Preparation of insoluble humic acid and optimization of Cr (VI) adsorption conditions

Abstract

In order to explore the best conditions of insoluble humic acid (IHA) treating heavy metal Cr(VI) wastewater, HA was extracted from weathered coal, then IHA was prepared by high-temperature calcification method, and its adsorption parameters of Cr(VI) were determined. The results show that the best preparation conditions of IHA were as follows: high temperature time is 90 min, CaCl2 solution concentration is 2 mol/L, CaCl2 solution soaking time is 120 min, washing NaNO3 concentration is 1 mol/L; after BET analysis IHA, its specific surface area increasesed, the pore volume increased, and adsorption capacity is obviously enhanced; the results of Cr(VI) adsorption experiments show that the modified IHA has better performance and stronger applicability, under the operating conditions of room temperature, pH=5, adsorption time is 2 h and stirring speed is 40 r/min, IHA dosage is appropriated the removal rate of Cr(VI) can reach 99%.

Keywords

• weathered coal
• humic acid
• high temperature calcilication
• adsorbent
• cr(vi)