# 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.

## Key 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.