Alkali pretreatment enhances biogas production in the anaerobic digestion of pulp and paper sludge

• Published in: Journal of hazardous materials Vol. 170; no. 1; pp. 366 - 373
• Main Authors: Lin, Yunqin, Wang, Dehan, Wu, Shaoquan, Wang, Chunmin
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.10.2009; Elsevier
• Subjects: Alkali pretreatment; Alkalies - chemistry; Anaerobic digestion; Anaerobiosis; Applied sciences; Biodegradation, Environmental; Biological and medical sciences; Bioreactors; Biotechnology; Chemical engineering; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Gases - metabolism; General treatment and storage processes; Industrial Waste - prevention & control; Methane - metabolism; Methane production; Methods. Procedures. Technologies; NaOH; Others; Pollution; Pulp and paper sludge; Reactors; Sewage - microbiology; Sodium Hydroxide - chemistry; Solubility; Various methods and equipments; Wastes; Alkali pretreatment; NaOH; Pulp and paper sludge; Methane production; Anaerobic digestion; Methane; Waste treatment; Laboratory scale; Biogas; Solubilization; Biological purification; Paper industry; Bioreactor; Production; Pretreatment; Biological treatment
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2009.04.086

The objective of this research was to develop an alkali pretreatment process prior to anaerobic digestion (AD) of pulp and paper sludge (PPS) to improve the methane productivity. Different concentrations of sodium hydroxide solution were used to pretreat PPS, and then followed by AD of PPS and monosodium glutamate waste liquor (MGWL). Laboratory-scale experiments were carried out in completely mixed bioreactors, 1 L capacity with 700 mL worked. Optimal amount of sodium hydroxide for organics solubilization in the step of pretreatment was 8 g NaOH/100 g TS sludge. Under this condition, the PPS flocs structure was well disrupted resulting in the void rate and fiber size decreased after pretreatment, and SCOD increased up to 83% as well as the peak value of VFA concentration attained 1040 mg acetic acid/L during AD. The AD efficiency of PPS with and without pretreatment was evaluated. The highest methane yield under optimal pretreatment condition was 0.32 m 3 CH 4/kg VS removal, 183.5% of the control. The results indicated that alkali/NaOH pretreatment could be an effective method for improving methane yield with PPS.