Abstract
The use of membrane as an innovative technology for water treatment process has now widely been accepted and adopted to replace the conventional water treatment process in increasing fresh water production for various domestic and industrial purposes. In this study, ultrafiltration (UF) membranes with different formulation were fabricated via phase inversion method. The membranes were fabricated by varying the polymer concentration (16 wt%, 18 wt%, 20 wt%, and 21 wt%). A series of tests, such as field emission scanning electron microscope (FESEM), pore size and porosity, contact angle, and zeta potential were performed to characterize the membranes. The membrane performance in terms of permeation flux and rejection were evaluated using a laboratory bench-scale test unit with mine water, lake water and tube well as model feed solution. Long hour filtration study of the membranes provides the information on its fouling property. Few pore blocking mechanism models were proposed to examine the behaviour of flux reduction and to estimate the fouling parameters based on different degree of fouling. 21 wt% PVDF membrane with smaller membrane pore size showed an excellent performance for surface water treatment in which the treated water complied with NWQS class II standard.
Key Words
membrane; water treatment; surface water; lake water; mine water; tube well; water; recycle and reuse
Address
Teow Yeit Haan,Ho Kah Chun and Abdul Wahab Mohammad:
1.) Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan, Malaysia
2.) Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan, Malaysia
Mubassir Shah:Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia,
43600 Bangi, Selangor Darul Ehsan, Malaysia
Muhammad Imran Khan, Tariq Mahmood Ansari, Shagufta Zafar, Abdul Rehman Buzdar6, Muhammad Ali Khan, Fatima Mumtaz, Prasert Prapamonthon and Mehwish Akhtar
Abstract
In this work, batch adsorption of anionic dye acid green-25 (AG-25) from aqueous solution has been carried out at room temperature using anion exchange membrane (DF-120B) as a noval adsorbent. The effect of various experimental parameters such as contact time, membrane dosage, ionic strength and temperature on the adsorption of dye were investigated. Kinetic models namely pseudo-first-order, pseudo-second-order, Elovich, liquid film diffusion, Bangham and modified freundlich models were employed to evaluate the experimental data. Parameters like adsorption capacities, rate constant and related correlation coefficients for every model are calculated and discussed. It showed that adsorption of AG-25 onto DF-120B followed pseudo-first-order rate expression. Thermodynamic study indicates that adsorption of AG-25 onto DF-120B is an exothermic and spontaneous process.
Key Words
adsorption; Acid Green-25; anion exchange membrane; kinetics; Freundlich kinetic model; thermodynamic; exothermic process
Address
Muhammad Imran Khan: 1.) CAS Key Laboratory of Soft Matter Chemistry, Lab of Functional Membranes, School of Chemistry and Material Science, University of Science and Technology of China, Hefei, Anhui 230026, P.R. China
2.)Fujian Institute of Research on Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, Fujian, P.R. China
Tariq Mahmood Ansari and Muhammad Ali Khan: Institute of Chemical Sciences, Bahauddin Zakariya University, Multan 60000, Pakistan
Shagufta Zafar and Mehwish Akhtar: Department of Chemistry, The Govt Sadiq College Women University, Bahawalpur, Pakistan
Abdul Rehman Buzdar:Department of CSE, HITEC University, Taxila Cantt 47050, Pakistan
Fatima Mumtaz:CAS Key Laboratory of Soft Matter Chemistry, Lab of Functional Membranes, School of Chemistry and Material Science, University of Science and Technology of China, Hefei, Anhui 230026, P.R. China
Prasert Prapamonthon: Department of Thermal Science & Energy Engineering, University of Science and Technology of China,Hefei, Anhui 230026, P.R. China
Abstract
The interactions of water soluble polymers with dye are studied by ultrafiltration using a molecular weight cut off of 10 KDa regenerated cellulose ultrafiltration membrane. Two water-soluble polymers, namely Poly (Sodium-4 Styrenesulfonate) (PSS) and Poly (Vinyl Alcohol) (PVA) were selected for this study. The effects of process parameters, such as, polyelectrolyte concentrations, transmembrane pressure, ionic strength and pH of solution on dye retention and permeation flux were examined.
PSS enhanced ultrafiltration achieved dye retention as high as 99% as a result of complexation between polyanion containing aromatic groups and cationic dye. This result was confirmed by the red shift. The retention of dye decreases as the salt concentration increases, a high retention was obtained at pH above 4. However, in case of PVA, relatively low retention (50%) was observed. Ionic strength and pH has no significant effect on the removal of MB. The permeate flux depended slightly on polyelectrolytes concentrations, transmembrane pressure, salt concentration and pH.
Address
Nadia Cheickh Mansour and Amor Hafiane: Wastewater Treatment Laboratory, Water Research and Technologies Center, Soliman, Tunisia
Hedia Ouni:1.) Department of Chemistry, Faculty of Science at Yanbu, Taibah University Yanbu, Medina Mounawara, Saudi Arabia
2.) Wastewater Treatment Laboratory, Water Research and Technologies Center, Soliman, Tunisia
Abstract
Copper pollution around the world has caused serious public health problems recently. The heavy metal adsorption on traditional membranes from wastewater is limited by material properties. Different adsorptive materials are embedded in the membrane matrix and act as the adsorbent for the heavy metal. The carbonized leaf powder has been proven as an effective adsorbent material in removing aqueous Cu(II) because of its relative high specific surface area and inherent beneficial groups such as amine, carboxyl and phosphate after carbonization process. Factors affecting the adsorption of Cu(II) include: adsorbent dosage, initial Cu(II) concentration, solution pH, temperature and duration. The kinetics data fit well with the pseudo-first order kinetics and the pseudo-second order kinetics model. The thermodynamic behavior reveals the endothermic and spontaneous nature of the adsorption. The adsorption isotherm curve fits Sips model well, and the adsorption capacity was determined at 61.77 mg/g. Based on D-R model, the adsorption was predominated by the form of physical adsorption under lower temperatures, while the increased temperature motivated the form of chemical adsorption such as ion-exchange reaction. According to the analysis towards the mechanism, the chemical adsorption process occurs mainly among amine, carbonate, phosphate and copper ions or other surface adsorption. This hypothesis is confirmed by FT-IR test and XRD spectra as well as the predicted parameters calculated based on D-R model.
Address
Yu Zhang and Su Chen: School of Urban Rail Transportation, Soochow University, China
Qiang Tang: 1.) School of Urban Rail Transportation, Soochow University, China
2.) Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, China
3.) Jiangsu Research Center for Geotechnical Engineering Technology, Hohai University, China
Fan Gu: National Center for Asphalt Technology, Auburn University, U.S.A.
Zhenze Li: Canadian Nuclear Safety Commission, Canada
Abstract
Maillard reaction products like melanoidins present in industrial fermentation wastewaters are complex compounds with various functional properties. In this work, novel ultrafiltration (UF) mixed matrix membrane (MMM) composed of polysulfone (PSF) and nanocomposites was prepared through a phase inversion process for the recovery of melanoidins. Nanocomposites were prepared with acid functionalized multiwalled carbon nanotubes (MWCNTs) as the reinforcing filler for chitosan-thermoplastic starch blend. Higher nanocomposites content in the PSF matrix reduced the membrane permeability and melanoidins retention indicating tighter membrane with surface defects. The membrane surface defects could be sealed with dilute polyvinyl alcohol (PVA) solution. The best performing membrane (1% nanocomposites in 18% PSF membrane sealed with 0.25% PVA coating) resulted in uniform melanoidins retention of 98% and permeability of 3.6 L/m2 h bar over a period of 8h. This demonstrates a low fouling PSF membrane for high melanoidins recovery.
Address
Subhankar Basu, Sanghamitra Mukherjee and
Malini Balakrishnan: The Energy and Resources Institute (TERI), Darbari Seth Block, IHC Complex, Lodhi Road, New Delhi -110003, India
M. V. Deepthi and R. R. N. Sailaja: The Energy and Resources Institute (TERI), Southern Regional Centre, Bangalore, India
Abstract
Artificial neural network (ANN) simulation is used to predict the dynamic change of permeate flux during wheat starch industry wastewater microfiltration with and without static turbulence promoter. The experimental program spans range of a sedimentation times from 2 to 4 h, for feed flow rates 50 to 150 L/h, at transmembrane pressures covering the range of 1x10^5 to 3x10^5 Pa. ANN predictions of the wastewater microfiltration are compared with experimental results obtained using two different set of microfiltration experiments, with and without static turbulence promoter. The effects of the training algorithm, neural network architectures on the ANN performance are discussed. For the most of the cases considered, the ANN proved to be an adequate interpolation tool, where an excellent prediction was obtained using automated Bayesian regularization as training algorithm. The optimal ANN architecture was determined as 4-10-1 with hyperbolic tangent sigmoid transfer function transfer function for hidden and output layers. The error distributions of data revealed that experimental results are in very good agreement with computed ones with only 2% data points had absolute relative error greater than 20% for the microfiltration without static turbulence promoter whereas for the microfiltration with static turbulence promoter it was 1%. The contribution of filtration time variable to flux values provided by ANNs was determined in an important level at the range of 52-66% due to increased membrane fouling by the time. In the case of microfiltration with static turbulence promoter, relative importance of transmembrane pressure and feed flow rate increased for about 30%.
Key Words
wheat starch industry wastewater; microfiltration; artificial neural networks
Address
Aleksandar I. Jokić,Nemanja R. Milović, Zita I. Šereš, Nikola R. Maravić and Ljubica P. Dokić: University of Novi Sad, Faculty of Technology, Bul. cara Lazara 1, 21000 Novi Sad, Serbia
Laslo L. Šereš: University of Novi Sad, Faculty of Economics in Subotica, Segedinski put 9-11, 24000 Subotica, Serbia
Žana Šaranović: Institute of Economics ad, Ulica Kralja Milana 16, 11000 Belgrade, Serbia, AD Fidelinka, Fidelinka – Starch, Čantavirski put 1, 24000 Subotica, Serbia
Abstract
Common aquaculture practices include the use of certain pharmaceuticals such as antibiotics in avoiding diseases and promoting a healthier growth of the culture. The aim of this study is to monitor and assess the influence of different low oxytetracycline concentrations on the transformation of nitrogen compounds under aeration condition in a lab-scale recirculating aquaculture system (RAS). Over 1 mg L-1 dose of oxytetracycline to aquaculture had induced ammonia(NH4-N), nitrate(NO3-N), soluble COD accumulation in RAS. In addition, nitrous oxide (N2O) emission from RAS was significantly reduced during the oxytetracycline dose periods. After ceasing the dose of oxytetracycline, ammonia oxidation and nitrous oxide re-emission were observed. This observation indicated that low concentrations of oxytetracycline could affect the nitrogen species in RAS. Also, the emission mechanisms of N2O may not be only dependent on nitrification process but also dependent on denitrification process in our RAS system.
Key Words
recirculating aquaculture system (RAS); oxytetracycline; ammonia; nitrification
Address
Carl A.D. Medriano and Hyojik Yoon: Program in Environmental Technology and Policy, Korea University, 2511 Sejong-ro, Sejong city, Republic of Korea
Kartik Chandran: Department of Earth and Environmental Engineering, Columbia University, 500 West 120th street, New York, NY 10027, United States
Samir.K. Khanal: Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa,
2500 Campus road, Honolulu, Hawaii, United States
Yunchul Cho: Department of Environmental Engineering, Daejeon University, 62 Daehak-ro, Daejeon Metropolitan city, Republic of Korea
Jaewoo Lee and Sungpyo Kim: 1.) Program in Environmental Technology and Policy, Korea University, 2511 Sejong-ro, Sejong city, Republic of Korea
4.) Department of Environmental Engineering, Korea University, 2511 Sejong-ro, Sejong city, Republic of Korea
Abstract
In this contribution, the control of multivariable reverse osmosis (RO) desalination plant using proportional-integral-derivative (PID) controllers is presented. First, feed-forward compensators are designed using simplified decoupling method and then the PID controllers are tuned for flux (flow-rate) and conductivity (salinity). The tuning of PID controllers is accomplished by minimization of the integral of squared error (ISE). The ISEs are minimized using a recently proposed algorithm named as teacher-learner-based-optimization (TLBO). TLBO algorithm is used due to being simple and being free from algorithm-specific parameters. A comparative analysis is carried out to prove the supremacy of TLBO algorithm over other state-of-art algorithms like particle swarm optimization (PSO), artificial bee colony (ABC) and differential evolution (DE). The simulation results and comparisons show that the purposed method performs better in terms of performance and can successfully be applied for tuning of PID controllers for RO desalination plants.
Key Words
desalination; integral of squared error (ISE), PID controller; reverse osmosis (RO); simplified decoupling; teacher-learner-based-optimization (TLBO)
Address
Natwar S. Rathore and V. P. Singh: Department of Electrical Engineering, National Institute of Technology Raipur 492010, India