Polluting the Environment
IMK Senate House Campus
As per 1989 survey, India has the world’s largest population of livestock, with nearly 191 million cattle. 70 million Buffaloes, 139 million Sheep and Goat,10 million Pigs and over 200 million poultry. About 36.5% of Goat, 32.5% of Sheep, 28% of Pigs, 1.9% of Buffaloes and 0.9% cattle are slaughtered every year. The reported per capita availability of meat in India is about 1.4 kg per annum, which is rather low compared to 60-90 kg in European countries. As reported by the Ministry of Food Processing, as of 1989, a total of 3616 recognized slaughter houses slaughter over 2 million cattle and buffaloes, 50 million sheep and goat, 1.5 million pigs and 150 million poultry annually, for domestic consumption as well as for export purposes.
The slaughter houses come under the purview of the animal husbandry division of Ministry of Agriculture mainly for the purpose of funding towards expansion and modernization activities, the respective local bodies are mainly responsible for day-to-day operation/maintenance of the slaughter houses. Most of the slaughter houses in the country are service-oriented and, as such, perform only the killing and dressing of animals without an onsite rendering operations. Most of the slaughter houses are more than 50 years old without adequate basic amenities viz. proper flooring, ventilation, water supply, lair age, transport etc.
In addition to these deficiencies, slaughter houses suffer from very low hygiene standard posing a major public health and environmental hazards due to discrete disposal of waste and highly polluted effluent discharge. Unauthorized and illicit slaughtering has also increased manifold and thus the related problems.
The story isn’t different in the case of slaughter house of Kollam Corporation. Slaughter house of Kollam Corporation is situated in the banks of Ashtamudi Lake. The effluents & waste from the slaughter house is dumped in the nearby places & on to the lake, resulting in a polluted, unhygienic environment, that’s why our group took it as our third assignment of environmental management”
MAGNITUDE OF THE PROBLEM
With growing annual per capita meat consumption, high meat export potential, large non-utilization of potential meat animals, there is a rapid development of meat industry in India and also in Kerala. But neither the government nor the other firms where willing to use state of the art of technology available in global meat market.
The wastes from the slaughter house in Kollam, when dumped to the lake will pollute the lake and also result in harmful effects for the living organisms (fish, birds, humans, etc) which depends either directly or indirectly to the particular lake. The waste generated is almost wholly organic, chiefly having dissolved and suspended material.
The principal deleterious effect of these wastes on streams and water courses is their deoxygenating. The unattended waste also leads to polluted air and bad odour. The decaying wastes might become breeding places for bacteria’s and viruses which may result in many illnesses to both humans and other living organisms. Chances of epidemic are very high and the authorities responsible are not taking any action to manage the waste effectively.
WASTES OF SLAUGHTERHOUSE
During the operations of the slaughter house the waste generated is of liquid and solid nature
The solid wastes from slaughterhouses are varied depending on the kind and scale of operations. Usually the quantity of wastes per animal is large in small scale operations where the recovery of offal’s is ineffective. In simple operations animals are slaughtered and have a very limited amount of by-product processing. Its main products are fresh meat in the form of whole, half or quarter carcasses or in smaller meat cuts. While in modern complex slaughterhouse does extensive processing of by-products. In such plants at least three additional operations; rendering, paunch and viscera handling, blood processing, and hide and hair processing are taken place. By these operations maximum recovery of edible and inedible materials from the offal’s is done and that results less production of wastes.
The main wastes of small scale slaughterhouses in our country includes hides, skins, blood, rumen contents, bones, horns, hoofs, urinary bladder, gall bladder, uterus, rectum, udder, fetes, snout, ear, penis, meat trimmings, hide and skin trimmings, condemned meat, condemned carcass, esophagus, hair and poultry offal’s (feathers, head). Only few of these by-products can be used directly.
The data collected on the solid waste quantity generated in the bovine, goat, sheep and pig slaughter houses through a survey is shown in the following table 2
Average solid waste generation from bovine slaughter houses is 275 kg/tonne of live weight killed (TLWK) which is equivalent to 27.5 per cent of the animal weight. In case of goat and sheep slaughter house, average waste generation amounts to be 170 kg per TLWK which is 17 per cent of animal weight. Solid waste generation from pig slaughtering is 2.3 kg/head equivalent to 4 per cent of animal weight.
The solid waste of slaughter houses can be broadly classified into two categories i.e. vegetable matter such
as rumen, stomach and intestine contents, dung, agriculture residues, etc, and animal matter like inedible offal’s, tissues, meat trimmings, waste and condemned meat, bones etc. These waste streams can be segregated and treated separately.
Liquid waste in a slaughter house mainly consists of Blood from the animals, urine, and other such internal fluids along with the water that is used to wash the place.
Slaughter house waste contains mostly biodegradable matter. Characteristics of solid wastes from goat and sheep slaughtering are given in table 3.
Currently there is no organized system for the disposal of solid wastes in the slaughter house. The entire solid waste is collected and dumped in lakes or disposed of as land fill, dung and rumen digesta are collected separately for composting.
MEASURES PROPOSED TO IMPROVE THE SLAUGHTER
HOUSE WASTE MANAGEMENT
Management of Solid Waste
Since it’s a large slaughter house, the generated solid wastes, could be processed in environmentally acceptable manner. For the particular slaughter houses, Bio-methanation is suggested to manage the solid waste. Bio-methanation requires less space, which is advantageous for the slaughter house in Kollam which has land constraints. Biomethanation of slaughterhouse is done in many places. The success of the process, especially the effective removal BOD has led Biogas plant to be acceptable for slaughter house.
Biomethanation plant can be constructed in two ways. The gas is produced in one or more digesters and then it can be stored in a separate gas holder from where it is drawn as and when required. The other alternative is that the digester and gas holder are built so as to form one single unit. The gas is produced in the lower part of the structure, while the upper tank serves as a gas holder. While the second option is extremely simple and cheap in construction, but it has the disadvantage that gas production is affected during recharge. On the other hand, with a separate gas holder, continuous supply of gas can be assured even when one or more digesters are being charged. It is, therefore, more practicable for larger units to have separate gas holders.
During the operations of the slaughter house the waste generated is of liquid and solid nature. The liquid waste should be washed away by safe potable and constant supply of fresh water at adequate pressure throughout the premises of slaughtering. The waste water from slaughter house is heavy in pollution and, therefore, it should not be allowed to mix with the municipal drain system without pre-treatment meeting sewage standards as per the Bureau of Indian Standards (BIS).
The waste water treatment system should essentially comprise of:
- Ø Self cleaning type screening or two stage screening (Bar type)
- Ø Anaerobic treatment;
- Ø Aerobic treatment; and
- Ø Filter press for dewatering of the sludge.
Collection of Blood
The blood available from the slaughter house should be collected and made use of in pharmaceutical industry. Bleeding areas should be clearly identified in the slaughter house and blood drains should be and collection should be done immediately so that its full potential could be utilized.
Improved Method of Dressing
Adequate tools should be provided for dehiding of the animals, hides and skins should be immediately transported out of the slaughtering area in a closed wheel-barrow or similar other devices. In no case the hides and skins should be spread on the floor of the slaughtering area for inspection. Legs, bones, hooves etc. should also be removed immediately from the slaughtering area through a spring load floor chute or closed wheel-barrow.
At slaughter houses adequate compartments for immediate separation and disposal of condemned material must be provided. The authority must take care that intestines are not punctured during evisceration to avoid contamination of carcasses
Safe Disposal of Waste Products
Slaughtering of animals generates wastes consisting of non edible offal (like lungs, large intestines, various glands, animal tissues, organs, various body parts, etc.) stomach/intestinal contents, dung, sludge from waste water treatment, bones, etc. All these types of wastes are required to be disposed by adopting methods like rendering/controlled incineration/burial/composting/Anaerobic digestion etc.
The tropical climate of our state enhances the process of degeneration of any tissue material remaining as a waste in the premises of the slaughter houses. Therefore, the slaughter house premises always give a particular stink. In order to avoid this stinking odour proper ventilation of slaughtering halls, washing of the floors with non-poisonous disinfectants and if need be use of aerobic deodorants must be provided at each slaughter house.
Pests (insect, rodents and birds) should be controlled to prevent their access to slaughterhouses, production areas and storage departments. This is best achieved by the construction of buildings and working places where access of insects, rodents and birds is hindered, but it will be almost impossible to secure buildings totally against pests. However good designs and constructions may delay the entry of pests which is a worthwhile objective of an overall rodent control program. Even if the buildings are well-constructed and as pest-proof as possible it will be necessary to have a regular pest control.
Modernisation of Slaughter House
The slaughter house is controlled by local bodies, which should follow the standards prescribed, but due to non-existence of modernised slaughter houses, environmental pollution arising out of the slaughtering activities cannot be controlled. The local bodies must, therefore, take up modernisation of the slaughter house in Kollam and achieve the pollution control norms.
All most all by-product of slaughter house can be utilized. However, various circumstances do not always permit by-product recovery. The reasons may be inadequate quantity of materials, lack of markets, cost of processing etc. In such instances, they simply form part of waste lot for which different methods of processing and disposal have to be considered. For the slaughter house wastes composting, biomethanation and rendering systems are suggested.
Selection of appropriate method, however, depends mainly on type of wastes and its quantity. Incineration is also an option for treatment of slaughter house waste. An appropriate selection of the above mentioned method will lead to a cleaner, healthier, environment for the residence of the Kollam Corporation.