Anaerobic digestion of cassava pulp with co-substrates : effect of organic loading rate | |
| Author | Arora, Nitasha |
| Call Number | AIT Thesis no.EV-14-09 |
| Subject(s) | Cassava industry--Environmental aspects Cassava industry--Waste disposal |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Environmental Engineering and Management |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. EV-14-09 |
| Abstract | Cassava pulp is a major solid waste produced from starch industries. Although, it contains high starch content on dry weight basis, but it has potential to produce methane. To provide a sufficient amount of nutrient to microbial community in anaerobic digestion process pig manure as a co-substrate was applied. An experiment was conducted to examine the effect of organic loading rate (OLR) on the performance and stability of single stage semi continuous stir tank reactor (CSTR) treating with three different feedstock at mesophillic temperature. Three different feedstock was fed in three different reactors, 10 L reactor was fed with mixed cassava pulp and pig manure (CP: PM) at ratio 77:23 % (w/w), 15 L reactor was fed with mixed cassava pulp, pig manure and molasses at ratio 36:36:28 % (w/w) and, 20 L reactor was fed with mixed molasses and pig manure at ratio 54.5:45.5 % (w/w). Feedstock were prepared according to maintain C/N ratio 35. Operating parameters were monitored to evaluate the biogas productivity and VS removal at various organic loading rates (1.0, 2.0 and 4.0 Kg Vs/m³ .d). An experiment was conducted in three phases startup phase, operational phase and digestate management phase. The results from start up phase brought out that molasses and pig manure 54.5:45.5% (w/w) has potential to improve the methane production. In the operational phase increasing of organic loading rate affected the 15L (CP: PM: MO) and 20 L (PM: MO) reactor performance as biogas production increased while methane yield decreased when comparing to 1.0 Kg Vs/m³ .d of OLR. However, increasing of OLR did not affect the 10L (CP: PM) reactor. As the biogas production rate (2.5L/Lreactor volume/d) and methane yield (0.35m³ /kgVS) increased with higher OLR 4.0Kg Vs/m³ .d. Therefore cassava pulp with co-substrate showed stable performance with high methane yield with high VSremoval around 87.9% during higher organic loading rate. Although the use of molasses at the initial start-up stage was beneficial for the reactor. |
| Year | 2014 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Environmental Engineering (EV) |
| Chairperson(s) | Annachhatre, Ajit P.; |
| Examination Committee(s) | Visvanathan, C. ;Nguyen, Thi Kim Oanh; |
| Scholarship Donor(s) | Asian Institute of Technology Fellowship; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2014 |