Safe Sludge Matrix

Figure 11.3 Applications of sewage sludge on different types of crops as defined within The Safe Sludge Matrix, available online from www.adas.co.uk.

Once the soil had settled after tillage, the designated containers and the six lysimeters were amended with sewage sludge pellets at a rate corresponding to about 20 tonnes per hectare. This exceeds the maximum rate specified in the Safe Sludge Matrix, but was considered necessary because the measured concentrations of tritium in the pellets were lower than had originally been expected. The pellets were incorporated into the top... 

Sometimes it is impossible to effectively design out waste, and safe means have to be found to dispose of it. Many industrial processes produce relatively high levels of waste in a finely divided or dispersed form, such as ash, contaminated soil, treatment sludges, and so forth. This contaminated material is difficult to handle and process. A common approach to tackling this problem is to stabihse and sohdify the waste using a binder that immobilises contaminants within a hard matrix. This does not destroy the contaminants, but keeps them from moving into the surroimding environment. 

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