Enhanced biomass and phycocyanin production of Arthrospira (Spirulina) platensis by a cultivation management strategy: Light intensity and cell concentration.

This work investigated the cultivation of Arthrospira (Spirulina) platensis BP in a photobioreactor under light intensities of 635, 980, 1300, and 2300 µmol m s, using a semi-continuous mode to keep cell concentration at optical densities (OD) of 0.4, 0.6, and 0.

Enhancement of biogas production from swine manure by a lignocellulolytic microbial consortium.

Anaerobic digestion of lignocellulosic wastes is limited by inefficient hydrolysis of recalcitrant substrates, leading to low biogas yield. In this study, the potential of a lignocellulolytic microbial consortium (LMC) for enhancing biogas production from fibre-rich swine manure (SM) was assessed. Biochemical methane potential assay showed that inoculation of structurally stable LMC to anaerobic digestion led to increase biogas production under mesophilic and thermophilic conditions.

Effect of recirculation rate on methane production and SEBAR system performance using active stage digester.

A project was undertaken to examine the feasibility of treating organic wastes from Thai fruit and vegetable markets using the sequential batch anaerobic digester (SEBAR) approach. A key feature of the SEBAR system is the regular interchanging, or recirculation, of portions of leachate between each freshly filled digester and a support digester to which it is coupled until it is ready to operate independently. Leachate transfer from this support digester to the fresh waste digester provides additional alkalinity to help counteract the effects of early high acid release rates; it also helps build a balanced microbial population in the fresh waste digester.

Neural-fuzzy control system application for monitoring process response and control of anaerobic hybrid reactor in wastewater treatment and biogas production.

Based on the developed neural-fuzzy control system for anaerobic hybrid reactor (AHR) in wastewater treatment and biogas production, the neural network with backpropagation algorithm for prediction of the variables pH, alkalinity (Alk) and total volatile acids (TVA) at present day time t was used as input data for the fuzzy logic to calculate the influent feed flow rate that was applied to control and monitor the process response at different operations in the initial, overload influent feeding and the recovery phases. In all three phases, this neural-fuzzy control system showed great potential to control AHR in high stability and performance and quick response. Although in the overloading operation phase II with two fold calculating influent flow rate together with a two fold organic loading rate (OLR), this control system had rapid response and was sensitive to the intended overload.

Combination effect of pH and acetate on enzymatic cellulose hydrolysis.

The productivity and efficiency of cellulase are significant in cellulose hydrolysis. With the accumulation of volatile fatty acids (VFAs), the pH value in anaerobic digestion system is reduced. Therefore, this study will find out how the pH and the amount of acetate influence the enzymatic hydrolysis of cellulose.

Kinetics and dynamic modelling of batch anaerobic digestion of municipal solid waste in a stirred reactor.

A series of batch, slurry anaerobic digestion experiments were performed where the soluble and insoluble fractions, and unwashed MSW were separately digested in a 200l stirred stainless steel vessel at a pH of 7.2 and a temperature of 38 degrees C. It was found that 7% of the total MSW COD was readily soluble, of which 80% was converted to biogas; 50% of the insoluble fraction was solubilised, of this only 80% was converted to biogas.