Influences of pH, heavy metals and phosphate and their co-influences on the sorption of pentachlorophenol on cyanobacterial biomass

► Speciations of metals and pentachlorophenol (PCP) greatly affected the sorption. ► Ion pairs of PCP−-metal cation facilitated the sorption which was pH dependent. ► Cu2+ inhibited the sorption at pH of 3.25 and 4.35 but enhanced it from 5.0 to 9.0. ► Sorption in the presence of Cd2+ was much lower than that solely affected by pH. ► Na3PO4 inhibited the sorption at pH lower than 5.0 but enhanced it from 6.0 to 9.0.