The Study Of Adsorption Properties Of Heavy Metal And Dye By Using Persimmon Peels And Leaves As Adsorbent Material

With the fast development of modern industry, heavy metals and dyes in environment wastewater become more severe. The elimination of heavy metals and dyes in wastewater are the outstanding problem in current environmental protection work. The biomass materials as a kind of new environmentally friendly adsorbent have many advantadges, including abundant resource, low cost, high binding capacity and without second pollution, which has a wide application prospect.This paper mainly investiged both the modified persimmon powder and natural persimmon leaf biomass as adsorbent, which are about adsorption properties of heavy metal chromium and methylene blue dye in wastewater. The adsorption mechanism has been studied. The more detailed novelty of this work can be categorized as follows:(1) In this work, persimmon powder with chemical modification by using acetone and sulfuric acid(SPP) was choosen as adsorbent materials for the adsorption of chromium(VI). Various factors on the affecting adsorption of Cr(VI), such as pH, contact time, temperature, adsorbent dosage were investigated in detail. The results show that the optimum adsorption effect was obtained in the condition of pH 3.0, contact time 2 h, 50 mg modified persimmon power, the adsorption rate of Cr(VI) could be up to 96%. Both the adsorption kinetics and thermodynamics parameters of the adsorption process were achived through the temperature range from 298 K to 328 K. The kinetics data were analyzed using three adsorption kinetic models. The results show that the pseudo-second-order equation and the Elovich equation fitted the experimental data very well. Langmuir isotherm equation model is suitable for describing the adsorption process.(2) In this work, the natural persimmon leaf was choosen as biological adsorbent materials on adsorption properties of methylene blue. The effects of the solution pH, contact time, the electrolyte, adsorbent dosage, initial concentration of MB and tetemperature have been stuied. The results show that the solution pH value is closed 6.0 which could not be adjusted in the process of regulation. When shaking 4 h, persimmon leaf of MB adsorption balance was reached, with equilibrium adsorption quantity of 94.2 mg?g-1. CaCl2 and NaCl were used as simulation of ionic strength, the results show that with the increase of ion concentration, the adsorption of MB down from 93.1 mg?g-1 to 83.0 mg?g-1, 63.4 mg?g-1, respectively. The isotherms data were analyzed using three adsorption isotherm models: Langmuir isotherm, Freundlich isotherm and Temkin isotherm. The results show that Freundlich and Temkin isotherm model fitted the experimental data better than Langmuir. The pseudo-second-order equation and the Elovich equation fitted the experimental data very well.