scholarly journals Nanoscale Zero-Valent Iron for Sulfide Removal from Digested Piggery Wastewater

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Sheng-Hsun Chaung ◽  
Pei-Fung Wu ◽  
Yu-Lin Kao ◽  
Weile Yan ◽  
Hsing-Lung Lien
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Surface Characterization ◽  
Iron Sulfide ◽  
Ph Effect ◽  
Zero Valent Iron ◽  
Laboratory Studies ◽  
Sulfide Removal ◽  
Nanoscale Zero Valent Iron ◽  
The Impact

The removal of dissolved sulfides in water and wastewater by nanoscale zero-valent iron (nZVI) was examined in the study. Both laboratory batch studies and a pilot test in a 50,000-pig farm were conducted. Laboratory studies indicated that the sulfide removal with nZVI was a function of pH where an increase in pH decreased removal rates. The pH effect on the sulfide removal with nZVI is attributed to the formation of FeS through the precipitation of Fe(II) and sulfide. The saturated adsorption capacities determined by the Langmuir model were 821.2, 486.3, and 359.7 mg/g at pH values 4, 7, and 12, respectively, for nZVI, largely higher than conventional adsorbents such as activated carbon and impregnated activated carbon. The surface characterization of sulfide-laden nZVI using XPS and TGA indicated the formation of iron sulfide, disulfide, and polysulfide that may account for the high adsorption capacity of nZVI towards sulfide. The pilot study showed the effectiveness of nZVI for sulfide removal; however, the adsorption capacity is almost 50 times less than that determined in the laboratory studies during the testing period of 30 d. The complexity of digested wastewater constituents may limit the effectiveness of nZVI. Microbial analysis suggested that the impact of nZVI on the change of microbial species distribution was relatively noticeable after the addition of nZVI.

The impact of nanoscale zero-valent iron particles on soil microbial communities is soil dependent

2019 ◽  
Vol 364 ◽  
pp. 591-599 ◽  
Author(s):  
María T. Gómez-Sagasti ◽  
Lur Epelde ◽  
Mikel Anza ◽  
Julen Urra ◽  
Itziar Alkorta ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Soil Microbial Communities ◽  
Zero Valent Iron ◽  
Iron Particles ◽  
Soil Microbial ◽  
Nanoscale Zero Valent Iron ◽  
The Impact

Adsorption of chromium (VI) from aqueous solutions on activated carbon

1994 ◽  
Vol 30 (9) ◽  
pp. 191-197 ◽  
Author(s):  
R. Leyva Ramos ◽  
A. Juarez Martinez ◽  
R. M. Guerrero Coronado
Keyword(s):  
Activated Carbon ◽  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Ph Effect ◽  
Freundlich Isotherm ◽  
Maximum Adsorption Capacity ◽  
Experimental Adsorption ◽  
Ph Values ◽  
Chromium Vi ◽  
Adsorption Data

The adsorption isotherm of chromium (VI) on activated carbon was obtained in a batch adsorber. The experimental adsorption data were fitted reasonably well to the Freundlich isotherm. The effect of pH on the adsorption isotherm was investigated at pH values of 4, 6, 7, 8, 10 and 12. It was found that at pH < 6, Cr(VI) was adsorbed and reduced to Cr(III) by the catalytic action of the carbon and that at pH ≥ 12, Cr(VI) was not adsorbed on activated carbon. Maximum adsorption capacity was observed at pH 6 and the adsorption capacity was diminished about 17 times by increasing the pH from 6 to 10. The pH effect was attributed to the different complexes that Cr(VI) can form in aqueous solution. The adsorption isotherm was also affected by the temperature since the adsorption capacity was increased by raising the temperature from 25 to 40°C. It was concluded that Cr(VI) was adsorbed significantly on activated carbon at pH 6 and that the adsorption capacity was greatly dependent upon pH.

Preparation of Activated Carbon Fiber Supported Nanoscale Fe0 for Simultaneous Adsorption and Dechlorination of Chloroform in Water

2011 ◽  
Vol 399-401 ◽  
pp. 1386-1391
Author(s):  
Yuan Yuan Wang ◽  
Qian Huang ◽  
Qi Ming Xian ◽  
Cheng Sun
Keyword(s):  
Activated Carbon ◽  
Carbon Fiber ◽  
Organic Contaminants ◽  
Ferrous Sulfate ◽  
Chemical Reduction ◽  
Activated Carbon Fiber ◽  
Zero Valent Iron ◽  
Simultaneous Adsorption ◽  
Nanoscale Zero Valent Iron ◽  
Chlorinated Organic

Nanoscale zero-valent iron (NZVI) particles were supported onto activated carbon fiber (ACF) by impregnating ACF with ferrous sulfate followed by chemical reduction with NaBH4. A new kind of material ACF/NZVI with approximate 9.64% (wt%) iron was prepared, the structure of the prepared ACF/NZVI was characterized bySEM, XRD and BET. The average NZVI particles with the size of 8.1nm were well dispersed on the ACF. The activity of the prepared ACF/NZVI was evaluated for removing chloroform in water. When 5g/L of ACF/NZVI was added into water with 10 mg/L chloroform, more than 90% of chloroform in water was removed in 48h at pH7.0 and (25±2) ºС. The dechlorination and adsorption of chloroform on ACF/NZVI took place at the same time. The total Chloroform removal by ACF/NZVI was 53.1% after 48h. Consequently, ACF/NZVI exhibits the potential of simultaneous adsorption and dechlorination for chlorinated organic contaminants in water.

scholarly journals Adsorption of phosphorus onto nanoscale zero-valent iron/activated carbon: removal mechanisms, thermodynamics, and interferences

2022 ◽  
Author(s):  
Adel Adly ◽  
Nagwan G. Mostafa ◽  
Abdelsalam Elawwad
Keyword(s):  
Activated Carbon ◽  
Removal Efficiency ◽  
Kinetic Models ◽  
Average Particle Size ◽  
Zero Valent Iron ◽  
Solution Temperature ◽  
Average Particle ◽  
Phosphorus Adsorption ◽  
Removal Mechanisms ◽  
Nanoscale Zero Valent Iron

Abstract This study investigated removal mechanisms, thermodynamics, and interferences of phosphorus adsorption onto nanoscale zero-valent iron (nZVI)/activated carbon composite. Activated carbon was successfully used as support for nZVI particles to overcome shortcomings of using nZVI include its tendency to aggregate and separation difficulties. A comprehensive characterization was done for the composite particles, which revealed a high specific surface area of 72.66 m2/g and an average particle size of 37 nm. Several adsorption isotherms and kinetic models have been applied to understand the removal mechanisms. Adsorption isotherm is best fitted by Freundlich and Langmuir models, which indicates that the estimated maximum phosphorus adsorption capacity is 53.76 mg/g at pH 4. Adsorption kinetics showed that the chemisorption process behaved according to a pseudo-second-order model. An adsorption mechanism study conducted using the intra-particle diffusion and Boyd kinetic models indicated that the adsorption rate is limited by surface diffusion. A thermodynamic study showed that phosphorus removal efficiency increased as the solution temperature increased from 15 to 37 °C. Finally, the results of an interference study showed that the presence of Ni2+, Cu2+, Ca2+, Na+ cations, nitrate ions (), and sodium acetate improves removal efficiency, while the presence of sulfate ions () and urea reduces removal efficiency.

scholarly journals Removal of Cr(VI) and methyl orange by activated carbon fiber supported nanoscale zero-valent iron in a continuous fixed bed column

2020 ◽  
Vol 82 (4) ◽  
pp. 732-746
Author(s):  
Jian Liu ◽  
Zhengji Yi ◽  
Ziling Ou ◽  
Tianhui Yang
Keyword(s):  
Activated Carbon ◽  
Methyl Orange ◽  
Carbon Fiber ◽  
Fixed Bed ◽  
Oxygen Demand ◽  
Breakthrough Curves ◽  
Activated Carbon Fiber ◽  
Zero Valent Iron ◽  
Breakthrough Time ◽  
Nanoscale Zero Valent Iron

Abstract The application of activated carbon fiber supported nanoscale zero-valent iron (ACF-nZVI) in the continuous removal of Cr(VI) and methyl orange (MO) from aqueous solution was studied in depth. The breakthrough curves of Cr(VI) in a fixed bed with ACF-nZVI were measured, and compared with those in the fixed bed with ACF. The catalytic wet peroxide oxidation (CWPO) process for MO was also carried out using ACF-nZVI after reacting with Cr(VI) in the same fixed bed. The results showed that the breakthrough time of ACF-nZVI was significantly longer than that of ACF. Higher pH values were unfavorable for the Cr(VI) removal. The breakthrough time increased with decreasing inlet Cr(VI) concentration or increasing bed height. The Yoon–Nelson and bed depth service time (BDST) models were found to show good agreement with the experimental data. The Cr(VI) removal capacity when using ACF-nZVI was two times higher than that when using ACF. Under the optimal empty bed contact time of 1.256 min, the fixed bed displayed high MO conversion (99.2%) and chemical oxygen demand removal ratio (55.7%) with low Fe leaching concentration (<5 mg/L) after continuous running for 240 min. After three cycles, the conversion of MO remained largely unchanged.

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