|Sourcebook of Alternative Technologies for Freshwater Augmentation in Africa (International Environmental Technology Centre - United Nations Environment Programme, 1998, 182 p.)|
|Part B - Technology profiles|
|3. Mining and industry|
|3.3 Wastewater treatment technologies and reuse|
A major thrust in the treatment of industrial effluent is to minimise the impact of pollutant loads leaving a factory premises and to promote an higher degree of water reuse within the factory. This involves the removal of excess carbohydrates (oxygen-consuming substances), cooling, removal of nitrates, and removal of heavy metals. Technologies which are applicable in various industrial situations have been developed within each major industrial sector. These technologies, then, act as a guideline for other industries to follow and as guidelines for local authorities in prescribing pollution control requirements for other, similar sector industries.
Extent of Use
Various guides in the “Water and Wastewater Management” series have been produced by the Water Research Commission in South Africa. These guides currently govern water and wastewater management in the following industries: malt and brewing; metal finishing; soft drinks; dairy; sorghum malt and beer; edible oils; red meat; laundry; poultry; tanning and leather finishing; sugar; paper and pulp; wine; and, textiles.
Operation and Maintenance
The operation and maintenance of the various technologies used in industry are industry specific, and implemented on a site-specific basis by individual manufacturing companies.
Level of Involvement
Each proprietor is responsible for the implementation of those guidelines most relevant to their industry. However, government involvement is often a prerequisite in the formulation of relevant pollution control regulations, and an enforcement agency might also oversee policing. Sometimes, industry councils or cooperatives may impose a degree of self-regulation upon their membership to reduce the need for governmental regulation of their industry.
The costs are technology- and industry-dependent.
The suite of technologies used to minimise water pollution have proven to be an effective water conservation technique which should be appropriate throughout Africa.
Reuse limits water wastage and wastewater treatment processes ensure that contaminants that would otherwise be pollutants are reduced or eliminated from the waste stream, resulting in better quality water downstream and overall benefit to the environment and other users.
Water reuse and reclamation within industries provides surplus water than can be used to meet other demands.
Some investment in equipment is almost always required. Operator training to ensure the optimal functioning of this equipment is essential.
Further Development of the Technology
Other industrial processes need to be evaluated with respect to their water saving potential. In South Africa, the Water Research Commission is continuing to gather and interpret data from various industries, and is publishing further guides in their “Water and Wastewater Management” series.
Council for Scientific and Industrial Research - Division of Water Technology, Post Office Box 395, Scientia, Pretoria, South Africa.
Water Research Commission, Private Bag 824, Pretoria 0001, South Africa.
Department of Water Affairs and Forestry (South Africa), Private Bag X313, Pretoria 0001, South Africa.
Holland, J.R. 1993. Infrastructural Analysis, Volume V: Water. Coopers and Lybrand Associates, Harare, p 60.