Cadmium Heavy Metal Removal in Water by Microalgae Sorption Activity Sinthya Desty Rahmadhania, Astri Rinanti*, Melati Ferianita Fachrul, Astari Minarti, Sarah Aphirta, Lutfia Rahmiyati, Sheilla Megagupita Putri Marendra, Thalia Sunaryo
Environmental Engineering Study Program, Faculty of Landscape Architecture and Environmental Technology, Universitas Trisakti, Jakarta, Indonesia
Abstract
Industrial waste that contains Cadmium (Cd) heavy metal can cause environmental problem because Cadmium is toxic, persistent, and can easily accumulated in the environment. Biosorption process is highly influenced by temperature, pH, light, initial metal ion concentration, microalgae biomass concentration, microalgae characteristics, contact time, and surface area ratio against total surface area. This literature study is focused on the effectiveness of temperature and contact time on Cd (II) biosorption process by Chlorella sp. mobile as biosorbent. Chlorella sp. microalgae possess functional groups that are able to react with metal ion in a solution, which makes it exploitable to overcome environmental pollution caused by heavy metal exposure. Chlorella sp. is cultivated on a controlled environment, inside a batch reactor filled with wastes that contain Cd (II) with BBM (Bolds Basal Medium) as growth media. Optimalization of heavy metal removal is conducted with a batch system filled with solution that contains 50 mg/L of Cadmium heavy metal (Cd), 1.53 g/L of biosorbent, pH level of 6.5 with observed temperature levels of 10, 27, and 35℃- and contact times of 15, 45, and 60 minutes. The analysis was conducted by using Atomic Absorption Spectroscopy (AAS), Fourier Transform Infra-Red (FTIR), and Scanning Electron Microscope (SEM). Research results revealed that the highest and the lowest removal rates are at 50 mg/L Cd (II) by 1.53 gr/L of Chlorella sp. microalgae on pH level of 6.5 respectively happens on 35℃- and 10℃- temperatures with removal efficiency between 60% to 100%. Freundlich^s Isotherm formula and two reaction orders are used to remove Cadmium (Cd) heavy metal by Chlorella sp. microalgae with linear regression coefficient value (R2) close to 1. The implementation of Cadmium Cd (II) heavy metal removal by Chlorella sp. microalgae on a pilot scale with 80 L of volume and 50 mg/L of concentration into 0.05 mg/L requires biosorbent mass of 5,123.08 gr and detention time of 2.52 hours. This literature study has provided us information that biosorption can be utilized as alternative technology to overcome Cadmium heavy metal in water.
Keywords: Cadmium (Cd), Biosorption, Chlorella sp. Microalgae, Function groups
