Development does bring about some environmental concerns. The manufacture of Sugar too, is associated with environmental concerns related to loss of habitat and biodiversity, pesticide and fertilizer run offs, loss of top soil, soil degradation and the impact of air and water Pollution. The Sugar Industry is placed in the Red Category of Industries as classified by the Central Pollution Control Board which includes highly polluting industries.
Like any responsible enterprise, the sector has worked very hard in the past years and has taken a number of steps to ensure robust environmental management and reductions in environmental impacts. All the Sugar mills in the state have installed adequate water and Air Pollution Control systems to the satisfaction of regulatory authorities and are meeting the prescribed standards. The provision of Sulphate removal systems, efficient condensate recovery and condensate polishing units have enabled the industry to recycle its waste waters optimally and bring about a reduction in fresh water use. Industries are now monitoring and auditing their water consumption to reduce wastages. The efforts of the industry towards recycle and reuse of hot water have considerably reduced the fresh water intake and industries now can even operate without any abstraction of fresh water. This has reduced the pressures on the ground water resources and made water availability easier for nearby competing water uses. Over the years, the Industry has also brought about a remarkable reduction in the volume of waste water discharged and is currently endeavoring to achieve waste water discharge of 200 liters per ton of cane crushed. There are some difficulties which the regulatory authorities may wish to examine and advise the industry accordingly. The reduction has eased pressures of disposal into land and inland surface waters. Air emissions from boilers have also been brought down to 150 mg/Nm3 to achieve improvements in ambient air quality.
As a part of their environmental commitments, most industries have undertaken adequacy assessment studies through institutions of repute and implemented measures to augment their environmental management systems.
Considerable work has also been done towards cost reductions and energy savings. The provision of diffusers for juice extraction, highly efficient cane preparatory devices, change to more efficient motors and gears, provision of condensate heaters, direct contact heaters and plate type heat exchangers has resulted in greater steam and power economy and lesser loss of sugar to bagasse. The Effluent treatment plants have been modernized and the provision of diffused air aeration system over the conventional surface air aeration in aerated lagoons has increased the efficiency of treatment. Traditional sludge drying beds have been replaced with mechanical filtering devices for dewatering of sludge.
Use of treated effluents in agriculture is an efficient approach for managing water resources and also for compensating water shortages caused by the irregular availability of water resources available for irrigation throughout the year. In addition it provides a source of plant nutrients and may augment growth and yield. The sugar industry has drawn up comprehensive irrigation management plans and has entered into agreements with local farmers to supply treated effluents for irrigation. This is helping farmers in a big way.
The Sugar Industry is also contributing significantly towards meeting the demands of ethanol for the ethanol blending program. Utilising ethanol blends reduces vehicular emissions. Carbon monoxide emission are 50% lower in two wheelers and 30% lower through four wheelers in E20 fuels as compared to unblended fuels. Hydrocarbon emissions may be lesser by 20%. The contribution of sugar mills in reducing green house gas emissions is significant. The 120 mills in U.P. contribute to the production of 175 crore liter of Ethanol annually.
Ethanol production is associated with the generation of large quantities of spent wash which are being currently treated through concentration and incineration and are less sustainable. Spent wash however also has a high energy, pesticidal, fertilization (being very rich in macro and micro nutrients with a power growth and yield augmenting records) and irrigation potential and can be used in agriculture as one time land application as per protocols developed by regulatory authorities. Regulatory authorities may need to encourage the use of Spent wash in agriculture. It is being internationally practiced. This will help substituting a considerable part of inorganic fertilizer costs and bring about an increase in growth and yield. Spent wash is also beneficial in sodic land reclamation and needs to be encouraged.
Biomass based cogeneration practiced by most of the mills has helped in making these units self sufficient in meeting their power requirements and also augment the power resources at the Grid. Biomass is a renewable source of energy and helps reduce the green house gas emissions and costs due to fossil fuel combustion. The production of electricity from sugar cane Bagasse presents a low carbon foot print (0.227 Kg Co2 equivalent/KWH) as compared to the diesel thermo electric process (1.060 Kg Co2 eq./KWH)
Dr. Yashpal Singh, Senior Advisor-Environment, UPSMA