Constructed wetlands: A possible solution for municipal wastewater treatment: A review
Crucial state of total available fresh water resources makes non-traditional water resources useful to meet incomparable global water demand. In this case, treated municipal waste water can serve as a valuable resource to reduce the demand of fresh water in number of countries. Over the years, several technologies, e.g., constructed wetlands, waste stabilisation pond, vermi-filtration, membrane bio-reactor, up-flow anaerobic sludge blanket reactor have been developed to treat different types of waste water. The present study focussed on the performance of constructed wetland (CW) for removal of different physical, chemical and biological contaminants to make the wastewater suitable for irrigation purpose. The investigation revealed that both surface and sub-surface flow wetlands were used for municipal wastewaters. Within sub-surface flow, both vertical and horizontal flow systems were designed. In addition, the applications of hybrid CWs for municipal wastewaters were also documented in this review article. The worldwide application of CWs suggested that CWs alone performed better for removal of physical (turbidity, total suspended solids) and some chemical impurities than biological impurities from municipal wastewater.