Comparative Study of Domestic Wastewaters Treatment Techniques by Aeration and Biosorption: Tests with and without Ca²⁺

Stenelvie Ngala Nsakou^1,2, Sarah Jerroumi^2,3, Brahim Lekhlif^1,2, and El Hassan Malil¹

3. Laboratory of Organic Synthesis Extraction, and Valorization, Faculty of Sciences Ain Chock, University Hassan-II, Morocco

Abstract: In the present work, tests were carried out on the treatment of domestic wastewater in two immersed bacterial beds with plastic packing media, one aerated (R1) and the other without aeration where the elimination of the pollution was done by biosorption (R2). Beforehand, R1 and R2 were subjected to adaptation tests to allow the colonization of plastic packing media. After adaptation, a series of tests were carried out in these same bioreactors, one with raw domestic wastewater and the other with domestic wastewater added with Ca2+. The aeration and biosorption treatment tests showed an abatement rate of COD and turbidity more or less high, better in the case of aeration. In the presence of Ca2+, these rates increased further because of the positive charge of calcium. The decrease in COD and turbidity has resulted in an increase in oxygen concentration, which was more pronounced in the case of the aeration. Concerning the pH, it showed a significant increase in R1. However, conductivity showed a decrease in all tests in both bioreactors. The two techniques used in the treatment of domestic wastewater showed a differentiated abatement performance of COD and turbidity, to the advantage of aeration. These performances exacerbated in the presence of Ca2+.