Sustainable and Affordable Adsorbent for the Lowering of Antibiotics Concentration in Water

Emerging water contaminants of pharmaceutical origin pose a serious threat to human health and the environment. The serious concerns are related to their mechanism of action and a persistent nature in the aquatic environment. The continuous presence of these pollutants has already resulted in the degradation of ground and surface water qualities, adversely affecting the health of living organisms. Several conventional water treatment procedures have been applied for the removal of these pollutants but they are associated with some notable drawbacks including high cost of operation, chemical coagulation and formation of by-products. In contrast, the adsorption is often a preferred choice due to its simple design, efficiency, adaptability, cost-effectiveness and the ease of operation. The aim of this study is to develop eco-friendly and cost-effective adsorbents for the elimination of vancomycin, a pharmaceutical contaminant from waters. The choice of vancomycin for this research is justified by its presence in water at concentrations levels ranging from 100.0 to 246.6 ng/l and due to its inclusion in the WHO priority list of antibiotics. In the current study, the seaweed sample, with particle sizes of 180-250 µm, was pre-treated with 2M sulphuric acid for 24 hours at room temperature and washed repeatedly with distilled water until a neutral pH of filtrate was achieved. An HPLC technique was utilized to determine the concentrations of vancomycin in water with the view to evaluate the impact of the following adsorption operational parameters: temperature, contact time, pH and initial concentration of antibiotic. Furthermore, appropriate instrumentation techniques were utilized to evaluate seaweed characteristics such as isoelectric point, particle size distribution, zeta potential, surface morphology, specific surface area and the chemical nature of functional groups. The time result show that both the raw and treated seaweed samples have adsorption efficiency above 90%. However, the raw seaweed had a removal efficiency of 97% compared to the treated seaweed at 94%. The results of this study will show how various adsorption parameters influence the adsorption of vancomycin using seaweed samples.