An empirical model for kinetics of boron removal from boron-containing wastewaters by the electrocoagulation method in a batch reactor


YILMAZ A. B., Boncukcuoglu R., Kocakerim M. M., KOCADAĞİSTAN E.

DESALINATION, vol.230, pp.288-297, 2008 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 230
  • Publication Date: 2008
  • Doi Number: 10.1016/j.desal.2007.11.031
  • Journal Name: DESALINATION
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.288-297
  • Keywords: Boron removal, Electrocoagulation, Aluminum electrode, Empirical kinetics model, WASTE-WATER TREATMENT, ION-EXCHANGE, ADSORPTION
  • Ataturk University Affiliated: Yes

Abstract

Boron removal from boron containing wastewaters prepared synthetically via the electrocoagulation method was studied. The experiments in which aluminum plate electrode was used were carried out in a batch reactor. The solution pH, initial boron concentration, current density, type of supporting electrolyte, temperature of solution and stirring speed were selected as experimental parameters. The obtained experimental results showed that efficiency of boron removal increased with increasing current density and decreased with increasing boron concentration in the solution. Supporting electrolyte had not significant effects on the percent of total boron removal. pH was very important parameter effecting boron removal and optimum pH was determined to be 8.0. This pH value reached an agreement with activity-pH diagrams for Al+3 species in equilibrium with AI(OH)(3) and boron species in aqueous media. As a result of increasing interaction between boron ions and dissolved aluminum ions in solution, the increasing solution temperature increased boron removal efficiency. Increasing stirring speed decreased boron removal efficiency where the increasing stirring speed decreased the capability of floc formation of aluminum ions. As a result, it was seen that about 99% of boron in the wastewater could be removed at optimum conditions. In addition, the process kinetics was predicted by using heterogeneous fluid-solid reaction models. It was seen statistically that the kinetics of this process agreed with the pseudo-second-order model as follows: X-B/(1-X-B) = 18,241*[OH]*[C](-3.45)*[CD](7.79)*[t](1.41)*[S](-3.65)*exp[-30,668/R*T].