Flow hydraulics consideration information of the greywater reuse: towards sustainable water management (Case Study: Chah-Anari region, Isfahan University of Technology, Isfahan, Iran)

The effects of irrigation with treated wastewater on soil chemical and physical properties have been studied in many researches, but a few studies have done about wastewater flow on the soil surface. In this study flow hydraulic of wastewater on soil surface was investigated and magnetic field effects on it was also studied. This research was done in the field with furrows (length of 42m, width of 60cm, depth of 25cm and slope of 0.1%) in Isfahan University of Technology and were used three water quality treatments consists of fresh water (FW), wastewater (WW) and magnetized wastewater (MW). Magnetic field was created by three magnets with constant magnetic field intensity of 10mili-Tesla for each one. Basic differences between three water treatments were in biological parameters (Chemical oxygen demand (COD), Total-coliform) and total suspended solids (TSS). The Collected data were included of advance and recession time, inflow and outflow rates with four replications and five irrigation events for each treatment (overall 60 practices), in a randomized complete block design. The inflow rate for furrows was determined 0.8 lit/sec. The results showed magnetic field have not a considerable effect on the physical and chemical characteristics of the wastewater, though it changes oxygen demand and especially total coliforms. Also, no significant difference was observed between the effects of water quality treatments on water infiltration characteristics, consist of basic infiltration rate (fo) and mean infiltration rate in two 30 minutes time intervals (0-30 and 30-60 minutes), but in mean infiltration rate in 0-30 interval, mean relative changes for the WW and MW were about twice of the FW. Mean infiltration rate of the FW has also less reduction than WW and MW in these intervals. However, scrutinizing of parameters variations in charts showed that WW and MW treatments relation to FW ones created more changes in downtrend of “fo” during irrigation season and magnetic field effect was inconsiderable. The “fo” in WW and MW was more than FW mostly. It was found that magnetic field causes increasing of the “fo” in MW related to WW. Similar results also were found in two-time intervals of infiltration process. Also excluding depletion time phase, evaluated time parameters, including advance time to furrow end, time to reach the “fo” and recession duration had not difference significantly influenced by water quality treatments, but values of advance time and time to reach the “fo” for WW and MW than FW were higher mostly. According to regressions equation between water quality parameters and flow hydraulic parameters, were found a negative correlation between “fo”, mean infiltration rate for 0-30min and 30-60min ranges and advance time withand irrigation number; and a positive correlation between these parameters with; also a negative correlation between time to reach the “fo” and depletion time with; and a positive correlation between these parameters withand irrigation number. In parameter of recession duration, positive correlations are with irrigation number and; and negative correlation is with. So as to current hydraulic examination of the sewage on the soil were experienced channel irrigations with sewage that the subsequent consequences were gained: Attractive ground result on WW superiority was not substantial, but electrical conductivity amplified a little. The straightforward penetration degree had downtrend throughout irrigation period. MW had similarly maximum standards of elementary penetration degree and for WW was developed than FW. Without period of reduction stage, components of current hydraulic of WW and MW on soil for example development, collapse and loading period had not alteration meaningfully inclined by water superiority conducts, then standards of development and loading period for WW and MW than FW were developed regularly.