A review on UV/TiO2 photocatalytic oxidation process

Ramesh Thiruvenkatachari,Saravanamuthu Vigneswaran,문일식 한국화학공학회 2008 Korean Journal of Chemical Engineering Vol.25 No.1

Advanced oxidation processes (AOPs) with UV irradiation and photocatalyst titanium dioxide (TiO2) are gaining growing acceptance as an effective wastewater treatment method. A comprehensive review of the UV-TiO2 photocatalytic oxidation process was conducted with an insight into the mechanism involved, catalyst TiO2, irradiation sources, types of reactors, comparison between effective modes of TiO2 application as immobilized on surface or as suspension, and photocatalytic hybrid membrane system. Photocatalytic degradation technique with titanium dioxide is generally applied for treating wastewater containing organic contaminants due to its ability to achieve complete mineralization of the organic contaminants under mild conditions such as ambient temperature and ambient pressure. Recently, photocatalysis studies using TiO2 have been gaining attention for the degradation of persistent organic pollutants and other organic chemicals which are known to be endocrine disruptors. Treatment of wastewater in a titanium dioxide- suspended slurry reactor has been widely utilized due to its simplicity and enhanced degradation efficiency. However, this system requires separation of TiO2 from water after the photocatalytic process. The final section of the manuscript focuses on the removal of TiO2 using a membrane hybrid system. A two-stage coagulation and sedimentation process coupled with microfiltration hollow-fibre membrane process was found to achieve complete removal of TiO2, and the recovered TiO2 can be reused for a photocatalytic process after regeneration

초청 총설 : 물속 유기물의 고도 특성 분석

김종호 ( Jong Ho Kim ),( Saravanamuthu Vigneswaran ),( Jaya Kandasamy ),손호경 ( Ho Kyong Shon ),김종범 ( Jong Beom Kim ) 한국공업화학회 2011 공업화학 Vol.22 No.1

물은 인간에게 가장 소중한 자원이지만 여러 유기물에 의해 오염되어 있다. 이러한 유기물은 인간과 환경에 큰 영향을 끼칠 수 있으므로 물 속 유기물의 특성 분석이 중요하다. 본 총설에서는 물 속 유기물의 자세한 분석 방법과 특성을 고찰하였다. 각 유기물의 물리적, 화학적, 생물학적면에 의거하여 전통적인 방법과 고도 특성 분석을 정리하였다. Water is the most precious resource to human being, but it is polluted by different organic compounds. Organic matter (OM) in aqeous solutions is one of the important parameters of concern for human and environmental impact, and thus, it is essential to better characterize specifically targeted organic matter in aggregated and individual level of concentrations. This review presents different analytical tools and protocols to investigate detailed properties and characterization. Physical, chemical and biological aspects of OM are envisaged in terms of traditional and advanced measurement methods.

Fouling study on vacuum-enhanced direct contact membrane distillation for seawater desalination

Naidu, Gayathri,Jeong, Sanghyun,Vigneswaran, Saravanamuthu,Jang, Eun-Kyung,Choi, Yong-Jun,Hwang, Tae-Mun Informa UK (Taylor Francis) 2016 Desalination and Water Treatment Vol.57 No.22

<P>Vacuum-enhanced direct contact membrane distillation (VE-DCMD) has been proposed to improve the DCMD system performance with better effective energy efficiency. However, the higher driving forces by the presence of vacuum pressure at permeate side of the VE-DCMD system could contribute to higher fouling development. In this study, thus, the biochemical fouling development of VE-DCMD with different vacuum pressures (700, 500, and 300mbar) for seawater desalination was investigated in comparison with DCMD (1,000mbar of pressure applied). VE-DCMD showed a significant increase in initial permeate flux while its flux decline was faster than DCMD. Low molecular weight (LMW) organics were found to be a dominant organic foulant on DCMD with thermally disaggregated humic substances (HS) to LMW HS-like organics. On the other hand, the presence of vacuum reduced the disaggregation HS to LMW HS-like organics. However, high driving force of VE-DCMD caused higher deposition of organic foulant including the LMW organics as well as HS. It also led to the higher LMW organic contents in permeate. Fluorescence excitation-emission matrix (F-EEM) analysis result showed that fulvic-like organic is a dominant HS foulant in VE-DCMD. Fouling development on membrane was observed using scanning electron microscope, contact angle, and confocal laser scanning microscope.</P>

Granular Activated Carbon (GAC) Biofilter for Low Strength Wastewater Treatment

Durgananda Singh Chaudhary,Saravanamuthu Vigneswaran,Huu Hao Ngo,Wang Geun Shim,Hee Moon 대한환경공학회 2003 Environmental Engineering Research Vol.8 No.4

Biofilter in Water and Wastewater Treatment

Chaudhary, Durgananda Singh,Vigneswaran, Saravanamuthu,Ngo, Huu-Hao,Shim, Wang Geun,Moon, Hee 한국화학공학회 2003 Korean Journal of Chemical Engineering Vol.20 No.6

Biofilter is one of the most important separation processes that can he employed to remove organic pollutants from air, water, and wastewater. Even though, it has been used over a century, it is still difficult to explain thmtically all the biological processes occurring in a hiofilter. In this paper, the fundamental of biological processes involved in the hiofilter is critically reviewed together with the mathematical modeling approach. The important operating and design parameters are discussed in detail with the typical values used for different applications. The most important parameter which governs this pmes is the biomass attached to the medium. The relative merits of Merent methods adopted in the measurement of the hiomass are discussed. The laboratory-and full-scale applications of the biofilter in water and wastewater treatment ax also presented. Their performances in terms of specific pollutant removal are highlighted.

Analytical methods of size distribution for organic matter in water and wastewater(Review)

김승현,Ho-Kyong Shon,Laszlo Erdei,Saravanamuthu Vigneswaran 한국화학공학회 2006 Korean Journal of Chemical Engineering Vol.23 No.4

Mathematical Modeling of Granular Activated Carbon (GAC) Biofiltration System

Shim, Wang Geun,Chaudhary, Durgananda Singh,Vigneswaran, Saravanamuthu,Ngo, Huu-Hao,Lee, Jae Wook,Moon, Hee 한국화학공학회 2004 Korean Journal of Chemical Engineering Vol.21 No.1

In this study, a mathematical model of a fixed bed Granular Activated Carbon (GAC) biofiltration system was developed to predict the organic removal efficiency of the filter. The model consists of bulk transportation, adsorption, utilization, and biodegradation of organics. The variation of the specific surface area due to biofilm growth and the effect of filter backwash were also included in the model. The intrapellet diffusion and the diffusion of substrate in the biofilm were described by linear driving force approximation (LDFA) method. Biodegradation of organics was described by Monod kinetics. Sips adsorption isotherm was used to analyze the initial adsorption equilibrium of the system. The model showed that the organic removal efficiency of the biofilter greatly depends on the parameters related to the biological activities such as the maximum rate of substrate utilization(k_(max)) and biomass yield(Y) coefficients. Parameters such suspended cell concentration (X_(s)) and decay constant(K_(d)) had little effects on the model simulation results. The filter backwash also had no significant impact on the performance of the biofilter.

Removal of metsulfuron methyl by Fenton reagent

Javeed Mohammed Abdul,Mahintha Kumar,Jaya Kandasamy,Saravanamuthu Vigneswaran 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.1

The removal of metsulfuron methyl (MeS)—a sulfonyl urea herbicide from contaminated water was investigated by advanced oxidation process (AOP) using Fenton method. The optimum dose of Fenton reagent (Fe2+/H2O2) was 10 mg/L Fe2+ and 60 mg/L H2O2 for an initial MeS concentration ([MeS]0) range of 0–80 mg/L. The Fenton process was effective under pH 3. The degradation efficiency of MeS decreased by more than 70% at pH > 3 (pH 4.5 and 7). The initial Fe2+ concentration ([Fe2+]0) in the Fenton reagent affected the degradation efficiency, rate and kinetics. The degradation of MeS at optimum dose of Fenton reagent was more than 95% for [MeS] 0 of 0–40 mg/L and the degradation time was less than 30 min. The determination of residual MeS concentration after Fenton oxidation by UV spectrophotometry was affected by the interferences from Fenton reagent. The estimation of residual MeS concentration after Fenton oxidation by high pressure/performance liquid chromatograph (HPLC) was interference free and represented the actual concentration of MeS and does not include the by-products of Fenton oxidation. The degradation kinetics of MeS was modelled by second order reactions involving 8 rate constants. The two reaction constants directly involving MeS were fitted using the experimental data and the remaining constants were selected from previously reported values. The model fit for MeS and the subsequent prediction of H2O2 were found to be within experimental error tolerances.

Experiments and modeling of a vacuum membrane distillation for high saline water

Gayathri Naidu,최용준,정상현,황태문,Saravanamuthu Vigneswaran 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

A modified design vacuum membrane distillation (VMD) system with high saline water was evaluated using different operating conditions (sustainable low feed temperature and flow velocity). At high salinity, a permeate flux of 13.9 to 15.8 L m-2 h-1 was achieved. Increasing the salinity from 1 to 3 M NaCl reduced the permeate flux by 18–20%. An increase in bulk feed temperature (310.2–319.2 K) significantly increased the permeate flux by 64%. The increase in flow velocity (1.1 to 2.2 m s-1) in turn increased the permeate flux by 14–20%. Model fluxes predicted was a good fit to experimental fluxes (R2 ≥ 0.94).

Mathematical Modeling of Granular Activated Carbon (GAC) Biofiltration System

문희,심왕근,Durgananda Singh Chaudhary,Saravanamuthu Vigneswaran,Huu-Hao Ngo,Jae Wook Lee 한국화학공학회 2004 Korean Journal of Chemical Engineering Vol.21 No.1

In this study, a mathematical model of a fixed bed Granular Activated Carbon (GAC) biofiltration system was developed to predict the organic removal efficiency of the filter. The model consists of bulk transportation, adsorption, utilization, and biodegradation of organics. The variation of the specific surface area due to biofilm growth and the effect of filter backwash were also included in the model. The intrapellet diffusion and the diffusion of substrate in the biofilm were described by linear driving force approximation (LDFA) method. Biodegradation of organics was described by Monod kinetics. Sips adsorption isotherm was used to analyze the initial adsorption equilibrium of the system. The model showed that the organic removal efficiency of the biofilter greatly depends on the parameters related to the biological activities such as the maximum rate of substrate utilization (kmax) and biomass yield (Y) coefficients. Parameters such as suspended cell concentration (Xs) and decay constant (Kd) had little effects on the model simulation results. The filter backwash also had no significant impact on the performance of the biofilter.