Utilization of Philippine Lime Waste (Citrofortunella macrocarpa) as a Natural Coagulant for ELJ Centre Domestic Wastewater Treatment

School of Chemical, Biological, and Materials Engineering and Sciences, Mapúa University, Intramuros, Manila 1002 Philippines

^* Corresponding author: kgnquiton@mapua.edu.ph

Abstract

Coagulation treatment is often performed prior to sedimentation and filtration. A coagulant is introduced to the wastewater and is used to remove suspended materials from water. Plant-based coagulants (PBC) are a type of coagulant that is widely used for the treatment of contaminated water in less urban areas because they appear to be lower in carrying cost-treated coagulates when compared to artificial coagulants. Citrus fruits are a type of PBC that is ongoing research. These naturally coagulate due to the presence of certain compounds, such as pectin, which is a structural fibre. In this study, the Philippine lime is dried, pulsed, and sieved to act as a coagulant for the wastewater treatment of domestic wastewater samples obtained from a commercial building. Using the jar test method, the coagulant’s optimum speed, dosage, duration, and settling time were determined based on the resulting turbidity. The optimal mixing speed is 80 rpm, the coagulant dosage is 15 mg/L, the mixing duration is 15 minutes, the settling time is 20 minutes, and the pH is 7.28. The optimal conditions for the Philippine lime coagulant were used for the orange coagulant in comparison. It was found that the pectin content of both coagulants has a significant effect on their coagulation efficiency. Philippine lime waste showed potential as a coagulant, efficiently reducing the turbidity of domestic wastewater. Philippine lime waste showed potential as a coagulant, efficiently reducing the turbidity of domestic wastewater.