Toxicological assessment of ZnO-Vernonia amygdalina nanoparticle-treated Asa River water in albino rats

Abstract

Traditional water purification methods are increasingly inadequate, leading to the exploration of novel approaches. This study investigated the application of plant-derived nanomaterials for heterogeneous photocatalytic water treatment using ZnO-Vernonia amygdalina nanoparticles (ZVAN). The study evaluated the efficacy of ZVAN in purifying Asa River water (ARW) and assessed its toxicological profile in rats. Synthesized ZVAN was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). ARW samples were collected according to standard guidelines and their physicochemical and bacteriological properties were analyzed. ARW was treated with ZVAN and alum separately. The effects of both treatments on various hematological, liver, and kidney parameters in albino rats were compared after 30 days of daily administration. The total suspended matter (TSM) levels in untreated and treated ARW exceeded approved standards. ZVAN treatment effectively eliminated cadmium (Cd) from the water (from 0.1 ppm to 0). Thermotolerant coliforms and enteric bacteria were also undetectable in ZVAN-treated samples. Compared to the control group, untreated ARW significantly decreased red blood cell (RBC) count (6.86±0.56 vs 2.75±0.11, p<0.05), hemoglobin (10.68±0.81 vs 3.80±0.22, p<0.05), hematocrit (40.78±2.49 vs 15.15±0.95, p<0.05), white blood cell (WBC) count (9.85±0.73 vs 1.60±0.08, p<0.05) and platelet count (377.75±26.96 vs 55.25±15.78, p<0.05). Additionally, statistically significant differences were observed in enzyme activities between experimental and control groups. This study demonstrates the high level of pollution in ARW. ZVAN treatment significantly reduced pollution and mitigated its associated detrimental effects, with minimal to no observed toxicity compared to alum treatment. These findings suggest the potential of ZVAN as a promising alternative for water purification.