Assessing quality of an irrigation canal ecosystem, through water and environmental parameters (temperature, total hardness, pH, D.O, EC, BOD_5, COD, N, P, Na~+, NO_3~-, Ce~-, PO_4~(3-), NH_4~+ and SO_4~-). A case study in Thessaly region, Greece

摘要

This study aimed to record and evaluate the physicochemical parameters (temperature, total hardness, pH, D.O., EC, BOD_5, COD, N, P, Na~+, NO_3~-, Ce~-, PO_4~(3-), NH_4~+ and SO_4~-) in sediment Asmaki canal in order to assess the quality of water used and the nature of pollution along the canal. Samples were collected and analyzed bimonthly at twelve sampling sites along the irrigation-drainage Asmaki canal (Thessaly, Greece) and a total of 12 samples was made (every two months) for two consecutive years (2008 - 2009). We observed increased concentrations of, pH, D.O., EC, BOD_5, COD_5, N, P, Na~+, NO_3~-, PO_4~(3-), Ce~-, SO_4~- and NH_4~+due to anthropogenic inputs, mainly because of the discharged contaminating waters from the large industrial and agricultural activity. Specifically, in many cases (especially in the area of Karla) the values of electrical conductivity (EC) were too high (which is apparently due to leaching of saline soils), high total hardness, elevated concentration of Na~+ ions, very high values of BOD_5, COD, low prices D.O. and high eutrophication. The "Asmaki" presented at many points apparent industrial pollution, high intense anoxic conditions and high organic pollution. The findings of the study do not show that the parameter values are not affected greatly by the time of year (winter and summer) and this is due to an uncontrolled pollution from point and non-point sources.