Recycled medical cotton industry waste as a source of biogas recovery

Anaerobic digestion is a technology widely used for treatment of organic waste for biogas production. In this study, medical cotton industry wastes were examined as a source for biogas production. The effects of inoculum addition, pretreatment of substrate, and temperature on the biogas production were taken into consideration. Results revealed that the effect of inoculum addition was more significant than the alkaline pretreatment of raw waste materials. The biogas recovery from inoculated waste materials exceeded its production from non-inoculated wastes by almost 46%. Whereby, the increase of biogas recovery from pretreated wastes was 20% higher than its production from untreated wastes. The thermophilic conditions improved the biogas yield by approximately 92%. The kinetic of bio-digestion process was well described by modified Gompertz model and the experimental and predicted values of biogas production were fitted well with correlation coefficient values >0.96 suggesting favorable conditions of the process.