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CONTENTS
Volume 13, Number 5, September 2022
 


Abstract
In the present research, Ficus religiosa Bark (FRB) is used as an adsorbent for the removal of heavy metal Cr (VI) ions. This Ficus religiosa Bark was characterized by Scanning Electron Microscope, Fourier transform infrared Spectroscopy, Thermo Gravimetric Analyzer and the results showed that activated adsorbent have high adsorption capacity and withstand even in high temperature. Batch and Continuous experiments were conducted to determine the effect of various parameters such as pH, contact time, adsorbent dose and initial metal concentration. The biosorption followed pseudo first order kinetic model. The adsorption isotherms of Cr (VI) on Ficus religiosa fitted well with the Temkin model. In Batch study, maximum biosorption capacity of Cr (VI) was found to be 37.97 mg g-1 (at optimal pH of 2, adsorbent dosage of 0.3 grams and concentration of Cr (VI) is100 mg L-1). The Continuous mode of study shows that 97% of Cr (VI) ion removal at a flow rate of 15 ml min-1. From the results, selected Ficus religiosa Bark has the higher adsorption capacity for the removal of Cr (VI) ions from wastewater.

Key Words
biosorption; Cr (VI); Ficus religiosa Bark; kinetics; Temkin model; wastewater treatment

Address
Karthick S, Palani R, Sivakumar D and Meyyappan N: Department of Chemical Engineering, Sri Venkateswara College of Engineering, Tamilnadu- 602117, India

Abstract
5th Assessment Report of the Intergovernmental Panel on Climate Change Weather (AR5) predicts that recent severe hydrological events will affect the quality of water and increase water pollution. To analyze changes in water quality due to future climate change, input data (precipitation, average temperature, relative humidity, average wind speed, and solar radiation) were compiled into a representative concentration curve (RC), defined using 8.5. AR5 and future use are calculated based on land use. Semi-distributed emission model Calculate emissions for each target period. Meteorological factors affecting water quality (precipitation, temperature, and flow) were input into a multiple linear regression (MLR) model and an artificial neural network (ANN) to analyze the data. Extensive experimental studies of flow properties have been carried out. In addition, an Acoustic Doppler Velocity (ADV) device was used to monitor the flow of a large open channel connection in a wastewater treatment plant in Ho Chi Minh City. Observations were made along different streams at different locations and at different depths. Analysis of measurement data shows average speed profile, aspect ratio, vertical position Measure, and ratio the vertical to bottom distance for maximum speed and water depth. This result indicates that the transport effect of the compound was considered when preparing the hazard analysis.

Key Words
artificial neural network; climate change; estimation of water quality; multiple linear regression analysis

Address
ZY Chen, Yahui Meng and Ruei-yuan Wang: School of Science, Guangdong University of Petrochemical Technology, Maoming 525000, Guangdong, China

Timothy Chen: California Institute of Technology, Pasadena, CA 91125, USA

Abstract
The objective of the study, to develop adsorbent based purifier for removal of radiological and nuclear contaminants from contaminated water. In this regard, 3-aminopropyl silica functionalized with ethylenediamine tetraacetic acid (APS-EDTA) adsorbent prepared and characterized by Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). Prepared APS-EDTA used for adsorptive studies of Cs(I), Co(II), Sr(II), Ni(II) and Cd(II) from contaminated water. The effect on adsorption of various parameters viz. contact time, initial concentration of metal ions and pH were also analyzed. The batch method has been employed using metal ions in solution from 1000-10000 µg/L, contact time 5-60 min., pH 4-10 and material quantities 50-200 mg at room temperature. The obtained adsorption data were used for drawing Freundlich and Langmuir isotherms model and both models were found suitable for explaining the metal ions adsorption on APS-EDTA. The adsorption data were followed pseudo second order reaction kinetics. The maximum adsorption capacity obtained 1.3037-1.4974 mg/g for above said metal ions. The results show that APS-EDTA have great potential to remove Cd(II), Co(II), Cs(I), Ni(II) and Sr(II) from aqueous solutions through chemisorption and physio-sorption.

Key Words
adsorption; aminopropyl silica; cesium and strontium; removal; toxic metal ions

Address
Rajesh Kumar, Sunita Verma, Geeta Harwani, Deepesh Patidar and Sanjit Mishra: Water Quality Management Group, Desert Environmental Science and Technology Division

Abstract
The paper presents the effect of operating temperatures and flow rates on the distillate flux that can be obtained from a hydrophobic membrane having the characteristics: pore size of 0.15 µm; thickness of 130 µm; and 85% porosity. That membrane in the present investigation could be the direct contact (DCMD) or the air-gap membrane distillation (AGMD). To model numerically the membrane distillation processes, the two-dimensional computational fluid dynamic (CFD) is used for the DCMD and AGMD cases here. In this work, DCMD and AGMD models have been validated with the experimental data using different flows (Parallel and Counter-current flows) in non-steady-state situations. A good agreement is obtained between the present results and those of the experimental data in the literature. The new approach in the present numerical modeling has allowed examining effects of the nature of materials (Polyvinylidene fluoride (PVDF) polymers, copolymers, and blends) used on thermal properties. Moreover, the effect of the area surface of the membrane (0.021 to 3.15 m2) is investigated to explore both the laminar and the turbulent flow regimes. The obtained results found that copolymer P(VDF-TrFE) (80/20) is more effective than the other materials of membrane distillation (MD). The mass flux and thermal efficiency reach 193.5 (g/m2s), and 83.29 % using turbulent flow and an effective area of 3.1 m2, respectively. The increase of feed inlet temperatures and its flow rate, with the reduction of cold temperatures and its flow rate are very effective for increasing distillate water flow in MD applications.

Key Words
CFD; co-polymers; Membrane Distillation (MD); temperature polarization; thermal conductivity

Address
Abdelfatah Marni Sandid, Driss Nehari and Taieb Nehari: Department of Mechanical Engineering, University of Ain Temouchent, 46000 Ain Temouchent, Algeria

Abstract
Water quality characteristics and their spatial variations in the Nakdong River were statistically analyzed by multivariate techniques including correlation analysis, CA, and FA/PCA based on water quality parameters for 17 sites over 2017–2019, yielding PI values for primary factors. Site 10 indicated the highest parameter concentrations, and results of pearson'Ss correlation analysis suggest that non-biodegradable organic matter had been distributed on the site. Five clusters were identified in order of descending pollution levels: I (Ib > Ia) > II (IIa > IIb) > III. Spatial variations started from sub-cluster Ib in which Daegu city and Geumho-river are joined. T-P, PO4-P, SS, COD, and TOC corresponded to VF 1 and 2, which were found to be principal components with strong influence on water quality. Sub-cluster Ib was strongly influenced by NO3-N and T-N compared to other clusters. According to the PIs, water quality pollution deteriorated due to non-biodegradable organic matter, nitrogen- and phosphorus-based nutrient salts in the middle and lower reaches, illustrating worsening water pollution due to inflows of anthropogenic sources on the Geumho-river, i.e., sewage and wastewater, discharged from Site 10, at which there is a concentration of urban, agricultural, and industrial areas.

Key Words
factor analysis/principal component analysis; correlation analysis; cluster analysis; Nakdong river; pollution index; water quality

Address
Shin Kim: Nakdong River Environment Research Center, National Institute of Environmental Research, 24-11, Gukgasandan-daero 52-gil, Guji-myeon, Dalseong-gun, Daegu, Republic of Korea



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