INCREASING ANAEROBIC DIGESTION PERFORMANCE OF WASTEWATER WITH CO-DIGESTION USING DECANTER CAKE

Thaniya Kaosol,Narumol Sohgrathok

doi:10.3844/ajessp.2014.469.479

Thaniya Kaosol, Narumol Sohgrathok

Open Access

https://doi.org/10.3844/ajessp.2014.469.479

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Abstract

Low biogas production in the frozen seafood wastewater anaerobic digestion is observed due to the low organic and Total Solids (TS) contents in the wastewater. In this research the decanter cake will be used in the anaerobic co-digestion process to improve the biogas production rate. The effect of co-digestion and Hydraulic Retention Time (HRT) will be investigated using the continuously stirred tank reactors under anaerobic conditions. Moreover, the study determines the biogas production potential of different HRTs and that of wastewater digestion alone. The anaerobic co-digestion is operated in continuous with continuously stirred reactors at HRT of 10, 20 and 30 days. The mechanical stirring units of all reactors are operated automatically. The stirring action occurred continuously during the experiments. The anaerobic co-digestion results show that the anaerobic co-digestion provides higher biogas production rate and higher methane yield than that of the wastewater digestion alone. The optimum HRT of the anaerobic co-digestion is 20 days. This reactor produces 2.88 L day-1, with 64.5% of methane and the maximum methane production rate of 1.87 L day-1 and the methane yield of 0.321 l CH4/g CODremoved. The anaerobic co-digestion of wastewater with decanter cake provides the higher methane yield potential production than that provided by the wastewater digestion alone at the ambient temperature. The best HRT is 20 days for anaerobic co-digestion between the wastewater and decanter cake. The experimental results reveal that HRT and co-digestion are the parameters that can affect the biogas production and methane yield.

Highlights

The biogas production source includes agricultural in the absence of oxygen
The experiments were conducted on frozen seafood wastewater digestion alone and co-digestion between frozen seafood wastewater and decanter cake at different Hydraulic Retention Time (HRT)
These results showed that the co-digestion can improve the anaerobic digestion rate and methane yield

Summary

Introduction

The biogas production source includes agricultural in the absence of oxygen. The typical biogas consists of wastes, animal wastes, agro-industrial wastes, solid 55-80% of methane, 20-45% of carbon dioxide, less wastes, industrial wastes and wastewater than 3% of hydrogen sulfide and trace amounts of other (Pipatmanomai et al, 2009; Roati et al, 2012). gases The anaerobic co-digestion benefits include improving the nutrient balance, increasing load of biodegradable organic matter, dilution of potential toxic compounds, increasing digestion rate and producing better biogas yield (Sosnowski et al, 2002). Anaerobic co-digestion of the frozen seafood wastewater with decanter cake offers some interesting way. The decanter cake is one of the organic wastes from the palm oil mills production (Er et al, 2011). It contains the high COD and organic substrates (Kaosol and Sohgrathok, 2012). The decanter cake is used as fertilizers and soil cover materials in the palm oil plantation areas which can reduce the waste management problems and improve the environmental quality in nearby community (Yahya et al, 2010)

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