV/TiO2 system were very efficient with reaction temperature fixed at 20 degrees C. It was suspected that reaction temperature might have influenced (OH)-O-. generation in the system, which needs further attention. (c) 2006 Elsevier Ltd. All rights reserved.

Endocrine disrupting chemicals (EDCs) are the focus of current environmental issues, as they can cause adverse health effects to animals and human, subsequent to endocrine function. The objective of this study was to remove a specific compound of EDCs (i.e. pentachlorophenol, C6OCL5Na, molecular weight of 288 g/mol) using low pressure reverse osmosis membrane (LPROM). A cross flow module of LPROM was used to observe the effects of operating parameters, i.e. pH, operating pressure and temperature. The design of the experiment was based on MINITAB(TM) software, and the analysis of results was conducted by factorial analysis. It was found that the rejection of pentachlorophenol was higher than 80% at a recovery rate of 60 to 70%. The rejection was subjected to increase with the increase of pH. The flux was observed to be increased with the increase of operating pressure and temperature. This study also investigated the interaction effects between operating parameters involved.

熱帯地域の下水処理システムについて考究するために、タイ国バンコク市内の大規模下水処理場と、旧来からの小規模下水処理場の流入水と処理状況について調査した。タイ国では伝統的に、家庭排水を一時貯留する浄化槽が設置され、一般にはトイレットペーパーが使われないこと、気温が高く、下水道（管）での滞留時間が長いこと、雨季には多量の雨水により下水が希釈されるなどの特性があり、大規模処理場への流入水の汚濁物質濃度は低く、汚濁物質の分解速度は大きい。大規模処理場は過大に設計されており、気候と伝統をも考慮した下水処理システムの構築について議論した。

Environmental pollution by low concentrations of 2,4-Dichlorophenoxyacetic acid (2,4-D) is a concern these days due to ever increasingly stringent regulations. Photocatalysis with immobilized TiO2 fiber is a promising oxidation method. Laboratory experiments on photocatalytic degradation of 0.045 mmol l(-1) 2,4-D with the world's first high-strength TiO2 fiber catalyst were carried out in a continuous flow reactor in which the degradations were, in general, similar to those with high 2,4-D concentrations investigated elsewhere. Degradation and mineralization of 2,4-D were significantly enhanced with no initial pH adjustments. The rate constants for total organic carbon (TOC) without pH adjustment were about two-fold bigger than the pH adjustment cases. CO2 gas measurement and carbon mass-balance were carried out for the first time, where about 34% organic carbon converted into CO2 gas during four-hour oxidation. 2,4-Dichlorophenol (2,4-DCP), phenol, benzyl alcohol and two unknowns (RT approximate to 2.65 and 3.78 min.) were detected as aromatic intermediates while Phenol was the new aromatic in HPLC analysis. Dechlorination efficiencies were high (> 70%) in all the cases, and more than 90% efficiencies were observed in chloride mass balance. Bigger flow rates and solution temperature fixed at 20 degrees C without pH adjustment greatly enhanced 2,4-D mineralization. These results can be an important basis in applying the treatment method for dioxin-contaminated water and wastewater.

PCBsやダイオキシン類等の有害有機物による底質汚染が顕在化している。有害有機物は粘土やシルトに高濃度で吸着しているため、汚染底質は底質を分級し、汚染濃度に応じて処理する方法が効率的である。本研究では比較的低温で底質を間接加熱し、底質中の有害有機物を気化させ浄化する間接熱脱着法に注目した。実験はダイオキシン類・PCBsを含む実汚染底質を全粒径、75-2000μm、20-75μm、20μm以下に分級した後、400℃ で間接加熱した。ダイオキシン類は粒子径が小さくなるほど除去効率が向上し、75μm以下の粒子径から95%以上の除去率を得た。PCBsはどの粒子径においても99%以上の除去率を示した。結果より、間接熱脱着法によるダイオキシン類汚染底質の処理は分級して行う方が効率的である事がわかった。

Human waste is a major component of sewage, but it could be an important source as fertilizer. Since night soil contains a larger amount of organic matter with its small volume, it can remarkably affect biological treatability and hazards in conventional wastewater treatment that has been widely accepted in developed countries. The objective of this laboratory experiment was to evaluate the influence of night soil on microbial communities in activated sludge fed with two distinct types of domestic wastewater in Bangkok. Most of domestic wastewater in Thailand is greywater with less fecal contamination due to the use of traditional Thai-style toilets having leaching cesspools. However, this study showed a large increase in organic loads to greywater, resulting in microfauna and microflora shifts in activated sludge assemblages when receiving human waste from direct toilet flush. The results exhibited the feasibility in alternative treatment options and a source separation strategy of household greywater and night soil, which could improve biological treatability of domestic wastewater and achieve a possible recycling policy of human waste as excess nutrients in Thailand. (c) 2005 Elsevier B.V. All rights reserved.

Dioxin pollution of aquatic sediments has been one of the important environmental problems in Japan. Grain size distribution and organic constituents may play important roles in dioxins contents in sediments, which have not been well investigated. This paper aims to quantify dioxins (PCDDs/Fs and coPCBs) in sieved surface sediment fractions obtained from Kizu and Sumiyoshi Rivers in Osaka, Japan. The samples were prepared and analyzed following the 'Manual of the Survey and Measurement of Dioxins in Sediment' (Environment Agency of Japan, 2000). The results showed that TEO concentrations of dioxins increased with decreasing grain size in sediment fractions. Sediment fractions with less than 20 mu m grain size showed the highest dioxin contents. Dioxins with five and six chlorine atoms dominated other congeners in less than 20 mu m fractions. The dioxin TEQ concentrations increased with total organic carbon (TOC), total carbon (TC), ignition loss (IL), total sulphur and nitrogen contents in the sediment fractions. Thus, reporting dioxin contents in sediments without considering grain size distribution may be erroneous and conventional, sedimentation and separation techniques might not be useful for treating contaminated sediments. This information can be useful for effective remediation of dioxin-contaminated sediments.

Dioxin pollution of aquatic sediments has been one of the important environmental problems in Japan.Grain size distribution and organic constituents may play important roles in dioxin contents in sediments, which have not been well investigated. This paper aimed to quantify dioxins (PCDDs/Fs and co-PCBs) in sieved surface sediment fractions obtained from Kizu and Sumiyoshi River in Osaka, Japan. The samples were prepared and analyzed following "the Manual of the Survey and Measurement of Dioxins in Sediment"(Environment Agency in Japan, 2000) and "Method for determination of tetra-through octa-chlorodibenzo-p-dioxins, tetra-through octa-chlorodibenzofutans and coplanar polychlorobiphenyls in industrial water and wastewater"(Japanese Standards Association, 1999) The results showed that TEQ concentrations of dioxins increased with increasing the contents of Ignition Loss (IL) in the sediment fractions. Thus, reporting dioxin contents in sediments without considering grain size distribution may be erroneous, and conventional sediments. This information can be useful for effective remediation of dioxin-contaminated sediments.

This study aimed to investigate the effects of coexisting substances on separation of endocrine disrupting chemicals (EDCs) in water and domestic wastewater effluents using low pressure reverse osmosis (LPRO) membrane. The coexisting substances included calcium chloride, glutamic acid sodium salt, acetic acid and humic substances whose molecular weight ranged up to twenty thousand. The results showed higher rejection of nonylphenol in a mixed solution of the coexisting substances. Thus, the results indicated that coexisting substances can affect rejection properties of EDCs in LPRO membranes. In using higher desalting membranes, much higher rejection rates of EDCs in domestic wastewater effluents were observed compared to rejection of a single solution, which shows over 95% rejection. However, rejection of E2 from domestic wastewater did not increase with relatively loose membrane.

Presented in this paper are the results of a series of column experiments and a pilot scale test conducted to develop the treatment system of freshwater and wastewater by their percolation through soil and the other materials at the rate of a few metres per day. Materials that had high ability to sorb fulvic acid (FA hereafter) and phosphate ion were selected based on the results of the batch sorption tests and were processed into beads before subjecting them to the column test. The results of the column experiment suggested that the reagents added to increase the strength of the beads reduced the sorption of FA, thus causing the early breakthrough of the FA injected into the column. Less effect from the bead processing was observed for the removal of phosphate ion. Pilot scale test showed that the removal of particulate fraction of phosphorus differed among the materials used. The bead processing technique that can ensure the high water permeability while maintaining the sorption capacity of the material was required for further development of the treatment system.

Algal bloom is one of the major environmental problems in closed water bodies. Reduced water currents and high inflow of nutrients to the water bodies are the main reasons behind this problem. Although many researches have been done, effective techniques to minimize the problem are still lacking. The objective of this investigation was to evaluate the effectiveness of mud gels and silver-contained ceramics in growth control of algal bloom. The experimental results showed that use of mud gels and silver-containing ceramics were very effective in controlling algal growth. Bacillus Megaterium was primarily affected while using mud gels. Photo catalysis and silver ions were mainly responsible for algal growth control while using silver-contained ceramics. Effectiveness of this technique increased when mud gels and silver-contained ceramics were used together probably due to synergic effects. This technique of controlling algal bloom can be more effective compared to other available methods.