Investigating the influences of season and coastal proximity on the elemental composition of harvested rainwater

摘要

AnPnRnSnUnUnCnAnEnChemical qualities of harvested rainwater were assessed at two residential study sites on theneast coast of Australia in relation to coastal proximity and surrounding land uses over the coursenof a winter and summer month. Daily rainwater samples were collected from the base outlet andnsurface levels of stored water for chemical analyses. High resolution inductively couplednplasma—mass spectrometry (ICP-MS) was used to analyse 26 elements in all samples.nThe summer sampling regime for the industrial coastal Site 1 was dominated by wind gustsnoriginating from the east with a total average elemental load of 25,900 ^ 17,000mg/L comparednto the significantly lower 10,600 ^ 3,370mg/L measured during the winter month, where 84% ofnwind gust events originated from the west. Data for the inland Site 2, with no proximity tonindustry, revealed no significant changes in total average loads between the wintern(4,870 ^ 578mg/L) and summer (4,760 ^ 2,280mg/L) months. The most abundant elements foundnat both sites included Na, K, Mg, and Zn. The rainwater storages at Site 2 fed from a relativelynnew concrete tiled roof catchment had significantly lower pH and conductivity measurementsncompared with those at Site 1 with an old galvanised iron roof catchment. It was concluded thatnseasonal differences in harvested water quality were likely influenced by prevailing wind directionnand external influences such as surrounding land uses and proximity to the coast.