Potentially toxic elements (PTEs) are metallic chemicals with densities that are higher than that of water. Water pollution by PTEs due to the discharge of untreated pharmaceutical industrial effluents is a risk to human health and ecological integrity. The present review paper provides an overview of the threats to human health due to water contamination by PTEs such as lead, cobalt, cadmium, nickel, and arsenic originating from pharmaceutical industrial wastewater. This review reveals the associated advantages and shortcomings of the outmoded and the modern methods and the challenges involved in addressing the shortcomings. Additionally, due to the increasing amount of uncontrollable pharmaceutical effluents entering the ecosystem, this paper reviewed the management approach supported by the World Health Organization and the Environmental Protection Agency. Studies revealed that PTEs find their way into human bodies through different pathways, which include drinking water, edibles, and dermal vulnerability at intervals. This paper focuses on how pharmaceutical effluents can be handled and how regulations and strategies can be reinforced step by step. To preserve public health and the environment, a comprehensive study on the environmental evaluation of carcinogenic substances, particularly toxic elements and metalloids, should be supported and advocated. To protect living organisms and the welfare of consumers, efforts should be made to reduce the presence of potentially hazardous elements on land and water.

In the present work $P-Zr{O}_{2}Ce{O}_{2}ZnO$ nanoparticles were synthesised for the first time using phytochemical extracts from Flacourtia indica leaves and applied in the photocatalytic degradation of Congo Red in the presence of Light Emitting Diode warm white light. The photocatalytic degradation was optimized with respect to $P-Zr{O}_{2}Ce{O}_{2}ZnO$ nanoparticle dosage, initial Congo Red concentration, and degradation time. The optimum conditions for $P-Zr{O}_{2}Ce{O}_{2}ZnO$ nanoparticle synthesis was pH 9, leaves extracts of F. indica dosage 4 g 100 mL⁻¹, Zirconia, Cerium and Zinc metal ion concentration 0.05 mg/L and metal ion to plant volume ratio of 1:4. The leaves extract dosage, pH and metal concentration had the most significant effects on the synthesis of the nanoparticles. The nanoparticles followed type III physisorption adsorption isotherms with surface area of 0.4593 m³g⁻¹, pore size of 6.80 nm, pore volume 0.000734 cm${}^{3}g^{-1}$ and average nanoparticle size 0.255 nm. A degradation efficiency of 86% was achieved and the optimum degradation conditions were 0.05 g/L of $P-Zr{O}_{2}Ce{O}_{2}ZnO$ nanoparticle dosage, 10 mg/L initial Congo red concentration, and 250 minutes irradiation time. Data from kinetic studies showed that the degradation followed pseudo first order kinetics at low concentration, with a rate constant of 0.069 min⁻¹. The superoxide, $h^{+}$ holes and light were the main determinants of the reaction mechanisms for the degradation of Congo Red. The investigation outcomes demonstrated that $P-Zr{O}_{2}Ce{O}_{2}ZnO$ nanoparticles offer a high potential for photocatalytic degradation of Congo Red.