The Effect Of Citric Acid (Acidum Citricum) Addition on Chromium (Cr) Levels in Wastewater

Abstract

Chromium (Cr) is a heavy metal that contaminates the environment and poses severe risks to human health. Using citric acid as an eco-friendly complexing agent is a potential method to reduce chromium levels. Objective: This study aimed to determine the effect of varying citric acid concentrations on chromium (Cr) levels in wastewater. Research Method: A true experimental laboratory study with a post-test only control group design was conducted. Treatments consisted of a control group (0%), and citric acid concentrations of 0.5%, 1%, and 1.5% (w/v) with a contact time of 40 minutes and six replications each. Chromium levels were measured using a UV-Vis spectrophotometer at a wavelength of 540 nm and calculated using a standard linear regression curve. Results: The mean remaining chromium concentrations for 0%, 0.5%, 1%, and 1.5% treatments were 0.4803 ± 0.0086 mg/L, 0.1952 ± 0.0287 mg/L, 0.1916 ± 0.0162 mg/L, and 0.1890 ± 0.0145 mg/L, respectively. Statistical testing using the Kruskal-Wallis test yielded an Asymp. Sig. value of 0.631 (p > 0.05). Conclusions: Descriptive results indicate that citric acid addition reduces chromium levels, with the lowest remaining chromium observed at 1.5% concentration. However, increasing the concentration from 0.5% to 1.5% did not yield a statistically significant difference in percentage reduction.