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CONTENTS
Volume 9, Number 6, November 2018
 

Abstract
Poly vinyl chloride (PVC) was chemically modified, and used for ultrafiltration to analyze the performance. Nonsolvent induced phase separation (NIPS) method was used to prepare membranes. The neat PVC membrane was casted and used as a control membrane. Modified membrane was prepared by reacting PVC with ethanolamine (EA) in the casting solution (labeled as CM-PVC). Pure water permeability (PWP) was evaluated by measuring pure water flux. Humic acid was used as model foulant solute to analyze flux and rejection ability of membranes. Flux and rejection data of neat and modified membranes were compared to prove the improvement in the filtration performance. The experimental results showed that for PVC and CM-PVC, PWP was calculated to be ~64 and ~143 L/m2.h, respectively, and the rejection of humic acid was found to be 98% and 100%, respectively. TGA was carried out to analyze the effect of chemical modification on the thermal stability of polymer. FT-IR analysis was another characterization technique used for the comparative study.

Key Words
polyvinyl chloride; permeate flux; ultrafiltration; humic acid; rejection

Address
Jainesh H. Jhaveri: Department of Chemical Engineering, Indian Institute of Technology, Bombay-400076, India
Chetan M. Patel and Z.V.P. Murthy: Department of Chemical Engineering, S.V. National Institute of Technology, Surat - 395007, India

Abstract
In this research commercial polyethersulfone (PES) membrane was modified using TiO2 nanoparticles (P-25 Degussa) and further irradiated using UV light to overcome the hydrophobicity and fouling nature of the membrane. Further the membranes were characterized using SEM and FTIR. Contact angle measurements study confirmed the hydrophilic tendency of the modified membrane by decreasing the contact angle from 73 degree to 20.28 degree. The modified membranes showed higher flux and better anti-fouling properties as compared to the unmodified counterparts. The optimum conditions were found to be 0.5 wt% TiO2 loading with 60 min membrane immersion and 10 min UV light illumination. The effect of different pH conditions of feed was analysed. Real wastewater filtration experiments also indicated better performance of modified membranes as opposed to neat PES membranes.

Key Words
ultrafiltration; TiO2 nanoparticles; UV irradiation; PES membranes; Acid Blue-80 dye

Address
Department of Chemical Engineering, Institute of Chemical Technology, Mumbai

Abstract
Persulfates (i.e., peroxymonosulfate and peroxydisulfate) are capable of oxidizing a wide range of organic compounds via direct reactions, as well as by indirect reactions by the radical intermediates. In aqueous solution, persulfates undergo self-decomposition, which is accelerated by thermal, photochemical and metal-catalyzed methods, which usually involve the generation of various radical species. The chemistry of persulfates has been studied since the early twentieth century. However, its environmental application has recently gained attention, as persulfates show promise in in situ chemical oxidation (ISCO) for soil and groundwater remediation. Persulfates are known to have both reactivity and persistence in the subsurface, which can provide advantages over other oxidants inclined toward either of the two properties. Besides the ISCO applications, recent studies have shown that the persulfate oxidation also has the potential for wastewater treatment and disinfection. This article reviews the chemistry regarding the hydrolysis, photolysis and catalysis of persulfates and the reactions of persulfates with organic compounds in aqueous solution. This article is intended to provide insight into interpreting the behaviors of the contaminant oxidation by persulfates, as well as developing new persulfate-based oxidation technologies.

Key Words
persulfate; peroxymonosulfate; peroxydisulfate; in situ chemical oxidation (ISCO); soil and groundwater remediation; oxidation; sulfate radical

Address
Changha Lee: School of Chemical and Biological Engineering, Institute of Chemical Process (ICP), Seoul National University, 1 Gwanak-ro,
Gwanak-gu, Seoul 08826, Republic of Korea
Hak-Hyeon Kim: School of Urban and Environmental Engineering, UNIST, 50 UNIST-gil, Ulju-gun, Ulsan 44919, Republic of Korea
oh-Back Park: National Institute of Fisheries Science (NIFS), 216, Gijanghaean-ro, Gijang-eup, Busan 46083, Republic of Korea

Abstract
Decision-makers have different and sometimes conflicting goals with utilities in operating dam reservoirs. As repeated interactions exist between decision-makers in the long-term, and the utility of each decision-making organization is affected not only by its selected strategy, but also by other rivals\' strategies; selecting and prioritizing optimum strategies from a decision maker\'s point of view are of great importance while interacting with others. In this paper, a model based on a fuzzy set theory, for determining the priority of decision-makers\' strategies in optimal qualitative-quantitative operation management of dam reservoir is presented. The fuzzy priority matrix is developed via defining membership functions of a fuzzy set for each decision maker\'s strategies, so that all uncertainties are taken into account. This matrix includes priorities assigned to possible combination for other decision makers\' strategies in bargaining with each player\'s viewpoint. Here, the 15-Khordad Dam located in the central part of Iran, suffering from low water quality, was studied in order to evaluate the effectiveness of the model. Then, the range of quality of water withdrawal agreed by all decision-makers was determined using the prioritization matrix based on fuzzy logic. The results showed that the model proposed in the study had high effectiveness model.

Key Words
reservoir operation; prioritization of fuzzy strategies, conflict resolution, water quality

Address
A.R. Mojarabi-Kermani: Department Water Science and Engineering, Khuzestan Science and research Branch, Islamic Azad University, Ahvaz, Iran, Department Water Science and Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran
Ehsan Shirangi: Department of Civil Engineering, Karaj Branch, Islamic Azad University, Karaj, Iran
Amin Bordbar, A.A. Kaman Bedast and A.R. Masjedi: Department Water Science and Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran

Abstract
In this work, desalination experiments were performed on vacuum membrane distillation (VMD). Process parameters such as feed flow rate, vacuum degree on permeate side, feed bulk temperature and feed salt concentration were optimized using sensitivity analysis and Taguchi method. The optimum values of process parameters were found to be 2 lpm of feed flow rate, 60 degree Celsius of feed bulk temperature, 5.5 kPa of permeate-side pressure and 5000 ppm of salt concentration. The permeate flux at these conditions was obtained as 26.6 kg/m2⋅hr. The rejection of salt in permeate was found to be 99.7%. The percent contribution of various process parameters using ANOVA results indicated that the most important parameter is feed bulk temperature with its contribution of 95%. The ANOVA results indicate that the percent contribution of permeate pressure gets increased to 5.384% in the range of 2 to 7 kPa as compared to 0.045% in the range of 5.5 to 7 kPa.

Key Words
vacuum membrane distillation (VMD); sensitivity analysis; desalination; Taguchi method; ANOVA

Address
Sushant Upadhyaya, Kailash Singh, Satyendra Prasad Chaurasia, Rakesh Baghel and Rajeev Kumar Dohare: Department of Chemical Engineering, Malaviya National Institute of Technology, Jaipur-302017, India
Jitendra Kumar Singh: Department of Chemical Engineering, JK Lakshmipat University, Jaipur-302026, India

Abstract
Although flotation techniques are often used for the removal of algal particles, the practicality of algae-harvesting technologies is limited owing to the complex and expensive facilities and equipment required for chemical coagulation. Here, we examined the feasibility of an approach to separating algal particles from water bodies without the need for chemical coagulants, depending on the condition of the algae, and to determine the optimal conditions. Using Anabaena sp., a cyanobacterium causes algal blooms in lakes, we stimulated auto-flocculation in algal particles without coagulants and conducted solid-liquid separation experiments of algal particles under various conditions. The six cultivation columns included in our analysis comprised four factors: Water temperature, light intensity, nutrients, and carbon source; auto-flocculation was induced under all treatments, with the exception of the treatment involving no limits to all factors, and algal particles were wellsettled under all conditions for which auto-flocculation occurred. Meanwhile, flotation removal of auto-flocculated algal particles was attained only when nutrients were blocked after algae were grown in an optimal medium. However, no significant differences were detected between the functional groups of the extracellular polymeric substances (EPSs) of floated and settled algal particles in the FT-IR peak, which can cause attachment by collision with micro-bubbles.

Key Words
algal bloom; auto-flocculation; bubble; coagulation; cyanobacteria; flotation

Address
Dong-Heui Kwak, Tae-Geum Kim: Jeongeup Industry-Academic Cooperation Support Center, Chonbuk National University,
9 Cheomdan Rd, Jeongeup, Jeonbuk 56212, Republic of Korea
Mi-Sug Kim: Dept. of Env. Eng. of Mokpo National University, 61 dorim-ri, 1666 Youngsan-ro, Cheonggye-myeon,
Muan-gun, jeonnam, 58554, Republic of Korea

Abstract
The measurement and monitoring of the biochemical oxygen demand (BOD) play an important role in the planning and operation of wastewater treatment plants. The most basic method for determining biochemical oxygen demand is direct measurement. However, this method is both expensive and takes a long time. A five-day period is required to determine the biochemical oxygen demand. This study has been carried out in a wastewater treatment plant in Turkey (Hurma WWTP) in order to estimate the biochemical oxygen demand a shorter time and with a lower cost. Estimation was performed using artificial neural network (ANN) method. There are three different methods in the training of artificial neural networks, respectively, multi-layered (ML-ANN), teaching learning based algorithm (TLBO-ANN) and artificial bee colony algorithm (ABC-ANN). The input flow (Q), wastewater temperature (t), pH, chemical oxygen demand (COD), suspended sediment (SS), total phosphorus (tP), total nitrogen (tN), and electrical conductivity of wastewater (EC) are used as the input parameters to estimate the BOD. The root mean squared error (RMSE) and the mean absolute error (MAE) values were used in evaluating performance criteria for each model. As a result of the general evaluation, the ML-ANN method provided the best estimation results both training and test series with 0.8924 and 0.8442 determination coefficient, respectively.

Key Words
artificial bee colony; artificial neural networks; biochemical oxygen demand; teaching-learning base algorithm; wastewater treatment plant

Address
Osman Tugrul BAKİ: Karadeniz Technical University, Faculty of Technology, Department of Civil Engineering, 61080 Trabzon, Turkey
Egemen ARAS: Bursa Technical University Faculty of Engineering and Natural Sciences Department of Civil Engineering 16310 Bursa, Turkey

Abstract
The present paper deals with the liquid-liquid extraction and flat sheet supported liquid membrane studies of Pd(II) separation from nitric acid medium using a novel synthesized ligand, namely, N,N,N\',N\'-tetraethyl-2,2- thiodiethanthiodiglycolamide (TETEDGA). The effect of various diluents and stripping reagents on the extraction of Pd(II) was studied. The liquid-liquid extraction studies showed complete extraction of Pd(II) in ~ 5 min. The influence of nitric acid and TETEDGA concentration on the distribution of Pd(II) has been investigated. The increase in nitric acid concentration resulted in increase in extraction of Pd(II). Stoichiometry of the extracted species was found to be Pd(NO3)2 . TETEDGA by slope analysis method. Extraction studies with SSCD solution showed negligible uptake of Pt, Cr, Ni, and Fe, thus showing very high selectivity and extractability of TETEDGA for Pd(II). The flat sheet supported liquid membrane studies showed quantitative transport of Pd(II), ~99%, from the feed (3 M HNO3) to the strippant (0.02 M thiourea diluted in 0.4 M HNO3) using 0.01 M TETEDGA as a carrier diluted in n-dodecane. Extraction time was ~160 min. Parameters such as feed acidity, TETEDGA concentration in membrane phase, membrane porosity etc. were optimized to achieve maximum transport rate. Permeability coefficient value of 2.66 x 10–3 cm/s was observed using TETEDGA (0.01 M) as carrier, at 3 M, HNO3 feed acidity across 0.2 um PTFE as membrane. The membrane was found to be stable over five runs of the operation.

Key Words
Pd(II), TETEDGA, liquid-liquid extraction, supported liquid membrane

Address
Department of Chemical Engineering, Institute of Chemical Technology, Matunga (East), Mumbai 400019, Maharashtra, India

Abstract
The effect of three iron-based adsorbents pre-depositing on ultrafiltration membrane for humic acid (HA) removal and membrane fouling was investigated. The result showed that pre-depositing adsorbents on membrane could not only reduce membrane fouling but also enhance HA removal. The flux was related to the adsorbent dosage and the optimal dosage for predeposition was 35.0g/m2. The dissolved organic carbon (DOC) removal of HA was 38.3%, 67.3% and 41.1% respectively when pre-deposited 35.0 g/m2 FeOxHy, MnFe2O4 and Fe3O4 on membrane. Different adsorption effect of adsorbents on HA contributed to increasing of the flux at different level. Zeta potential of three adsorbents all decreased after adsorbed HA. The adsorption capacity of the three adsorbents was FeOxHy > MnFe2O4 > Fe3O4. Atomic Force Microscopy (AFM) measurement showed the thickness of pre-deposition layers formed by different adsorbents was different. The scanning electron microscope (SEM) detection showed the morphology and compactness of pre-deposition layers formed by different adsorbents was different.

Key Words
adsorption; humic acid; filtration flux; membrane fouling; pre-deposition; ultrafiltration

Address
Hailong Tian, Xi Duan: School of Environment and Energy Engineering, Beijing University of Civil Engineering and Architecture,
No.1 zhanlanguan Road, Beijing, China
Lihua Sun, Cuimin Feng: Key Laboratory of Urban Stormwater System & Water Environment

Abstract
Membrane clogging or fouling of the membrane caused by organic, inorganic, and biological on the surface is one of the main obstacles to achieve high flux over a long period of the membrane filtration process. So researchers have been many attempts to reduce membrane fouling and found that there is a close relationship between membrane surface hydrophilicity and membrane fouling, such that the same conditions, a greater hydrophilicity were less prone to fouling. Nanotechnology in the past decade is provided numerous opportunities to examine the effects of metal nanoparticles on the both hydrophilic and antibacterial properties of the membrane. In the present study the improvement of hydrophilic and antimicrobial properties of the membrane was evaluated by adding nanoparticles of titanium dioxide and copper oxide. For this purpose, 4% copper oxide and titanium dioxide nanoparticles with a ratio of 0, 30, 50, and 70% of copper oxide added to the polymeric membrane and compare to the pure polymeric membrane. Comparison experiments were performed on E. coli PTCC1998 in two ways disc and tube and also to evaluate membrane hydrophilic by measuring the contact angle and diameter of pores and analysis point SEM has been made. The results show that the membrane-containing nanoparticle has antibacterial properties and its impact by increasing the percentage of copper oxide nanoparticles increases.

Key Words
membrane process, hydrophilic, antibacterial properties, nanoparticles, titanium dioxide, copper oxide

Address
Department of chemical engineering, Quchan branch, Islamic Azad University, Quchan, Iran


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