Abstarct: The reverse osmosis process is widely used in industries to remove various pollutants, and it is exposed to various types of fouling due to its high removal efficiency. In this research, the effectiveness of micro-nano bubble technology has been investigated in controlling the RO membrane fouling and improving its performance. For this purpose, the effects of micro-nano air bubbles were evaluated on inorganic scaling (calcium sulfate dehydrate), colloidal fouling (colloidal silica) and simultaneous inorganic-colloidal fouling of a BWRO membrane by a lab-scale plate-and-frxame module. baxsed on the results, in the membrane scaling with gypsum, the formation of a concentration polarization laxyer and the scale cover on the membrane surface caused adverse effects on the membrane performance (decrease in the permeate flux (30%) and salt rejection (0.83%)). However, micro-nano air bubbles (AMNBs) can control the formation of scale laxyer on the membrane surface and improve the permeate flux (13%) and salt rejection (1.6%). It was because the presence of AMNBs can efficiently weaken the concentration polarization, increase the ability of ion transport in the flow channel and reduce the fluid viscosity. In absence of AMNBs, the colloidal fouling with silica particles led to sharp decrease in flow flux (24% to 56%) and salt rejection (1.25% to 4.18%) because of both the high hydraulic resistance of the fouling laxyer and the CEOP phenomenon. In the other hand, the presence of AMNBs decreases the sedimentation rate of silica particles significantly, and increases the porosity of the fouling laxyer. Also, AMNBs can play an effective role in improving the membrane performance (flow flux (21%-40%) and salt rejection (1.2%-2.6%)) and complete recovering of its performance during the CIP process. In the absence of micro-nano air bubbles, the simultaneous inorganic and colloidal fouling forms successive laxyers of colloidal and inorganic fouling. So, it causes a severe fouling on the active surface of the membrane and reduces the permeate flux (76.3%) and salt rejection (3.76%). The decrease of permeate flux in the simultaneous inorganic and colloidal fouling processes is much more severe than other two types of fouling. In the presence of AMNBs, the permeate flux has a decreasing trend which is lower than the permeate flux value in each of inorganic and colloidal fouling. But in general, there is a huge difference between the permeate flux values in the two states of the absence and presence of AMNBs. It can be explained by the proper performance of AMNBs in controlling of simultaneous inorganic and colloidal fouling processes. Therefore, the micro-nano bubble technology with negligible energy consumption is capable of controlling the fouling processes (inorganic, colloidal and inorganic-colloidal combined), improving membrane performance, increasing the time interval between CIP periods, and reducing specific energy consumption with no negative effects on the environment.