Research Article Open Access
Jalil et al., Int J Waste Resour 2019, 9:1
Research Article Open Access
International Journal
of Waste Resources
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ISSN: 2252-5211
Volume 9 • Issue 1 • 1000369
Int J Waste Resour, an open access journal
ISSN: 2252-5211
*Corresponding author: Dr. Abdul Jalil, Department of Civil Engineering,
Bangladesh University of Engineering and Technology (BUET), Bangladesh,
E-mail: jalilcebuet@gmail.com
Received January 08, 2019; Accepted June 06, 2019; Published June 13, 2019
Citation: Jalil A, Karmaker S, Basar S, Hoque S (2019) Anaerobic Digestion
of Vegetable Wastes for Biogas Production in Single Chamber and Double
Chamber Reactors. Int J Waste Resour 9: 369.
Copyright: © 2019 Jalil A, et al. This is an open-access article distributed under
the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original author and
source are credited.
Abstract
The compositions of solid wastes of a rural market of Bangladesh and the results of two sets of laboratory
experiments on biogas generation from the easily biodegradable wastes under daily feed condition are presented
in this paper. Cow dung, caulifower stick, papaya and potato were the major biodegradable wastes. Daily average
composition of the biodegradable wastes was used in the experiments. The average Total Solids (TS) and Volatile
Solids (VS) concentrations of the raw substrate were determined as 18.90% and 15.10% respectively. The
experimental setups were placed in a large closed chamber containing two room heaters. The room heaters were
operated alternatively at 35°C to maintain a favorable condition for anaerobic digestion of the substrate. In the frst
setup, a single chamber reactor and a double chamber reactor were used. In the single chamber reactor, 750 g
wastes and required amount of inoculum were added initially to make the effective volume of 2 L. For the double
chamber reactor, each chamber was initially fed with 350 g wastes and inoculum was added to make the effective
volume of 1 L. The single chamber reactor was operated for 58 days and the double chamber reactor was run for
23 days. From the 2
nd
day of operation, each reactor was fed daily with a mixture of 18.75 g wastes and the required
volume of tap water to make the total volume of 50 mL after taking out equal volume of slurry from the reactor. The
second set of experiment was similar to the double chamber reactor of the frst setup, but it was operated for 54
days including the last 16 days operation at room temperature as the heaters became out of order. In case of the
frst setup, the temperature varied from 31°C to 36°C and the rate of biogas generation was not affected due to this
variation. The results of the experiments revealed that for the Organic Loading Rate (OLR) of 1.42 g VS/L/d, the daily
stable biogas generation rate was 0.22 m
3
/kg of VS added for the single chamber reactor, and apparently the daily
stable average rate of biogas production was 0.37 m
3
/kg of VS added for the double chamber reactor. During the
second set of experiment, the temperature varied in between 32°C and 36°C when the chamber-heater was on and
the rate of biogas generation was not affected, and the stable rate of biogas generation was 0.26 m
3
/kg of VS added
for the OLR of 1.42 g VS/L/d. The temperature of the chamber varied from 22°C to 25°C when the heater became
out of order and the sudden drop of the temperature by about 10°C affected the rate of biogas production greatly. At
the ambient temperature, the stable rate of biogas generation was only 0.08 m
3
/kg of VS added.
Anaerobic Digestion of Vegetable Wastes for Biogas Production in Single
Chamber and Double Chamber Reactors
Abdul Jalil*, Santosh Karmaker, Samiul Basar and Shamsul Hoque
Department of Civil Engineering, Bangladesh University of Engineering and Technology (BUET), Bangladesh
Keywords: Anaerobic digestion; Biodegradable waste; Biogas;
Hydraulic retention time; Single chamber reactor; Double chamber
reactor; Organic loading rate
Introduction
Cities and rural growth centers are places of rapid economic
growth, trade, education and employment resulting in increasing the
consumption of resources and generation of wastes. Te world is facing
the burning problems of management of large quantities of solid wastes
produced in these places and meeting the energy requirements due
to rapid growth of urban population. Te vegetable markets of these
areas produce large quantities of biodegradable wastes which are very
poorly managed in developing countries producing malodorous gases,
greenhouse gases, and leachate during on-site degradation and pollute
the water when the wastes are thrown into local water bodies. Hence,
the wastes should be properly managed to have clean environment and
reduction of greenhouse gas emission to slow down the climate change.
Te high moisture and Volatile Solids (VS) contents in vegetable wastes
make these more suitable for anaerobic digestion than incineration and
composting. Anaerobic digestion of solid wastes is becoming popular
day by day as a method of solid waste management as it produces
biogas which can be used for steam heating, cooking and generation of
electricity [1-4]. Te residual slurry can be used as a bio-fertilizer and
soil conditioner [5].
Huge amount of biodegradable solid wastes are generated in the
markets of Bangladesh and these are the potential sources of biogas
generation. An investigation on the type and quantity of solid wastes
produced in a rural vegetable market of Bangladesh was carried out,
and the biogas generation from the wastes was quantifed through
laboratory scale single chamber and double chamber reactors under
daily feed condition at controlled temperature and sharp decrease
in ambient temperature. Te investigation was done to compare the
results with those found in the available literature and to see the efect
of the change in the ambient temperature on the gas generation. In
addition, fnding the diference in biogas production between single
chamber and double chamber reactors were the objective as short
circuiting of the added wastes is likely to happen in case of single
chamber reactor. Tis paper presents the results of the investigation.
Anaerobic digestion process
Anaerobic digestion is a complex fermentation process brought
about by the symbiotic association of diferent types of bacteria with
ultimate products being mainly methane and carbon dioxide [6-9]. Te
products generated by one group of bacteria serve as substrates for the