Removal and Fouling Influence of Microplastics in Fertilizer Driven Forward Osmosis for Wastewater Reclamation

Abstract

Insufficient removal of microplastics (MPs) and nanoplastics (NPs) may exert negative effects on the environment and human health during wastewater reclamation. The fertilizer-driven forward osmosis (FDFO) is an emerging potential technology to generate high-quality water for irrigation of hydroponic systems. In this study, the removal of MPs/NPs by the FDFO process together with their impact on FDFO membrane fouling was investigated, due to FDFO’s low molecular weight cut-off and energy requirement by using fertilizer as draw solution. Plastic particles with two different sizes (100 nm and 1 μm) and extracellular polymers released by real wastewater bacteria were utilized as model compounds for FDFO performance comparison. Results show that FDFO membrane system could generate high-quality irrigation water with only fertilizer, completely removing extracellular polymers, MPs and NPs from wastewater. It was found that the MPs and NPs themselves do not cause a significant membrane fouling. Moreover, it could help to reduce the membrane fouling caused by extracellular substances. That is probably because MPs and NPs helped to form a loose and porous fouling layer. Therefore, the FDFO process could be a long-term stable (low fouling) process for the reclamation of wastewater with high-quality requirements.

Forward Osmosis Membrane: Review of Fabrication, Modification, Challenges and Potential

“…In recent studies, fertilizers with different osmotic pressures were selected as DS to achieve the purpose of high-quality water recovery from synthetic wastewater (containing microplastics and nanoplastics) [1], domestic wastewater [128], local municipal wastewater [128], synthetic brackish water [146], and raw sewage [177]. However, most of the reported water flux was relatively low using CTA membrane due to solute build-up in the final FS which was mainly attributed to reverse nutrient (K + , NH + 4 , and PO 3− 4 ) fluxes.…”

“…In past decades, freshwater demand has risen substantially owing to population growth, economic development, and different consumption patterns [1]. This ultimately, induced a global clean water scarcity and this scenario will only get worse in the next few decades.…”

Various advanced wastewater treatment methods to remove microplastics and prevent transmission of SARS-CoV-2 to airborne microplastics

“…The wind transfer is credited with creating 7% of all ocean contamination (Chen et al 2020 ). There may also be sources of AMPs, such as plastic fragments released from clothing and house furnishings, materials in buildings, waste incineration, landfills, industrial emissions, particle resuspension, particles from traffic, synthetic particles used in horticultural soils (e.g., polystyrene peat), sewage sludge used as fertiliser, and tumble dryer exhaust (Prata 2018 ; Wang et al 2021a , b , c ). Fashion and season play a significant role in influencing the amount and quality of MPs particles in airborne clothing.…”

“…The MPs can absorb persistent organic pollutants (such as polychlorinated biphenyls) (Wang et al 2021a , b , c ) as well as heavy metals (Mao et al 2020 ). A million times more persistent organic pollutants can adhere to plastics than to ambient air, which can further be desorbed by organisms, causing them to accumulate at higher trophic levels (Bakir et al 2014 ) ( Fig.…”

Water Treatment Process

“…Membrane separation processes were proposed in several different treatment schemes for the reuse of water and valuable by-products from wastewater. In this context, Wang et al [ 2 ] evaluated the feasibility of a forward osmosis system to reclaim water for irrigation purposes from wastewater containing nano- and microplastic particles. They found that in the presence of nano- (0.1 μm) and micro (1 μm)-plastic particles, the hydraulic resistance of the fouling layer decreased compared with the control experiments when no particles were present.…”