Upgrade of the Taskila WWTP with an MBR line: the first treatment results, performance assessment and lessons learnt

In this paper, we present the first results of a large-scale membrane bioreactor application implemented for increasing the wastewater treatment plant capacity. The Taskila plant in Finland was upgraded in 2018 and is now operated as a hybrid system with parallel membrane bioreactor and conventional biological lines. The results showed that membrane filtration improved the plant performance significantly in terms of the solids and pathogens removal. Nitrogen removal has been stable with the current operating set-points and notably better than before the plant expansion. The analysis using key performance indicators showed that there were no significant differences in operational expenditures between the membrane and conventional lines. The membrane filtration results highlight the importance of maintaining the good sludge filterability properties that enable higher operational fluxes and reduced energy consumption. The low membrane aeration flow-rate mode, the standard operating mode with good sludge filterability, enabled reduction of total aeration energy consumption by 34% for the membrane bioreactor, including both activated sludge and membrane aeration. Fine-tuning of the hybrid plant is still going on and, therefore, improved overall results are expected in the forthcoming years.

Membrane aeration as an energy-efficient method for supplying oxygen to microbial fuel cells

Membrane aeration consumes less energy and enhances coulombic efficiency compared to diffused aeration in a microbial fuel cell.

Studies the Factors of the Simultaneous Removal of Nitrogen and Carbon on Membrane Aeration Bioreactor

A Membrane aerated bioreactor (MABR) capable of simultaneous nitrification and denitrification in a single reactor vessel was developed to investigate the factors of the simultaneous removal of nitrogen and carbon. The results showed that when the bubble point pressure of membrane modules is 25kPa, the relationship between oxygenation efficiency and intransmembrane pressure were not positively correlated, controlling the transmembrane pressure was 15kPa, oxygen supply rate (OSR) was the highest. During the earlier stage of operation, reducing the hydraulic retention time of MABR could improve the integral removal efficiency, when the HRT was 2h, the removal of COD and ammonia - nitrogen were respectively 70.29% and 52.3%. The dissolved oxygen in the reactor had a significant influence, with the dissolved oxygen （DO） concentration about 0.5mg/L, ammonia-nitrogen and total nitrogen removal efficiency was better, the removal rate were 79.5% and 63% respectively. The reaction tank had CO2 accumulation, and caused pH reduced to 5.8, the operation should maintain the pH at 7.5 by increasing the alkalinity of the raw water.