Pretreatment of saline wastewater with Fe–C alloy filler

Abstract

Fe–C alloy filler was prepared using iron powder and activated carbon. And it was proved to be efficient in getting rid of chloride from water, especially saline wastewater. Generally, biochemical treatment efficiency will be low if the concentration of chloride ion (Cl−) in water reaches 10,000 mg/L. Once the Cl− content exceeds 20,000 mg/L, most microbes will lose activity because of the high osmotic pressure. Besides, it will not only affect the microbes’ survival but also be toxic to the microorganisms. This paper studied chloride removal efficiency with iron-carbon alloy. Factors affecting the removal efficiency and the possible removal mechanism were also investigated. Treatment effect for actual salinity wastewater with the filler was reported. The results showed that the new filler could effectively remove chloride ions and chemical oxygen demand (COD). CODCr removal rate of the chosen practical wastewater samples was higher than 55%, and the Cl− removal rates were 27%, 30% and 25%, respectively. The oxygen consumption curves of the wastewater that were obtained from chemical industries showed that the biodegradability of wastewater could be greatly improved due to removal of Cl− using the new filler.