Low-cost Adsorbents Used in Heavy Metal Contaminated Waste Water Treatment

In this review, adsorbents used in wastewater treatment and their technical feasibilities are reviewed. Adsorbents are classified as natural adsorbents, and the adsorbents obtained from industrial and agricultural wastes. They all were compared with each other condensing the metal binding capacities, costs and metal removal performances in waste water treatments. Although commercial activated carbon is widely used in wastewater treatment applications, it has high costs. Instead of activated carbon, we focused on the inexpensive materials like chitosan, zeolite, and clay as natural adsorbents; waste slurry and ash as industrial waste; and, rice husk and coconut shell as agricultural waste. It was shown that these alternative adsorbents had sufficient binding capacity to remove heavy metals from wastewater.