Unique characteristics of algal dissolved organic matter and their association with membrane fouling behavior: a review

Abstract

Over the last several decades, the frequent occurrence of algal bloom in drinking water supplies, driven by increasing anthropogenic input and climate change, has posed serious problems for membrane filtration processes, resulting in reduced membrane permeability and increased energy consumption. It is essential to comprehensively understand the characteristics of algal dissolved organic matter (DOM) and the subsequent effects on the filtration processes for better insight into membrane fouling mitigation. Many studies have revealed that algal DOM has displayed unique characteristics distinguished from other sources of DOM with respect to the chemical composition, the structures, and the molecular weight distributions. Algal DOM is considered to be a major obstacle in understanding membrane fouling due to its complicated interactions among dissimilar algal DOM constituents as well as between algal DOM and membrane material matrices. The present review article summarizes (1) recent characterizing methods for algal DOM, (2) environmental factors affecting the characteristics of algal DOM, (3) the discrepancies between algal DOM and other sources of aquatic DOM, particularly terrestrial sources, and (4) potential fouling effects of algal DOM on membrane filtration processes and their associations with algal DOM characteristics. A broad understanding of algal DOM-driven membrane fouling can lead to breakthroughs in efficient membrane filtration processes to treat algal bloom water sources.

Role of phytoplankton in aquatic mercury speciation and transformations

“…Six thiols (mercaptoacetic acid, cysteine, homocysteine, N-acetyl-cysteine, mercaptoethane-sulfonate, and glutathione) were detected with total concentrations of 7-153 nM in boreal lake waters Björn 2014, Liem-Nguyen et al 2015). Recent studies have shown that several green algae excrete some ligands, particularly thiol-containing ligands that form strong complexes with Hg species and thus modify Hg speciation and bioavailability (Mangal et al 2016, Ly et al 2017, Mangal et al 2019a).…”

Pretreatment of Reverse Osmosis Concentrate from Reclaimed Water for Conventional and High-Efficiency Reverse Osmosis and Evaluation of Electrochemical Production of Reagents

“…The main cause of low recoveries from water reclamation is membrane fouling by autochthonous organic matter produced during biological wastewater treatment. 8,9 This type of organic matter has a high membrane fouling potential and is primarily composed of the extracellular polysaccharides that are responsible for floc formation in activated sludge processes. 10,11 High-efficiency reverse osmosis (HERO) may be able to reduce membrane fouling by autochthonous organic matter and prevent biofilm growth on RO membranes.…”

“…Low recoveries are problematic because they decrease the amount of recoverable water and increase the amount of concentrate solutions requiring treatment or disposal. The main cause of low recoveries from water reclamation is membrane fouling by autochthonous organic matter produced during biological wastewater treatment. , This type of organic matter has a high membrane fouling potential and is primarily composed of the extracellular polysaccharides that are responsible for floc formation in activated sludge processes. , …”

Insights into the roles of recently developed coagulants as pretreatment to remove effluent organic matter for membrane fouling mitigation

“…EEM-PARAFAC has recently become a popular and useful tool to probe the dynamic changes in EfOM for natural and engineering systems [4,[24][25][26]. However, EEM-PARAFAC is not able to reflect non lightabsorbing constituents (e.g., (poly)saccharides) [27]. Size exclusion chromatography (SEC) equipped with organic carbon detector (SEC-OCD) [28] can be a good complementary tool to overcome the limitation.…”