Variation Significance of Reclaimed Water Qualities and Irrigation Suitability in Beijing, China

The qualities of reclaimed water influence the security and suitability of agricultural irrigation largely, which could be represented by indices total salt content, ALK, LAS, coliform groups and TN. What is the rule of variation of water qualities? The method of principle component analysis (PCA) and analysis of variance (ANOVA) could give the best answer. The result showed not only total salt content, ALK, LAS but also nutrition component in reclaimed water such as NO^3-, PO₄^3-, TP and organic compound reduce. Which presents two different meanings, one side, the phenomenon could be in favor of reducing irrigation risk by reducing risk of salination, injurant diffusing and pollution of ground water, on the other hand, the nutrient component reduce meanwhile and counteract the function of reclaimed water as nutrient source.