Techno Press
Tp_Editing System.E (TES.E)
Login Search
You logged in as

mwt
 
CONTENTS
Volume 13, Number 2, March 2022
 


Abstract
Choline chloride-glycerol (1:2 mol), a natural deep eutectic solvent (NADES) is examined as a draw solution in forward osmosis (FO) for dewatering application. The NADES is easy to prepare, low in toxicity and environmentally benign. A polyamide thin film composite membrane was used. Characterization of the membrane confirmed porous membrane structure with good hydrophilicity and a low structural parameter (722 µm) suitable for FO application. A dilute solution of 20% (v/v) NADES was enough to generate moderate water flux (14.98 L m-2h-1) with relatively low reverse solute flux (0.125 g m-2h-1) with deionized water feed. Application in dewatering industrial wastewater feed showed reasonably good water flux (11.9 L m-2h-1) which could be maintained by controlling the external concentration polarization and fouling/scaling mitigation via simple periodic deionized water wash. In another application, clarified sugarcane juice could be successfully concentrated. Recovery of the draw solute was accomplished easily by chilling utilizing thermo responsive phase transition property of NADES. This study established that low concentration NADES can be a viable alternative as a draw solute for dewatering of wastewater and other heat sensitive applications along with a simple recovery process.

Key Words
forward osmosis; flux; ionic liquid; membrane; wastewater

Address
Supritam Dutta: Department of Chemical Engineering, L. D. College of Engineering, Ahmedabad 380015, Gujarat, India

Pragnesh Dave: Department of Chemistry, Sardar Patel University, Vallabh Vidyanagar 388 120, Gujarat, India

Kaushik Nath: Department of Chemical Engineering, G. H. Patel College of Engineering & Technology, Vallabh Vidyanagar 388 120, Gujarat, India

Abstract
In the present study, we compared the adsorption capacity of Pb (II) from contaminated water of used cardboard (UC) and a commercial powdered activated carbon (PAC), the latter has been characterized by different techniques, namely X-ray diffraction (XRD), scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS), wavelength dispersion x-ray fluorescence (WDXRF), infrared spectroscopy (IR) and surface area B.E.T analyzer. The effect of various parameters, such as the pH, the contact time, the amount of adsorbent, and the temperature on the adsorption of Pb (II) on both materials was investigated. The Pb (II) adsorptions are perfectly described by a pseudo-second-order model, while the intraparticle diffusion is a decisive step after the first minutes of contact. The fit to the Langmuir and Redlich-Peterson models seems perfect for these adsorption reactions. (PAC) showed a greater affinity for Pb (II) compared to (UC) and the adsorption of Pb (II) ions is strongly pH-dependent, on the other hand, the increase in temperature doesn't have much influence on the two solids. This study showed that the capacity of (UC) to adsorb Pb (II) from an aqueous solution is greater than two-thirds of that of (PAC).

Key Words
adsorption; modeling; Pb (II); powdered activated carbon; used cardboard

Address
Fouad. Mekhalef Benhafsa: Centre de Recherche Scientifique et Technique en Analyses Physico-chimiques CRAPC, BP 384, Bou-Ismail, 42004, Tipaza, Algeria/ Laboratory of Advanced Materials and Physicochemistry for the Environment and Health (MAPES), Djillali Liabes University, P.B. 89 Sidi Bel Abbes 22000, Algeria/ Laboratoire de Structure, Elaboration et Application des Materiaux Moleculaires (SEA2M), Faculte des Sciences et de la Technologie, BP 188, Universite Abdelhamid Benbadis, Mostaganem, Algeria

Abdelghani. Bouchama: Centre de Recherche Scientifique et Technique en Analyses Physico-chimiques CRAPC, BP 384, Bou-Ismail, 42004, Tipaza, Algeria/ Laboratoire de Structure, Elaboration et Application des Materiaux Moleculaires (SEA2M), Faculte des Sciences et de la Technologie, BP 188, Universite Abdelhamid Benbadis, Mostaganem, Algeria

Aicha. Chadli: Biotechnology applied laboratory to agriculture and environmental preservation, higher school of agronomy, Ex-hall of technology kharoubba, Mostaganem (27000), Algeria

Belgacem. Tadjer: Centre de Recherche Scientifique et Technique en Analyses Physico-chimiques CRAPC, BP 384, Bou-Ismail, 42004, Tipaza, Algeria

Djelloul. Addad: Laboratoire des Eco Materiaux Fonctionnels et Nanostructures, Universite de Mohammed Boudiaf, Oran, Algeria

Abstract
Tetrachloroethylene (PCE) and trichloroethylene (TCE), critical pollutants to human health and groundwater ecosystems, are managed by groundwater quality standards (GQS) in South Korea. However, there are no GQSs for their by-products, such as cis-dichloroethylene (DCE) and vinyl chloride (VC) produced through the dechlorination process of PCE and TCE. Therefore, in this study, we monitored PCE, TCE, cis-DCE, and VC in 111 national groundwater wells for three years (2016 to 2018) to evaluate their distributions, a biological dechlorination possibility, and human risk assessment. The detection frequency of them was 30.2% for PCE, 45.1% for TCE, 43.9% for cis-DCE and 13.4% for VC. The four chlorinated compounds were commonly detected in 21 out of 111 wells. In the results of statistical analysis with 21 wells data, DO and ORP also had a negative correlation with four organic chlorinated compounds, while EC and sulfate has a positive correlation with the compounds. This indicates that the 21 wells were relatively met with suitable environments for a biological dechlorination reaction compared to the other wells. Finally, cis-DCE had a non-carcinogenic risk of 10-1 and the carcinogenic risk of VC was 10-6 or higher. Through this study, the distribution status of the four chlorinated compounds in groundwater in South Korea and the necessity of preparing plans to manage cis-DCE and VC were confirmed.

Key Words
biological dichlorination; groundwater; risk assessment; PCE; TCE

Address
Sunhwa Park, Deok Hyun Kim, JongHyun Yoon, JongBeom Kwon, Hyojung Choi, Moonsu Kim, Sun-Kyoung Shin and Hyun-Koo Kim: National Institute of Environmental Research, Hwangyong-ro 42, Seo-gu, Incheon, 404-708, Republic of Korea

Ki-In Kim: Mokpo National University 1666, Muan-gun, Jeollanamdo, Republic of Korea

Kyungjin Han: Korea national university of transportation, Daehak-ro 50, Daesowon-myeon, Chungju-si, Chungcheongbuk-do, Republic of Korea



Abstract
With a small particle size, specific surface area and chemical nature, Pd/Cu-Fe nanocomposites can efficiently remove the organic compounds. In order to understand the applicability for in situ remediation of contaminated groundwater, the degradation of p-nitrophenol by Pd/Cu-Fe nanoparticles was investigated. The degradation results demonstrated that these nanoparticles could effectively degrade p-nitrophenol and near 90% of degradation efficiency was achieved by Pd/Cu-Fe nanocomposites for 120 min treatment. The efficiency of degradation increased significantly when the Pd content increased from 0.05 wt.% and 0.10 wt.% to 0.20 wt.%. Meanwhile, the removal percentage of p-nitrophenol increased from 75.4% and 81.7% to 89.2% within 120 min. Studies on the kinetics of p-nitrophenol that reacts with Pd/Cu-Fe nanocomposites implied that their behaviors followed the pseudo-first-order kinetics. Furthermore, the batch experiment data suggested that some factors, including Pd/Cu-Fe availability, temperature, pH, different ions (SO42-, PO43-, NO3-) and humic acid content in water, also have significant impacts on p-nitrophenol degradation efficiency. The recyclability of the material was evaluated. The results showed that the Pd/Cu-Fe nanoparticles have good recycle performance, and after three cycles, the removal rate of p-nitrophenol is still more than 83%.

Key Words
Cu/Fe; degradation; iron; nanoparticles; p-nitrophenol; reduction

Address
Zhang Wenbin, Liu Lanyu, Zhao Jin, Gao Fei and Wang Jian: Ecological and Environmental Monitoring Center of Chongqing, Chongqing 401147

Fang Liping: China University of Geosciences, No. 388, Lumo Road, Wuhan 430074, China

Abstract
Al2O3 positively charged nanofiltration composite membrane was successfully prepared with aluminate coupling agent (ACA) as modifier, sodium bisulfite (NaHSO3) and potassium persulfate (K2S2O8) as initiator and methacryloyloxyethyl trimethylammonium chloride (DMC) as crosslinking monomer. The surface of the membrane before grafting and after polymerization were characterized by SEM and FT-IR. Three factor and three-level orthogonal experiments were designed to explore the optimal conditions for membrane preparation, and the optimal group was successfully prepared. The filtration experiments of different salt solutions were carried out, and the retention molecular weight was determined by polyethylene glycol (PEG). The results showed that the polymerization temperature had the greatest effect on the rejection rate, followed by the reaction time, and the concentration of DMC had the least effect on the rejection rate. The rejection rates of CaCl2, MgSO4, NaCl and Na2SO4 in the optimal group were 83.8%, 81.3%, 28.1% and 23.6% (average value), respectively. The molecule weight cut-off of 90% (MWCO) of the optimal group was about 460, which belongs to nanofiltration membrane.

Key Words
desalination; membrane; nanofiltration; orthogonal test; positively charged

Address
Lian Li, Xiating Zhang, Lufen Li, Zhongcao Yang and Yuan Li: Zhejiang College of Security Technology, Wenzhou, 325016, Zhejiang, China


Techno-Press: Publishers of international journals and conference proceedings.       Copyright © 2022 Techno-Press
P.O. Box 33, Yuseong, Daejeon 34186 Korea, Tel: +82-2-736-6800 (SCS, EAS, WAS, ANR) +82-42-828-7995 (GAE, SEM, SSS, CAC) Fax : +82-2-736-6801, Email: info@techno-press.com