Innovative Algal-Bacterial Wastewater Treatment

Microalgae photosynthesize using CO₂ (from bacterial respiration), releasing oxygen which supports aerobic bacteria. 

Bacteria produce CO₂ and other metabolites (organic carbon, vitamins) which aid algal growth. 

High removal of chemical oxygen demand (COD) via heterotrophic bacterial degradation, often enhanced by algal oxygen supply. 

Ability to treat complex pollutants including dyes, phenols, pharmaceuticals, personal care products (micropollutants) through combined mechanisms: biodegradation, adsorption, photodegradation. 

Algae assimilate inorganic nitrogen (ammonia, nitrates) & phosphorus into biomass. 

Bacterial nitrification & denitrification (and in some systems anammox) happen in various micro‐zones within the biofilm or granules. 

Because algae produce oxygen via photosynthesis, mechanical aeration (one of the major energy consumers in conventional treatment plants) can be reduced. 

Lower power‐costs especially for systems exposed to light or natural sunlight.

The biomass produced (algae + bacteria) can be used as fertilizer, biofuel feedstock, maybe even for high‐value bioproducts (pigments, proteins). 

Potential for circular economy approach: converting waste to value rather than only discarding it. 

Systems show good tolerance to fluctuations in load, pH, temperature, even toxic substances to some extent, due to the layered structure (biofilms or granules) where different zones (aerobic, anoxic, anaerobic) exist and community diversity helps buffer shocks. 

Sludge settleability is often good when algae are well‐incorporated, making harvesting / biomass separation more manageable.

Algal‐bacterial consortia can remove or degrade micropollutants (pharmaceuticals, personal care products), via co‐metabolism, adsorption to biomass, or photodegradation. 

Potential pathogen reduction due to high dissolved oxygen, pH fluctuations, algal photoactive compounds.