Experimental Research On Decolorization Of 1-amino-4-bromo-anthraquinone-2-sulfonic Acid By Zero-valent Iron

In this paper, decoloration experiment of 1-amino-4-bromo-anthraquinone-2-sulfonic acid (BAK) was studied in immobile bed and fluidized bed by zero-valent iron. The efficiency and operation condition of zero-valent iron method was studied. Degradation kinetics and decolorization mechanisms of BAK were also studied.The result of experiment indicated that the decolorization efficency of BAK in immobile bed and fluidized bed both reached above 97%, and the react velocity of fluidized bed is higher compared with immobile bed. On experinment conditions, the best run conditon for immobile bed was that pH is about 3-5 and scale of iron and coke is about 10, the best inflow flux of BAK solution is 1500 ml/min, the best pH is about 3 in fluidized bed. When gas inflow flux was less than critical suspend gas inflow flux, the efficiency of decolorization was higher with increasing gas inflow flux, the Qc increased when more iron powder was put into fluidized bed.Agglomeration expeiment for filling-up indicated that immobile bed filling harden was worked by the sediment of differ configuration iron rust resultants : FeO(OH), Fe2O3 H2O and oxidion on the iron surpace. Immobile bed was easier hardened when intermissionrun compared to continuous run. When the filling was dehydrated, the immobile bed was much easier hardened. The activition of filling surpace can be resumed by bounce-back wash and scheduled time activation. When the disposal effiency was under 70% after activation, the filling should be insteaded. The filling harden didn't happen in iron powder fluidized bed, but the phenomenon of filling loss probably occur, so the gas flux should be strictly controlled.The decolorization of BAK accord with first order reaction .Its reaction kinetics was well accorded by first order exponential decay model Ct= ae-kt+b. The experiment result indicated that decolorization kinetics of BAK was mostly that based on zero valent iron electrochemistry corruption principle , and the BAK molecule group for chromogenic radicle was destroyed under the function of new produced [H], Fe2+, OH and etc.The most absorb wavelengh excursed to shortwave in visible light extent and the chroma of BAK was distinctly descended. The reaction production was settled and pulled off by adsorption and flocculation of Fe(OH)a and Fe(OH)3, which were produced by electrode reaction.