ANAEROBIC RECYCLING OF PREHYDROLYSATE GENERATED DURING THE MANUFACTURE OF RAYON GRADE PULP

Anaerobic treatment of prehydrolysate from eucalyptus stems has been e xplored using active seed cultures (vol. 5 litres) from cattle dung, p oultry waste and domestic sewage sludge. While the cattle dung reduced chemical oxygen demand (COD) by 28% and generated 100 litres of bioga s containing 50% CH4, poultry waste reduced COD by 55% and generated a total of 37 litres of gas, containing 54% CH4. On the basis of (a) hi gher COD reduction and (b) biogas generation, poultry waste and cattle dung were superior inocula, respectively. Domestic sewage sludge was an inferior inoculum for methane generation. Upon biogas generation, b oth the effluents (with reduced COD) showed promising application in a griculture, suggesting that recycling of prehydrolysate in biogas and agricultural production was feasible.