Blending based optimisation and pretreatment strategies to enhance anaerobic digestion of poultry manure. (January 2018)

• Record Type: Journal Article
• Authors: Rodriguez-Verde, Ivan; Regueiro, Leticia; Lema, Juan M.; Carballa, Marta
• Is Part Of: Waste management. Volume 71(2018)
• Page Start: 521
• Page End: 531
• Publication Date: 2018-01
• Subjects: Ammonia inhibition -- Co-digestion -- Lignocellulosic material -- Livestock waste -- Methane; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2017.11.002
• Languages: English
• ISSNs: 0956-053X

Abstract

Highlights: Anaerobic co-digestion (ACoD) of poultry (PoM) with pig manure (PM) was evaluated. Combined thermochemical pretreatment coupled to ammonia stripping was applied. A optimal mixture of 24:76 of PoM:PM (volume basis) was proposed. ACoD of pretreated PM:PoM was improved by 37% in comparison to unpretreated mixture. Abstract: Anaerobic digestion of poultry manure is limited by the excessive levels of nitrogen and the high concentration of dry matter. These limitations are usually overcome either by applying procedures to remove nitrogen or by employing pretreatments that allows to solubilise organic matter. In this work, the treatment of poultry manure was enhanced by co-digestion with pig manure through the methodological determination of optimal mixtures combined together with a thermochemical pretreatment coupled to ammonia stripping. The optimum poultry-pig mixture, resulting in a 24%:76% (volume basis) poultry-pig manure, was determined by applying a methodology based on linear programming which calculates the proportions of the blend which returns the maximum methane production while keeping a stable process. Pretreatment batch experiments, consisting of increasing both temperature and pH simultaneously with ammonia stripping process was optimised for a temperature of 90 °C and a pH of 10 resulting in a nitrogen removal efficiency of 72% and a 1.2-fold higher methane production in comparison to the unpretreated mixture. Continuous anaerobic co-digestion of pretreated optimum mixture enhanced the COD removal efficiency by 37% when compared with the treatment of unpretreated feedstock (37% vs 27%, respectively). This study indicates that combining blending optimisation of substrates, thermochemical pretreatments and ammonia stripping procedures prior to anaerobic co-digestion becomes a good strategy to overtake the limitations offered by solid- and nitrogen-rich substrates, such as poultry manure.