Use of Bentonite and Zeolite to Stabilize Nutrients and Heavy Metals Within Earthen Pond Sediments

Abstract

Leaving out the sediments of earthen ponds for several years without disinfection or treatment leads to high concentrations of nitrogen and phosphate compounds, heavy metals and increasing sediment pollutants which release into the water. Therefore, this study aimed to evaluate the effectiveness of capping or mixing of bentonite and zeolite in different percentages for the stabilizing of nutrients and heavy metals in earthen pond sediments for interrupt their release to the water. The pH and electrical conductivity (EC), NH4-N, NO3-N, PO4-P and heavy metals (Cd, Cu, Fe, Mn, Ni, Pb and Zn) in the sediments were measured by 45-day laboratory incubation experiments. The results showed that the highest stabilization efficiency of NH4-N, NO3-N, Cd, Cu, Pb and Zn in the sediments was recorded with zeolite capping of 6% of the sediment weight (ZC 6%) by 65.4%, 41.8%, 66.0 %, 63.9 %, 54.2 % and 57.3 %, respectively, while, the highest stabilization efficiency of PO4-P, Fe, Mn and Ni was with bentonite capping of 6% of the sediment weight (BC 6%) by 61.9%, 42.7 %, 57.0 % and 52.6 %, respectively. Therefore, it is recommended to use bentonite or zeolite as capping material for sediment at a rate of 6% at the bottom of the pond can be effective for the control of nutrients and heavy metals when they are increased in earthen pond sediments for interrupt their release into water.

Impact of Zeolite to Maintain Water Quality and Increasing the Growth of Mono-sex Male Nile Tilapia Cultured in Concrete Ponds

“…In Egypt, rapid development has happened in the form of fish farming activity (Ali, 2021), and it's shown the biggest growth among the different fisheries. Therefore, aquaculture is the viable optimal option to decrease the gap between fish productivity and consumption (Soliman and Yacout, 2016).…”