Efficiency of Different Moringa oleifera (Lam.) Varieties as Natural Coagulants for Urban Wastewater Treatment

Abstract

There is a great need to find cheaper but still efficient treatment methods for wastewater. This study aimed to test the purifying performance of three different Moringa oleifera varieties that were cultivated in Tunisia on raw (RUW) and secondary treated urban wastewater (TUW). The seeds of the Mornag, Egyptian, and Indian varieties were powdered, added to the water (at concentrations of 0, 50, 100, and 150 mg·L−1), and stirred for 45 min at 120 rpm, and then left to settle for two hours. A physicochemical characterization of the wastewater was carried out before and after treatment. The investigated treatments decontaminated both types of urban wastewater. The best treatments were obtained with the Egyptian variety (at 150 mg·L−1), which excelled at the reduction of EC, TSS, BOD5, Cl, SO4, Ca, Na, Cd, and Fe in RUW and BOD5, EC, Na, Mg, Cl, and Cd in TUW. High amounts of TKN was found in both types of Moringa-treated wastewater, meaning that it could be used in agricultural irrigation, leading to less use of chemical nitrogen fertilizers and thus improving sustainability for crops, soils, animals, and humans. The Egyptian Moringa variety constitutes a cost-effective and environmentally friendly adsorbent that can be used as a replacement for more expensive treatment technologies.