No abstract

Electroplating copper industry was discharged huge amount wastewater and cause serious environmental and health damage in Taiwan. This research applied electrical copper recovery system to recover copper metal. In this work, electrotreatment of a industrial copper wastewater ([Cu] = 30000 mg L−1) was studied with titanium net coated with a thin layer of RuO2/IrO2(DSA) reactor. The optimal result for simulated copper solution was 99.9% copper recovery efficiency in current density 0.585 A/dm2and no iron ion. Due to high concentration of iron and chloride ions in real industrial wastewater, the copper recovery efficiency was down to 60%. Although, the copper recovery efficiency was not high as simulated copper solution, high environmental economic value was included in the technology. The possibility of pretreating the wastewater with iron is the necessary step, before the electrical recovery copper system.

A manganese immobilization technology in a fluidized-bed reactor (FBR) was developed by using a waste iron oxide (i.e., BT-3) as catalyst which is a by-product from the fluidized-bed Fenton reaction (FBR-Fenton). It was found that BT-3 could easily reduce potassium permanganate (KMnO 4 ) to MnO 2 . Furthermore, MnO 2 could accumulate on the surface of BT-3 catalyst to form a new Fe-Mn oxide. Laboratory experiments were carried out to investigate the KMnO 4 -reduction mechanism, including the effect of KMnO 4 concentration, BT-3 dosage, and operational solution pH. The results showed that the pH solution was a significant factor in the reduction of KMnO 4 . At the optimum level, pH f 6, KMnO 4 was virtually reduced in 10 min. A pseudo-first order reaction was employed to describe the reduction rate of KMnO 4 .