Chromium Removal through Biosorption and Bioaccumulation by Bacteria from Tannery Effluents Contaminated Soil

Abstract

Four bacterial isolates (two resistant and two sensitive to chromium) were isolated from soil contaminated with tannery effluents at Jajmau (Kanpur), India, and were identified by 16S rDNA gene sequencing as Stenotrophomonas maltophilia, Exiguobacterium sp., Pantoea sp., and Aeromonas sp. Biosorption of chromium by dried and living biomasses was determined in the resistant and sensitive isolates. The effect of pH, initial metal concentration, and contact time on biosorption was studied. At pH 2.5 the living biomass of chromium resistant isolate Exiguobacterium sp. ZM-2 biosorbed maximum amount of Cr 6þ (29.8 mg/g) whereas the dried biomass of this isolate biosorbed 20.1 mg/g at an initial concentration of 100 mg/L. In case of chromate sensitive isolates, much difference was not observed in biosorption capacities between their dried and living biomasses. The maximum biosorption of Cr 3þ was observed at pH 4.5. However, biosorption was identical in resistant and sensitive isolates. The data on chromium biosorption were analyzed using Langmuir and Freundlich isotherm model. The biosorption data of Cr 6þ and Cr 3þ from aqueous solution were better fitted in Langmuir isotherm model compared to Freundlich isotherm model. Metal recovery through desorption was observed better with dried biomasses compared to the living biomasses for both types of chromium ions. Bioaccumulation of chromate was found higher in chromate resistant isolates compared to the chromate sensitive isolates. Transmission electron microscopy confirmed the accumulation of chromium in cytoplasm in the resistant isolates.

Depletion of Cr(VI) from aqueous solution by heat dried biomass of a newly isolated fungus Arthrinium malaysianum: A mechanistic approach

“…Biosorption is a cutting-edge technology, which involves sorption of dissolved substances by a biosorbent which can significantly reduce the cost of chemical usage and pollution compared to the other traditional Cr(VI) removal processes 14 , 17 , 18 . Several investigations have been reported on metal binding efficiencies of various strains of bacteria, algae and fungi 4 , 14 , 19 – 26 . Among them, fungi are the best choice because of high cell wall material percentage and outstanding metal binding properties 2 , 8 , 14 , 23 , 27 .…”

Utilization to Remove Pb (II) Ions from Aqueous Environments Using Waste Fish Bones by Ion Exchange

“…Recently, researchers have reported that materials with biological and natural origins, such as agricultural, banana peel, peel waste, and animal waste, are effective and usable in the removal of metals [9,[12][13][14][15][16]. Some sorbents such as seaweed (Gymnogongrus Torulosus) [17], leaf powder (Ficus religiosa) [18], and bacteria (Tannery Effluents Contaminated Soil) [19] were used for metal removal. Bones are composed of 30% organic compounds and 70% inorganics by weight [20].…”

Non-Pathogenic bacteria in Bioremediation of Cr (VI) for decontamination of ground water: An Extensive Review

“…Both the living and dried biomass of Exiguobacteriumsp. absorbed maximum amount of Cr(VI) from aqueous solution 64 . Furthermore indigenous chromium reducing bacterial strain, Ochrobactrumintermedium RB-2 was isolated from tannery waste samples and was examined for its potential to reduce Cr(VI) to Cr(III).…”