Microbial Growth Rate Kinetics in Biogas Production by Anaerobic Digestion of Chicken Manure

Abstract

Kinetic study of microorganism’s growth in chicken manure (CM) when producing biogas is often studied for scale-up purposes. CM are considered as waste, and can cause serious environmental consequences when not properly disposed. The objective of the study is to know the characteristics of the bioreactor condition or environment responsible for CM degradation and biogas production. Methods involves serial dilution, pour plating, cell count and the determination of Monod parameters. POLYMATH regression results shows that CM of particle density 0.0163 g/cm3 gives a maximum specific growth rate, ?_max of 0.007316 hr^(-1) and half saturation constant, K_s of 3.8×?10?^8mg/l which points to substrate sufficiency for the survival of microorganisms and biogas production.

Kinetic Study of Microbial Growth in Anaerobic Digestion of Solid Waste

“…The carbon content was determined using the blank titter, while nitrogen content was determined using the micro kjeldahl method based on ASTM standard as reported by ( Abubakar et al, 2022).…”

“…Therefore, to generate appropriate data for Monod plot the following Equations (1.8 -3.0) were used as follows: the colony forming unit (X) was calculated using equation 3.11 as reported by (Abubakar et al, 2022;Khan et al, 2021)…”

“…A predictive value of X known as X predicted was obtained using several guess in order to obtain K value using excel solver by regression to find the value that fit XExpr using Equation 2.4 ( Abubakar et al, 2021( Abubakar et al, , 2022. K was estimated to be 0.01…”

“…At an initial substrate concentration 𝑆0 = 1.0×106 mg/l, and decreases to an average constant value 5.8×105 mg/l. Although, Abubakar et al,( 2022) state that, Precision in bacterial population count is right challenging and baffling, nevertheless, this data assumes that single bacteria grows to form a single colony, multiple bacteria forming single colony hides some number of viable cells that were unknowingly counted as one. Values of X for that reason, doesn't word a 100% precise data because it fails to include gain in concentration due to growth in weight/size of the bacteria.…”

“…There are diverse categories of microorganisms, specifically, Salmonella spp., Escherichia coli (E. coli), and Cryptosporidium, to mention, for the period of anaerobic batch fermentation these microorganisms, grow based on certain assortment of physical, chemical, and nutritional situations (Khan et al, 2021). This happens, by extracting nutrients from the used of various organic waste or combination of two or more organic waste in a single phase and converting them into biological compounds (Abubakar et al, 2023).…”