Abstract
ABSTRACT There is limited information on the optimal processes to remove heavy metals in greywater. A Response Surface Methodology (RSM) via the Box–Behnken Design (BBD) approach was applied in this study to investigate and optimise the process variables of activation time (1.5–2.5 h), impregnation ratio (0.25–0.75) and zinc chloride (ZnCl2) percentage (20–60%) for the removal of heavy metal ions (Cd, Cu, Pb and Ni) associated with greywater treatment. The quadratic model was chosen to describe the effects of the process variables (activation time, impregnation ratio, ZnCl2 percentage) on predicting the responses (heavy metal ions removal) with low p-values (<.0001), high-adjusted R 2 and predicted R 2 values. Second order polynomial equations, ANOVA and three-dimensional surface plots were developed to evaluate the effects of each independent process variable and determine the optimal condition of each factor for heavy metal ions removal. The optimal activation time for the activated carbon variables was 1.8 h, with 56% ZnCl2 and 0.60 impregnation ratio. This showed that the observed values for removing the heavy metal ions (Cu, Cd, Pb and Ni) were close to the predicted values. A RSM-based field test via the BBD approach, involving different types of greywater samples (bathtubs, showers, hand basins and laundry machines) showed that the percentages of heavy metal ions removal fit the experimental results.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
