Novel environmentally friendly approach to wastewater treatment eliminates aluminum sulfate and chlorination

Abstract

Wastewater treatment uses harmful chemicals, including aluminum sulfate and chlorine. Aluminum sulfate, a common metal-based coagulant, can be toxic to both humans and aquatic life if ingested. Chlorine is used to disinfect wastewater by killing bacteria and other harmful microorganisms, and if ingested, chlorine and its byproducts can lead to respiratory irritation and cancer. The purpose of this research was to find equally efficient, environmentally safe alternatives to aluminum sulfate and chlorine water treatments. We investigated the effectiveness of zeolite, Moringa oleifera seed powder, and activated charcoal for wastewater filtration using common water contaminants and compared to the purification with aluminum sulfate. We tested lemon and orange peels as environmentally safe alternatives to chlorination by measuring the amount of bacterial growth suppression. We used inductively coupled plasma optical emission spectrometry (ICP-OES), colorimetric analysis (Lachat), bacteria colony counting, and scanning electron microscopy to analyze the effectiveness of these alternatives. For all the tested water contaminants and for analytical techniques used, our data demonstrated zeolite and charcoal were better or comparable to aluminum sulfate at removing the metals and nutrients tested. Lemon peels were very effective in suppressing bacteria growth, although further research is needed to compare chlorine to lemon peels in identical conditions to ensure that lemon peels could be a viable alternative to chlorination.