Resource detail

Background

When toxic substances enter water bodies they lie suspended in water, are deposited on the river bed or are dissolved. Due to rapid industrialization of India over the last 50 years, water pollution is concentrated to a few sub-sectors mainly in the form of toxic wastes and organic pollutants, which are readily identifiable. A substantial portion of this pollution can be attributed to the textile industry.

Lying in the north-eastern region of Rajasthan along the banks of the Luni River, the towns of Balotra and Jasol in the Barmer District are bustling hubs of textile activity, where hundreds of small scale textile units carry out various operations of dyeing, printing and washing. The village Bithuja, 5 kms upstream from Balotra is a cluster of textile pre-processing units.

Table 1: Various processes carried out in the textile units at Balotra, Bithuja and Jasol:

Source: Wastewater Management in Textile sector, Indian Journal of Environmental Protection, Vol 31, No. 1, January 2011

A typical pre-processing unit requires on an average 350-450 m³ depending upon the quantity of cloth washed, which is supplied from either groundwater or tankers from nearby areas. Water for human consumption is sourced from water tankers from nearby areas as groundwater is deemed unfit for human consumption.

Discharge of untreated industrial effluent has long been a contentious issue. This subject came to be highlighted, when the existing common effluent treatment plant (CETP) of 6MLD capacity was deemed unfit to process the industrial wastewater released by more than 800 textile units.

Table 2: Characteristics of combined wastewater in mg/L

Source: Wastewater Management in Textile sector, Indian Journal of Environmental Protection, Vol 31, No. 1, January 2011

Due to the nature of the industry COD, BOD, SS and other parameters mentioned above are quite high in Balotra. However the comparatively low BOD to COD ratio in Balotra indicates substantial non-biodegradable elements in the wastewater. The presence of oil and grease is attributed to the establishment of synthetic textile processing units. The wastewater from Bithuja and Jasol in contrast, has a high BOD to COD ratio pointing toward better biodegradability of the wastewater.

Initiative

The Balotra Water Pollution and Research Foundation Trust (BWPRFT) retained NEERI in 1993 to conduct a feasibility study for the wastewater generated by the industrial units. Subsequently a 6MLD CETP was established to cater to an outflow of 5.7 MLD generated by approximately 319 small scale processing units in the RIICO estate based in Balotra.

Table 3: Daily wastewater flow in Balotra, Bithuja and Jasol

Source: Wastewater Management in Textile sector, Indian Journal of Environmental Protection, Vol 31, No. 1, January 2011

The rise in purchasing power has increasingly generated a demand for improved consumer goods and infrastructural inputs. Easy availability of finance and an ever expanding consumer base has seen a rapid increase in the number of small scale industries increasing from 319 plants to more than 600 small scale units generating about 11.5-12 MLD of wastewater.

Needless to say the existing CETP was insufficient to cater to such large amounts of effluents. By virtue of their economics of scale, lack of affordable and cost effective treatment technology and their unplanned growth, these units individually have been unable to comply with environment standards, the problem compounded by their large numbers and diverse production activities. Thus, it is not feasible to set up individual treatment plants for each of these processing units. Also, the processing units in Bithuja and Jasol had no effluent treatment facility at this time, consequently discharging their industrial waste directly into the Luni River.

Table 4: Pollution loads in the region

Source: Wastewater Management in Textile sector, Indian Journal of Environmental Protection, Vol 31, No. 1, January 2011

TERI, New Delhi in its project report for 2003 suggested to the Ministry of Textiles the construction of additional 12 MLD CETP at Balotra and a new 30 MLD CETP at Bithuja to tap into the wastewater, which at this time was discharged untreated into the river.

Figure: Treatment scheme of 30 MLD CETP at Bithuja

Source: Wastewater Management in Textile sector, Indian Journal of Environmental Protection, Vol 31, No. 1, January 2011

Outcome/ Benefits

By establishing a CETP, the processing units have not only saved on capital, operations and trained manpower costs which they would otherwise have to bear individually, but also on land costs. The processing units so set up would need to create space from existing landholdings or purchase more land if singular treatment plants were to be established, which given the small nature of these units, was a difficult proposition.

The neutralization and equalization of heterogeneous waste makes its treatment techno-economically viable, the contribution of nutrient and diluting potential has made the complex industrial waste more amenable to degradation, the disposal of wastewater and sludge becomes more organized and is assured to be viable environmentally. More importantly, it ensures better compliance to environmental standards as the regulatory authority has a can monitor the station with ease.

Given the sandy nature of the soil in the region, the industrial effluent discharged without treatment would seep into the ground and contaminate groundwater already deemed unfit for human consumption. Through the construction of this CETP and a related network for transfer of wastewater to the plant, a potentially disastrous environmental problem has been averted.

The Luni River having suffered years of abuse is now able to slowly regain its ecological balance. The following table shows the results of the tests carried out on samples collected from the river and groundwater.

Table 5: Results of pre and post water quality monitoring in mg/L

Source: Wastewater Management in Textile sector, Indian Journal of Environmental Protection, Vol 31, No. 1, January 2011

Other benefits from the CETP include better aesthetics of the area, the option to recycle the treated water, creating awareness towards the environment and compliance of the prescribed environment standards.

While the establishment of the CETP was due to regulatory pressure, the community has also come forward in an effort to minimize the wastewater at its source. A workshop on “Cleaner Production” organized by TERI in collaboration with the Gandhi Nagar Cleaner Production Centre identified 3 industrial units to carry out the CP Assessment. Various steps of the CP audit involve:

- Detailed study of product, raw material and by-product

- Detailed process study including flow diagram with input and output

- Material balance in major operations

- Water balance

- Efficiency analysis of boiler

- A general electrical audit

- Identification of major waste stream and its cost

- Identification of Cleaner Production options based on above study

- Preparation of a Cleaner Production implementation plan

Imminent Concerns and Prospects

As can be seen from table 5, there has been a significant improvement in the water quality after the construction of the effluent treatment plant. However, given the increasing presence of small scale industrial units dotting the banks of the Luni, it is apparent that soon, the outflow of wastewater shall surpass the treatment capacity of even these newly constructed CETP’s. the regulatory authority must ensure that in such a scenario, the environment standards are met either through fresh CETP’s or by reduction in the quantity of wastewater so generated.