Investigating olive pomace activated carbon for degrading organic dyes in water.

Olive pomace was used as raw material and then activated by potassium hydroxide to obtain olive pomace activated carbon (OP-AC). The effects of different dosage, pH and adsorption time of OP-AC on the removal of seven organic dyes (methylene blue MB, methyl orange MO, Congo red CV, neutral red CR, malachite green MG, crystal violet BL and rhodamine B RHB) in water were investigated. The adsorption behavior of OP-AC on seven organic dyes was studied through adsorption experiments, and the feasibility of treating mixed printing and dyeing water by OP-AC was also discussed. The results show that the removal rate of seven organic dyes is better when the dosage of OP-AC is 0.6 g and the adsorption time is 24 h. The removal efficiency of dyes is different under different pH conditions, among which the removal rate of MO, CR and BL is better in acidic environment (pH = 4), while it is beneficial to the removal of MB, RHB, MG and CV in alkaline environment (pH = 12). The removal efficiency of dyes under better conditions is CV > MB > RHB > Mo > BL > Mg > Cr. The adsorption process of olive pomace activated carbon for seven dyes is more in line with Langmuir isothermal adsorption model, and the correlation coefficients are all greater than 0.98, indicating that the adsorption process of seven dyes is of single layer adsorption; The adsorption kinetics is more in line with the quasi-second-order kinetic model, and chemical adsorption is dominant in the adsorption process, with correlation coefficients greater than 0.97. Under the conditions of OP-AC dosage of 4.0 g, adsorption time of 24 h and pH equaling 10.9 (unadjusted), the removal efficiency of RHB is the highest (99.6%) and that of CR is the lowest (59.6%), and the removal efficiency of mixed organic dyes is the highest. The removal efficiency of seven organic dyes is: RHB > MG > MB > CV > BL > MO > CR.Kindly check and confirm the corresponding affiliation has been correctly processed.The author's affiliation is checked and correct.Please confirm the inserted city name for the affiliation 4 is correct and amend if necessary.affiliation 4 is correct.