Short communication: Industrial effluent treatments using heavy-metal removing bacterial bioflocculants

Abstract

Bioflocculants produced by Herbaspirillium sp. CH7, Paenibacillus sp. CH11, Bacillus sp. CH15 and a Halomonas sp. were preliminarily evaluated as flocculating agents in the treatment of industrial wastewater effluents. Industrial (1 local chemical-industry and 2 textile-industry: Biavin 109-medium blue dye and Whale dye) effluent (9 mℓ) containing various heavy metals was vortexed with 1 mℓ of bioflocculant in a 25 mℓ test tube. One mℓ of water (Millipore Elix purification system, 17 megaΩ) was substituted for the bioflocculant in the control. After 5 min, the heavy metal concentrations, the microbial population and the turbidity of the top layer of the industrial effluent were determined using ICP-OES, spread-plate technique and a turbidity meter respectively. The flocculating activity was calculated based on absorbance at a wavelength of 550 nm. Bioflocculants produced in this study were capable of removing several heavy metals from industrial effluents simultaneously and effectively. This was significant (p < 0.05) when applied to Biavin medium blue dye, with 95% of Cr 2+ and 94% of Ni 2+ removed by the presence of bioflocculants. Bioflocculants also removed almost all of the bacteria and reduced 50-80% of the turbidity of the chemical effluent sample, simultaneously. Bacterial bioflocculants may provide an alternative means of treating industrial wastewater resulting in environmental and economical benefits. However, our findings suggest that the treatment of industrial effluents using bioflocculants might be effluent-dependent. In order to explore the potential of bioflocculants in the treatment of industrial effluents, a preliminary study to determine the optimal conditions is crucial.

Removal of Heavy Metals Using Bacterial Bio-Flocculants of Bacillus Sp. And Pseudomonas Sp.

“…has a higher capability of adsorption of Pb 2+ as compared to Pseudomonas sp. Similar findings are recorded by Lin, Harichund (2011a) who found that bio-flocculant produced by Bacillus sp. CH15 was capable of removing Pb 2+ (87%) and Cr 2+ (86%).…”

“…Bio-flocculants were recovered from the supernatant after centrifugation (4000 rpm) for 15 min and precipitated by adding 2 volumes of ethanol at 4 °C overnight. The pellet was centrifuged at 4000 rpm for 15 min and dried in desiccators containing anhydrous cobalt chloride at room temperature under reduced pressure (Kurane et al 1994;Lin, Harichund 2011a). …”

Pb and Zn contamination as rate-regulation agents on decomposition of two emergent macrophytes: a systemic approach

“…KNO 3 was considered as a control treatment, once is not a toxic element and present potassium and nitrogen as a nutrient source. Our motivation to use the Zn and Pb concentrations in decomposition (Table 1) were focused on higher concentrations of these metals often found in mine waste (Schaider et al, 2007) and industrial effluents (Lin & Harichund, 2011). In Doce River (Mariana, MG, Brazil) the concentration of Pb varied from 0.013 to 0.097 mg L -1 (Carvalho et al, 2017).…”

Microbial Flocculants as an Alternative to Synthetic Polymers for Wastewater Treatment: A Review

“…In addition to organic pollutant removal, microbial bioflocculants were shown to be able to remove metals from an ion solution and real wastewater, as represented in Table 5 [17,22,34,44,[74][75][76][77][78][79]. Among the works using real wastewater, a bacterial culture broth of two strains (xn11 + xn7) was used to flocculate electroplating wastewater (Cr (VI) initial concentration of 280 mg/L).…”