Rhizodegradation gradients of phenanthrene and pyrene in sediment of mangrove (Kandelia candel (L.) Druce)

► Self-design rhizobox was used to separate the thinner consecutive sections from the root. ► Mangrove rhizodegradation gradients of phenanthrene and pyrene in sediment were investigated. ► The degradation gradient order was near rhizosphere > root compartment > bulk sediment. ► Rhizosphere was effective in promoting the depletion of the PAHs. ► Root promoted biodegradation was the predominant contribution to the remediation.