Plant-microbe synergistic remediation of a micro-polluted lake
To remediate the problem of micro-polluted lake water induced by rainwater overflow,an micro-model was established to simulate the micro-pollution process in lake water.Three different remediation treatments were tested:a composite denitrifying agent alone and in combination with Mg-modified maifan stone or ecological particles.The influence of the different treatments on water quality,submerged plants(Vallisneria),and sediment microbial communities was assessed.The results showed that the composite denitrifying bacterial agent accelerated the restoration of water bodies.The simultaneous addition of either Mg-modified maifan stone or ecological composite particles improved the removal of NH4+-N,TN,and COD from water bodies.Compared with deintrifying agent alone or denitrifying agent plus ecological particles,the denitrifying agent plus Mg-modified maifan stone performed best in terms of removal of coupling nitrogen removal and promotion of Vallisneria growth.The alpha diversity of the sediment bacterial community was not significantly affected by the addition of any of the three treatments.The FAPROTAX function prediction showed that the heterotrophic nitrification-aerobic denitrifying bacteria,such as Anaerolineaceae,were the dominant sediment microorganisms in the plant-microbe synergistic nitrogen removal process.The combined dosage of composite nitrogen-removing bacteria agents and Mg-modified maifan stone or the ecological particles could accelerate the development of the microbial community.Under the synergistic effect of plants and microorganisms,the leaf length of Vallisneria increased by 26.5%and 11.8%,and the root length increased by 45.2%and 35.5%,respectively.
micro-polluted waterdenitrifying agentVallisneriasynergistic remediationmaifan stone