Determination of water quality and efficient removal of arsenic and iron from groundwater using mahogany fruit husk and banana peduncle charcoals

Abstract

The groundwater (GW) of Bangladesh is predominantly contaminated with arsenic (As) and iron (Fe) which has a bad impact on human health. We tried to remove these elements with easily available mahogany-fruit (Swietenia mahagoni) husk charcoal (MHC) and banana (Musa acuminata) peduncle charcoal (BPC). The trial was implemented with 3 replications throughout the research. The sampled GW contained 0.06 mg As L−1 and 4.83 mg Fe L−1. Firstly, the pH was 3, 5, 7, and 9 with a 250 mg L−1 dose. The MHC removed almost 91.05 % of As at pH 5.0, and BPC removed almost 86.67 % of As at pH 9. However, in the case of Fe, the MHC removed almost 100 % at pH 7 and 9; and BPC removed the same quantity at pH 5, 7, and 9. Secondly, the contact times were 0, 5, 10, 20, and 40 min with a 250 mg L−1 dose at pH 7.0. The maximum removal of As and Fe was 100 % with MHC and BPC at 5 min. The pseudo-first-order kinetic, pseudo-second-order kinetic, and intra-particle diffusion models were considered. The result showed that the rate of adsorption followed the pseudo-second-order kinetic model. Lastly, the adsorbent doses were 0, 50, 150, 250, and 350 mg L−1. At pH 7, the highest removal of As was 79.47 % and Fe removal was 100 % at 350 mg L−1 dose for MHC. Similarly, the values were 79.29 % and 100 % for the same at 350 mg L−1 dose of BPC, indicating these charcoal are good for heavy metals removal.