{"id":2357,"date":"2023-04-20T19:32:31","date_gmt":"2023-04-20T19:32:31","guid":{"rendered":"https:\/\/horizon.peachpuff-wolverine-566518.hostingersite.com\/?p=2357"},"modified":"2023-04-20T19:32:31","modified_gmt":"2023-04-20T19:32:31","slug":"in-india-natural-ways-to-clean-up-wastewater-promise-big-benefits","status":"publish","type":"post","link":"https:\/\/scienceblog.com\/horizon\/2357\/in-india-natural-ways-to-clean-up-wastewater-promise-big-benefits\/","title":{"rendered":"In India, natural ways to clean up wastewater promise big benefits"},"content":{"rendered":"

European researchers are working alongside Indian experts to rethink the collection, decontamination and reuse of sewage in the world\u2019s most populous country.<\/p>\n

By<\/em><\/strong>\u00a0\u00a0HELEN MASSY-BERESFORD<\/p>\n

Winding its way through the mountains and plains of northern India, the Ganges River is sacred to the Hindu religion. More prosaically, its water and nutrients are vital to the region\u2019s farmland, hundreds of millions of residents and India\u2019s economy.<\/p>\n

The Ganges is personified as Ganga, the Hindu goddess of purification and forgiveness. But like many rivers around the world, the Ganges is severely polluted, threatening the health of the people who live nearby and the crops they grow.<\/p>\n

Major potential<\/strong><\/p>\n

Two projects jointly funded by the EU and India are\u00a0improving the collection, sanitisation and reuse of wastewater \u2013 an increasingly urgent challenge as climate change puts greater strains on water supplies.\u00a0Called\u00a0PAVITR<\/a>\u00a0and\u00a0PAVITRA GANGA<\/a>, the two initiatives are part of an\u00a0EU-India Water Partnership<\/a>.<\/p>\n

PAVITR is using the natural filtering power of trees to turn sewage into a resource. The goal fits with the EU drive towards a\u00a0circular economy<\/a>, in which\u00a0resources get reused instead of discarded.<\/p>\n

\u2018With the focus on the circular economy, India has a huge potential,\u2019 said Mirko H\u00e4nel, PAVITR\u2019s\u00a0European coordinator.<\/p>\n

PAVITR, which began in 2019 and runs through January 2024, is also an example of a\u00a0nature-based solution<\/a>.<\/p>\n

The project\u2019s use of tree plantations to treat wastewater not only is inspired and supported by nature but will provide local environmental, social and economic benefits.<\/p>\n

The team dammed municipal wastewater in one hectare of land to grow a dense crop of bamboos, willows and poplars. The system works in perfect harmony: the nutrients such as nitrogen and phosphorus in the wastewater help the trees grow while the bacteria in the roots naturally clean the water.<\/p>\n

Analysis shows this natural treatment results in the wastewater meeting the necessary regulations, according to H\u00e4nel.<\/p>\n

Welcome returns<\/strong><\/p>\n

The system is cheap to install and operate compared to the high running costs in chemicals and electricity of a standard wastewater treatment plant \u2013 and the trees, in addition to cleaning the water, will attract birds, insects and other wildlife.<\/p>\n

The Aligarh Muslim University, one of the India-based project partners, has set out to catalogue the species at the site.<\/p>\n

The trees and bamboo can be harvested every two to three years, providing a sustainable timber crop to be sold to import-dependent Europe and an income stream for farmers in India. It could also, ideally, replace less sustainable, fossil-fuel-derived construction and manufacturing materials.<\/p>\n

No additional fertilisation or irrigation is required as the wastewater provides it all. Chemical fertiliser, another increasingly scarce and expensive resource, isn\u2019t needed. The root system remains in place, ready to grow again and keep treating the water.<\/p>\n

Looking beyond PAVITR, H\u00e4nel says efforts will need to focus on business ideas for moving the system from exploratory research to the commercial market and to more areas along the Ganges as well as other rivers.<\/p>\n

Chemicals clean-up<\/strong><\/p>\n

While PAVITR has focused on standard municipal wastewater,\u00a0PAVITRA GANGA\u00a0has been tackling the kind contaminated by industrial chemicals.<\/p>\n

Also a five-year initiative running through January 2024, PAVITRA GANGA\u00a0is looking at how to remove dangerous compounds from insufficiently treated wastewater. The project\u00a0focuses on wastewater in urban and surrounding \u2013 peri-urban\u00a0\u2013 areas, seeking to ensure it can be safely reused to help grow crops.<\/p>\n

In the industrial city of Kanpur, which has more than 400 tanneries, sewage plants are unable to cope with the large volumes and with illegal dumping of industrial waste into municipal sewers.<\/p>\n

Analysis of the wastewater showed high concentrations of substances such as chromium that can cause cancer.<\/p>\n

Unless properly treated, this pollution can contaminate soils, harm the health of farmers and reduce crop yields if used to irrigate agricultural land, according to Paul Campling, the project coordinator. He\u2019s also international business development manager at a Belgian cleantech research organisation called VITO.<\/p>\n

PAVITRA GANGA aims to find the best technologies to remove harmful compounds from the wastewater so it can be safely reused for crop irrigation.<\/p>\n

The team also uses sensors and modelling technologies to monitor and predict the quality of regional water bodies affected by discharged wastewater and helps local governments plan safer measures to deal with the natural, untreated water in rivers, lakes and groundwaters.<\/p>\n

Local and global\u00a0<\/strong><\/p>\n

In Kanpur, the team is piloting a secondary filtration treatment system as well as \u201cpolishing\u201d technologies to remove contaminants including chromium.<\/p>\n

First, a specific type of membrane filters the sewage by separating it into \u201cpermeate\u201d, which is water that will be reused, and \u201cretentate\u201d, which is the remaining organic matter.<\/p>\n

Constructed wetlands then further clean the permeate. A combination of sorbent substances specifically designed to remove pollutants can also be added at this stage. These are known as polishing technologies.<\/p>\n

Even the compounds such as chromium can be returned to the circular economy system if collected in sufficient quantities.<\/p>\n

The project\u2019s local industry partners have a big role to play, working with a knowledge institute called IIT Kanpur.<\/p>\n

\u2018They are testing out the treatment systems in Kanpur and could easily scale these up if they see the benefits,\u2019\u00a0said Campling. \u2018We want to reach the point at which local companies could take the technologies further once the project ends.\u2019<\/p>\n

The hope is that the approaches become embedded in the industry\u2019s decision-making and are recognised by local authorities.<\/p>\n

The activities could ultimately yield benefits far beyond Kanpur and India, which\u00a0this week<\/a>\u00a0overtook China as the world\u2019s most populous country.<\/p>\n

\u2018If it works well in India, it will probably work well in Africa and South America too,\u2019 said Campling.<\/p>\n

Research in this article was funded by the EU. The article was originally published\u202fin <\/em>Horizon<\/em><\/a>, the EU Research and Innovation Magazine.\u00a0<\/em><\/p>\n

More info<\/p>\n