“…Basic studies of water movement inside the system [10,11], wastewater treatment mechanisms [9], material composition of SMB and PL [7,[12][13][14], aeration effects [13], horizontal flow MSL system [15], and the relationship between treatment capacities, HLR, and contamination levels [16,17] have been conducted on these systems. More applied studies have included water purification for river water [18], domestic wastewater [18,19], livestock wastewater [20], textile wastewater [21], leachate from unsanitary landfills [22], and olive mill wastewater [23] and have been carried out using regional resources. Based on the results of these basic and applied studies, some MSL systems have been put into practical use for the treatment of river water and wastewater from toilets in parks and small communities.…”