ADE-ADE-BIOTEC present their first on-site plant for the treatment of pig purines

The novelty of the system lies in the possibility of having an on-site installation at the farm itself, thus avoiding the transport of the purines to other, off-site plants for their treatment.

ADE Biotec has undertaken the treatment of these residues in locations in Gipuzkoa, other areas of the Basque Country and a patented technology. In the case in hand, the purine treatment plant is installed on a pig farm at Egiluze in Renteria (Gipuzkoa).

Nowadays, the purines (excrement mixed with waste water from the farm) represent one of the most serious problems in agriculture, both from an environmental perspective (massive use thereof produces contamination of the water table and land) as well as for, an economic point of view (waste management demands much time and effort).

The kernel of the problem lies in the intensification of agriculture: farms have increasingly greater numbers of animals. This, logically, produces an increase in purines on the farmlands, and also an increase in the amount of land where this fertiliser is used.

The new technique for the purification of purines is based on electroflotation and involves in transferring the purine from one iron plate to another while a low-voltage electric current is passed between the two electrodes. By means of this electro technique, two phenomena are observed:

• On the one hand, the iron from the plates (Fe+2) is dissolved, coagulating and flocculating the organic material from the purine. In this way, the organic material takes the form of small balls that can be subsequently separated with ease from the liquid.
• On the other hand, hydrogen bubbles are formed, which make the balls of organic material float on the water and create an upper layer that can be extracted easily.

In this way, more than 80% of the oxygen consumed by the compounds that oxidise in the water – phosphorous and nitrogen – can be removed from the purines.

Other advantages of this technique are its low cost, the fact that there is no need for chemical reagents an there is no limitation of scale and its easy automation.