Research On Ballast Water Treatment By Pulsed Arc Electrohydraulic Discharge

Pollution of the marine environment caused by ship's ballast water is increasingly serious, which is more and more paid attention by countries and relevant organizations. International Maritime Organization (IMO) adopted the "International Ship Ballast Water and Sediments Convention on the Control and Management" in February 2004, which required that in 2016, ballast water must be treated and accordance with the convention requirements. In recent years, countries are working on the method of ballast water treatment, and currently there are about 25 treatments being studied.The method of Pulsed arc electrohydraulic discharge (PAED) is applied to treat ballast water in this paper. PAED produced a series of physical, mechanical, chemical and biological effects, these combined effects in ship ballast water treatment can sterilize effectively. This method can treat ballast water in line with the international standards, and it also has the characteristics of low investment and low operating cost, which leads to good economic benefits.In this paper, ballast water treatment by PAED is studied, which includes:the design of the PAED reactor and discharge electrode for water treatment, completion of basic tests, spectral analysis, stress wave analysis, water bactericidal effect test in static and dynamic water. Through experiments, typical waveforms of PAED, and discharge characteristics of different electrode gap, different water conductivity were got. Analysis of spectrum from the discharges showed that PAED can produce significant ultraviolet, free radicals, and electrohydraulic cavitation phenomena, etc. At the same time, PAED can produce a strong pressure wave which has the characteristic of reflected enhanced. Treatment in the static experiment, tungsten is the most efficient electrode material, and it has longer life expectancy characteristic. Sterilizing efficiency is better in higher discharge energy and deeper location of electrodes. PAED can treat a variety of bacterial concentration of water, while the flow of water, there was a marked bactericidal effect.