Synthesis, modification and antimicrobial potential of biochar and its modifications against water-borne pathogens: A review

Biochar is a solid substance with a charcoal-like appearances. It is highly flammable and is made from the burning of agricultural and forest-based organic wastes by various controlled processes like pyrolysis. Biochar is rich in carbon and storage of the same in soil is highly recommended to ease off climate change by sequestration of carbon along with enhancing agricultural yield and production of energy. According to the World Health Organization, one of the biggest threats to human life in the present century is livestock water contamination. Among different contaminants, microbial contamination is responsible for several harmful diseases many of which are fatal. The current disinfectant methods are quite useful but they produce harmful by-products which can cause more hazards to human health. Magnetic biochar which is a modification of normal biochar is a green, facile, and cost-effective bacteriocide that has immense antimicrobial potential against water-borne pathogens. Magnetic biochar in conjugation with quaternary phosphonium salt produces Magnetic Biochar-Quaternary phosphonium salt MBQ, which is a further modification of magnetic biochar that holds much better antimicrobial properties than biochar or magnetic biochar. It can successfully undergo inhibition of water-borne pathogens like Escherichia coli and Staphylococcus aureus . MBQ can disrupt the bacterial membrane and induce oxidative damage inside the bacteria, causing their inactivation and inhibition. MBQ also shows biocidal effects. In this review, we will discuss biochar, its properties, various methods of synthesis of biochar, different methods of modification of biochar, antimicrobial and antibacterial properties of biochar, magnetic biochar, and MBQ. Synthesis, Characterization, and antimicrobial properties of MBQ against waterborne microorganisms are also discussed in detail.