Characterization and production of a Bacillus mycoides Bioflocculant for sustainable effluent treatment

TL;DR

This study explores a sustainable bioflocculant from Bacillus mycoides that effectively treats industrial wastewater, offering a non-toxic and scalable alternative to chemical coagulants.

Contribution

The first kinetic and scale-relevant evaluation of B. mycoides S39 bioflocculant for wastewater treatment.

Findings

The bioflocculant achieved 95.56% flocculation for textile effluent and 92.84% for steel wastewater.

It showed non-cytotoxicity and stability across pH and temperature ranges.

The bioflocculant's performance was scalable from 0.01 to 10 L.

Abstract

Industrial effluent treatment relies on chemical coagulants, which incur higher costs and generate toxic sludge. This study isolated and identified bioflocculant-producing Bacillus mycoides (S39) strain and enhanced yield using one-factor-at-a-time optimization. Characterization studies of purified bioflocculant reveal a crystalline polysaccharide bearing amine, hydroxyl, and carboxylate groups that drive adsorption and polymer bridging. The bioflocculant exhibited flocculation activities of 95.56 % for textile effluent and 92.84 % for steel wastewater with Ca2+ activation. Bioflocculant remained stable across pH and temperature. Kinetics followed a pseudo-first-order model, yielding rate constants, an optimized dosage, and assistance with sizing. Hemolysis (<5 %) and viability (>80 %) assays indicated non-cytotoxicity. The bioflocculant maintained performance ranged from 0.01 to 10 L, supporting S39 as a sustainable alternative to chemical coagulants. This study investigated the potential of B. mycoides bioflocculant, which showed promise as a sustainable and high-efficiency alternative to conventional coagulants and, to the best of our knowledge, the first kinetic and scale-relevant evaluation of this strain for wastewater treatment.

•Soil isolate B. mycoides (S39) confirmed by 16S rRNA sequencing method.•The bioflocculant were purified and characterized using FTIR, SEM-EDX, and XRD analysis.•High-performance flocculation activity while treating textile and steel industrial wastewater.•Pseudo-first-order kinetics provide rate constants for contact-time prediction for real-world treatment.•Robust, safe and scalable from 0.01 to 10 L.

Soil isolate B. mycoides (S39) confirmed by 16S rRNA sequencing method.

The bioflocculant were purified and characterized using FTIR, SEM-EDX, and XRD analysis.

High-performance flocculation activity while treating textile and steel industrial wastewater.

Pseudo-first-order kinetics provide rate constants for contact-time prediction for real-world treatment.

Robust, safe and scalable from 0.01 to 10 L.

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