Integration of polyelectrolyte enhanced ultrafiltration and chemical reduction for metal-containing wastewater treatment and metal recovery

2015 ◽  
Vol 72 (7) ◽  
pp. 1096-1101 ◽  
Author(s):  
Jui-Hsuan Yu ◽  
Yi-Hsuan Chou ◽  
Yang-Min Liang ◽  
Chi-Wang Li
Keyword(s):  
Removal Efficiency ◽  
Ph Value ◽  
Chemical Reduction ◽  
Sample Pretreatment ◽  
Particle Size Analysis ◽  
Reduction Reaction ◽  
Copper Removal ◽  
Molar Ratio ◽  
Size Analysis ◽  
Copper Particles

Chemical reduction was firstly employed to treat synthetic wastewaters of various compositions prepared to simulate the retentate stream of polyelectrolyte enhanced ultrafiltration (PEUF). With fixed Cu:polyethylenimine (PEI) monomer:dithionite molar ratio, increasing copper concentration increases copper removal efficiency. Under fixed Cu:dithionite molar ratio and fixed Cu concentration, increasing PEI monomer:copper molar ratio decreases copper removal efficiency. The formation of nano-sized copper particles, which readily pass through 0.45 μm filter used for sample pretreatment before residual copper analysis, might be the reason behind the decreasing copper removal efficiency observed. Particle size analysis shows that the size of copper particles, which are formed through reduction reaction, increases with decreasing pH value and increasing reaction time. As ultrafiltration is capable of removing these nano-sized particles, integration of chemical reduction and PEUF is proposed to simultaneously achieve regeneration of polyelectrolyte and recovery of copper in one process. Results show that the proposed process could achieve almost complete copper removal without being affected by reaction pH.

Recovery of Cu(II) by chemical reduction using sodium dithionite: effect of pH and ligands

2015 ◽  
Vol 72 (11) ◽  
pp. 2089-2094 ◽  
Author(s):  
Yi-Hsuan Chou ◽  
Jui-Hsuan Yu ◽  
Yang-Min Liang ◽  
Pin-Jan Wang ◽  
Chi-Wang Li ◽  
...  
Keyword(s):  
Metal Removal ◽  
Ethylenediaminetetraacetic Acid ◽  
Chemical Reduction ◽  
Metallic Copper ◽  
Sample Pretreatment ◽  
Copper Removal ◽  
Experimental Result ◽  
Molar Ratio ◽  
Metallic Nanoparticle ◽  
Industrial Sectors

Wastewaters containing Cu(II) and ligands are ubiquitous in various industrial sectors, and efficacy of copper removal processes, especially precipitation, is greatly compromised by ligands. Chemical reduction, being commonly employed for production of metal nanoparticles, is also effective for metal removal. Adjustment of pH and addition of ligands are important to control the particle size in metallic nanoparticle production. Exploiting the fact that ligands and metals coexist in many wastewaters, chemical reduction was employed to treat ligand-containing wastewater in this study. The experimental result shows that depending on pH, type of ligands, and copper:ligand molar ratio, copper could be removed by either the reduction or precipitation mechanism. Almost complete copper removal could be achieved by the reduction mechanism under optimal condition for solutions containing either EDTA (ethylenediaminetetraacetic acid) or citrate ligands. For solutions containing ammonia, depending on pH and Cu:ammonia molar ratio, copper was removed by both precipitation and reduction mechanisms. At pH of 9.0, formation of nano-sized particles, which readily pass through a 0.45 μm filter used for sample pretreatment before residual copper analysis, results in the lowest copper removal efficiency. Both cuprous oxide and metallic copper are identified in the solids produced, and the possible explanations are provided.

scholarly journals Study of metal-polymer copper nanocomposites using the method of UV spectroscopy

2021 ◽  
Vol 11 (1) ◽  
pp. 165-170
Author(s):  
A. A. Ivanova ◽  
A. I. Emel’yanov ◽  
S. A. Korzhova ◽  
A. S. Pozdnyakov
Keyword(s):  
Copper Ions ◽  
Chemical Reduction ◽  
Uv Spectroscopy ◽  
Electronic Devices ◽  
Copper Acetate ◽  
Reduction Reaction ◽  
Molar Ratio ◽  
Copper Particles ◽  
Brown Colour ◽  
Metal Polymer

New polymer copper-containing nanocomposites based on poly-N-vinylimidazole were obtained. The formation of nanocomposites was carried out using the method of chemical reduction of copper ions from a solution of copper acetate with ascorbic acid in an aqueous medium in the presence of a polymer. Nanocomposites were prepared at the polymer:Cu (II) molar ratio of 10:1 and 5:1. The reduction reaction yielded powder nanocomposites of a red-brown colour and having a metallic shine. It was found that the content of copper in the obtained nanocomposites depends on the initial molar ratio of the stabilising poly-N-vinylimidazole and Cu (II), reaching 5.9% and 11.7%. The formation of nanosized copper particles was investigated and confirmed by UV spectroscopy. The optical spectra of aqueous solutions of the obtained copper-containing nanocomposites contained maxima at 537–541 and 646–651 nm, which confirmed the formation of ultradispersed copper in the nanosized state. The obtained copper-containing nanocomposites based on poly-N-vinylimidazole are promising materials for use in medicine and catalysis, as well as in optical, sensor and electronic devices.

Hydrothermal Synthesis of Rod-Like Copper Oxide Crystals

2007 ◽  
Vol 534-536 ◽  
pp. 77-80 ◽  
Author(s):  
Jae Hwan Pee ◽  
Dong Wook Lee ◽  
Ungsoo Kim ◽  
Eui Seok Choi
Keyword(s):  
Copper Oxide ◽  
Ph Value ◽  
Copper Nitrate ◽  
Synthesis Temperature ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
X Ray Diffraction ◽  
Solution Ph ◽  
Uniform Size ◽  
Oxide Crystals

A hyrdrothermal reaction process has been developed to prepare rod-like crystals of copper oxide using copper nitrate trihydrate as a function of synthesis temperature, stirring speed and solution pH value. The properties of the fabricated crystals were studied using scanning electron microscopy, X-ray diffraction and particle size analysis. The morphology of the synthesized CuO was dependent on both the pH value of the solution and the morphology of the seed materials. Synthesized particles have regular morphologies and a uniform size distribution.

scholarly journals Effect of Nanosized Colloidal Copper on Cotton Fabric

2010 ◽  
Vol 5 (3) ◽  
pp. 155892501000500 ◽  
Author(s):  
D.P. Chattopadhyay ◽  
B.H. Patel
Keyword(s):  
Particle Size ◽  
Cotton Fabric ◽  
Colloidal Solution ◽  
Chemical Reduction ◽  
Average Particle Size ◽  
Particle Size Analysis ◽  
Nano Particles ◽  
Size Analysis ◽  
Average Particle ◽  
Sem Images

This research deals with the synthesis of nanosized copper as colloidal solution and its application to cotton fabric. Copper nano colloids were prepared by chemical reduction of copper salt using sodium borohydride as reducing agent in presence of tri-sodium citrate. The size and size distribution of the particles were examined by particle size analyzer and the morphology of the synthesized particles was examined by SEM and AFM techniques. X-ray fluorescence spectroscopy detected the presence of copper in the treated fabric. The results of particle size analysis showed that the average particle size varied from 60 nm to 100 nm. The nano copper treated cotton was subjected to soil burial test for the assessment of its resistance towards microbial attack. SEM images of treated fabric indicate copper nano particles are well dispersed on the surface of the specimens. The treatments of nano copper colloidal solution on cotton not only improve its antimicrobial efficiency but also influenced the tensile strength of the fabric sample positively. The treatment was found to enhance the color depth and fastness properties of direct dyed cotton fabric samples.

Study on Treatment of Ammonium Nitrogen in Desulfurization and Denitrification Wastewater with Sodium Hypochlorite

2013 ◽  
Vol 864-867 ◽  
pp. 438-441
Author(s):  
Zhen Zhou ◽  
Da Long Hu ◽  
Chu Qiao Zhang ◽  
Xue Lian Shen ◽  
Chun Hua Wu ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Sodium Hypochlorite ◽  
Ph Value ◽  
Ammonium Nitrogen ◽  
Molar Ratio ◽  
Distillation Method ◽  
Good Reliability ◽  
Initial Concentration ◽  
N Removal ◽  
Effects Of Ph

Based on the investigation of measurement method of ammonium nitrogen (NH4-N) desulfurization and denitrification wastewater (DDW) by distillation method, effects of pH, Cl/N and the initial concentration of NH4-N on the removal of NH4-N in DDW by sodium hypochlorite were studied. Results of parallel test and standard recovery test demonstrated good reliability and accuracy of the distillation method for the measurement of NH4-N in DDW. The NH4-N removal efficiency increased with pH from 5.0 and 8.0, and then decreased with pH higher than 8.0. Therefore, the optimum pH value was 8.0 with NH4-N removal efficiency of 74.7%. NH4-N removal efficiency was increased from 16.9% to 84.1% with Cl/N molar ratio rose from 1 to 5. The initial concentration of NH4-N showed insignificant effect on the removal amount of NH4-N, and the removed NH4-N was about 12~13mg/L with the addition of 4.86mmol/L sodium hypochlorite.

Investigation of Noble Metal Nanoparticles (Ag, Au, Pd, Pt) Produced by Chemical Reduction

2010 ◽  
Vol 659 ◽  
pp. 115-120 ◽  
Author(s):  
Ágnes Bajáki ◽  
János L. Lábár ◽  
Ágnes Csanády ◽  
Olga Geszti ◽  
Hajnalka Hargitai ◽  
...  
Keyword(s):  
Metal Nanoparticles ◽  
Noble Metal ◽  
Growth Models ◽  
Chemical Reduction ◽  
Particle Size Analysis ◽  
Atomic Scale ◽  
Noble Metal Nanoparticles ◽  
Size Analysis ◽  
Environmental Friendly ◽  
Water Filters

This work describes atomic-scale, crystalline structure and size distribution for noble metal nanoparticles produced by water-based, environmental friendly technologies. The process was developed and implemented to produce noble metal nanoparticles to be used in water filters, sensors and cosmetics. The particles were investigated by TEM methods and particle size analysis. Growth process of the crystallites in sols made by chemical reduction in aqueous solutions is discussed. Comparison with growth models for vacuum deposited thin films is also identified.

Synthesis and Characterization of MgFe2O4 /MgO Composite Films from Layered Double Hydroxides Precursors

2013 ◽  
Vol 690-693 ◽  
pp. 342-350
Author(s):  
Ying Chao Zhang ◽  
Ting Ting Chen ◽  
Lan Yang
Keyword(s):  
Magnetic Properties ◽  
Composite Films ◽  
Xrd Analysis ◽  
Particle Size Analysis ◽  
Molar Ratio ◽  
Size Analysis ◽  
X Ray ◽  
Single Source Precursor ◽  
Double Hydroxide ◽  
Double Hydroxides

MgFe2O4/MgO composite films have been successfully fabricated by a facile route using magnesium iron layered double hydroxide (MgFe-LDH) as a single-source precursor. This strategy mainly involves the formation of MgFe-LDH film by casting the slurry of MgFe-LDH precursor on the α-Al2O3substrate, followed by calcination at 900°C. The structure, morphology and magnetic properties of the resulting films were characterized by means of X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FT-IR), laser particle size analysis, scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX) and vibrating sample magnetometer (VSM). The results show that the composite films are composed of spherical or elliptical grains with diameters of less than 150nm and their thickness range was 2~3 μm. EDX mapping analysis reveals that the composite films have uniform distribution of MgFe2O4particles in MgO matrix. Further investigation indicates that the magnetic properties of the composite films can be tailored by altering the Mg/Fe molar ratio of LDH precursors.

scholarly journals Synthesis and Characterization of Novel Hybrid Flocculants Based on Potato Starch Copolymers with Hollow Carbon Spheres

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1498
Author(s):  
Beata Schmidt ◽  
Krzysztof Kowalczyk ◽  
Beata Zielinska
Keyword(s):  
Laser Scanning ◽  
Potato Starch ◽  
Particle Size Analysis ◽  
Laser Scanning Microscopy ◽  
Molar Ratio ◽  
Size Analysis ◽  
Carbon Spheres ◽  
Scanning Calorimetry ◽  
Kaolin Suspension ◽  
Flocculation Efficiency

Novel carbon nanofiller-based starch-g-polyacrylamide hybrid flocculation materials (St-PAM-CS) were in situ prepared using potato starch (St), acrylamide (AM), and hollow mesoporous carbon spheres (CSs; diameters of 300–400 nm). Structures of different St-PAM-CS systems were characterized by Fourier transform infrared (FTIR) spectroscopy, X-Ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), laser scanning microscopy (LSM), and particle size analysis. The flocculation tests were evaluated by removing high turbidity kaolin suspension—initial absorbance 1.84. The effect of the St to AM molar ratio, doses, and content of CSs in hybrids on flocculation efficiency were examined. Satisfactory flocculation efficiency was obtained for all hybrids with 1 wt.% of the CS component. The highest reduction of the kaolin suspension absorbance (to 0.06) was observed for a 3 mL dose of the starch hybrid with the highest AM content. Additionally, St-PAM-CS showed a reduction in the sludge volume in time. The hybrids reached better flocculation efficiency in relation to the reference systems without CSs. The proposed flocculation mechanism (considering bridging, patching, and formation of hydrogen bonds) has been confirmed by the recorded results.

Assessment of sludge particle removal from wastewater by disc filtration

2012 ◽  
Vol 7 (2) ◽  
Author(s):  
B.-M. Wilén ◽  
Ann Johansen ◽  
Ann Mattsson
Keyword(s):  
Pore Size ◽  
Removal Efficiency ◽  
Total Phosphorus ◽  
Particle Size Analysis ◽  
Effluent Treatment ◽  
Size Analysis ◽  
Particle Removal ◽  
Solids Concentration ◽  
Low Concentrations ◽  
Sludge Particle

To meet stricter effluent discharge limits of total phosphorus, microscreens can be applied for tertiary effluent treatment. The Rya WWTP has recently been upgraded with microscreens in the form of disc filters. Extensive characterisation of the wastewater from different locations in the plant (influent, after primary settling) and secondary settler effluent, was performed to increase the understanding of the potential of removing different components from the wastewater. The wastewater was fractionated by filtration through filter cloths with pore sizes 40, 20, 15, and 10 μm and through finer filters with pore size 1.2, 0.45, 0.2 and 0.1 μm. Particle size analysis (PSA) was used to assess the removal efficiency of the filter cloths. High removal degrees were achieved were particles larger or equal in size to the pore size were strained. Some floc break-up took place leading to an increased number of small particles (1–5 μm) after filtration. The suspended solids concentration could be reduced to 1 mg/l with total phosphorus concentrations of <0.2 mg/l. Some removal of metals could be observed when filtering wastewater with higher concentrations (influent and secondary settler effluent) whereas no effect could be seen for the effluent wastewater, probably due to the low concentrations present. The results from this study indicate a poor removal efficiency of pathogens measured as indicator microorganisms.

scholarly journals Stabilization of Leachate Effected Laterite Soil using Bio-Enzyme(Terrazyme)

2020 ◽  
Vol 8 (5) ◽  
pp. 4195-4203
Keyword(s):  
Particle Size ◽  
Soil Compaction ◽  
Ph Value ◽  
Particle Size Analysis ◽  
California Bearing Ratio ◽  
Size Analysis ◽  
High Concentration ◽  
Effective Technique ◽  
Corrosive Liquid ◽  
Properties Of Soil

The present study provides an effective technique of improving properties of leachate effected soil using bio-enzyme named TERRAZYME.Soil pollution is an consequence especially in a country like INDIA unscientific disposal and dumping of solid waste leads to generation of leachate. High concentration of leachate has less pH value (i.e., acidic in nature) which reduces the particle size. Due to reduction in particle size the properties of soil are also effected. A laboratory testing program was carried out on soil to determine the behavior of leachate effected soil and terrazyme. For that we performed particle size analysis, compaction and California bearing ratio tests on 5% 10% and 15% leachate effected soil to vary the degree of contamination.Terrazyme is a natural non-toxic, non-flammable, non-corrosive liquid enzyme formulated fermented from vegetables that improves the engineering qualities of soil, facilitates higher soil compaction densities and increases stability. It can be used as soil stabilizer and also improve CBR value, durability and decreases the omc, plasticity index of soil. Terrazyme on soil is permanent and soil becomes biodegradable in nature.So we used terrazyme as a stabilizing agent to improve the properties of leachate effected soil. By using this enzyme we can improve the strength effectively, mainly California bearing ratio

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