Research Of Sodium Alginate/slag Composite Material Water And Fertilizer Retention Performance

Water absorbent and retention material is a polymer material that has strong water absorb and retention ability. This is a polymer material that has 30 years development history, it is widely used in many fields, such as gardens, farm, desert, medication, construction, chemistry industry, foodstuff and environment protect, playing an increasingly important role, have good market prospects. But traditional organic composite materials with high water absorption and high production costs due to salt and water retention performance was poor, so their use has been greatly restricted, promotion and application is slow.This thesis, especially aim at farming land rainfall short, soil organic matter content is low and poor water holding capacity in Northern China, to reduce production cost, simplify the production process, increase salt and water retention as the starting point. Using natural polymer materials--sodium alginate and inorganic slag as the main raw material, prepare the sodium alginate/slag water absorbent composite material. Experiment shows that on the one hand greatly reduces the cost of production, the other hand, the material preparation process is simple and experiment process can easily be control.Using centrifugal water retention method and constant temperature water retention method to evaluate the water retention properties, and compared properties of the composites material and pure water retention alginate gel .The result show that, the properties of composites material better than pure water retention alginate gel, no matter under centrifugal or constant temperature condition.In order to evaluate the water retention properties of composite material, research the influence of composite water retention material on npk through chemical analysis method. The result show that, the leaching lose of npk largely decrease because the use of composite water retention material.This thesis also introduce the theory of fractal and fractal dimension, explained difference of water retention ability of four kinds of composite material. the pore fractal dimensions of 4 kinds of slags were calculated by the microscopy and image analysis techniques, moreover, the relationship between the water retention and pore fractal dimension of slags was gained. The results indicated that the pore fractal dimension of slags can be got by this method, the range of the fractal dimensions of 4 kinds slags was range from1.0267 to 1.4753, and when the fractal dimension is bigger, the performance of the water retention is better. So the mode of this experiment build can provide a good way for appraise the water retention ability of composite porous material.