# Influence of Photoperiod on Membrane Fouling Reported in a Membrane Photobioreactor for Reclamation of Anaerobic Effluent

## TL;DR

This study explores how light exposure affects membrane fouling and wastewater treatment performance in a membrane photobioreactor.

## Contribution

The study reveals that longer photoperiods enhance sustainable nitrogen conversion and simplify membrane cleaning.

## Key findings

- Light exposure significantly influences organism activity and membrane fouling in wastewater treatment.
- Longer photoperiods improve nitrogen conversion and reduce residual fouling on membranes.
- Physical cleaning is more effective under longer daylight conditions.

## Abstract

The combination of anaerobic and membrane photobioreactor
(MPBR)
technologies has generated interest as a sustainable strategy for
domestic wastewater treatment. The former allows lower sludge production
than aerobic technologies and energy recovery through biogas production,
while MPBRs act as an advanced secondary effluent treatment. This
study shows the effects of the light photoperiod on the suspension
characteristics and overall performance of bench-scale MPBRs applied
to an advanced secondary effluent treatment of a pilot upflow anaerobic
sludge blanket (UASB). The results of the experimental runs showed
the key role played by light incidence on the organisms developed
and consequently on wastewater recovery performance and membrane fouling.
The two light/dark photoperiods tested (9/15 h and 12/12 h) resulted
in similar values for regeneration performance and membrane fouling.
However, the longer photoperiod promoted a more sustainable process
of nitrogen conversion associated with photosynthetic activity. In
addition, longer daylight hours contributed to membrane performance
characterized by more easily removable fouling using physical cleaning
methods and with less residual character. Consequently, the tested
technology can further improve performance in terms of long-term membrane
operation and contributes to the design of an overall sustainable
process.