Loofah immobilized with Cladosporium cladosporioides CEL14 is a potential bioremediating agent for hexavalent chromium in tannery wastewater

Tannery wastewater is the most challenging due to the complex toxic pollutants it releases into the environment. Similarly, coffee husk from coffee processing operations pollutes the environment. The use of coffee husk to remove hexavalent chromium (VI) and Zink (II)from tannery wastewater solves pollution problems due to untreated tannery wastewater and coffee husk. A batch adsorption process was conducted to determine chromium (VI) and Zink (II)adsorptive capacity of waste coffee husk to treat tannery wastewater. The effects of adsorbent dose (0.2-2.4 g/L), contact time (20- 60 min), agitation speed (50-250 rpm), and pH value (2-8) on the adsorptive capacity of coffee husk on the removal of hexavalent chromium (VI) & zinc (II) from tannery wastewater were studied. Using 2.4 g/L adsorbent dose, 250 rpm agitation speed, 60 min contact time, and pH value of 2, a maximum Cr(VI) removal capacity of coffee husk was 83%. The maximum Zn(II) removal capacity of coffee husk was found to be 79% at an adsorbent dose of 2.4 g/L, 60 min contact time, pH 7, and agitation speed of 250 rpm. Therefore, it can be concluded that coffee husk achieved significant removal of hexavalent chromium (VI) and zinc (II) from tannery wastewater.

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Adaptability of Teff husk activated carbon for removal of hexavalent chromium from tannery wastewater at optimized process condition

Applied Water Science ◽

10.1007/s13201-020-01269-1 ◽

2020 ◽

Vol 10 (8) ◽

Author(s):

Tsegaye Adane ◽

Awrajaw Dessie

Keyword(s):

Activated Carbon ◽

Hexavalent Chromium ◽

Process Condition ◽

Tannery Wastewater

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Removal of hexavalent chromium in tannery wastewater by Bacillus cereus

Canadian Journal of Microbiology ◽

10.1139/w11-096 ◽

2012 ◽

Vol 58 (1) ◽

pp. 23-28 ◽

Cited By ~ 13

Author(s):

Changqing Zhao ◽

Qinhuan Yang ◽

Wuyong Chen ◽

Bo Teng

Keyword(s):

Bacillus Cereus ◽

Continuous Culture ◽

Hexavalent Chromium ◽

Maximum Rate ◽

Removal Rate ◽

Cellular Component ◽

Tannery Wastewater ◽

Optimum Conditions ◽

Sem Images ◽

Whole Cells

Bacillus cereus was used to remove chromium (Cr(VI)) from medium containing tannery wastewater under different conditions. The maximum rate of Cr(VI) removal was attained at a temperature of 37 °C, pH of 7.0–9.0, and biomass of 20 g/L when the initial Cr(VI) concentration was less than 50 mg/L. Under the optimum conditions, the Cr(VI) in tannery wastewater was treated with each cellular component of B. cereus to detect its ability to reduce Cr(VI). The results showed that the removal rate of Cr(VI) for the cell-free extracts could reach 92.70%, which was close to that of the whole cells (96.85%), indicating that the Cr(VI) reductase generated by B. cereus is primarily intracellular. Additionally, during continuous culture of the B. cereus, the strain showed good consecutive growth and removal ability. After treatment of 20 mg/L Cr(VI) for 48 h, the B. cereus was observed by SEM and TEM–EDX. SEM images showed that the B. cereus used to treat Cr(VI) grew well and had a uniform cellular size. TEM–EDX analysis revealed large quantities of chromium in the B. cereus cells used to treat Cr(VI). Overall, the results presented herein demonstrate that B. cereus can be used as a new biomaterial to remove Cr(VI) from tannery wastewater.

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