Choosing reasonable design parameters for ceramic emitters used in subsurface irrigation is important for reducing the deep percolation of water and improving the water use efficiency. Laboratory experiments and numerical simulations with the HYDRUS-2D software were carried out to analyze the effect of soil texture on the infiltration characteristics of porous ceramic emitters used for subsurface irrigation. HYDRUS-2D predictions of emitter discharge in soil and wetting front are in agreement with experimental results, and the HYDRUS-2D model can be used to accurately simulate soil water movement during subsurface irrigation with ceramic emitters in different soil textures. Results show that soil texture has a significant effect on emitter discharge, soil matrix potential around the emitter, and wetting front. For 12 different soil textures, the aspect ratio of the wetting front is basically between 0.84–1.49. In sandy soil, the wetting front mainly appears as an ellipse; but in the clay, the wetting front is closer to a circle. As irrigation time increases, emitter discharge gradually decreases to a stable value; however, emitter discharge in different texture soils is quite different. In order to improve the crop water use efficiency in sandy soil, soil water retention can be improved by adding a clay interlayer or adding water retention agent, reducing the risk of deep percolation and improving the water use efficiency.

The instability of diafiltration is a widespread problem in the practical application of microporous ceramic filtration membranes. In this paper, a series of microporous ceramic filter membranes were prepared using inexpensive standard sand and river sand as matrix materials. Semi-empirical formula for the effective permeability radius of ceramic membranes with respect to time was established from analysis of the response mechanism between water flow and material properties. Finally, on the basis of theoretical analysis, some measures were proposed to improve permeate flux. The experimental results showed that during the initial stage of filtration, the microporous ceramic filter membrane had a large change in permeate flux, and during the late stage of filtration, permeate flux tended to be stable. Over time, open porosity and closed porosity changed the actual seepage area of the ceramic membrane, and this affected the stability of permeate flux and final stable permeate flux. The roughness of the inner wall of microporous ceramic pores affected the hydraulic loss coefficient, and this controlled the outflow process. Trace elements that were rich in sand produced a large amount of glass phase after sintering. The glass phase was rich in polar groups and formed a temporary hydrogen bond with the small flow of water molecules. It led to an increase in viscous resistance effect of the side wall along the water flow and the extent of the permeate flux of the ceramic membrane changed with time.