Increasing Effectiveness of Heavy Metal Sorption by Biosorbent Microalgae Beads

Abstract

This research was conducted to overcome the Cu2+ heavy metal pollution in the environment through a biotechnological approach with heavy metal sorption process by microalgae beads. Biosorbent in form of beads was produced from Chlorella sorokiniana, Monoraphidium sp., and Scenedesmus obliquus tropical microalgae mobilized with Na-alginate polymer. The sorption process is observed on a controlled batch culture with variations of temperature (25, 35, and 45 °C), and observation periods (200th, 220th, 250th, 270th min) as contact time. The absorption efficiency on each temperature variation reaches more than 90%, but the highest absorption efficiency rate is at 92.20% on 35 °C temperature and 200 minutes of contact time. Biosorbent beads with 2–3 mm of diameters show the best sorption ability than the 3–4 mm and 4–5 mm ones. Sorption process is also evident with the existence of intensity alteration on amide, ketone, and sulfhydryl function groups which were consistently weakened until the end of the sorption process. The beads utilized in this research are potentially reusable as biosorbent. Thus, further examination is required to acknowledge the maximum reutilization rate of the beads as biosorbent on heavy metal absorption process