Characterization and biodegradability of sludge from a high rate A-stage contact tank and B-stage membrane bioreactor of a pilot-scale AB system treating municipal wastewaters

Abstract

In light of global warming mitigation efforts, increasing sludge disposal costs, and need for reduction in the carbon footprint of wastewater treatment plants, innovation of treatment technology has been tailored towards energy self-sufficiency. The AB process is a promising technology to achieve maximal energy recovery from wastewaters with minimum energy expenditure and therefore inherently reducing excess sludge production. Characterization of this novel sludge and its comparison with the more conventional B-stage sludge are necessary for a deeper understanding of AB treatment process design. This manuscript presents a case study on a pilot-scale AB system treating municipal wastewaters as well as a bio-(biochemical methane potential and adenosine tri-phosphate analysis) and physico-chemical properties (chemical oxygen demand, sludge volume index, dewaterability, calorific value, zeta potential and particle size distribution) comparison of the organic-rich A-stage against the B-stage activated sludge. Compared to the B-sludge, the A-sludge yielded 1.4 to 4.9 times more methane throughout the 62-weeks operation.

Spontaneous mainstream anammox in a full‐scale wastewater treatment plant with hybrid sludge retention time in a temperate zone of China

“…Since the hybrid system was not initially designed for autotrophic nitrogen removal, no special organic pre‐concentration step (e.g. A‐stage sorption (Kartal et al, 2010; Trzcinski et al, 2016)) was used in this case. Further investigation is needed to explore the long‐term impact of the combination of organic pre‐concentration which could either help to optimize mainstream anammox with enhanced autotrophic nitrogen removal or damage the process robustness built on a balance of hybrid PN/A and N/DN system.…”

High-rate activated sludge systems combined with dissolved air flotation enable effective organics removal and recovery

“…Compared with physical-chemical primary treatment, HRAS systems offer the advantage that they can effectively remove soluble organics as well. In full-scale AB plants treating domestic wastewater, the A-stage typically removes around 45-68% of TSS, and 45-74% of COD (de Graaff et al, 2016;Ge et al, 2017;Trzcinski et al, 2016). However, sludge produced at high loading rates and short SRTs suffers from poor settling characteristics.…”

Effects of Physico-Chemical Post-Treatments on the Semi-Continuous Anaerobic Digestion of Sewage Sludge

“…The emitted light was quantified using a luminometer in relative light units (RLUs) which were converted to actual ATP concentrations (ng/mL) after calibration with 1 ng/mL standard. Cellular and dissolved ATP were measured or calculated according to a procedure explained elsewhere [24]. Additionally, the biomass stress index (BSI) was calculated as the ratio of dead-cell ATP to total ATP [24].…”

“…Cellular and dissolved ATP were measured or calculated according to a procedure explained elsewhere [24]. Additionally, the biomass stress index (BSI) was calculated as the ratio of dead-cell ATP to total ATP [24].…”