title: Role of algal biofilm in improving the performance of free surface, up-flow constructed wetland.
abstract: The role of algal biofilm in a pilot-scale, free-surface, up-flow constructed wetland (CW), was studied for its effect on chemical oxygen demand (COD), ammonia and phosphate removal during three seasons-autumn, winter and early spring. Effect of hydraulic retention time (HRT) was also investigated in presence and absence of algal biofilm. Principal Component Analysis was used to identify the independent factors governing the performance of CW. The study showed algal biofilm significantly improved nutrient removal, especially phosphate. Ammonia removal varied with HRT, biofilm and ambient temperature. Increase in biofilm thickness affected ammonia removal efficiency adversely. Algal biofilm-assisted COD removal compensated for reduced macrophyte density during winter. Two-way ANOVA test and the coefficients of dependent factors derived through multiple linear regression model confirmed role of algal biofilm in improving nutrient removal in CW. The study suggests that algal biofilm can be a green solution for bio-augmenting COD and nutrient removal in CW.
authors.affiliation: CSIR-National Environmental Engineering Research Institute, Nagpur, Maharashtra 440020, India.
authors.forename: Neha
authors.initials: N
authors.lastname: Badhe
authors.affiliation: CSIR-National Environmental Engineering Research Institute, Nagpur, Maharashtra 440020, India.
authors.forename: Shaswati
authors.initials: S
authors.lastname: Saha
authors.affiliation: CSIR-National Environmental Engineering Research Institute, Nagpur, Maharashtra 440020, India. Electronic address: ra_biswas@neeri.res.in.
authors.forename: Rima
authors.initials: R
authors.lastname: Biswas
authors.affiliation: CSIR-National Environmental Engineering Research Institute, Nagpur, Maharashtra 440020, India.
authors.forename: Tapas
authors.initials: T
authors.lastname: Nandy
mesh_terms: D000641:Ammonia / Q000302:isolation & purification; D000704:Analysis of Variance; D001673:Biodegradation, Environmental; D018441:Biofilms / Q000254:growth & development*; D057919:Biological Oxygen Demand Analysis; D016014:Linear Models; D010710:Phosphates / Q000302:isolation & purification; D010865:Pilot Projects; D025341:Principal Component Analysis; D015203:Reproducibility of Results; D012212:Rheology; D012621:Seasons; D013499:Surface Properties; D032401:Typhaceae / Q000502:physiology*; D053833:Wetlands
chemical_list: D010710:Phosphates; D000641:Ammonia
keywords: Algal biofilm; Constructed wetland; Free-surface; Green solution; Nutrient removal