Methane production from food waste using a feedback control strategy in a sequencing batch reactor

Abstract

The performance of a feedback control strategy in the operation of a sequencing batch reactor was evaluated. This strategy uses the online biogas flow measurements to define the duration of the reaction phase of each operating cycle, thereby increasing the energy production of the system and maximizing the methane production rate. The reaction phase is ended when the biogas flow rate reaches a sustained value significantly lower value than the maximum flow rate achieved, as a consequence of the depletion of the CODsoluble. The implementation of the depletion-time control was successful and reached a maximum methane production rate of 1.22 LCH4/d, showing an average productivity of 0.73 ± 0.3 LCH4/d. The reaction phase varied from 1.2 to 6 days with hydraulic retention times from 6 to 30 days. The use of this feedback control strategy increased the methane production and the energy production in 80% of the evaluated cycles (from 10.4 to 43.8%) compared to the operation of conventional anaerobic digestion without a control strategy. Furthermore, the strategy is easy to implement since it does not require complex calculations and uses a readily available biogas flow rate sensor.

The gastrointestinal microbiome of browsing goats (Capra hircus)

“…To determine the bacterial and archaeal diversity the hypervariable regions V3-V4 and V4-V5 of the bacterial and archaeal 16S rRNA genes were amplified. The set of primers used in these amplifications for domain Bacteria were 357wF 5’- -3’ and 926wR 5’- -3’ [ 14 ] and for domain Archaea were 517F 5’- -3’ and 909R 5’- -3’ [ 15 ].…”

Spatial analysis of heavy metals in septic tank sewage

“…Before now, studies relating to septic tank systems are usually and understandably focused on methanogenesis with an emphasis on energy generation from biogas. [26][27][28][29][30] . Others have focussed on characterizing heavy metals in water and wastewater effluent samples and comparing their concentrations with various guideline values.…”