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.

scholarly journals One-step synthesis of nitrogen-grafted copper-gallic acid for enhanced methylene blue removal

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shella Permatasari Santoso ◽  
Vania Bundjaja ◽  
Artik Elisa Angkawijaya ◽  
Chintya Gunarto ◽  
Alchris Woo Go ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Gallic Acid ◽  
Synthesis Method ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
One Step ◽  
Detailed Assessment ◽  
Higher Temperature

AbstractNitrogen-grafting through the addition of glycine (Gly) was performed on a metal- phenolic network (MPN) of copper (Cu2+) and gallic acid (GA) to increase its adsorption capacity. Herein, we reported a one-step synthesis method of MPN, which was developed according to the metal–ligand complexation principle. The nitrogen grafted CuGA (Ng-CuGA) MPN was obtained by reacting Cu2+, GA, and Gly in an aqueous solution at a molar ratio of 1:1:1 and a pH of 8. Several physicochemical measurements, such as Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), N2 sorption, X-ray diffraction (XRD), and thermal gravimetry analysis (TGA), were done on Ng-CuGA to elucidate its characteristics. The analysis revealed that the Ng-CuGA has non-uniform spherical shaped morphology with a pore volume of 0.56 cc/g, a pore size of 23.25 nm, and thermal stability up to 205 °C. The applicational potential of the Ng-CuGA was determined based on its adsorption capacity against methylene blue (MB). The Ng-CuGA was able to adsorb 190.81 mg MB per g adsorbent at a pH of 6 and temperature of 30 °C, which is 1.53 times higher than the non-grafted CuGA. Detailed assessment of Ng-CuGA adsorption properties revealed their pH- and temperature-dependent nature. The adsorption capacity and affinity were found to decrease at a higher temperature, demonstrating the exothermic adsorption behavior.

Study of Continuos Settling Vessels Operating with Suspensions Previously Floculated

2008 ◽  
Vol 591-593 ◽  
pp. 358-361
Author(s):  
J.F. Nunes ◽  
J.R. Lira ◽  
João Jorge Ribeiro Damasceno
Keyword(s):  
Wastewater Treatment ◽  
Solid Particle ◽  
Aluminum Sulfate ◽  
Cylindrical Part ◽  
Continuous Operation ◽  
Circular Section ◽  
Operational Conditions ◽  
The Stability ◽  
Solid Liquid ◽  
Solid Liquid Separation

The settling vessels are equipment destined to solid-liquid separation; usually have continuous operation, with a circular section, presenting one conic and one cylindrical part. They are very used in chemical industries: wastewater treatment, minerals industries; to concentrate or to remove the solids. The solid particle splitting with small granular becomes difficult through the operation of conventional sedimentation. An expedient very used in the industry is the flocculant substance addition, whose objective is to promote the precipitation of particles, with decantation speed is upper than the single one. The present work aim the study of the burst operational conditions that influence the formation and the stability of these aggregates, the flake, the effect of pH and the concentration of flocculant using kaolin suspension and genfloc, that contains aluminum sulfate, as a flocculant; and the capacity of conventional settling vessel, which area of the transversal remains constant, considering this operational conditions.

scholarly journals Cellulose Based Cation-Exchange Fiber as Filtration Material for the Rapid Removal of Methylene Blue from Wastewater

2021 ◽  
Author(s):  
Xinyi Shao ◽  
Jian Wang ◽  
Zetan Liu ◽  
Na Hu ◽  
Min Liu ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Cation Exchange ◽  
Natural Fiber ◽  
Filter Material ◽  
Separation Performance ◽  
Fiber Morphology ◽  
Liquid Separation ◽  
Simple Method ◽  
Solid Liquid ◽  
Solid Liquid Separation

Abstract The development of eco-friendly adsorbent with perfect solid/liquid separation performance is of great practical importance for the efficient purification of dye-containing wastewater. Herein, cellulose based cation-exchange fibrous bio-adsorbent (CEF) was successfully obtained via an industrialized cellulose etherification process. The fiber morphology can be maintained with the average degree substitution (DS) of CEF as about 0.19. The CEF showed high efficiency adsorption for methylene blue (MB): achieving 82% of equilibrium uptake (447.69 mg·g-1) within 5 min. Especially, the non-woven porous filter material, formed by CEFs and glass fibers, showed the praisable solid/liquid separation characteristics, fast water filtration rate (≈ 6.3 m3·m-2·h-1) and high removal rate (≈ 99.2%) when it was used to adsorb MB (150 ppm) from wastewater. In addition, CEFs filter material can be regenerated via a simple method. This study demonstrates that green natural fiber materials are promising for the economical and efficient purification of dye-containing wastewater.

Effect of C/N ratio on nitrous oxide emission from swine wastewater treatment process

2004 ◽  
Vol 49 (5-6) ◽  
pp. 359-371 ◽  
Author(s):  
N. Kishida ◽  
J.H. Kim ◽  
Y. Kimochi ◽  
O. Nishimura ◽  
H. Sasaki ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Wastewater Treatment ◽  
Treatment Process ◽  
N2o Emission ◽  
Swine Wastewater ◽  
N2o Emissions ◽  
Wastewater Treatment Process ◽  
Phase Study ◽  
Solid Liquid ◽  
Solid Liquid Separation

To evaluate control parameters for nitrous oxide (N2O) emissions in the swine wastewater treatment process, the N2O emission was compared in the activated sludge from SBRs acclimated in different carbon/nitrogen (C/N) ratios. N2O emission from a denitrification phase was very strongly dependent on C/N ratio of swine wastewater, and the total N2O emission in the operating condition of BOD5/TN ratio of 2.6 was approximately 270 times greater than that in BOD5/TN ratio of 4.5. However, the effect of C/N ratio on N2O emission amount from nitrification was not significant in an oxic phase study. It is considered that stabilization of the C/N ratio through optimal solid-liquid separation of slurry or use of an external carbon source is indispensable for effective N2O emission control from nitrogen removal process of swine wastewater.

Household Membrane Bioreactor in Domestic Wastewater Treatment

1993 ◽  
Vol 27 (1) ◽  
pp. 171-178 ◽  
Author(s):  
C. Chiemchaisri ◽  
K. Yamamoto ◽  
S. Vigneswaran
Keyword(s):  
Wastewater Treatment ◽  
Hollow Fiber Membrane ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Experimental Unit ◽  
Transmembrane Pressure ◽  
Working Volume ◽  
Operational Life ◽  
Solid Liquid ◽  
Solid Liquid Separation

The activated sludge process coupled with hollow fiber membrane for solid-liquid separation was applied to treat low strength domestic wastewater. Pilot-scale experimental unit used in this study consisted of 2 modules of 0.03 μm pore size with 9 m2 surface area each, immersed in the reactor which has a maximum working volume of 1.5 m3. Even when sewage was fed at varying rates following its diurnal flow variation to the bioreactor, good stability of the process was achieved which was shown by the consistency in treated water quality. The effluent turbidity and COD were well within the limits (less than 0.5 NTU and 3-5 mg/L). The transmembrane pressure drop was less than 20 cm Hg even after 2 months of operation. Application of jet aeration could be used to prolong the operational life of the membrane in the bioreactor. This system is an ideal one to be used as household wastewater treatment system.

scholarly journals Adsorption of nitrate and nitrite from aqueous solution by magnetic Mg/Fe hydrotalcite

2021 ◽  
Author(s):  
Jing Chen ◽  
Yawei Wei ◽  
Haoyu Ji ◽  
Pengliang Guo ◽  
Dongjin Wan ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Langmuir Model ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Magnetic Strength ◽  
Calcination Method ◽  
Co Precipitation ◽  
Nitrate And Nitrite ◽  
Solid Liquid ◽  
Solid Liquid Separation

Abstract In this study, magnetic Mg/Fe hydrotalcite calcined material (M-CHT) was synthesized through co-precipitation and calcination method, and was used to effectively remove nitrate and nitrite from water. M-CHT can restore its original layered structure after the adsorption of nitrate or nitrite, and can be easily separated by the applied magnetic field. The first-order and pseudo-second-order kinetic models (R2 ≥ 0.97) can better describe the adsorption kinetic process. The equilibrium isotherm showed that the Langmuir model provided a better fit to the experimental data than the Freundlich model for nitrates and nitrites. With temperature increased from 298 to 308 K, the maximum adsorption capacity obtained by the Langmuir model increased from 10.60 to 16.90 mg-N/g for nitrate and 7.89 to 14.28 mg-N/g for nitrite, respectively. The adverse effect of coexisting anions ranked in the order of ClO4− > Cl− > SO42− > F− > CO32− > PO43−. The actual Fe2+/Fe3+ value of M-CHT (0.56) is nearly consistent with the theoretical value of 0.5, and the saturation magnetic strength value of M-CHT is 9.15 emu/g, greatly contributing to the solid-liquid separation. Overall, M-CHT with features of magnetic properties and satisfactory adsorption capacity exhibits the greatly promising for application in wastewater purification.

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.

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