Electricity Generation from Sugar Mill Wastewater by Microbes
Published on Feb 27, 2019
Rapid urbanization and industrialization in the developing countries like India pose severe problems in collection, treatment and disposal of effluents. This leads to serious public health problems and other environmental problems. Disposal of wastes and their management is the most important environmental problem faced by the world today. Agricultural waste, household waste and industrial waste are best substrates for energy production as they are rich in organic contents.
One of the promising methods for wastewater treatment is the use of microbial fuel cells (MFCs). In the last few decades MFC have gained importance due to their ability to produce bioelectricity from renewable sources. MFCs are unique devices that can utilize microorganisms as catalysts for converting chemical energy into electricity under anaerobic condition, representing a promising technology for simultaneous energy production and wastewater treatment. Electricity has been generated in MFCs form various organic compounds including carbohydrates, proteins and fatty acids.
Keywords : Microbial fuel cells (MFC), Sugar mill wastewater, Cathode, Anode, Carbon brush, Carbon cloth, Salt bridge, COD removal efficiency, Power generation.
1. To study the characteristics of Sugar mill wastewater.
2. To fabricate the single chambered MFC with double cathodes.
3. To optimize the hydraulic retention time (HRT) in MFCs by observing power generation.
4. To find out the maximum COD removal efficiency.
5. To compare the efficiency (in terms of COD removal and power generation) of MFCs using different shapes of carbon brushes.
A substrate such as carbohydrates, fats, proteins are initially oxidized under anaerobic condition and release electrons. Electrons are stored as intermediates and provide energy to living cell. Microorganisms are used in MFC to convert organic matter into electrical energy by transferring electrons to electric circuit; microbes can transfer the electrons in three modes namely; by mediators, without using mediators but use electrochemically active bacteria and by direct transfer of electrons from microbes to electrode. Anode chambers of MFC-A and MFC-B are filled with anaerobic sludge from sugar mill industry (80% of the volume of the reactor). The
different HRTs of 24h, 18h, 12h, 6h, 3h, 2h and 1h were maintained by using sugar mill wastewater for the electrode configurations.
MFCs are the alternative technology for wastewater treatment and generation of electricity. In this study sugar mill wastewater is used as substrate and is inoculated with anaerobic sludge from sugar mill industry for the production of electricity. This study explores application of single chambered MFC in generation of electricity using different shapes carbon brushes. The maximum average voltage, average current and average power generation in MFC-A (Wheel shaped carbon brush) was 50.85mV, 0.23mA and 11.67μw respectively at 3h HRT, measured across 220Ω resistor and the COD removal efficiency is 42.5%. The maximum average voltage, average current and average power generation in MFC-B (Simple carbon brush) was 20.57mV, 0.094mA and 1.95μw respectively at 3h HRT, measured across 220Ω resistor and the COD removal efficiency is 12.33%. MFC-A produced more power than the MFC-B and the COD removal efficiency in MFC-A is maximum than the MFC-B. Single chambered MFC with double cathodes is more advantageous on the bases of electrical power production but would have higher capital costs due to the use of more electrodes.
Scope For Future Work:
The main aim of this project is to compare the efficiency in terms of power generation and COD removal efficiency of MFC using different shapes of carbon brushes.
1. The study of other physiochemical characteristics of sugar mill wastewater.
2. The study can be carried out to increase the efficiency by using different cathodes and anodes and as well as different type of substrates.
3. The study can be carried out by using mediators and Geo-bacteria for generation of electricity.
Project Done By Ms. Shivani Obaleppanavar, Ms. Aruna Banakar, Ms. Jyoti Chakkadi, Ms. Rajeshwari Bilagi