Water quality assessment of Qarun Lake and heavy metals decontamination from its drains using nanocomposites

Abstract

Qarun Lake is one of the most important lakes in Egypt; it is the shrunken remnant of Moeris Lake. It is a closed ecosystem represented as a tank for discharged agricultural wastewater of El-Fayoum province. To assess the quality of the lake water for fishing and aquatic live utilization, Oregon water quality and metal pollution indices are computed. Based on the obtained results, water of the Qarun Lake is classified as very poor for the fishing utilization, where water quality index changed from 17.05 to 67.4 at the different stations. The metal indices; Pollution index (PI) and metal index (MI); showed that Qarun Lake water undergoes from a several grade of contamination for usage of aquatic life because of the enormous amount of wastes that discharging into the lake. Novel synthesized alginate nanocomposites (alginate, chitosan-alginate, and LDH-alginate and LDH-chitosan-alginate beads) were applied to remove heavy metal such as (Cd2+, Cu2+, Cr6+, Mn2+, Fe2+, Ni2+, Pb2+, and Zn2+) from different wastewater discharging into Qarun Lake. LDH-chitosan-alginate beads the exhibited the maximum removal efficiency that varied between 92.253 and 98.833 % for Cr6+ and Fe2+, respectively; in contrast, the alginate beads recorded the lowest one. The study indicated that the nanocomposite adsorbents, especially, LDH-chitosan-alginate beads are an effective substance for metal removal from different wastewater.