Reuse of Post-Treated Water in Irrigation Test Using a Biological Model Ryegrass Perenn

Introduction

Different wastewater technologies should not only guaranty color, COD and BOD5 removal, but also they have to be capable of produced by-products less toxic that pattern compounds. Taking that into account, The aim of this study was use the post-treated effluent of a pilot plant as irrigation wáter using the biologic model Ryegrass perenn.

Experimental Design

Greenhouse re-use test

The effluent obtained after each cycle of treatment was characterized in order to establish its quality for being used as irrigation water. The grass was selected as a biologic model for greenhouse tests. A Factorial experiment with a completely randomized design was applied. The different factors were irrigation water, soil type and the mixing ratio. The effluent obtained from each treatment cycle was tested, cycle 1 (TEC1), cycle 2 (TEC2) and cycle 3 (TEC3) and also untreated wastewater. As control drinking water was evaluated (DWW). The response variable was RDW (Root Dry Weight). The Analysis of variances was performed using R statistical software in R wizard platform.

Results

FIGURE 1.

Figure 1. showed the mean and value distribution between water, soils and dilutions. The results followed a normal distribution: Test Kolmogorov-Smirnov with Lilliefors correction (p = 0.7345) and Shapiro-Wilk (p=0.8372). Variance homogeneity was also found for the three evaluated factors (p = 0.5807, 0.0536 y 0.4306). There were differences in root weight and type of water (ANOVA, F1;57 = 4.20, p= 0,0047). No differences were found either for the type of soil (ANOVA, F2;57 = 0.01, p= 0,8976) or dilution (ANOVA, F3;57 = 0.20, p= 0,8155). The results of Tuckey test showed significant differences when comparing water from Cycle 1, Cycle 3 (p= 0.06344) and potable water (p= 0.00925).

Conclusion

Finally, biomass of Lolium perenne was higher when post-treated water was used in comparison with untreated wastewater and drinking water.