The re-use of Waste-Activated Sludge as part of a "zero-sludge" strategy for wastewater treatments in the pulp and paper industry.
The possibility of introducing the thermo-alkali hydrolysis of Waste-Activated Sludge (WAS) was investigated, in order to enable the use of its solid residue as a raw material in cardboard production and the use of its liquid portion for anaerobic digestion in an UASB reactor. The evaluation of the hydrolysis at pH>12 and T=70°C showed that the microbe cells were disrupted with more than 90% efficiency in less than 2h. The solid portion was hygienised, therefore making it possible to integrate it into the cardboard production as a raw material for less demanding cardboards. Up to 6% addition of the liquid portion of hydrolysed WAS to wastewater decreased the specific biogas production in a pilot-scale UASB from 0.236 to 0.212 m(3)/kg(COD), while the efficiency of the COD removal decreased from 80.4% to 76.5%. These values still guarantee an adequate treatment of the wastewater and an increased biogas production by 16%.
Količevo Karton, Papirniška 1, SI-1230 Domžale, Slovenia. Electronic address: leon.kaluza@mm-karton.com.
Leon
L
Kaluža
Matej
M
Suštaršič
Vera
V
Rutar
Gregor D
GD
Zupančič
D056804:Biofuels; D057919:Biological Oxygen Demand Analysis; D005374:Filtration; D006868:Hydrolysis; D007220:Industrial Waste / Q000032:analysis*; D010209:Paper; D010865:Pilot Projects; D059027:Recycling; D012722:Sewage / Q000737:chemistry*; D014835:Volatilization; D062065:Wastewater / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
D056804:Biofuels; D007220:Industrial Waste; D012722:Sewage; D062065:Wastewater
Anaerobic digestion; Hydrolysis; Pulp and paper wastewater; Waste-activated sludge reuse; Zero sludge