Chitosan and its Derivatives for Removing Antibiotics and Bacteria from Hospital Wastewater and Aquatic Environment

Hospitals are a major source of contamination due to the extensive use of antibiotics, leading to the emergence of resistant bacteria. The study was conducted in Kirkuk, Iraq. Wastewater samples were collected from the treatment plant at Azadi Teaching Hospital in Kirkuk, and bacteriological tests were conducted at the Kirkuk Environment Department. Four antibiotics (amoxicillin, azithromycin, ciprofloxacin and metronidazole) were evaluated using HPLC at the Scientific Research Authority - Environment and Water Technology Research Center/Baghdad. Chitosan and its derivatives were extracted from carp scales and were analyzed using (FTIR). Chitosan and its derivatives were used at concentrations of 5,10, and 15g per liter for water treatment by coagulation.  The results showed that salicylaldehyde chitosan was the most effective in removing antibiotics—amoxicillin, azithromycin, ciprofloxacin, and metronidazole—at concentrations of 17.79 ± 8.47, 18.10 ± 7.66, 16.90 ± 8.05, and 6.10 ± 3.53ppm, respectively. Vanillin chitosan removed these antibiotics at concentrations of 21.35 ± 8.45, 19.78 ± 7.12, 19.21 ± 8.20, and 7.95 ± 4.25ppm, while chitosan achieved removal rates of 36.32 ± 10.34, 38.21 ± 7.44, 27.58 ± 6.35, and 12.00 ± 4.35ppm. The treatment efficiency of salicylaldehyde chitosan was 91% for amoxicillin, 84% for azithromycin, 90% for ciprofloxacin, and 90% for metronidazole. The vanillin chitosan derivative achieved 89% efficiency for amoxicillin, 82% for azithromycin, 88% for ciprofloxacin, and 87% for metronidazole. Chitosan alone achieved efficiencies of 81% for amoxicillin, 66% for azithromycin, 83% for ciprofloxacin, and 80% for metronidazole. Regarding bacterial removal, chitosan demonstrated an improved efficiency compared to pretreatment, although the results were not statistically significant.