PESTICIDE REMOVAL FROM CONTAINER NURSERY RUNOFF IN CONSTRUCTED WETLAND CELLS

Constructed wetlands may be designed to clean runoff water from agricultural sites, including container nurseries. The study evaluated 14 constructed wetlands cells that collected pesticide runoff. One-half of the cells were vegetated with bulrush (scirpus validus). The cells were loaded at 3 rates of flows of 0.240,0.120 and 0.006 m3/d. Herbicides, simazine and metolachlor were applied at different rates. Pesticides removals were analysed at different flow rates. Gravel subsurface flow constructed wetlands removed of the pesticides with the greatest removal occurring at lower rates in vegetated cells.