Toxicity assessment of treated sewage effluent using the zebrafish embryo model

Abstract

Background: In a context of tremendous economic value, the management and protection of water resources in Qatar has long been a significant issue as part of the global wastewater management plan. The process is based on several stages of treatment in order to deliver high-quality effluent standard. Treated sewage effluent (TSE) can potentially be used for agriculture in Qatar and it should be biologically evaluated before releasing it to the environment. TSE water can be further filtered with techniques that include reverse osmosis, forward osmosis, and nanofiltration. Aim:This project aims to assess the toxicity of differently treated sewage effluent water on the environement using the zebrafish model. Our approach will also be relevant to the assessment of the water quality for agriculture use. Methods:Zebrafish embryos were cultured in different effluent water samples filtered with different techniques. Toxicicity of water was assessed via multiple assasys including: survival rate, tail flicking, and hatching rate. Cardiotoxicity assessment was performed via blood velocity, cardiac output and vessels diameter measurement in major vessels, as well as gene expression for heart failure markers of ANP and BNP by PCR. Results: Samples filtered via Reverse osmosis and nano-filtration resulted in most toxicity. Total dissolved solvent (TDS) measurements were also highest in those samples, suggesting these filteration techniques may result in release of toxic compounds to effluent water. Toxicity assessment is currently ongoing to confirm the findindgs. Conclusion: Utilization of TSE for environmental and agricultural purposes will have an economical value in the nation. It is critically important to determine the most efficient and less toxic ways of water filteration. Zebrafish is a practical model that can be used to assess water toxicity. This project aims to examine toxicity of effluent water filteration techniques using the zebrafish model