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Steep rises in energy costs coupled with government incentives for the generation of renewable energy have led to increased interest in the implementation of anaerobic digestion for industrial effluent treatment.

Granular biomass processes are most commonly employed with these typically being UASB (Upflow Anaerobic Sludge Blanket) or EGSB (expanded granular sludge bed) plants or variants thereof. These are predominantly employed in the brewing, beverage, paper and pharmaceutical industries due to the high temperatures and organic concentrations of the effluent.

Aqua Enviro specialise in the optimisation of UASB/EGSB performance, maximising methane production (revenue) and determining the financial viability of anaerobic treatment on sites where it is not yet employed. Examples of problems we have encountered and developed solutions for include:

• An increase in the proportion of dissolved fats processed leading to saponification, attachment of chemically altered fats to biomass and loss of granular sludge
• Non-optimal operation of the pre-acidification phase leading excessive production of volatile fatty acids (VFAs) creating toxicity/instability
• Inhibitory levels of sulphide and excessive hydrogen sulphide in the biogas
• Low COD:sulphate ratios causing sulphate reducing bacteria to out compete methanogens for VFA’s
• Erratic control of recirculation rates leading to uneven upflow rates, short circuiting, septicity and an increased risk of VFA toxicity
• Reduced influent wastewater temperatures (resulting from a waste minimisation programme) leading to conditions that were marginally mesophilic
• Nutrient deficiencies for granule formation and retention
• Introduction of inhibitory chemicals to the wastewater
• Ammonia release from particulate organics leading to consent failures

We offer onsite support to evaluate performance and deliver plant operator training and our purpose built treatability laboratory permits us to model different process parameters.