Can sewage help fix our country’s energy requirement?
Summer in India is extremely hot, many states are already amid droughts. At the same time, water-intensive agriculture, rapid urban expansion, increased industrial activity and increased energy production are pushing up the country's water demand. It is now believed that more than half of India is severely plagued by water. Part of the problem is that India manages water as an infinite resource with a linear model of abstraction, consumption, and disposal. However, a more efficient management model is to look at water from a "circular economy" perspective. The water does not have to end when it is drained into the drain. Rather, industrial and household wastewater can be seen as a valuable resource with available water, nutrients, and even renewable energy.
Sewage treatment plants in most cities are basic:
Wastewater treatment plants in most cities are basic. Sludge- energy systems can fulfil the dream of a circular closed cycle of sewage treatment by turning waste into inputs rather than outputs. These systems can be developed as independent distributed units that require minimal external energy to operate. From raw sewage, we produce useful products: energy, solid digested material,and water, which can be reused for agriculture, industry and even household use such as watering gardens and washing toilets.
This is how it works.
The sewage treatment plant first separates the wastewater into solid "sludge" and liquid water. This methane-rich sludge then uses biogas to remove pathogens quickly and efficiently through two processes: thermal hydrolysis and anaerobic fermentation. The resulting biogas can be used as on-site energy for operating sewage treatment plants, or further refined and sold as natural gas. In addition, the solid digested material remaining after anaerobic digestion can be used for soil improvement. (However, if the digest contains certain heavy metals, it may not be suitable for use on land.)
Depending on the economic needs of the facility and the technical capabilities of its operators, what type of sludge energy technology can be used, should be chose. This criterion has been selected to be incorporated into existing sewage treatment plants, reducing the need for new infrastructure. This saves time, space, and money.
The urban population of India is so large that its wastewater treatment system cannot keep up with the amount of human waste it produces. We have the capacity of treating only 37% of sewage and that’s only if they operate at maximum capacity continuously. Even less than 37 percent of sewage is probably treated—the rest is dumped in waterbodies or on land. Sewage that is not treated contains large concentrations of pathogens and other contaminants that makes people sick.
The government is pushing for new policies to efficiently deal with Sewage problem.Despite these policies to deal with urban sanitation, there`s been limited uptake of traditional wastewater treatment facilities due to problems such as high installation capital and maintenance costs, the large amount of energy required to run such units, and the need for trained technical staff. In addition, traditional treatment plants require large amounts of additional space in India`s alreadydense urban areas. Non-traditional, smaller sludge to energy systems could overcome these barriers by selling natural gas and digestate for revenue, and by using biogas to meet energy needs onsite. Sludge to energy systems can help wastewater treatment become financially feasible, provide renewable energy, and reduce greenhouse gas emissions—all while helping to meet India`s growing water and sanitation needs.
For more information, contact Netsol Water Solutions!