After a while in the human body, the antibiotics will be excreted outsides, afterward easily be found in the sewage of hospitals, pharmaceutical factories, or livestock farms. The antibiotics residue in the water can create antibiotic-resistant genes in the microbiota, which have extremely negative effects on human health and the environment.

Tran Van Son had first heard of chitosan, a bioactive polymer with properties like non-toxicity and biodegradability that is used to treat wastewater, in 2015 when he was looking for a topic to write a master’s thesis on to graduate from the University of Technology Sydney in Australia.

When he dug deeper, he realized its wide applicability in the treatment of contaminants and decided he would continue to research into it after returning to Vietnam.

Tran Van Son and his colleagues collected shrimp and crab shells at seafood markets and cleaned, deodorized, deproteinized, and deacetylated to obtain chitosan in high purity, which can be used in many different forms for practical applications.

Shells of crab and shrimp contain up to 27.2 – 30 percent of chitin, a precursor of chitosan biopolymer, in which the amino and hydroxyl functional groups have good absorption ability. It is these two functional groups that make chitosan electrically neutral, easily chemically modified, for use in adsorbing dyes or organic pollutants.

To improve the durability and processing ability of chitosan when removing the antibiotics in wastewater, the team also combined it with some other materials such as biochar and a cross-linking agent.

Lab test showed wastewater samples treated with chitosan met the requirements for discharge into the environment as it removed 95 percent of sulfonamide bacteriostatic antibiotics and heavy metals contaminated by antibiotics.

According to