Anaerobic Digestion process monitoring and enhanced biogas production - Case Study

Characterizing impact of pre-treatment:

• The pre-treatment accounted a 22.9% increase in biogas production between the test and control system. Further analysis of fractionation of the remaining organic material could be beneficial for understanding the full effect of the pretreatment.
• The pre-treated wastewater showed more consistent activity throughout the week, suggesting the pretreatment was having a good effect of maximizing the biological activity in the reactor. This also suggested that a potentially longer HRT could produce even higher biogas production and removal rates.

Biogas production:

• Biogas production (and therefore reactor activity) trended well with SENTRY output. This shows great promise as a way to fill in the gaps of data that exist in daily sampling.
• This biogas trend was especially helpful for understanding reactor A (no pretreatment) as the batch mode beginning and end was clearly noticed (typically between noon and 7pm). IWT believes additional loading to this reactor could be achieved during times of low MET.
• The pretreatment step has clearly increased the potential for biogas production of the microbes based on the current HRTs of the reactor.

Process feeding monitoring:

• The SENTRY sensors were able to pick up distinct batch run cycles for each system. 3 times higher average biological activity (MET) and longer cycles were noted in the reactor receiving the pre-treated influent (reactor B), suggesting a more biologically active feed material.