India is currently witnessing challenging times with regard to the quality of water in its waterbodies. Most of the rivers have been polluted, some to the extent of having water that is unfit even for non-potable purposes. Factors such as unchecked disposal of waste, rampant discharge of sewage and industrial effluents, as well as large-scale deforestation along the basins have limited the capacity of rivers to meet the growing water demand. Industries have been a major source of pollution of waterbodies due to the disposal of partially treated or untreated effluents. However, with strict mandates from the government and pollution watchdogs, along with increasing consciousness towards the preservation of the environment, there has been a significant change in the attitude of industries towards this. Of late, they have become more receptive to the idea of deploying advanced technologies to treat effluents, as well as recycling and reusing them for industrial purposes and green belt development.
Generation and management
As per industry experts, the country’s industrial sector generates 500 million litres per day (mld) of effluents. Of this, the paper and pulp industry accounts for the maximum effluent generation of over 200 mld. Further, sectors such as power, steel, textiles, distilleries, refineries and sugar are other major contributors to effluent generation. At present, of the total effluent generation in the country, roughly 60 per cent is treated by the industries while the remaining is discharged into waterbodies.
In a bid to address the alarming rise in contamination of water resources, the government has come up with regulations that enforce the treatment and usage of effluent by industries. Stringent water usage rules have increased recycling and reuse initiatives by players, resulting in the setting up of a number of effluent treatment plants (ETPs). In addition, common effluent treatment plants (CETPs) have catered to the effluent treatment needs of small-scale industries. The CETPs not only reduce the cost of effluent treatment but also provide better collective treatment and reduce the land requirement for small-scale industries. Therefore, they capitalise on economies of scale while protecting the environment.
ETPs and CETPs offer a solution to water scarcity by facilitating recycling and reuse of water for operational purposes. The treatment methods used by these plants are often conventional. However, recently, there has been a shift towards advanced technological solutions for effluent treatment such as reverse osmosis, ultrafiltration, nanofiltration and membrane bioreactor. Industries are also increasingly adopting zero liquid discharge (ZLD) systems to ensure that no effluent leaves their premises, but is instead recycled and reused for their own operations, thereby cutting down the use of fresh water.
Regulations for effluent management
In a bid to monitor and regulate effluents generated by industries, the Central Pollution Control Board (CPCB) has developed industry-specific charters and guidelines. In addition, it has released emission norms for 56 sectors and effluent standards for 44 sectors. As per the guidelines, setting up of chemical recovery plants and the of ZLD standards have been made mandatory for agro-based paper mills and distilleries respectively. Further, water conservation measures have been made mandatory for the paper, sugar and textile sectors and the CPCB regularly evaluates the performance of the CETPs. To ensure compliance with regulations and norms, from 2016-17 onwards, the CPCB has been inspecting highly polluting industries, selecting them based on SMS alert systems generated by online continuous emission monitoring systems (OCEMs). The CPCB undertakes real-time monitoring of the water quality of waterbodies, and traces the pollution sources with the help of a live data feed on its portal. In addition, it inspects grossly polluting industries (GPIs) every year as per the centre’s directives. At present, about 815 out of 1,109 GPIs have OCEMs connected to the CPCB server. The respective state pollution control boards regularly monitor the compliance status of these GPIs. In a noteworthy development, the government has also released guidelines for groundwater management wherein no-objection certificates are not to be granted to any new industries in over-exploited zones, except those falling into the category of micro, small and medium enterprises. Besides, expansion of existing industries that need more water is not to be permitted, as per the guidelines. This calls for strict measures by industries to efficiently treat, manage and reuse the wastewater generated.
Technological developments in the field have been evolving quickly, with indigenous development of membranes for various applications including water recovery from effluents. The development of OCEMs allows remote monitoring of effluent levels in the water on a real-time basis. The system comprises a GPRS gateway and sensors that measure various parameters in effluents such as biochemical oxygen demand, total suspended solids, pH, flow and turbidity. At fixed intervals, 24×7, the system sends water quality readings to the central server. The system also sends alerts via SMS to the engineers, if the water quality readings exceed the prescribed limits. They ensure that effluent levels in the discharged water are within regulatory norms and any problem is identified immediately. These measures can lead to cost savings by increasing the efficiency of the treatment process. The adoption of OCEMs can lead to cost savings by increasing the efficiency of the treatment process.
Key sector-wise use cases
Steel Authority of India Limited is taking steps to set up treatment and recycling facilities in order to achieve ZLD at its plants. Of the three outfalls at the Bhilai and Bokaro steel plants, it has developed a facility for treatment and recycling of effluent from one outfall at each plant whereas the works for the remaining outfalls are under way. After treatment, most of the effluent is recycled back for steelmaking processes.
Another major player in the steel sector, JSW Energy has installed an effluent recycling plant at its Vijayanagar plant. Further, Tata Steel’s manufacturing facilities at Tata Steel Jamshedpur and Tata Steel Kalinganagar (TSK) have seen a considerable decline in the effluent discharge intensity. During 2018-19, the effluent discharge intensity at the TSK facility declined by over 50 per cent.
Among power sector players, NTPC Limited has set up an ETP with a capacity of 4.5 mld at Bharuch, Gujarat, whereas Jindal Steel and Power Limited has set up a 8.64 mld ETP at Angul, Odisha. Further, Torrent Power implemented ZLD systems at its SUGEN plant and DGEN plant in August 2017 and April 2016, respectively, to facilitate reuse and recycling of effluents.
A number of CETPs have been set up by textile sector players. Some of the key CETPs in the sector are Palsana Gujarat Eco-Textile Park Limited, Baleshwar in Surat (60 mld), Bithuja CETP in Badmer (30 mld), Taloja CETP Cooperative Society Limited in Thane (22.5 mld), and S.P.I. Sangaria Industrial Area, Phase II, in Jodhpur (20 mld), amongst others.
Further, in a major development, Indian Oil Corporation Limited is undertaking a project to make the Mathura refinery the first one to use 100 per cent effluent discharge and sewage water for industrial use. In 2019-20, it successfully recycled about 87 per cent of the effluent generated. It has one of the largest ETPs in the refinery sector located at its Paradip refinery, with a treatment capacity of 48 mld. Another ETP with the same treatment capacity has also been set up by Reliance Industries Limited at the Jamnagar refinery.
The way forward
The industrial segment has been facing water scarcity in the past few years. The situation has only worsened over time, bringing to the fore the need for the sustainable practices with regard to effluent management. Developments such as the Global Reporting Initiative, introduction of the Corporate Social Responsibility Act, 2013, and the threat to operational continuity on the back of non-availability of water has led many companies to set up captive wastewater treatment plants or ETPs and look for alternatives. Besides, most of the states and union territories have introduced acts and laws mandating that certain industries adhere to water consumption and effluent discharge norms.
Going forward, the imposition of stricter penalties for failure to effectively treat and manage effluents will play a crucial role in the wastewater treatment industry. In the past, judicial directives such as ruling for textile industries discharging untreated effluents in waterbodies by the Madras High Court have proved to be pivotal in effluent management. Besides, the evolving technology landscape with respect to innovative treatment solutions will open up opportunities for other stakeholders such as technology developers, equipment suppliers and consultants.