scholarly journals Recovery of Waste Polyurethane from E-Waste. Part II. Investigation of the Adsorption Potential for Wastewater Treatment

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7587
Author(s):  
Vincenzo Santucci ◽  
Silvia Fiore
Keyword(s):  
Methylene Blue ◽  
Wastewater Treatment ◽  
Adsorption Equilibrium ◽  
Freundlich Isotherm ◽  
Adsorption Potential ◽  
Liquid Ratio ◽  
Batch Tests ◽  
Pre Treatment ◽  
Solid Liquid ◽  
Rough Cut

This study explored the performances of waste polyurethane foam (PUF) derived from the shredding of end-of-life refrigerators as an adsorbent for wastewater treatment. The waste PUF underwent a basic pre-treatment (e.g., sieving and washing) prior the adsorption tests. Three target pollutants were considered: methylene blue, phenol, and mercury. Adsorption batch tests were performed putting in contact waste PUF with aqueous solutions of the three pollutants at a solid/liquid ratio equal to 25 g/L. A commercial activated carbon (AC) was considered for comparison. The contact time necessary to reach the adsorption equilibrium was in the range of 60–140 min for waste PUF, while AC needed about 30 min. The results of the adsorption tests showed a better fit of the Freundlich isotherm model (R2 = 0.93 for all pollutants) compared to the Langmuir model. The adsorption capacity of waste PUF was limited for methylene blue and mercury (Kf = 0.02), and much lower for phenol (Kf = 0.001). The removal efficiency achieved by waste PUF was lower (phenol 12% and methylene blue and mercury 37–38%) compared to AC (64–99%). The preliminary results obtained in this study can support the application of additional pre-treatments aimed to overcome the adsorption limits of the waste PUF, and it could be applied for “rough-cut” wastewater treatment.

Wet-Purification of a Sodium-Based Bentonite

2013 ◽  
Vol 743-744 ◽  
pp. 692-696
Author(s):  
Shui Lin Zheng ◽  
Yang Yang Huai ◽  
Zhen Wei Li ◽  
Hao Ran Cui ◽  
Zhi Ming Sun
Keyword(s):  
Methylene Blue ◽  
Diffraction Analysis ◽  
Purification Process ◽  
X Ray Diffraction ◽  
Liquid Ratio ◽  
X Ray ◽  
Solid Liquid

Bentonite mainly consists of montmorillonite, but is always associated with other impure minerals. In order to increase the montmorillonite content in raw bentonite from Xinjiang, this paper adopts wet-purification process which integrates the scrubbing process with streamlined centrifugalization. The optimum experiment condition is solid - liquid ratio (wv) 130, macerating time 20h, scrubbing time 10min, centrifugation time 13min, centrifugation velocity 1260r/min, ZHL dosage 0.4% and ZHC dosage 0.4%. According to the amount of methylene blue absorption raising from 64.5mmol/100g to 110mmol/100g and X-ray diffraction analysis, the montmorillonite content raises from 48% to 82%.

scholarly journals EQUILIBRIUM, KINETIC AND THERMODYNAMIC STUDIES OF ADSORPTION OF METHYLENE BLUE ON ACTIVATED CARBON FROM COCOA POD SHELLS

2021 ◽  
Vol 9 (11) ◽  
pp. 62-72
Author(s):  
Akissi Lydie Chantal Koffi ◽  
◽  
Djamatche Paul Valery Akesse ◽  
Herman Yapi Yapo ◽  
David Leonce Kouadio ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Freundlich Isotherm ◽  
Entropy Change ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Physiochemical Parameters ◽  
Batch Tests ◽  
Pseudo Second Order

The aim of this research is to investigate the feasibility of using activated carbon from cocoa pod shells, waste from agriculture to adsorb methylene blue from aqueous solutions through batch tests. Various physiochemical parameters such as, contact time, initial dye concentration, adsorbent dosage, pH of dye solution and temperature were investigated in a batch-adsorption technique. The process followed the pseudo-second order kinetics model which showed chemical adsorption. Langmuir and Freundlich isotherm models were used to determine adsorption constants. The maximum adsorption capacity at 30°C is 526.31 mg/g. Thermodynamic parameters such as enthalpy change (∆Hº), free energy change (∆Gº) and entropy change (∆Sº) were studied, and the adsorption process of BM was found to be exothermic and spontaneous.

scholarly journals Elimination of Methylene Blue by low-cost Biomaterial prepared from Local Natural Residue

2020 ◽  
Vol 2 (01) ◽  
pp. 60-66
Author(s):  
Fatma LANSARI ◽  
Meryem EDJEKOUANE ◽  
Omar KHELIFI ◽  
Ishak BOUKHETECHE ◽  
Ishak LAKSACI
Keyword(s):  
Methylene Blue ◽  
Adsorption Process ◽  
Adsorption Equilibrium ◽  
Low Cost ◽  
Freundlich Isotherm ◽  
Freundlich Model ◽  
Batch System ◽  
Natural Support ◽  
Uv Visible

This study aims to assess the use of natural waste (fruit kernels) for the preparation of a bimaterial in order to use it as a natural support for the elimination of a dye (methylene blue) from aqueous solutions for environmental protection. The biomaterial was characterized physicochemically and the determination of methylene blue concentration was carried out by a UV-Visible spectrophotometer. In order to clarify the adsorption process, experiments in a batch system were carried out to study the effect of operating parameters such as the initial concentration of methylene blue (2-10 mg·L-1), biomaterial (0.1-1 g) and the contact time (10-120 min). To describe the adsorption equilibrium, the experimental data were analyzed by the Langmuir isotherm and the Freundlich isotherm. The equilibrium is perfectly described by the Freundlich model (R2>0.99) and the adsorption process is multilayer. The results of the present study suggest that washingtonia seed (WS) can be advantageously used as a low-cost biosorbent for water discoloration

scholarly journals Impact of hydrothermal pre-treatment on the anaerobic digestion of different solid–liquid ratio sludges and kinetic analysis

RSC Advances ◽  
2019 ◽  
Vol 9 (33) ◽  
pp. 19104-19113 ◽  
Author(s):  
Lei Gong ◽  
Xiaoqi Yang ◽  
Zaizhao Wang ◽  
Jun Zhou ◽  
Xiaogang You
Keyword(s):  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Kinetic Analysis ◽  
Biogas Production ◽  
Liquid Ratio ◽  
Pre Treatment ◽  
Solid Liquid

This study is an assessment of hydrothermal pre-treatment (HTP) of different solid–liquid ratio (SLR) sewage sludge for enhancement of biogas production by anaerobic digestion.

scholarly journals Removal of methylene blue by biosorption onto Stipa tenacissima L. (Alfa) plants: Kinetics, equilibrium and thermodynamic studies

2021 ◽  
pp. 33-44
Author(s):  
Samir Ladjali ◽  
Nadjib Dahdouh ◽  
Samira Amokrane ◽  
El Mekatel ◽  
Djamel Nibou
Keyword(s):  
Methylene Blue ◽  
Contact Time ◽  
Blue Dye ◽  
Order Kinetic ◽  
Liquid Ratio ◽  
Stipa Tenacissima ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Solid Liquid

This study examines the ability of Stipa tenacissima L. (Alfa) to biosorb the Methylene Blue dye. Biosorption tests were performed in aqueous solution based on certain essential parameters such as solution?s pH (2-12), solid/liquid ratio (1-6 g/L), initial dye concentration (25-125 mg/L) and contact time (0-300 min). The Langmuir, Freundlich, Temkin and Elovich models were applied. It was found that the equilibrium data could be fitted to the Langmuir isotherm for MB biosorption with a maximum capacity qmax 55, 95 mg/g. The kinetic study shows that the experimental data correspond to the pseudo-second order kinetic model. The negative Gibbs values free energy ?G? reveal the spontaneity of MB biosorption at the surface of Stipa tenacissima L. The positive value of ?H? reveals the endothermic nature of the process.

scholarly journals One-Step Carbothermal Synthesis of Super Nanoadsorbents for Rapid and Recyclable Wastewater Treatment

Crystals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 75
Author(s):  
Wen-chan Ji ◽  
Ping Hu ◽  
Xiao-yu Wang ◽  
Sandra Elizabeth Saji ◽  
Tian Chang ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Magnetic Properties ◽  
Wastewater Treatment ◽  
Adsorption Capacity ◽  
Industrial Wastewater ◽  
Magnetic Response ◽  
Carbothermal Synthesis ◽  
One Step ◽  
Solid Liquid ◽  
Solid Liquid Separation

As a potential magnetic super adsorbent in wastewater treatment, Fe3O4 has been researched intensively up to date. However, its key problem of poor comprehensive magnetic properties is still challenging. In this work, an effective solution to this problem has been developed by a one-step carbothermal synthesis of Fe3O4 crystals, which are merited with pure-stoichiometry (FeO-phase free), high crystallinity, small-size (~10 nm), strong magnetism and sensitive magnetic response. The unveiled saturation magnetization of Fe3O4 nanoparticles reaches as high as 90.32 emu·g−1, and the fastest magnetic response time is as short as only 5 s. Such magnetic Fe3O4 super adsorbents exhibit outstanding performance when applied as an adsorbent for wastewater treatment. They can quickly and effectively adsorb methylene blue with an adsorption capacity of 62.5 mg·g−1, which is much higher than that of Fe3O4 adsorbents prepared by other methods reported in the literature. Importantly, this capacity is refreshable after removing the adsorbed methylene blue just by ultrasonic cleaning. With such combined outstanding magnetic properties and recyclable adsorption capacity, the problems associated with the conventional adsorbent solid–liquid separation could be resolved, thus making a forward development towards industrial wastewater treatment.

Environmental Impact Evaluation of Istanbul Wastewater Treatment and Marine Disposal Systems

1992 ◽  
Vol 25 (9) ◽  
pp. 85-92 ◽  
Author(s):  
I. Ozturk ◽  
T. Zambal ◽  
A. Samsunlu ◽  
E. Göknel
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Environmental Impact ◽  
Quality Parameters ◽  
Sea Of Marmara ◽  
General Evaluation ◽  
Marine Outfall ◽  
Secondary Stage ◽  
Pre Treatment

Metropolitan Istanbul Wastewater Treatment System contains 14 marine outfalls, seven of which include secondary stage biological treatment processes. The others have only mechanical treatment units including bar screens and grit chambers. Only one mechanical pre-treatment and marine disposal system, Yenikapi plant, has been operated since 1988 among these 14 plants and six of them are ready for construction. In this paper, the environmental impact of Yenikapi pretreatment and marine disposal system on the water quality of the Bosphorus and the Sea of Marmara has been investigated. Long term water quality measurements which were performed in pre-and post-dischange applications have been evaluated. Water quality parameters including pH, DO, BODs, TKN, P and total coliforms were measured at various sampling stations around the discharge points. A general evaluation of marine outfall systems to be constructed in the scope of Istanbul wastewater treatment project, on the water quality of the Sea of Marmara and the Bosphorus has been presented.

Performance of hybrid small wastewater treatment system consisting of jet mixed separator and rotating biological contactor

1997 ◽  
Vol 35 (6) ◽  
pp. 63-70 ◽  
Author(s):  
Yoshimasa Watanabe ◽  
Yoshihiko Iwasaki
Keyword(s):  
Wastewater Treatment ◽  
Electric Power ◽  
Hybrid System ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Treatment System ◽  
Municipal Wastewater Treatment ◽  
Wastewater Treatment System ◽  
Pre Treatment ◽  
Organic Particles

This paper describes a pilot plant study on the performance of a hybrid small municipal wastewater treatment system consisting of a jet mixed separator(JMS) and upgraded RBC. The JMS was used as a pre-treatment of the RBC instead of the primary clarifier. The treatment capacity of the system was fixed at 100 m3/d, corresponding to the hydraulic loading to the RBC of 117 L/m2/d. The effluent from the grid chamber at a municipal wastewater treatment plant was fed into the hybrid system. The RBC was operated using the electric power produced by a solar electric generation panel with a surface area of 8 m2 under enough sunlight. In order to reduce the organic loading to the RBC, polyaluminium chloride(PAC) was added to the JMS influent to remove the colloidal and suspended organic particles. At the operational condition where the A1 dosage and hydraulic retention time of the JMS were fixed at 5 g/m3 and 45 min., respectively, the average effluent water quality of hybrid system was as follows: TOC=8 g/m3, Total BOD=8 g/m3, SS=8 g/m3, Turbidity=6 TU, NH4-N=7 g/m3, T-P=0.5 g/m3. In this operating condition, electric power consumption of the RBC for treating unit volume of wastewater is only 0.07 KWH/m3.

scholarly journals Preparation and Characterization of the Sulfur-Impregnated Natural Zeolite Clinoptilolite for Hg(II) Removal from Aqueous Solutions

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 217
Author(s):  
Marin Ugrina ◽  
Martin Gaberšek ◽  
Aleksandra Daković ◽  
Ivona Nuić
Keyword(s):  
Chemical Modification ◽  
Aqueous Solutions ◽  
Specific Surface ◽  
Surface Area ◽  
Natural Zeolite ◽  
Contact Time ◽  
Liquid Ratio ◽  
X Ray ◽  
Solid Liquid

Sulfur-impregnated zeolite has been obtained from the natural zeolite clinoptilolite by chemical modification with Na2S at 150 °C. The purpose of zeolite impregnation was to enhance the sorption of Hg(II) from aqueous solutions. Chemical analysis, acid and basic properties determined by Bohem’s method, chemical behavior at different pHo values, zeta potential, cation-exchange capacity (CEC), specific surface area, X-ray powder diffraction (XRPD), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), as well as thermogravimetry with derivative thermogravimetry (TG-DTG) were used for detailed comparative mineralogical and physico-chemical characterization of natural and sulfur-impregnated zeolites. Results revealed that the surface of the natural zeolite was successfully impregnated with sulfur species in the form of FeS and CaS. Chemical modification caused an increase in basicity and the net negative surface charge due to an increase in oxygen-containing functional groups as well as a decrease in specific surface area and crystallinity due to the formation of sulfur-containing clusters at the zeolite surface. The sorption of Hg(II) species onto the sulfur-impregnated zeolite was affected by the pH, solid/liquid ratio, initial Hg(II) concentration, and contact time. The optimal sorption conditions were determined as pH 2, a solid/liquid ratio of 10 g/L, and a contact time of 800 min. The maximum obtained sorption capacity of the sulfur-impregnated zeolite toward Hg(II) was 1.02 mmol/g. The sorption mechanism of Hg(II) onto the sulfur-impregnated zeolite involves electrostatic attraction, ion exchange, and surface complexation, accompanied by co-precipitation of Hg(II) in the form of HgS. It was found that sulfur-impregnation enhanced the sorption of Hg(II) by 3.6 times compared to the natural zeolite. The leaching test indicated the retention of Hg(II) in the zeolite structure over a wide pH range, making this sulfur-impregnated sorbent a promising material for the remediation of a mercury-polluted environment.

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