The processed slurry may be treated with a halide to reduce mercury emissions in the final product.

A filtering plant has a reactor that causes sludge previously treated with chemicals to flocculate.

The electroporated-treated sludge releases hitherto unreleased biosolids exiting from the PEF-electroporation system, which are returned to aeration tanks.

Instead, treated sewage sludge that still contains some heavy metals is given free to some farmers to use sparingly.

The method is characterised in that the sludge that is treated is made to contain dissolved iron and phosphorus at a molar ratio Fe:P of above 1:1.

To improve the water removal rate of treated sludge, the pressure to the extrusion device (6) provided by the pressing device (5) is not less than 15 Kg/cm2.

In France the delay is six weeks - reduced to three for sanitised sludge, i.e. sludge treated in such a way that pathogenic micro-organisms cannot be detected.

Moreover, treated sludge could be turned into biogas that could power wastewater treatment plants.

The treated slurry is mechanically and thermally dewatered resulting in a renewable fuel product in dried particulate or pelletized form that is a viable energy source having a positive heating value.

In the Flemish Region treated sludge may be spread on cropland only if the soil pH is higher than 5.

A portion of the processed slurry may be recirculated and mixed with cool, pressurized feedstock prior to reaching a mechanical mixing device to preheat and reduce the viscosity of the feedstock.

We still have more we can achieve in this area, but we’ve already come a long way since we used to have to pay farmers to take the treated sludge away!

We still have more we can achieve in this area, but we’ve already come a long way since we used to have to pay farmers to take the treated sludge away!