New treatment facility proposed at Marsa abattoir

Animal waste is set to be treated before incineration to avoid energy loss and damage to the present thermal facility which began operating in 2007.

Plans for the creation of a new pre-treatment facility date back to 2011, and WasteServ has now presented MEPA with an update to previous Environment Impact Assessments.

The incinerator was originally introduced to cater specifically for animal waste.

The abattoir incinerator at Albert Town in Marsa, as approved by MEPA in 2005, was designed to incinerate a staggering 12,910 tonnes of animal and food-derived waste each year.

But a study carried out by the Management Efficiency Unit in 2006 concluded that the amount of abattoir waste which can be incinerated was just 3,460 tonnes.

As a result, it was concluded that the only way to keep the plant operational in an efficient manner was to add new streams, which would include the incineration of hazardous industrial waste and clinical waste from hospitals.

But the incineration of animal waste in the absence of any treatment was in itself resulting in damage to the plant.

The latest addition to the plant is aimed to increase its efficiency. The pre-treatment facility for animal tissue waste will result in the reduction of the quantity of raw animal waste treated by incineration. This will, in turn, increase the capacity of the facility to accommodate other kinds of waste for which incineration is the only possible method of destruction.

This will require the extension of the current site in Marsa to an additional 4,100 m2 of land, which is currently occupied by a waste-management facility, the Temporary Marsa Storage and Sorting Facility.

The extension will make room for a wastewater treatment plant and purpose-built storage facilities.

The new plant will demand less energy, compared to the incineration process. The byproducts it produces can also serve as fuel for the incinerator.

Moreover, eliminating water from the animal waste prior to incineration will reduce the damage to the refractory of the rotary kiln due to thermal shocks.

The rendering process will separate bone meal and meat meal from animal fat. The resulting mix will be poured into a percolator, where the fat will be separated by gravity, pumped into a decanter to remove any solid particles and then stored in a settling tank. The mix of bone and meat meal will subsequently be passed through a filter press to remove any entrapped fat, leaving a very dry product. This material will then pass through a crusher to produce a fine odourless powder, which will then be stored in bags or silos. The final product will be incinerated.