Treatment of Landfill Water by Electrolysis and Magnetic Separation

Abstract

In the 21st century, an environmentally benign system is necessary for the environmental treatment and material resources that will ensure human survival. This paper describes a new water treatment system with electrolysis and magnetic separation. The system is composed of two different types of electrolysis reactors and a superconducting magnetic separation apparatus. The first iron electrolysis reactor produces iron phosphate and the paramagnetic iron hydroxide particles that absorb some organic compounds. These products are collected by the magnetic filter because of high-gradient magnetic separation. The second PbO2 electrolysis reactor treats the nitrogen and resultant organic compounds by electrochemical oxidation. This system has the following advantages in comparison with the conventional water treatment system that is a result of microbiology-and physical and chemical treatments: -no medicine, no secondary products, fast treatment, requires but small space, is easy to operate and is maintenance-free. This system was applied to on-site test for treating landfill water in the Tokyo Bay area for four months in 2001, from September to December. The flow rate of tested water is 100 liter per hour. The landfill water contains about 200 kinds of species; nitrogen, phospherous, organic compounds, bisphenol A, and others. The total removal efficiencies of this system are as follows; 88% for total phosphate, 77% for total nitrogen, and 62% for COD (chemical oxygen demand). These removal efficiencies are the same as or greater than those of the conventional landfill water treatment system. The results show the possibility of new water treatment system for treating landfill water.