Effect of floating balls on evaporation reduction from open water resources (Case study:Tailing dam of Sarcheshmeh copper mine), Kerman

Evaporation is one of the most important sensible losses from water resourcese, especially in desert areas that humans have the lowest level of intervention. Climate is the most important index at the amount of these losses in different areas. Different methods has been presented for reducing of water evaporation rate . In this study, in order to evaporation reduction from tailing dams and open water resources of Sarcheshmeh copper complex investigated performance of three types balls as evaporation reducing coating for the first time. Used balls are different in the mechanism of action, size and material. They are including two types of polyethylene balls, mono-aperture and multi-aperture, with a diameter of 8 cm and a type of small polypropylene white ball with a diameter of 1 cm. For evaluating of performance of these coatings, several small ponds with an area of 1m2 in the vicinity of Sarcheshmeh tailing dam were built and evaporation losses were measured for a month from 03.04.2016 until 03.05.2016 in each covers with two repeats. Based on the Tukey and Duncan multiple comparison tests, there are significant differences between covers, in 5% significant level. Results showed, the mono-aperture balls with performance of 65.1%, had the greatest impact on reducing evaporation, while multi-aperture balls and small balls with 51.7% and 38.8% respectively were in the next priorities. Finally, the mono-aperture balls were identified as the best evaporation reducing coating, because these types of balls had the most roughness on the surface and amount of empty spaces was constant in during time.