Biological degradation of a mixture of municipal wastewater and organic garbage leachate in expanded bed anaerobic reactors and a zeolite filter

Abstract

Municipal wastewater was amended with organic garbage leachates at a concentration around 700 mgCOD(soluble)/L and fed to three different anaerobic systems to compare their performance: a down flow fluidized bed (DFFB), an expanded granular sludge bed (EGSB) and a zeolite-packed anaerobic filter reactor (ZPF). The DFFB and EGSB reactors were operated at HRT of 6 and 4 h and the ZPF reactor at 12 and 36 h. Organic loads rate for the DFFB reactor were 2.3+/-0.9 and 4.8+/-1.8 gCOD/L.d, with removal efficiencies around 40% and a methane productivity of 0.2+/-0.03 L/L(reactor).d. For the EGSB reactor, organic loads tested were 2.1+/-0.9 and 4.3+/-1.3 gCOD/L.d, removal efficiencies attained were of 77.6+/-12.7% and 84.4+/-4.9%, respectively at both conditions and total suspended solids were removed in 54.6+/-19.3%, while methane productivity at 4 h HRT was of 1.29+/-0.4 L/L(reactor).d. The ZPF reactor was operated at lower organic loading rates, 1.4+/-0.27 and 0.42+/-0.13 gCOD/L.d and attained removal efficiencies of 48+/-18% and 83+/-8%, respectively, reaching a methane productivity of 0.21+/-0.09 and 0.12+/-0.04 L/L(reactor).d, 83+/-8.0% of total suspended solids were retained in the reactor and as HRT was increased ammonium concentrations increased in 39%. Specific methanogenic activity in all systems was around 0.2 gCOD-CH(4)/gVSS d.

Application of natural zeolites in anaerobic digestion processes: A review

“…Anaerobic fixed-bed reactors are based on the principle of the immobilization of microorganisms on a support, reducing the HRT. Compared with other high-rate anaerobic reactors, the fixed-bed digester has several favourable characteristics (Umaña et al, 2008;Nikolaeva et al, 2009;Castilla et al, 2009). This reactor configuration is more suitable for handling high pollution-load wastewaters because it has a high substrate removal efficiency.…”

“…Fixed-bed reactors with zeolite support have also shown to be effective in the anaerobic treatment of low-strength wastewater such as a mixture of municipal wastewater and organic bargage leachate (COD: 700 mg/L) at HRTs of 12 and 36 h. (Castilla et al, 2009). COD removal efficiencies of 83% were achieved at an organic loading rate (OLR) of 0.42 g COD/(L day) with 83% of total suspended solids being retained in the reactor.…”

Factors influencing the degradation of garbage in methanogenic bioreactors and impacts on biogas formation

“…Anaerobic treatment systems that are used with supporting materials include the fixed-bed, packed-bed, and fluidized-bed reactors. A variety of materials, such as carbon fiber, glass, polyethylene fiber, and zeolite filter, are used for the degradation of garbage or garbage leachate (Ueno et al 2007a;Castilla et al 2009;Sasaki et al 2010a;Zhang et al 2011). In addition, clay fiber, polypropylene membrane, polyurethane foam, polyvinyl-chloride sheets, and tire rubber are used as supporting materials for wastewater treatment (Wilkie and Colleran 1984;Show and Tay 1999;Picanço et al 2001;Tatara et al 2004;Chauhan and Ogram 2005;Umaña et al 2008).…”

“…Previous researchers have performed shredding of the substrate to prevent clogging (Ueno et al 2007a;Sasaki et al 2009). Zeolite also plays a role in improving microbial activity by supplementing trace elements (Castilla et al 2009). …”

Tratamiento biológico de escurrimientos de basura orgánica en reactores anaerobios

“…El influente pasa a través del medio filtrante, que actúa como separador líquidogas-sólido y ayuda a proveer un flujo uniforme dentro del reactor, propiciando un mayor contacto del residuo con los microorganismos. Este tipo filtro se ha utilizado para el tratamiento de escurrimientos de basura orgánica (Castilla et al, 2009y Gan et al, 2013 El empleo de zeolita como soporte en este prototipo ha sido reportado anteriormente por Castilla et al (2009) y Gan et al (2013) y se ha demostrado que tiene propiedades absorbentes y adsorbentes, propiciando el intercambio iónico de Ca + , Mg + y Na + de manera natural mejorando la actividad de los microorganismos metanógenos (Gómez, 2001). El filtro anaerobio empacado con zeolita se ha utilizado para el tratamiento de escurrimientos de basura orgánica (Castilla et al, 2009y Gan et al, 2013.…”