A Solution for Cleaning Water: Cold Plasma

Amit Kumar (ESR4)

I am from India, where 37 % of India’s population lives in the Ganga river basin. The Ganga is a holy river in India, with a total length of 2,525 km. This river is an essential source of water for a vast area, and it provides more than one-third of India’s surface water. About 47 % of irrigation in India depends on the Ganga basin alone. It also provides water for drinking purposes to about 40 % of India’s population.

Unfortunately, the Ganga river is getting polluted with hazardous chemicals each day, and it is in trouble. Industrial waste, human waste, and the ones generated as a result of religious practices are the leading causes of river pollution. According to a report by the WHO, domestic wastewater and industrial sewage that contaminate the Ganga have been estimated at about 1.4 × 106 m3/day and 0.26 × 106 m3/day, respectively, which are almost equivalent to emptying 140,000 and 26,000 milk trucks every day!

Several organic micropollutants, such as dyes, pharmaceuticals, surfactants, and pesticides, have been found in trace amounts in groundwater and surface water samples from the nearby regions of the Ganga river basin. These pollutants can cause cancers, physical abnormalities, harm to aquatic life, and also affect the lower productivity of agricultural land.

Organic micropollutants are very resistant to degradation, and they cannot be removed from water by conventional water treatment processes/plants.

However, a new treatment technique could play a significant role in the degradation of those trace non-biodegradable organic micropollutants. It is named cold plasma, and it can make water reusable for drinking and/or irrigation.

But what is cold plasma? And how can it be used?

Cold plasma is an advanced oxidation technique that leads to the formation of various types of oxidizing agents, such as hydroxyl radical (HO·), atomic oxygen (O), hydrogen peroxide (H2O2), and ozone (O3).

These oxidizing agents are capable of eliminating a large number of organic micropollutants from water and killing microorganisms (e.g., bacteria, viruses, etc.) present in water. While conventional disinfection involves the use of chlorine that is a hazardous chemical, treating water with cold plasma is an environmentally friendly way to obtain safe drinking water. Additionally, since cold plasma operates at room temperature and atmospheric pressure is more sustainable than its similar hot plasma.

Several organizations, both national and international, are already working to clean up the mighty Ganga river now severely contaminated by industries, cities, and agriculture. This is of great importance because hundreds of millions of people and a vast range of wildlife rely on it.

The sacred river the Ganges is crucial for India: culturally, economically, and environmentally. This river means life, and this life has been endangered for years.

When, at the end of my Ph.D. studies, I will return to my hometown to my family and friends, I don’t want to go back empty-handed.

I want to return with a solution to this enormous pollution problem that afflicts my loved ones and my country in general: a solution that will ensure a healthier future for them. Armed with an acute knowledge and specific skills, I want to contribute to developing long-lasting technologies to clean up the Ganges River.

My work on cold plasma treatment could apply to the Ganga river problem because it could be developed into a simple, valuable, and easy to use technology. So it would be an attractive option for every country regardless of its financial status, expertise, and experience.