Impacts of seasonality and operating conditions on algal-dual osmosis membrane system for potable water reuse: Part 2

J Environ Manage. 2022 Feb 15:304:114295. doi: 10.1016/j.jenvman.2021.114295. Epub 2021 Dec 27.

Abstract

This study investigated the impact of seasonal variation and operating conditions on recovery of potable quality water from municipal wastewater effluent using an integrated algal treatment process with a dual forward osmosis (FO)-reverse osmosis (RO) membrane system. Pilot study of the algal process treating primary effluent validated the technical viability and seasonal performance during warm weather (May to October, 25-55 °C) using an extremophilic algal strain Galdieria sulphuraria, and during cold weather (November to April, 4-17 °C) using polyculture strains of algae and bacteria. Algal effluents from both seasons were used as the feed solution for the laboratory FO-RO study. In addition, pilot-scale FO-RO experiments were conducted to compare the system performance during treatment of algal effluent and secondary effluent from the conventional treatment facility. At 90% water recovery, the FO-RO achieved over 90% overall rejection of major ions and organic matter using the bench-scale system and over 99% rejection of all contaminants in pilot-scale studies. Detailed water quality analysis indicated that the product water from the integrated system met both the primary and secondary drinking water standards. This study demonstrated that the FO-RO system can be engineered as a viable alternative to treat algal effluent and secondary effluent for potable water reuse independent of seasonal variations and operating conditions.

Keywords: Algal wastewater treatment; Forward osmosis; Potable water reuse; Reverse osmosis; Seasonal variation.

MeSH terms

  • Drinking Water*
  • Membranes, Artificial
  • Osmosis
  • Pilot Projects
  • Wastewater
  • Water Purification*

Substances

  • Drinking Water
  • Membranes, Artificial
  • Waste Water