The darkroom work in photography by its very nature produces waste products, the photographer should be aware of the nature of these products and what can be done to minimize their impact on environment. The responsible disposal of waste produce in laboratories is an important function in the equation that balances the environmental friendliness, general health of staff, and workflow management in laboratories. Materials for recycling come in many forms- plastics, metals ands even cameras. Some of these may be immediately recyclable by the photographic companies while other materials may not be easily recyclable. A photographic film typically comes in two forms - sheet or roll-and is made from cellulose triacetate, PET (polyester), or PEN (plastic). Photographic film waste is usually a developed negative that displays an image of poor quality. Discarded film may be thrown out as a result of process problems, over-or under-development, or poor inventory management.
The recyclablity of different types of film depends on factors such as the film type, the market place for recycled material, the proximity of facilities available for recycling. Many types of film are recycled because of the resident silver and plastic support value. Polyester film is typically used for medical and industrial x-ray and aerial films. The polyester film can be recycled once its coatings are removed. Film negatives used for motion pictures are composed of triacetate. Acetate based films are identifiable because they can be easily torn. Acetate based film can be recycled easily. The most dangerous film is nitrate based film used in motion picture industry. Most companies have stopped manufacturing this type of film. Nitrate film will typically decompose into unstable products. We should take special precautions when handling, storing, and moving this material. The film should be disposed of as a hazardous waste.
The factors affecting waste management are volume of effluent, temperature of effluent, types of chemicals used, and the ratio of chemical waste to waste water. Photographic chemicals are generally bio-degradable and will not harm municipally run biological treatment systems. It is not advisable to discharge photographic wastes directly into a septic tank and/or leach field unless the amount is small in comparison to domestic discharge volumes or has been greatly diluted. The photographic silver effluent in the waste water is in the form of soluble silver thiosulfate is converted by Municipal Processing Plants into soluble silver sulfide and some metallic silver. Since the earth and its resources are finite, photographic chemicals should be conserved and recycled whenever possible. The use of replinshers instead of one-shot chemistry is advised were feasible.
The main photographic chemical that is recycled is silver. It can be removed from fixing baths by several methods-metallic replacement, electrolytic recovery, and ion exchange. For larger, commercial photographic darkrooms with high flow rates, electrolytic or ion exchange are economically reasonable. One of the prime requirements by any recycling facility is the proper storage and shipping of the materials to be disposed. By this way we not only save the cost of proper disposal, it also covers up the cost in terms of the efforts and time spent.
About Author / Additional Info:
Department of History,
Madras Christian College(Autonomous),
Tambaram, Chennai-6000 59.