TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Components: The wastewater is obtained from sewage (preferably municipal sewage, household waste, slaughterhouse waste, human waste, animal waste and/or industrial waste). The biomass material is carbohydrate-containing material (preferably glucan containing material such as a lignocellulosic material, starch containing material, cellulose, starch, organic waste material, household waste, paper material, paper pulp, return paper, straw, maize stem, maize stem, forestry waste (log slash, bark, small branches, twigs etc), sawdust, wood-chips, simple monomeric sugar and molasse from sugar beet or sugar cane). The ratio of carbohydrate-containing material and the wastewater is 1:99 - 1:1 (preferably 1:49 - 1:2, especially 1:9 - 1:4).Preferred Process: (m1) is pretreated by thermal treatment, wet oxidation, steam explosion, dilute sulfuric acidic or other acids, alkaline solutions and/or organic solvents before being subjected to fermentation. The pretreated or untreated biomass is hydrolyzed by enzymatic treatment and/or chemical hydrolysis. Prior to adding the biomass material, the wastewater is treated by thermal treatment, fermentation, enzymatic treatment, acid hydrolysis, wet oxidation and/or filtration (preferably thermal treatment, fermentation (anaerobic digestion) or filtration). The amount of ammonium, phosphor and COD resulting from thermal treatment is 2000 - 2500 mg/l, 150 - 200 mg/l and 50000 - 75000 mg/l respectively, and the amount of ammonium, phosphor and chemical oxygen demand (COD) resulting from thermal treatment, fermentation (anaerobic digestion) and filtration is 2500 - 3000 mg/l, 200 - 250 mg/l and 2000 - 5000 mg/l respectively. The wastewater is sterilized prior to fermentation process, and is supplemented with at least one nutrient compound (preferably nitrogen, phosphor, magnesium, zinc, manganese, cobalt, copper, calcium, iron, molybdenum, boron and/or compound containing any of such element). Water is added to the slurry. (m1) or the slurry is subjected to either chemical hydrolysis and/or to enzymatic hydrolysis. (P1) is performed using a microorganism selected from bacteria, yeast and fungi (preferably ethanol fermenting microorganism, especially Saccharomyces cerevisiae); or using a mixed culture of organisms. (P1) is an anaerobic fermentation process or aerobic fermentation process; and is continuous process. The wastewater is recycled. EXAMPLE - A wastewater derived from sewage was subjected to thermal hydrolysis at 180 degrees Centigrade for one hour followed by anaerobic microbial digestion and filtration. After thermal hydrolysis the wastewater contained (mg/l) 2000 - 2500, 150 - 200 and 50000 - 75000 ammonium-N, phosphor-P and COD respectively. After thermal hydrolysis followed by anaerobic digestion and filtration wastewater contained (mg/l) 2500 - 3000, 200 - 250 and 2000 - 5000 ammonium-N, phosphor-P and chemical oxygen demand (COD) respectively. A paper pulp derived from processing wastepaper was used as biomass material, the cellulose content of which was 93% and inorganic material such as kaolin was 7%. In blue cap flasks (250 ml) wet paper pulp (103 g) was mixed with sterilized (15 minutes at 121 degrees Centigrade) wastewater (177 ml). The thick suspension was liquefied by enzymatic treatment at 50 degrees Centigrade for 24 hours. After liquefaction the suspension was cooed on ice and freeze dried Baker's yeast (0.8 g) and 24% urea (1 ml) was added together with another portion of enzymes making the total enzyme loadings in the two experiments at 7 and 10 FPU/g DM respectively. The flasks were weighed. The ethanol yield during fermentation was calculated from the carbon dioxide loss. The results showed higher enzyme loading yielded higher ethanol after a short lag phase. Using a highest enzyme loading of 10 FPU/g DM the fermentation was completed after 120 hours reaching a level of 30 g/l corresponding to 62% conversion of the cellulose. Thus ethanol is obtained without specific removal of heavy metals or other components.