Q1: #1 Surface flow constructed wetlands (SF systems) #2 Horizontal subsurface flow constructed wetlands #3 Vertical flow constructed wetlands #4 Floating aquatic plant wetlands system #5 Tidal flow constructed wetlands #6 Intensified constructed wetlands Q2: In SF systems, water flows slowly through wetland and allowing suspended particles to be removed by sedimentation and filtration. Organisms and plants utilize decomposed pathogens as their nutrients. Q3: There are three key factors to have successful sustainable solutions, which are cost, community interaction and economic importance --- Cost: since the cost of building constructed wetlands can be saved by using local labor and materials for constructions, there is no need to import expensive equipment and maintenance and operation costs on completed system must be low. Community interaction: by facing environmental issues together, people can visualize what they need to do to improve current situations and it results in increasing dependency upon local community throughout construction process. Economic importance: more economically tangible return is necessary- constructed wetlands are capable of producing revenue because it has potential products such agriculture, construction materials, creative implementations and habitat creation for wildlife.