Experimental studies on removal of pollutants by adsorption

Abstract

Wastewater treatment has increasingly become a critical focus in recent years due to the escalation in the levels of toxins present in industrial effluents. Of particular concern are the high concentrations of toxic heavy metals like chromium (VI) found in aqueous streams, stemming from the release of untreated effluents containing metals into water sources, posing a significant environmental challenge. Adsorption stands out as an efficient technique for eliminating chromium (VI) from wastewater. The exploration of biosorbents has emerged as a key area of interest for removing chromium (VI) ions from aqueous solutions at ambient temperature. In this study, raw tamarind fruit shells after being activated through treatment with concentrated hydrochloric acid (98% w/w) was used as an adsorbent. Equilibrium studies showed that adsorption of chromium (VI) is more effective at lower solution pH values. Packed beds are known for their ability to remove contaminants efficiently and are generally used in industries. Bed design is crucial for achieving effective contaminant removal. Reducing particle size results in increased mass transfer rates resulting in small mass transfer zones and more effective utilization of adsorbent bed. But challenges related to high pressure drop are encountered with small particles that would effectively stop operation specially when flow through the bed is gravity driven. To overcome the limitations associated with small particles, a potential solution involves coating inert beads with adsorbent particles on the outer surface. The experimental study outlined in this paper provides valuable insights into the practical implications of these design considerations, offering a pathway for enhancing treatment efficiency and addressing challenges effectively.