Enhanced bio-methane production from ammonium-rich waste using eggshell-and lignite-modified zeolite (ELMZ) as a bio-adsorbent during anaerobic digestion. (June 2019)

• Record Type: Journal Article
• Authors: Zhang, Nan; Zheng, Hanying; Hu, Xiaohong; Zhu, Qi; Stanislaus, Mishma Silvia; Li, Siyang; Zhao, Chenyu; Wang, Qinghong; Yang, Yingnan
• Is Part Of: Process biochemistry. Volume 81(2019)
• Page Start: 148
• Page End: 155
• Publication Date: 2019-06
• Subjects: Eggshell and lignite modified zeolite (ELMZ) -- Bio-adsorbent -- Ammonia inhibition -- Anaerobic digestion -- Bio-methane production; Biochemical engineering -- Periodicals; Biotechnology -- Periodicals; Biochemistry -- periodicals; Biotechnology -- periodicals; Chemical Engineering -- periodicals; Génie biochimique -- Périodiques; Biotechnologie -- Périodiques; Biochemical engineering; Biotechnology; Periodicals; 660.63
• DOI: 10.1016/j.procbio.2019.03.001
• Languages: English
• ISSNs: 1359-5113

Abstract

Graphical abstract: Highlights: A bio-adsorbent, ELMZ, has been developed for ammonium-rich anaerobic digestion. The ammonium was adsorbed by the ELMZ adsorbent efficiently. The abundant cations, especially high Ca 2+ content benefits the bioactivity. High bio-methane production has been achieved by addition of bio-adsorbent ELMZ. ELMZ is promising to recover methane from ammonium-rich substrate practically. Abstract: In this study, a calcium-rich natural material utilized bio-adsorbent, composed of eggshell-and lignite-modified zeolite (ELMZ) was developed for enhancing methane production at high ammonia concentrations. The ELMZ showed a maximum NH4 + -N adsorption capacity of 55 mg/g, which was 5.9 folds of the natural zeolite (9.2 mg/g) and 1.4 folds zeolite modified by calcium chloride (40 mg/g), respectively. The ammonium adsorption process well fitted the pseudo-second-order kinetic model and the Freundlich isotherm. It indicated that its process was an ion-exchange process. The high abundance of cations, especially high Ca 2+ in ELMZ supported the ion-exchange, which stimulated the anaerobic digestion process. The anaerobic digestion with ELMZ as a fixed-bed (initial NH4 + -N concentration: 4.1 g/L), exhibited the best performance at methane yield of 250 mL CH4 /g-DOCremoval, which is 7 folds higher than that achieved with natural zeolite (32 mL/g-DOCremoval ) at the same ammonia level. As a bio-adsorbent, ELMZ contributes to enhance methane production and further benefits to a sustainable process since the eggshell waste is re-circulated.