Exploring the Potential of Green Microalgae-Based Phycoremediation Treated Wastewater for Sustainable Concrete Production

Table 1

Comparison of environmental impact and sustainability of phycoremediation with traditional methods with reference to standard guidelines.

Factor	Phycoremediation	Traditional methods	Standards/guidelines
Energy consumption	Lower energy consumption, especially with natural sunlight	Moderate to high energy consumption, e.g., aeration and pumping	ISO 14046:2014—energy intensity (kWh/m^3)
Chemical usage	Minimal or no chemical usage, relying on biological processes	Moderate to high chemical usage for coagulation, flocculation, etc.	ISO 14001:2015—chemical oxygen demand (COD) removal efficiency
Biosolids production	Can produce biomass for reuse (e.g., biofuel, fertilizer)	Generates biosolids requiring disposal, may need further treatment	EPA 40 CFR Part 503—biosolids quality standards
Land use	Can be implemented in open bonds or photobioreactors	Requires larger treatment facilities and more land	ISO 14040:2006—land use intensity (e.g., m^2/year)
Nutrient removal	Effective in removing nutrients like nitrogen and phosphorus	Can remove nutrients but may need additional processes	WEF nutrient removal manual—nutrient removal efficiency
Carbon footprint	Captures and utilizes CO2, potentially sequestering it	May have a carbon-intensive footprint depending on energy use	ISO 14064-1:2018—CO2 equivalent emissions
Water quality improvement	Enhances water quality, pollutant removal, oxygennation	Effective in pollutant removal but may have limitations in oxygenation	WHO guidelines for drinking—water quality
Cost considerations	Variable initial setup costs lower operational costs	Higher upfront and operational costs, depending on complexity	ISO 14007:2019—life cycle cost analysis