Work

The potential of microalgae as an all-in-one bioremediation system of agricultural drainage water: A comprehensive review

Year: 2025

Type: article

Abstract: Agricultural drainage water is an underutilized resource in water-scarce regions, but its reuse is limited by complex pollutant mixtures of nutrients, salinity, organic matter, pesticides, heavy metals, and pathogens. Conventional treatment methods are often fragmented, costly, and poorly suited to integrated removal. Microalgae offer a single-step bioremediation approach, coupling pollutant removal with biomass generation for value-added uses. This review synthesizes 1266 experimental datasets from 256 peer-reviewed studies (2010–2025) to quantify pollutant-specific removal efficiencies, identify top-performing genera, and evaluate operational factors across laboratory, pilot, and field scales. Median removal efficiencies were 84 % for total nitrogen (IQR: 66.5–95.1 %; 95 % CI: 80.8–87.1 %; n = 300), 88.8 % for total phosphorus (IQR: 76.9–98 %; 95 % CI: 85.3–92.3 %; n = 190), 70 % for pesticides (IQR: 37–90 %; 95 % CI: 53.6–78.5 %; n = 78) and 99 % for pathogens (IQR: 98.1–99.9 %; 95 % CI: 85.4–100 %; n = 16), with Chlorella excelling as a generalist, Scenedesmus achieving high COD and TDS removal, and halophiles such as Dunaliella thriving in saline environments. Performance was influenced by pollutant concentration, salinity, hydraulic retention time, and reactor configuration, with field systems showing 22 % lower efficiency than laboratory trials. Implementation analysis highlights photobioreactors for precision control and high-rate algal ponds for cost-effective scale-up. Key challenges include seasonal variability, contamination, harvesting costs, and biomass market barriers. This synthesis provides evidence-based pathways for advancing microalgae-based agricultural drainage water treatment from proof-of-concept to field deployment, supporting water reuse and circular bioeconomy goals in agriculture.

Source: Algal Research

DOI: 10.1016/j.algal.2025.104443

Authors: Bassma Taher, Ahmed S. El-Gendy

Institutions: National Water Research Center, American University in Cairo

Language: English

Topic: Algal biology and biofuel production

Subfield: Renewable Energy, Sustainability and the Environment

Field: Energy

Domain: Physical Sciences

SDGs: Clean water and sanitation, Responsible consumption and production, Zero hunger

Open Access status: hybrid

Estimated APC paid: $4,190