“…The value of the above said parameters generally remains below unity, but they were >1 for both the test metals in the present case. The value of n RP and n S > 1 is not commonly observed, but has also been reported by some other workers [27][28][29]. It seems that types and distribution of the binding sites on biomass surface are extremely complex in nature, and hence a natural sorbent, like Pithophora, will not completely follow any ideal assumption of sorption theory.…”