Recent changes in legislation have forced UK industries to seek alternative methods for sludge disposal. When the dried sludge is processed in a particular way a marketable product can be created. For example it can be used as a fuel source for incinerators, as a construction material or as a fertilizer/solid conditioner. For each of these uses different attributes are important and gaining a level of consistency is essential. Therefore, product characterisation is very important. Standard sludge characteristics such as; dry solids, volatile solids content, pH, FOG (fats, oils and grease) and nutrient content all have well defined analytical procedures.

Knowing the fibre content within dried sludge is gaining relevance as research has shown it has significant effects on the physical characteristics of dried sludge e.g. bulk density. One problem is that the proportion of secondary sludge being treated has increased. Secondary sludges tend to have fibre content and this can lead to a dried sludge that disintegrates easily, making it unsuitable for disposal to land due to the dust levels generated. Once the fibre content has been obtained sludge streams can be blended in proportions that create a product that meets the required criteria.

Aqua Enviro provides a full range of sludge analysis including a fibre content service. The standard fibre content service provides:

•  Total Solids
•  Total Volatile Solids
•  % Fat, Oils and Grease
•  % Inorganic & Fibre of dried sample
•  % Fibre of Dried sample
•  Photomicrograph

Turnaround time is sample dependent.

•  If dried sample provided – 2 days
•  If liquid sample provided – 2 to 4 days