UASB-technology will be piloted in pulp and paper industry at pilot-scale for pretreatment of p&p-industry's waste waters. Technical specifications for full scale implementation will be determined. Economical feasibility study will be provided based on the results achieved by pilot-tests and theoretical calculations.

The following collaboration project aims at contributing through fundamental, theoretical and experimental research to the developement and implementation of efficient anaerobic digestion of sludge and waste water with the final aim of reducing sludge management and recover energy in the form of biogas. the proposed activities and tasks will be validatet at lab- and pilot-scale. The developments are directed towards obtaining integrated solutions, which can be later implement at large scale. 

Anaerobic digestion (AD) is nowadays the most common process for waste treatment. It consist of a series of biological transformations, in which several microbial populations break down the biodegradable matter in the absence of oxygen. During the biodegradation of the waste, biogas is generated, which consist mainly of methane and carbon dioxide. The biogas can be combusted to generate electricity and heat, or can be upgrated into renewable biomethane and used transportation fuel. Compared to other processes for waste and wastewater treatment, anaerobic digestion provides several advantages among which the most important ones are the higher potential for clean, renewable energy production and th substantally lower sludge production (waste minimization).

AD applied in the forest industry has focused mainly on primary and secondary sludge digestion from aerobictreatment of wastewaters mainly from paper industries. Sludge is produced in great amounts and disposal isa costly; this is why studies have concluded that it is more effective to reduce sludge formation by changes in the wastewater (such as including AD) than reducing the amount of sludge by post-treatment. Little attention has been focused on the direct AD of streams of chemical pulping wastewater. Effluent emissions are generated in wood handling, debarking and chip washing, wood cooking, pulp washing and pulp bleaching. Effluents are general high in chemical oxygen demand (COD) which underlines their potential for AD, however they also contain many inhibiting compounds for methanogenic bacteria such as degradation products of lignin, sulfur compounds, polysaccharides, wood extractives and chlorine compounds that can produce absorbable arganic halides. Several studies have concluded that despite challenges in the AD of pulp and paper wastewater, all of its effluents are to some extent degradable.