Enhancement on the removal of Rhodamine B (RhB) by means of the Enlarged Anode Electric Biological (EAEB) reactor.

The Enlarged Anode Electric Biological (EAEB) Reactor was proposed, as an alternative to the common BAF. The goal of this research was to develop a new process for simultaneously removing, NH4+-N and Rhodamine B (RhB) from dyeing wastewater. The performance of EAEB was evaluated based on COD, NH4+-N and RhB removal efficiency in the effluent. The study found that the removal rate of RhB, which is a characteristic of the inoculation and start period, reaches 80% in EAEB and 30% in common BAF. A current intensity of 0.5 A, HRT of 3.5 h, and electrode area of 0.13 m2 were identified as operating parameters that could guarantee excellent RhB removal efficiency. It is worth noting that the removal of RhB in the two reactors was mainly concentrated in the 80 cm-140 cm area (measuring upwards at the top of the support layer). The removal rate of EAEB in this area was 97.7%, and the common BAF was 84.3%. Besides, in each segment of EAEB, the removal effect of RhB was better than in common BAF. This study elucidated the synergistic effects of electricity and biofilm on contaminant removal and identified important roles of improvements to the anode electro-biodegradation process. As compared to conventional technologies, the proposed process provides a highly efficient new alternative to dyeing wastewater treatment technology.