Abstract
Hydrophilic and high modulus PPTA molecules were incorporated into PVDF matrix via the in situ polymerization of PPD and TPC in PVDF solution. PPTA/PVDF/NWF blend membrane was prepared through the immersion precipitation phase inversion method and nonwoven coating technique. The membrane integrated technology including PPTA/PVDF/NWF blend membrane and reverse osmosis (RO) membrane was employed to treat the polyester/viscose spunlace nonwoven process wastewater. During the consecutive running of six months, the effects of membrane integrated technology on the COD, ammonia nitrogen, suspended substance and pH value of water were studied. The results showed that the removal rate of COD, ammonia nitrogen and suspended substance filtered by PPTA/PVDF blend membrane was kept above 90%. The pH value of the permeate water was about 7.1 and the relative water flux of blend membrane remained above 90%. After the deep treatment of RO membrane, the permeate water quality can meet the water circulation requirement of spunlace process.
Key Words
spunlace nonwoven wastewater; in situ polymerization; PVDF; PPTA; fouling; water flux
Address
Hongbin Li, Wenying Shi, Longwei Qin, Hongying Zhu,Yuheng Su,and Haixia Zhang: School of Textiles Engineering, Henan University of Engineering, Henan Engineering Laboratory of New Textiles Development, Zhengzhou, 450007, P.R. China
Qiyun Du: State Key Laboratory of Hollow Fiber Membrane Materials and Processes, Tianjin Polytechnic University, Tianjin, 300387, P.R. China
Xiaohong Qin:
1) School of Textiles Engineering, Henan University of Engineering, Henan Engineering Laboratory of New
Textiles Development, Zhengzhou, 450007, P.R. China
2) School of Textiles Science, Donghua University, Shanghai, 201620, P.R. China
Abstract
The main challenge in many applications of acetic acid is acid dehydration and its recovery from wastewater streams. Therefore, the performance of polyamide thin film composite is evaluated to separate acetic acid from water. To reach this goal, the formation of polyamide layer on polysulfone support membrane was investigated via interfacial polymerization (IP) of meta-phenylenediamine (MPD) in water with trimesoyl chloride (TMC) in hexane. Also, the effect of synthesis conditions, such as concentration of monomers and curing temperature on separation of acetic acid from water were investigated by reverse osmosis process. Moreover, the separation mechanism was discussed. The solute permeation was carried out under applied pressure of 5 bar at 25oC. Surface properties of TFC membrane were characterized by ATR-FTIR, SEM and AFM. The performance test indicated that 3.5 wt% of MPD, 0.35 wt% of TMC and curing temperature of 75oC are the optimum conditions. Moreover, the permeate flux was 4.3 L/(m^2 h) and acetic acid rejection was about 43% at these conditions.
Key Words
acetic acid rejection; interfacial polymerization; thin film composite; reverse osmosis
Address
Hesam Mirfarah, Seyyed Abbas Mousavi, Seyyed Sajjad Mortazavi, Masoud Sadeghi and Dariush Bastani: Chemical and Petroleum Engineering Department, Sharif University of Technology, Azadi Ave., Tehran, Iran
Abstract
Membrane fouling at different solids retention times (SRT) (7, 12 and 20 days) was studied under well-controlled conditions in a laboratory-scale aerobic submerged membrane bioreactor under constant biomass concentration using a synthetic high strength wastewater. An increase in SRT was found to improve membrane performance and this correlated to changes in the total production of bound extracellular polymeric substances (EPS), and the composition and properties of bound EPS using X-ray photoelectron spectroscopy (XPS) and Fourier transform-infrared spectroscopy (FTIR) and floc sizes. A larger amount of total bound EPS was found at the lowest SRT (7 days) tested but the ratio of proteins (PN) to carbohydrates (CH) in bound EPS increased with an increase in SRT. Similarly, the quantity of soluble microbial products (SMP) decreased with an increase in SRT and the SMP PN/CH ratio increased with an increase in SRT. SMP concentrations positively correlated to the percentage of membrane pore blocking resistance. The quantity of total bound EPS and total SMP positively corresponded to the membrane fouling rate, while the PN/CH ratio in the bound EPS and SMP negatively correlated to the membrane fouling rate. The results show that both the quantity and composition of bound EPS and SMP and floc sizes are important in controlling membrane fouling.
Address
L. Hao and B. Q. Liao: Department of Chemical Engineering, Lakehead University, 955 Oliver Road, Thunder Bay,
P7B 5E1, ON, Canada
S. N. Liss: School of Environmental Studies and Department of Chemical Engineering, Queen
Abstract
In India, the current operation of condenser cooling system & effluent disposal system in existing power plants aims to reduce drawal of seawater and to achieve Zero Liquid Discharge to meet the demands of statutory requirements, water scarcity and ecological system. Particularly in the Steam-Electric power plants, condenser cooling system adopts Once through cooling (OTC) system which requires more drawal of seawater and effluent disposal system adopts sea outfall system which discharges hot water into sea. This paper presents an overview of closed-loop technology for condenser cooling system and to achieve Zero Liquid Discharge plant in Steam-Electric power plants making it lesser drawal of seawater and complete elimination of hot water discharges into sea. The closed-loop technology for condenser cooling system reduces the drawal of seawater by 92% and Zero Liquid Discharge plant eliminates the hot water discharges into sea by 100%. Further, the proposed modification generates revenue out of selling potable water and ZLD free flowing solids at INR 81,97,20,000 per annum (considering INR 60/Cu.m, 330 days/year and 90% availability) and INR 23,760 per annum (considering INR 100/Ton, 330 days/year and 90% availability) respectively. This proposed modification costs INR 870,00,00,000 with payback period of less than 11 years. The conventional technology can be replaced with this proposed technique in the existing and upcoming power plants.
Key Words
condenser cooling system; effluent disposal system; steam-electric power plants; once-through cooling (OTC) system; closed-loop cooling system; cooling tower system; zero liquid discharge plant
Address
D. Sankar, S. Rajagopal, and T. Thankarathi: Development Consultants Private Limited, Consulting Engineers, Chennai, 600006, TN, India
M. Balachandar: Anna University, Guindy Campus, Chennai, 600025, Tamil Nadu, India
T. Anbuvanan: MN Dastur & Company Private Limited, Nandanam, Chennai, 600035, TN, India
N. Deepa: Presidency College (Autonomous), Chennai, 600005, Tamil Nadu, India
Abstract
Performance evaluation of four commercially available tubular membranes (AFC 80, AFC 30, PU 608, ES 404) was accomplished in self-assembled membrane testing unit. Effects of varying transmembrane pressure, feed concentration and anion type were investigated. Aqueous solutions of salts such as calcium chloride, calcium sulfate, tin chloride and tin sulfate were prepared for this study. It was noted that the investigated parameters e.g., pressure and concentration had significant effects on membrane\'s performance. Nevertheless, anion type effectively played its role in the rejection of salts since salt having SO4-2 anions had a better rejection than the salts containing Cl-1. It is observed that rejection was dominated by Donnon exclusion for strongly charged nanofiltration membranes whereas for weakly charged ultrafiltration membranes, size exclusion was the key mechanism to reject the ions.
Key Words
tubular membranes; nanofiltration; ultrafiltration; salt analysis; tin salts; performance analysis
Address
Danial Qadir, Hilmi Mukhtar and Lau Kok Keong: Department of Chemical Engineering, University Teknologi PETRONAS, 32610, Bandar Sri Iskandar, Perak, Malaysia
Abstract
The inorganic components in tobacco sheet extract have significant influence on the sensory taste of the cigars and the harmful component delivery in cigarette smoke. To identify the contributions of the divalent inorganic components on harmful components delivery in cigarette smoke, a self-made selective electrodialysis was assembled with monovalent ion-selective ion exchange membranes. The influences of current density and extract content on the desalination performance were investigated. Result indicates that the majorities chloride, nitrate, and sulfate ions were removed, comparing with 50-60% of potassium and only less than 10% of magnesium and calcium ions removed in the investigated current density. The permselectivity of the tested cations across the Selemion CSO cation exchange membranes follows the order: K+>Ca2+>Mg2+. A current density of 15 mA/cm2 is an optional choice by considering both the energy consumption and separation efficiency. When the extract contents are in the range of 7%-20%, the removal ratios the potassium ions are kept around 60%, while the removal ratios of the calcium and magnesium ions fluctuate in the range of 16-27% and 8-14%, respectively. The tobacco smoke experiments indicated that the divalent metal ions have dual roles for the harmful component delivery in cigarette smoke. The divalent potassium and calcium ions were unfavorable for the total particulate matter emission but beneficial to decrease the HCN delivery in the mainstream cigarette smoke. The selective electrodialysis is a robust technology to decrease the harmful component delivery in cigarette smoke.
Key Words
electrodialysis; monovalent ion-selective ion exchange membranes; reconstituted tobacco; papermaking tobacco sheet
Address
Chuanrun Li:
1) CAS Key Laboratory of Soft Matter Chemistry, Laboratory of Functional Membranes, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui, 230026, People\'s Republic of China
2) School of Pharmacy, Anhui University of Chinese Medicine, Hefei, Anhui, 230012, People\'s Republic of China
Shaolin Ge, Zhao Zhang, Shike She and Lan Huang: China Tobacco Anhui Industrial Co., LTD, Hefei, Anhui, 230088, People\'s Republic of China
Wei Li and Yaoming Wang:
1) CAS Key Laboratory of Soft Matter Chemistry, Laboratory of Functional Membranes,
School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui, 230026, People\'s Republic of China
2) Hefei ChemJoy Polymer Materials, Co., LTD, Hefei, Anhui, 230601, People\'s Republic of China
