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Role of extracellular polymeric substances from Chlorella vulgaris in the removal of ammonium and orthophosphate under the stress of cadmium

2015; Elsevier BV; Volume: 190; Linguagem: Inglês

10.1016/j.biortech.2015.04.080

1873-2976

Biao Chen, Feng Li, Na Liu, Fei Ge, Huaixian Xiao, Yixuan Yang,

Constructed Wetlands for Wastewater Treatment

The interactions between the soluble extracellular polymeric substances (S-EPS), bound EPS (B-EPS) of algae and heavy metal, would affect the removal of ammonium (NH4+-N) and orthophosphate (PO43−-P) from wastewater by algae-based techniques. This study investigated the role of Cd2+-mediated EPS from Chlorella vulgaris on NH4+-N and PO43−-P removal. The results showed that the removal efficiencies of NH4+-N and PO43−-P still separately remained 62.6% and 64.9% under 1.0 mg/L Cd2+, compared to those without Cd2+, mainly attributing to enhanced S-EPS and B-EPS contents of the algae. The increased of PS (polysaccharides) and PN (proteins, e.g., tryptophan-like and tyrosine-like components) led to accelerated interactions of Cd2+ with PS and PN in EPS fractions, especially for B-EPS, due to a higher detected distribution of Cd2+ (e.g., about 55.4% in B-EPS). Thus, algae-based techniques are stable treatment methods for wastewater in which NH4+-N and PO43−-P coexist with heavy metals.