Using reclaimed water such as wastewater treatment plants effluent in different parts, especially in agriculture, has special significance. In this research, at first, the Mahallat wastewater treatment plants in physical and chemical parts were investigated. Parameters like pH, BOD5, COD, EC, nutrients like nitrogen, phosphate, potassium, heavy metals, SAR and RSC were evaluated for a year. Inlet and outlet effluent quality compared together and assessed with existing standards. Results compared to Iran's Environment Protection Agency showed that, inlet effluent cannot be used in agriculture. But with proper function of aeration lagon, outlet effluent can be used in agriculture. Then using distilled aerated effluent, water without Coliform obtained. The distillation efficiency was %75 and water analysis results showed that MPN index was less than 1.1. The effect of water from distillation effluent, inlet effluent and aerated effluent at 3 treat and 3 repeat on an ornamental flower (Zannia elegans) were evaluated. The Completely Randomized Design (CRD) was used. In the greenhouse, the soil and pot size to be the same for all of 45 tests and indexes such as plant height, stem length, root length, stem diameter and the number of leaves were considered. In the study of Zannia eleganus height, 3 treat had significant difference. Irrigation with inlet effluent, increased the plant height. Maximum height and length of stem were for inlet wastewater, distilled effluent and aerated effluent treats, respectively. For the number of leaves, there was no significant difference between treats. However the largest diameter of the stem belonged to inlet wastewater, aerated effluent and distilled effluent treats, respectively. Inlet wastewater treat had maximum number of leaves. Significant difference was observed for plants root length and aerated effluent treat had smaller root length than the other 2 treats. Key Words: treatment plants, Mahallat, wastewater, aeration, distillation, greenhouse, Zannia elegans.
