Comparing the Ability of Orange Peel and Orange Peel Activated Carbon in Removing Heavy Metals from Wastewater by Absorption

Urban wastewater includes heavy metals that make humans and the environment concerned. The studyexamined the removal of heavy metals such as chromium, lead, nickel and copper from municipal wastewaterby adsorption method using the peel and activated carbon of orange peel. To make orange peel biochar, thepeel was placed in the oven at 550 ° C for 1 hour. Activated carbon prepared from orange peel was first soakedseparately in 2 ml NaOH (0.4 mol / l) and HNO (0.4 mol / l) and double distilled water for 24 hours. It wasthen rinsed with double distilled water to reach a neutral pH. The adsorbents were then dried for 24 hours at 20and 30°C for studying the effect of temperature on adsorption percentage. Overall, 3 treatment levels includingdifferent dosage of orange peel and activated carbon with 0.2, 0.4 and 0.6 g and two temperature levels wereperformed. The density of all pollutants in the wastewater was measured before and after the treatments usingAtomic Absorption Spectroscopy. The project was conducted as factorial in a completely randomized designwith three replications. Analysis of variance and mean comparison of all data from each treatment wereperformed using Duncan s Multiple Range Test (DMRT) at 1% statistical level and SAS-19 software. Theresults showed that the highest lead absorbed by orange peel was 75.63% and for activated carbon 79.22%,whereas the highest rate of copper absorption by orange peel was 42.6% and for activated carbon 45.63%.Moreover, for cadmium, these values were 60.6% and 62.7% for skin and biochar, respectively. The highestabsorption of nickel was 47.78% and 49.37% for skin and biochar, respectively. Overall, the results showedthat orange skin and biochar could be a better adsorbent for the removal of lead rather than other metals.

Keywords:

activated carbon , heavy metals , DMRT , adsorption , orange peel