ENVIRONMENTAL  EFECT OF LEATHER SUGAR AND DISTILLERIES 

Environmental impact of leather industries

Leather is a product with high environmental impact, most notably due to:

·         the impact of livestock

·         the heavy use of polluting chemicals in the tanning process

·         air pollution due to the transformation process (hydrogen sulfide during dehairing and ammonia during deliming, solvent vapors).

·         Leather biodegrades slowly; it takes 25–40 years to decompose.

One tonne of hide or skin generally leads to the production of 20 to 80 m³ of wastewater including chromium levels of 100–400 mg/L, sulfide levels of 200–800 mg/L and high levels of fat and other solid wastes, as well as notable pathogen contamination. Pesticides are also often added for hide conservation during transport. With solid wastes representing up to 70% of the wet weight of the original hides, the tanning process comes at a considerable strain on water treatment installations.

Tanning is especially polluting in countries where environmental regulations are lax, such as in India, the world's third-largest producer and exporter of leather. To give an example of an efficient pollution prevention system, chromium loads per produced tonne are generally abated from 8 kg to 1.5 kg. VOC emissions are typically reduced from 30 kg/t to 2 kg/t in a properly managed facility. A review of the total pollution load decrease achievable according to the United Nations Industrial Development Organization posts precise data on the abatement achievable through industrially proven low-waste advanced methods, while noting that "even though the chrome pollution load can be decreased by 94% on introducing advanced technologies, the minimum residual load 0.15 kg/t raw hide can still cause difficulties when using landfills and composting sludge from wastewater treatment on account of the regulations currently in force in some countries."

In Kanpur, the self-proclaimed "Leather City of World" and a city of 3 million people on the banks of the river Ganges, pollution levels were so high that despite an industry crisis, the pollution control board has decided to seal 49 high-polluting tanneries out of 404 in July 2009. In 2003 for instance, the main tanneries' effluent disposal unit was dumping 22 tonnes of chromium-laden solid waste per day in the open. Scientists at the Central Leather Research Institute in India have developed biological methods for pretanning as well as better chromium management.

The higher cost associated to the treatment of effluents that to untreated effluent discharging leads to illegal dumping to save on costs. For instance, in Croatia in 2001, proper pollution abatement cost 70-100 USD/t of raw hides processed against 43 USD/t for irresponsible behavior.

No general study seems to exist but the current news is rife with documented examples. In November 2009 for instance, it was discovered that one of Uganda's main leather producing companies directly dumped its waste water in a wetland adjacent to Lake Victoria.

Environmental impact of Sugar Industries

According to the World Wildlife Fund (WWF), roughly 145 million tons of sugars are produced in 121 countries each year. Sugar production does indeed take its toll on surrounding soil, water and air, especially in threatened tropical ecosystems near the equator.

Responsible for more biodiversity loss than any other crop, due to its destruction of habitat to make way for plantations, its intensive use of water for irrigation, its heavy use of agricultural chemicals, and the polluted wastewater that is routinely discharged in the sugar production process.

One extreme example of environmental destruction by the sugar industry is the Great Barrier Reef off the coast of Australia. Waters around the reef suffer from large quantities of effluents, pesticides and sediment from sugar farms, and the reef itself is threatened by the clearing of land, which has destroyed the wetlands that are an integral part of the reef’s ecology.

Meanwhile, in Papua New Guinea, soil fertility has declined by about 40 percent over the last three decades in heavy sugar cane cultivation regions. Some of the world’s mightiest rivers—including the Niger in West Africa, the Zambezi in Southern Africa, the Indus River in Pakistan, and the Mekong River in Southeast Asia—have nearly dried up as a result of thirsty, water-intensive sugar production.

In the United States the health of one of the country’s most unique ecosystems, Florida’s Everglades, is seriously compromised after decades of sugar cane farming. Tens of thousands of acres of the Everglades have been converted from teeming sub-tropical forest to lifeless marshland due to excessive fertilizer run-off and drainage for irrigation.

A tenuous agreement between environmentalists and sugar producers under a “Comprehensive Everglades Restoration Plan” has ceded some sugar cane land back to nature and reduced water usage and fertilizer run-off. Only time will tell if these and other restoration efforts will help bring back Florida’s once teeming “river of grass.”

Distilleries  

Distilleries are one of the 17 most polluting industries listed by the Central Pollution Control Board. At present, there are 319 distilleries in India with an installed capacity of 3.29 billion lit. of alcohol. The cane growing states like Uttar Pradesh and Maharashtra have the highest installed capacity constituting more than 40% of the total installed capacity, followed by Madhya Pradesh (14.2%) and Tamil Nadu (9.7%).

For every litre of alcohol produced, molasses based distilleries generate 8-15 l of waste water characterized by high BOD and high COD. The effluent causes apprehension of environmental pollution owing to its very high organic content. Many a times this wastewater is discharged in the water bodies either untreated or partially treated, resulting in depletion of oxygen causing wide spread mortality of aquatic organisms. As the effluent contains considerable amount of organic matter and plant nutrients, particularly potassium and sulphur, this can be applied to arable land as irrigation water and as an amendment. When applied to crops it may act as a source of plant nutrients (N, K, P, Ca, S, Cu, Mn and Zn) and has been reported to increase the yield of the crops.