As India progresses rapidly to achieve its development objectives and become a multi-trillion-dollar economy, the consumption rate of natural resources will undoubtedly be high. For leap-frogging in any sector, water is the most essential resource in any sector. Water is an integral element in all sectors of the economy, with varied uses and utilization extent. As per the report of the National Commission for Integrated Water Resources Development (NCIWRD), the demand for freshwater in India will reach 973 to 1180 billion cubic metres (BCM) by the year 2050, while the utilizable water quantity is 1,126 BCM.
A huge amount of the freshwater gets wasted in India. According to data on population projections, wastewater generation is expected to rise by roughly 75–80% during the next 25 years, or 50000–55000 MLD by volume. The total predicted wastewater generation will reach about 1.3 lakh MLD. By 2050, the total annual wastewater volume is predicted to approach 48 BCM, with an extra 0.8 BCM of wastewater generated annually at this rate. This amount is roughly 3.5 times the installed wastewater treatment capacity currently in place. It clearly shows the high need for wastewater treatment plants across different sectors and industrial plants.
There are various reasons that make wastewater management quite challenging in India. Some of the major reasons are the mixing of all kinds of used water, lack of sewage networks, issues related to improper/lack of maintenance, and a major misconception about the abundance of freshwater availability. However, the most prevalent reasons are the gap in the existing treatment capacity and the lower penetration of advanced treatment technology in wastewater treatment plants in the industries.
As the industrial plants are still utilizing outdated wastewater treatment technologies, only one-third of its sewage load is being treated which is equivalent to 9.81 BCM annually. This scenario will further aggravate as the demand for water will increase. Furthermore, the treatment capacity is not expanding at the same rate as urbanization. Also, there is a significant gap between installed capacity and actual utilization.
The technological gap in the treatment capacity is the biggest challenge in effectively managing industrial wastewater. The untreated water finds its way to freshwater sources or aquifers, thus adding stress to freshwater availability. In addition to this, the lack of a sewer network, connectivity issues, and the capability of wastewater treatment plants to handle peak loads also affect the efficiency of sewage collection.
Another major parameter in the wastewater treatment technology used in industrial plants. In India, although there are advanced wastewater treatment technologies available, the most prevalent technologies are the Activated Sludge Process (ASP) and the Sequential Batch Reactors (SBRs). Advanced wastewater treatment technologies include Reverse Osmosis, Ion-Exchange Method, Moving Bed Biofilm Reactor, Zero-Liquid Discharge, and others.
Currently, in India, most of the treated wastewater is either released into rivers and streams or used for watering parks, lawns, and other public places. However, its reuse for other non-drinking purposes, like farming, industrial use, and replenishing groundwater, is still uncommon. Only a fractional part is put in high utility, even though it can help in reducing the huge shortage of water.
As per the data shared by CPCB, less than 1,000 MLD (about 3% of treated wastewater and 1% of total wastewater) is used for meaningful purposes. The underutilization of the treated wastewater effectively wastes valuable resources, the money spent on wastewater treatment plants, and the costs of wastewater treatment.
There are several benefits of using the treated wastewater. First, it helps in maintaining the health of the soil and prevents the contamination of groundwater. Second, it reduces the health problems that can arise from exposure to polluted water and food grown with untreated water. Third, it can replace or supplement freshwater resources for irrigation, which can help manage a major problem of excessive usage of groundwater.
The usage of treated wastewater in agricultural fields in the proximity of wastewater treatment plants, which were otherwise being irrigated from a much farther water source, can reduce water distribution losses to a great extent. Further, the treated wastewater could be clubbed with micro-irrigation methods for horticulture crops. Thus, the actual savings on fresh water will be much more than the quantity of TUW used for irrigation.
The quality of agricultural land soil has decreased due to nutrient depletion from water erosion and other land degradation problems. The soils of most states in India are lacking in important micronutrients such as zinc and macronutrients like nitrogen, phosphorus, and potassium. Due to the efficiency of nutrients, crop yields decline, and more artificial fertilizer is required. This issue can be resolved by carefully using nutrient-rich treated wastewater, which will partially offset the need for chemical fertilizers.
Creating demand for wastewater is highly required to ensure the sustainability of the reuse of treated wastewater. Since freshwater is almost free of cost, it is quite difficult to raise awareness among people of the benefits of using wastewater that aligns with sustainability. There should be clearly visible and convincing advantages to using treated wastewater, or there must be reasonable pricing for the freshwater. While the latter option doesn’t seem to be easy to implement, the former option could be tried out in select and specific areas where there is no bounty of free freshwater.
The needs, benefits, and necessity of recycling treated wastewater for productive purposes are well acknowledged. In order to promote the reuse of treated wastewater, various states in India have developed policies in this regard. Reusing treated wastewater in urban and peri-urban agriculture is crucial due to the high rate of urbanization in India, which acts as a strong catalyst for freshwater demand.
At Wipro Water, we encourage the usage of advanced wastewater treatment techniques for industrial plants that yield high-quality treated wastewater. Our wastewater treatment solutions treat industrial wastewater, which can be further used for human consumption, reuse in industrial plants, discharge into freshwater bodies, and other purposes.