การดูดซับโลหะหนักด้วยดินเหนียวเบนโทไนท์ผสมกับซีเมนต์และวัสดุปอซโซลาน

Abstract

At present, Thailand is facing the smuggling of wastewater to nature which consists of heavy metal contamination causing soil and water pollution. The heavy metals cannot be decomposed naturally and also able to accumulate in humans, animals, and plants. Moreover, when getting in large quantities, it can affect the body system. This laboratory-based study experimented by using bentonite clay to adsorb two heavy metals: copper and zinc. Bentonite clay was used and mixed with cement and various pozzolanic materials, consisting of 1) bottom ash 2) fly ash 3) rice husk ash 4) kaolinite 5) blast slag and 6) silica fume with batch adsorption test. These materials were analyzed for chemical composition and the basic properties of bentonite clay. The parameters on the adsorption process were the initial concentration of the heavy metal solution and equilibrium time. The results showed that the adsorption began to enter the equilibrium at 48 hours. The effects of adsorption capacity by using bentonite clay mixed with cement and pozzolanic materials were analyzed by Langmuir’s adsorption isotherm. The adsorption capacity of the samples was in the order of bentonite clay mixed with cement > fly ash > bottom ash > blast slag > kaolinite > silica fume > rice husk ash respectively