EXPERIMENTAL SETUP AND METHODS
This chapter explains the experimental setup and methods that are done and followed in the project work based on our objective and also the characterization of substrates i.e. cow dung and food waste. Physio-chemical characteristization was found out based on a series of tests and were also compared on before and after digestion basis. Rate and amount of biogas and methane production was also measured and recorded continuously. Tests were performed on batches to analyse the generation in all the digesters. Temperature was kept constant as the digesters were kept in an incubator but pH was measured regularly and in another they were kept in ambient conditions. The biogas was measured by the water displacement method and methane content using sensor. The setup and methods used has been explained thoroughly here.
3.2 DESCRIPTION OF THE SETUP
This section describes the substrates used, materials fed, and the digester used for the experimental works. In the previous work done, digesters used were inverted floating type digester where 3 digesters AD1, AD2 and AD3 were setup. AD1 consist of 100% cow dung, AD2 consist 100% food waste and AD3 consist 50% cow dung and 50% food waste. Cow dung was used as inoculum in add three digesters in addition with 1.5 litres of sewage water from nearby biogas plant. The capacity of the container was 60 litres with height of 45 cm and inverted bucket of 20 litres with height 35 cm. The fitting consist of ½ inch tank connection nipple, ½ inch valve, ½ inch nipple and gas cork. The digesters were kept for a period of 60 days. They were kept outside the Fluvial Hydraulics Laboratory in the Civil Department of Jaypee University of Information Technology, Waknaghat (H.P) so as to keep them exposed to sunlight and were covered with a green cover to enable the setups to absorb more heat.
In the next work done, twelve batch digester bottles were setup in an incubator at 30?C. Here the temperature is kept controlled. Bottles used were of 1litre capacity where in digesters 1 to 6 cow dung was fed and in 7 to 12 cow dung and food waste was fed. Water was used as inoculum and filled upto 700ml mark. Cork was fitted in all the bottles and drip was inserted in them as a pipe. The another setup prepared consist of a container to hold water, a cylindrical measuring cylinder fitted with a pipe(drip) at the bottom.
Fig. digesters used in previous work
Fig. Digesters used in next work kept in incubator
Fig. water displacement setup
3.3 DETAILS AND SOURCE OF SUBSTRATES
This study focuses on the co-digestion of cow dung and food waste along with their capacity to produce biogas and methane. The sewage water used as inoculum was brought from the already running biogas plant in the campus of our university. So the substrates were accumulated according to their ease of conveniency. Food waste was taken from the mess of the university continuously for six days and pine needles were brought from the jungle in the campus.