Possibilities of protection of water resources with the use of constructed wetland systems: a review

This paper presents a review of information about the method of sewage purification by constructed wetland systems (CWs) and the results of the efficiency of pollution removal in such systems. Data from various countries of the world indicate that single-stage CWs are characterised by a fairly high, above 80%, efficiency of removal of total suspended solids and reduction of BOD5 and COD, but lower efficiency of removing biogenic compounds - below 50%. Significantly higher efficiency of removing pollutants can be achieved with the use of multi-stage hybrid CWs whose efficiency in total nitrogen removal is from 61 to 86%, and of total phosphorus 70-99%. The results obtained indicate that the application of CWs may provide effective protection of water resources against pollution.