Optimizing modified rice bran for treating aqueous solutions polluted by Cr (VI) ions: isotherm and kinetics analyses

Abstract

This study investigated the possibility and efficiency of absorbing chromium (VI) (Cr [VI]) ions from the polluted solutions by employing the chemically modified adsorbents (alkali, biochar, and acid rice bran), focusing on the possible impacts of the solution’s pH values, adsorbent’s dosages, concentrations, and contact times. The colori-metric method was used for Cr determination by employing an ultraviolet/visible spectrophotometer. The scanning electron microscope and Fourier transform infrared spectroscopy were used to analyze the characteristics of the modified adsorbents. The findings indicated that the optimized acid, biochar, alkali, and unmodified rice bran removal efficiency for Cr (VI) were 94.50%, 94.27%, 88.60%, and 90.18%, respectively. The increase of adsorbent dosage up to 2 g/L led to a rise in removal effectiveness (82.06%). Furthermore, the highest removal efficiency was obtained (94%) at the pH of 2.0, the contact duration of 100 min, Cr (VI) concentration of 50 mg/L, and dosage of 2 g/L, which was statistically the optimal condition for the modified rice bran. The adsorption kinetics was agreeably suited to pseudo-second-order, whereas the Freundlich isotherm equation was also suitably expounded the study’s findings. The findings implied that the acid and biochar rice bran performed remarkably in the reme-diation of the wastewater compared with alkali rice bran for reuse for industrial, agricultural, and environmental purposes.

Origin, dietary exposure, and toxicity of endocrine-disrupting food chemical contaminants: A comprehensive review

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Safety Stressors and Coal Miners’ Safety Performance: The Mediating Role of Resilience and Coping Styles

“…[5][6][7][8][9] Environmental pollution in soil, 10 food, water resources, 35 air, [36][37][38] is increasing with the industrialization of countries [39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54] and may reduce workplace safety. These pollutants including mycotoxins, 47,[55][56][57][58][59] radioactive elements, 60 microbial, [61][62][63] heavy metals, [64][65][66][67][68][69][70][71][72] hormones, 73 pesticides, [74][75][76] antibiotics 77,…”

Concentration ciguatoxins in fillet of fish: A global systematic review and meta-analysis

“…With increasing population and decreasing food resources and also the industrialization of countries [ 24 ], concern on entry of contaminats such as oxic polycyclic polyethers [ 25 ], metconazole [ 26 ], heavy metal [ [27] , [28] , [29] , [30] , [31] ], mycotoxins [ [32] , [33] , [34] , [35] , [36] , [37] , [38] ] into the food chain and endangering food safety and security has increased [ 24 , 39 ].…”