A Novel Pb-Resistant Bacillus subtilis Bacterium Isolate for Co-Biosorption of Hazardous Sb(III) and Pb(II): Thermodynamics and Application Strategy

Abstract

The present work is the first to study co-biosorption of Pb(II) and Sb(III) by a novel bacterium and its application strategy. The biosorption characteristics of Pb(II) and Sb(III) ions from aqueous solution using B. subtilis were investigated. Optimum pH, biomass dosage, contact time and temperature were determined to be 5.00, 6.00 mg/L, 45 min and 35 °C, respectively. Langmuir, Freundlich, Temkin and Dubinin-Radushkevich (D-R) models were applied to describe the biosorption isotherm of the metal ions by B. subtilis. Results showed that Langmuir model fitted the equilibrium data of Pb(II) better than others, while biosorption of Sb(III) obeyed the Freundlich model well. The biosorption capacity of B. subtilis biomass for Pb(II) and Sb(III) ions was found to be 17.34 ± 0.14 and 2.32 ± 0.30 mg/g, respectively. Kinetic data showed the biosorption process of Pb(II) and Sb(III) ions both followed the pseudo-second-order kinetic model, with R2 ranging from 0.974 to 0.999 for Pb(II) and from 0.967 to 0.979 for Sb(III). The calculated thermodynamic parameters, negative ∆G and positive ∆H and ∆S values, indicated the biosorption of Pb(II) and Sb(III) ions onto B. subtilis biomass in water was feasible, endothermic, and spontaneous. Bacterial bioleaching experiment revealed B. subtilis can increase the mobility of Pb(II) and Sb(III) in polluted soil when pH was close to 6 at low temperature. Consequently, B. subtilis, as a cheap and original bacterial material, could be a promising biomass to remove Pb or isolate Sb from industrial wastewater and to assist phytoremediation of Pb and Sb from weak acid or near neutral pH polluted soils at low temperature.

Evaluation of the Potential Role of Bacillus altitudinis MT422188 in Nickel Bioremediation from Contaminated Industrial Effluents

“…Similar findings in Bacillus sp. were reported by Cai et al [56]. The thermodynamic parameters were also investigated in order to evaluate the feasibility of the process.…”

Lead metal biosorption and isotherms studies by metal‐resistant Bacillus strain MRS‐2 bacterium

“…Pollution of heavy metals has become one of the highly concerned environmental issues worldwide in the last three decades. Rapid industrialization, urbanization, and various natural processes have led to the increased release of heavy metals into the soil and water causing a serious threat to the ecosystem [1–4]. Heavy metals from contaminated water and soil accumulate into the food chain, leading to toxic effects on human health [2,5,6].…”

“…Pb does not have any essential role in biological function unlike other metals such as Zn and Fe which play an essential role as cofactors in enzyme activity. The highest safe permissible Pb limit in drinking water was reported as less than 15 μg/L [2,16]. It is not easily degradable and highly persistent in nature due to its long half‐life leading to toxicity even at low concentrations in plants, animals, and humans [17,18].…”

Pb2+ biosorption from aqueous solutions by live and dead biosorbents of the hydrocarbon-degrading strain Rhodococcus sp. HX-2

“…Lead pollution specifically is a major concern, as lead accumulation in the environment dates back to industrialization [7]. There are various sources of lead such as gasoline, batteries, mining, electroplating, lead smelting, photographic materials, and explosives [8]. Considering its toxicity and diffusion in the environment, lead is the primary target of heavy metal management [9].…”