Enhanced decolourisation of methylene blue by LDH-bacteria aggregates with bioregeneration

•The released Ni and Fe improved the activity and growth of the bacteria.•LDH-bacteria aggregates were used for wastewater decolourisation.•The aggregates can effectively adsorb MB from water.•The decolourisation mechanisms are chemical and physical adsorption.•The aggregates can be bioregenerated and reused with high efficiency.