Industrial Wastewater Recycling Crucial to Conservation Efforts
Given that the oceans make up more than 70% of our planet’s surface and account for more than 96% of all water on earth, one might reasonably expect that there was little chance we would experience shortages. Though only a little saltier than blood plasma, ironically, that small difference can be sufficient to cause death by dehydration, should anyone be forced to drink seawater for a protracted period. That which is both safe and accessible is confined to rivers, lakes, and underground aquifers. Consequently, industrial wastewater recycling is crucial if we are to ensure these vital sources are kept free of harmful contaminants.
As part of their routine operation, many industries are required to employ corrosive or toxic chemicals that, upon completion of a particular process, are of no further use. In the past, many simply disposed of their contaminated effluents into the surrounding area, allowing them to penetrate the ground and eventually to pose a threat to both surface and subsurface reserves of potentially potable water. Once made aware of this serious danger to public health, governments introduced legislation governing the permissible composition of the effluent from factories. While some settled for suitable pretreatments to conform with legislation, others adopted. industrial wastewater-recycling programmes as a more conservative approach. The latter offers the dual benefit of being eco-friendly and reducing operating costs by enabling the reuse of a resource already paid for.
Treatment plants for on-site use are available in a variety of forms, depending upon the nature of the contaminants present in the effluent. That which has been treated to render it safe for disposal will find its way first into surface water and underground aquifers, eventually to be processed by one of the nation’s municipal treatment plants to render it potable before redistributing it to local consumers, rather like industrial wastewater recycling, though on a far larger scale.
Though mining, construction, and manufacturing, in general, are all major consumers of water, it is the agricultural sector that is the thirstiest by far. Arable and livestock farming accounts for more than 60% of South Africa’s total consumption and thus every drop re-used by the nation’s farmers can represent a significant addition to the increasingly important efforts by the nation’s consumers to conserve this precious life-giving resource. In the case of farmers, industrial wastewater recycling can at least allow the reuse of treated effluent for purposes such as irrigation, cleaning agricultural equipment, and even for watering game animals.
With some further treatments to rid it of potentially harmful bacteria, the recycled agricultural effluent could even be made sufficiently pure for human consumption. At the same time, a valuable byproduct of the processing is a sludge from which it is possible to recover methane. Because this is a natural fertiliser, its use offers yet another way in which farmers can reduce their costs.
A number of different technologies are commonly used for industrial wastewater recycling. Of these, the simplest, and normally the first stage of several, is filtration, during which any large solids present in the effluent are physically separated. Following filtration, the attention switches to the smaller, insoluble particles present with the introduction of a clarification stage. Often, these will settle out under the action of gravity but some extra-fine colloidal particles may first need to be aggregated by the addition of a chemical flocculant in order to form particles that are sufficiently dense to sediment out.
Following first physical and then chemical treatment, the next steps in the process of industrial wastewater recycling require the use of biological action. With the goal of removing any dissolved organic material present, the pretreated effluent is next subjected to successive aerobic and anaerobic digestion stages and on completion, the clear, colourless, and odourless final product may be safely disposed of or reused for selected purposes according to the company’s requirements.
Whether for use in industries such as petrochemical, pharmaceuticals, automotive manufacturing, or food and beverages or for the commercial production of drinking water, efficient treatment plants have long since become vital as part of a planet-wide campaign to manage this dwindling resource. It is a campaign that requires not only industrial wastewater recycling but also similar efforts on the part of domestic consumers and it is one to which WaterIcon, a company widely acknowledged as one of South Africa’s leaders in water treatment technologies, is totally dedicated.