Reverse osmosis desalination system and algal blooms Part I: harmful algal blooms (HABs) species and toxicity
AbstractHarmful algal blooms (HABs) are a serious concern in the countries surrounding the Arabian Gulf (AG). A recent HAB event (2008–2009) forced partial (or full) shutdown of desalination plants, and reduced their productivity. Strong fouling in filter media occurred, and frequent backwash was not sufficient to maintain their removal. Some plants were shut down for as much as 32–55 d—in places where water storage may only be a few days—when pretreatment processes struggled to remove the increased biomass caused by the HAB species, and were shut down before more irreversible fouling of the reverse osmosis (RO) membranes could occur. HAB challenges are not limited to the algal biomass that may foul membranes, but extend to the toxins that can pass through the membranes and find their way into finished water. Within the AG region, great care is given to the engineering part (operation and maintenance) under normal conditions of the seawater; however, challenges in all levels and scales emerge due to HAB i...