Effects of filter with uniform sandy filtration medium used in micro-irrigation on mass fraction of particles and turbidity of water with fly ash

The aim of the research is to make clear the filtration effect of the uniform sandy filtration medium in micro-irrigation. An experimental research on the effects of filter with uniform in micro-irrigation on mass fraction of particles and turbidity of water with fly ash was carried out. The results of mass fraction of particles test showed that, the average removal rate of the mass fraction of particles was above 59%. However, the variation range of test data was large which indicated a complicated filtration process. Removal rate of the mass fraction of particles in filtered water was negatively correlated with filtration speed, and positively correlated with the mass fraction of particles of influent water. The conclusion described by the Mintz filter equation was showed its correctness in micro-irrigation through this study, namely, the filtration was a course that adsorption and abscission ocoured alternatively. The filtration flow regime was proven to be non-laminar flow, in most cases, might be in the transition region between the level flow and turbulence. The results of the turbidity test showed that the filtration layer thickness played decisive role in the removal rates of turbidity. Both the adsorption time and the abscission time were all about 5–6 min. The effect of the filtration rate on the removal rates of turbidity was limited. It could be summarized by comparing the two tests that the mass fraction of particles of filtered water and turbidity were two parameters that were not related with each other. The two filtration processes were different, so it was not correct that judge the effects of filtering and backwashing by turbidity index. The experiment can provide some references for the development of the future micro-irrigation.