In the early 1990s, concern over the safety of tap water grew, and measures to address organic chlorinated compounds—such as trihalomethanes—became a key issue. In December 1993, new tap water quality standards went into effect, and water treatment plants began introducing advanced water treatment systems that combined ozone and activated carbon in addition to conventional treatment methods. At the Kanamachi Water Treatment Plant in Tokyo, advanced water treatment using ozone and bio-activated carbon had been underway since June 1992. Amid this trend, Mitsubishi Chemical supplied advanced water purification systems using pitch-based activated carbon to the Kanamachi Water Treatment Plant and the Murano Water Treatment Plant in Osaka Prefecture. Activated carbon adsorbs organic substances and other contaminants in its microscopic pores, but its adsorption capacity declines with prolonged use. Consequently, the company focused on a system for calcining and reusing spent granular activated carbon; it established a regeneration facility in Kakogawa, Hyogo Prefecture, and moved forward with plans to set up a regeneration facility in the Kanto region as well. The article also cited a forecast that demand for activated carbon would double or triple by around the year 2000.
No comments:
Post a Comment