Acid and ultrasound assisted modification of boron enrichment process waste and using for methylene blue removal from aqueous solutions

In this study, raw boron enrichment waste was treated with hydrochloric acid and ultrasound at 35-kHz frequency for 60 minutes. To optimize the adsorption conditions for removal of methylene blue (MB) from synthetic wastewaters using raw boron enrichment waste (BEW), acid modified boron enrichment waste (HBEW) and ultrasound modified BEW (UBEW) by adsorption process and to compare the adsorption efficiency of chemical and ultrasonic modifications of BEW were aimed. The optimum adsorption conditions were determined economically and eco-friendly aspect and MB removal percents were found as 80%, 80% and 92% at optimum conditions for BEW, HBEW and UBEW, respectively. The maximum regression coefficient values were obtained as 0.911, 0.998 and 0.984 for BEW, HBEW and UBEW, respectively at Langmuir isotherm model. The adsorption rate was fitted well to pseudo-second order kinetics according to a good correlation coefficient. The adsorption of MB onto adsorbents studied is spontaneous in nature and feasible because of negative ∆G values. The results indicated that the boron enrichment process waste could be a suitable adsorbent for removal of MB from aqueous solution. The maximum adsorption capacities were equal to about 107,0 mg/g, 160,7 mg/g and 145,3 mg/g for BEW, HBEW and UBEW adsorbents at 298 K, respectively. The maximum dye removal percent was achieved for UBEW as 92% and ultrasound assisted modification was found more efficient method compared with acidic modification for MB removal.