Phenol and nitrogen removal in microalgal–bacterial granular sequential batch reactors

Abstract

BACKGROUND: Microalgal-bacterial systems work on the principle of the symbiotic relationship between algae and bacteria. The ability of algal-bacterial photobioreactors for the treatment of wastewater containing ammonia and phenol has been poorly addressed. In this work a self-sustaining synergetic microalgal-bacterial granular sludge process was thus developed to treatment of industrial wastewater based upon the low cost of photosynthetic oxygenation and the simultaneous phenol and nitrogen removal. The performance of a conventional sequential batch reactor (SBR) based on aerobic bacterial communities (SBR B ) and a microalgal-bacterial granular SBR (SBR MB ) were comparatively assessed. The major challenges associated with microalgal-bacterial systems were discussed.RESULTS: A complete removal of phenol (100 mg L −1 ) was achieved in both reactors. The reactors SBR B and SBR MB showed similar performance in term of removal of inorganic nitrogen. Nitrogen mass balances estimated nitrogen assimilation, nitrification and denitrification. Higher simultaneous nitrification and denitrification (70% SND) occurred in SBR B as determined by mass balances. The higher nitrogen assimilation (17.9%) by the microalgal-bacterial biomass compensated the lower denitrifying activity in SBR MB (54% SND), resulting in a removal of inorganic nitrogen (61%) similar to that obtained in SBR B (66%). N 2 O was not detected in the headspace of any system. CONCLUSION: Granular microalgal-bacterial consortia implemented in SBR constitute an efficient method for industrial wastewater treatment achieving complete removal of ammonia and phenol. The application of SBR MB would be more cost effective than SBR B mainly due to the significant energy savings in SBR MB resulting in a sustainable system that contributes to the circular bioeconomy.

Research Progress on the Configurations and Performance of Reducing Pollution and Carbon Emissions by Bacterial–Algal Reactor

“…Yasmeen [19] indicated that an algal membrane photobioreactor (MPBR) will be helpful in either supplying the O 2 by recirculating the O 2 -rich effluent produced into the MBR or improving water quality by reducing the nutrients before entering into the MBR. Bucci et al [20] compared the effect of a bacterial aerobic granular sludge SBR and bacterial and algal aerobic granular sludge on the removal of phenol and ammonia nitrogen. They found that the phenol removal rate reached 100% in 24 h and the NH 4 + -N removal rate of bacterial aerobic granular sludge SBR was 100%, while the NH 4 + -N removal rate of bacterial aerobic granular sludge SBR was 0.5%.…”

Ultratrace Aromatic Anhydride Dopant as Intermediate Island to Promote Charge Transfer of Graphitic Carbon Nitride for Enhancing the Photocatalytic Degradation of Rhodamine B

“…In recent years, the environmental hazards caused by textile and dyeing industry wastewater have been increasing, which is mainly reflected in the fact that the wastewater produced not only destroys the natural environment but also flows into residential areas. Especially, dyestuff wastewater is difficult to decompose naturally and exists for a long term in the ecological cycle, which causes skin or respiratory diseases and damages human health. − In order to remedy the worsening water environment, many treatments, including physical adsorption, , microbiological degradation, − electrocatalytic degradation, − and photocatalyst degradation, were used to treat dyestuff wastewater. Among them, the photocatalysis technology is gaining significant attention as a clean and energy-saving method. , The key limitation to the large-scale application of the photocatalysis technology is the lack of inexpensive, safe, and high-efficiency photocatalysts.…”