Delhi's Chandrawal Water Treatment Plant to have 3 Ozone Generators for purification

Three ozone generators will be deployed for water purification at Chandrawal Water Treatment Plant in Delhi. This will be one of the largest ozonation systems, scale-wise, for a water treatment plant in India.

Being executed by Delhi Jal Board, Toshiba Infrastructure Systems & Solutions Corporation (TISS) has concluded a contract with Larsen & Toubro Limited (L&T) for the three ozone generators. The project is funded by Japan International Cooperation Agency (JICA) under the Delhi Water Supply Improvement Project.

Ozone is a powerful oxidant and has many applications, including dechlorination, deodorization, inactivation of viruses and bacteria, oxidation of organic and inorganic substances and a reduction in trihalomethane formation during chlorination. Ozone breaks down organic matter which is the cause of the unpleasant odour and another one that causes discolouration. For disinfection, the cell membranes of bacteria and DNA/RNA of viruses are directly oxidized to inactivate or kill bacteria and viruses. In addition, ozone has hardly any adverse impact on the environment because it simply reverts to oxygen after use.

How Ozone Generator Works:

A large amount of ozone is generated efficiently by silent discharge. The silent discharge continually occurs without spark when a high AC voltage is applied between the two electrodes placed parallel to each other through the dielectric material. When dry air or oxygen flows between the electrodes, oxygen atoms (O) are ionized, and ozone (O3) is formed in the recombination of ionized oxygen atoms (O) and unionized oxygen molecules (O2). Only feed gas and electric power are required for ozone generators, making the ozone system has a low impact on the environment.

In Japan, ozone treatment is commonly used at large water treatment plants, especially in urban areas. Toshiba commenced the development of ozonation systems in the 1970s and has delivered more than 130 ozonation systems for over 100 projects.