Agriculture and Environment: Rubber
Better Management Practices: Processing & Wastewater Management
There are several different practices that can be used to treat effluent from rubber factories prior to release or use as a soil amendment.
In countries such as Malaysia treatment before release into natural waterways is required and increasingly enforced.
A number of different treatments have been developed. For example, rubber factory effluents can be treated in an anaerobic pond system, in oxidation ditches, or in algae pond systems.The settling ponds technology
However, the most common effluent treatment technology, which is the use of settling ponds, has a few drawbacks - not the least of which is that it takes sixty days (Goldthorpe 1993). That means that a considerable volume of water has to be held over time for treatment. Creating the treatment ponds requires a large area of land, construction expenses, and time.
Increasingly, effluent is tested and processing plants are required to reach certain levels of quality before they are allowed to release the material. Many rubber producers prefer to apply the effluent to their plantations as a soil amendment rather than to treat it to the level required before legally releasing it into rivers and streams.
Good results have been reported from the experimental application of this effluent either through furrow irrigation by gravity, piped irrigation with sprinklers or trickle nozzles, or spray guns from tankers (Goldthorpe 1993).
Prior to application, however, the rubber particles need to be removed. This can be done through rubber traps or by allowing the effluent to sit for three days so the particles settle out. The effluent has a foul door, but this can be mitigated by adding microorganisms that partially decompose the compounds.
One experiment has shown that the effluent can be concentrated into a slurry with up to 60 percent solids or further concentrated into a powder. Both make effective fertilisers (Panfilo Tabora, personal communication). Apparently, such applications do not result in a build-up of toxic substances in the soil.
