Removal of Molybdenum(VI) from Raw Water Using Nano Zero-Valent Iron Supported on Activated Carbon

Traces of Molybdenum (Mo) in drinking water pose potent dangers owing to its harmful effects on the health of humans. This study used nanoscale zero-valent iron (Fe0) supported by activated carbon (NZVI/AC) for removing Mo(VI) from raw water. In an attempt to gain an understanding of the various factors that affect the process, we designed the study to look into the impact of various experimental parameters including pH, adsorption kinetics, and coexisting ions on the Mo(VI) removal using fixed-bed column runs and a batch-adsorption method and for Mo(VI) removal using NZVI/AC. The optimum conditions were found to be pH 4.5 and an equilibrium time of 9 h and 72 h for simulation water (SW) and raw water (RW), respectively. The removal of Mo(VI) was remarkably inhibited by the presence of silicate (SiO42−) and phosphate (PO43−), while the impact of humic acid and some other anions was insignificant. Metal cations such as Fe3+, Al3+, Zn2+, and Ni2+ enhanced the adsorption of Mo(VI). The influent contaminant concentration Mo(VI) in raw water was found to be 0.1603 mg/L, the empty-bed contact time (EBCT) was 3 and 6 min, whereas the breakthrough empty-bed volumes were 800 and 1100 and at the value of 70 μg/L provided by WHO provisional guidelines, respectively.

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Investigating the performance of agricultural wastes and their ashes in removing phenol from leachate in a fixed-bed column

Water Science & Technology ◽

10.2166/wst.2020.274 ◽

2020 ◽

Vol 81 (10) ◽

pp. 2109-2126 ◽

Cited By ~ 1

Author(s):

Seyed Omid Ahmadinejad ◽

Seyed Taghi Omid Naeeni ◽

Zahra Akbari ◽

Sara Nazif

Keyword(s):

Activated Carbon ◽

Large Scale ◽

Fixed Bed ◽

Walnut Shell ◽

Continuous Systems ◽

Phenol Removal ◽

Adsorption Method ◽

Fixed Bed Column ◽

Saturation Time ◽

Coconut Shell Activated Carbon

Abstract One of the major pollutants in leachate is phenol. Due to safety and environmental problems, removal of phenol from leachate is essential. Most of the adsorption studies have been conducted in batch systems. Practically, large-scale adsorption is carried out in continuous systems. In this research, the adsorption method has been used for phenol removal from leachate by using walnut shell activated carbon (WSA) and coconut shell activated carbon (CSA) as adsorbents in a fixed-bed column. The effect of adsorbent bed depth, influent phenol concentration and type of adsorbent on adsorption was explored. By increasing the depth of the adsorbent bed in the column, phenol removal efficiency and saturation time increase significantly. Also, by increasing the influent concentration, saturation time of the column decreases. To predict the column performance and describe the breakthrough curve, three kinetic models of Yon-Nelson, Adams-Bohart and Thomas were applied. The results of the experiments indicate that there is a good match between the results of the experiment and the predicted results of the models.

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Removal of Dyes from Wastewater of Artisanal Dyeing Plants by Adsorption in a Fixed Bed Column of Deactivated Lichens

International Research Journal of Pure and Applied Chemistry ◽

10.9734/irjpac/2021/v22i530405 ◽

2021 ◽

pp. 1-11

Author(s):

Kouassi Kouadio Dobi-Brice ◽

Yacouba Zoungranan ◽

Dje Daniel Yannick ◽

Ekou Lynda ◽

Ekou Tchirioua

Keyword(s):

Ivory Coast ◽

Fixed Bed ◽

Batch Adsorption ◽

Real Problem ◽

Adsorption Method ◽

Fixed Bed Column ◽

Good Efficiency ◽

Continuous Adsorption ◽

Column Adsorption ◽

Study Laboratory

Aims: Pollution by wastewaters from various urban activities such as artisanal dyeing plants is a real problem for developing countries. The treatment of wastewater by the adsorption method is carried out by means of less expensive and available adsorbent media. Two techniques of the adsorption method are possible: adsorption in continuous mode (column adsorption) and adsorption in discontinuous mode (batch adsorption). The choice of the continuous adsorption technique is justified by its ability to process large volumes of solutions. In this study, dyes contained in wastewater from artisanal dyeing plants were removed by continuous adsorption in a fixed-bed column of deactivated lichen biomass (Parmotrema dilatatum). Study Design: Random design Place and Duration of Study: Laboratory of Thermodynamics and Environmental Physico-Chemistry (University Nangui Abrogoua, Ivory Coast) between May 2020 and October 2020. Methodology: Four (4) categories of wastewater were collected in artisanal cotton and leather dyeing plants through two municipalities of the city of Abidjan, economic capital of Ivory Coast. Two (2) wastewaters colored in blue from dyeing of cotton boubous and jeans and two (2) wastewaters colored in red from dyeing of leather jackets and bags. These wastewaters were treated through the fixed bed column of deactivated lichens. The column feed rate was set at 0, 07 L.min-1 and the adsorbent bed mass at 100 g. Results: The study showed that, regardless of the nature of the dyed object and regardless of the target dye, the amount of dye adsorbed was better with waters of higher initial concentration. Thus the best amount of adsorbed dye is 44.444 mg.g-1 and the best removal rate is 97.9%. These values are obtained with the red wastewater of bags (RWB) treatment which was the most concentrated wastewater. Conclusion: Good efficiency of deactivated lichen bed as adsorbent for the in situ removal of dyes from wastewater by continuous adsorption.

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Removal of Organic Micropollutants by Grainy Bentonite-Activated Carbon Adsorbent in a Fixed Bed Column

Water ◽

10.3390/w10121791 ◽

2018 ◽

Vol 10 (12) ◽

pp. 1791 ◽

Cited By ~ 5

Author(s):

Gabriela Kamińska

Keyword(s):

Activated Carbon ◽

Calcination Temperature ◽

Operating Time ◽

Fixed Bed ◽

Treatment Plant ◽

Carbon Adsorbent ◽

Quality Parameters ◽

Batch Adsorption ◽

Organic Micropollutants ◽

Fixed Bed Column

Organic micropollutants enter effluent streams and then flow into receiving waters. The volume adversely affects aquatic biota substantially. Therefore, many efforts have been made to develop methods for their elimination. The aim of this study was the removal of organic micropollutants with different properties from WWTP (wastewater treatment plant) effluent in fixed bed columns packed with several combinations of sand, granular activated carbon (GAC), and granular clay-carbonaceous composite. Two types of bentonite-powder activated carbon-based granules (Ben-AC) were prepared within this work, with different calcination temperature. It was found that higher calcination temperature enhanced the surface porosity and adsorption potential versus studied micropollutants due to dihydroxylation resulting in higher chemical activity. Introduction of these granules in the place of GAC in a fixed bed column enhances the removal degree of micropollutants and typical water quality parameters. For example, the reduction degree of color, phosphate, and nitrate concentrations increased from 83%, 69%, and 4% to 95%, 83%, and 24% for column I and II, respectively. The concentration of carbamazepine, octylphenol, nononylphenol, and anthracene was reduced by 75%, 83%, 72%, 99% in column I, while using column II or III their removal was: 86%, 97%, 99%, 99%, respectively. Independent of the column filling, the removal of carbamazepine was the lowest (75–86%), while the highest retention was obtained for anthracene (99%). The study of column performance in the treatment of effluent in time showed that column filled with Ben-AC-400 guaranteed high removal degree in the operating time. The batch adsorption data were better described by both the Langmuir model.

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Adsorption Kinetics of Arsenic (V) on Nanoscale Zero-Valent Iron Supported by Activated Carbon

Nanomaterials ◽

10.3390/nano10091791 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1791

Author(s):

Huijie Zhu ◽

Mingyan Shi ◽

Xiuji Zhang ◽

Bo Liu ◽

Dahu Yao

Keyword(s):

Activated Carbon ◽

Adsorption Kinetics ◽

Negative Impact ◽

Zero Valent Iron ◽

Batch Adsorption ◽

Adsorption Method ◽

Factors Affecting ◽

Adsorbent Dosage ◽

Nanoscale Zero Valent Iron ◽

Kinetics Of

The presence of arsenic (As) in drinking water is of serious concern due to its negative impact on human health. This work reports on the kinetics of nanoscale zero-valent iron (Fe0) supported by activated carbon (NZVI/AC) for the removal of As (V) species from aqueous solutions. To better understand the factors affecting this process, we investigated the effects of various experimental parameters including initial As (V) concentration, adsorbent dosage, pH, temperature, and coexisting ions on the adsorption kinetics using a batch-adsorption method. The optimum conditions for As (V) removal by NZVI/AC were found to be: 318 K, pH 3.5, an adsorbent dosage of 1.5 g/L, and an equilibrium time of 72 h. A greater mass of NZVI/AC, lower concentration of As (V) and lower pH positively promoted adsorption kinetics. The presence of phosphate (PO43−) and silicate (SiO42−) markedly inhibited As (V) removal kinetics. However, in the presence of 4.5 g/L NZVI/AC, ≥99.9% of As (V) was removed from raw groundwater.

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