Research On Interaction Between Super Absorbent Resin And Ammonium Ion

In order to raising the utilization rate of fertilizer and moisture content, many scientific research workers have made unremitting efforts. They put forward delaying fertilizer and do research on Super Absorbent Resin(Water Retaining Agent)in the hope of solving this problems. But used to consider these two problems individually and emphasize the separated effect with divided research. Through deeply research, scientists found that the reasonable mixture of water and fertilizer will result in measured water by fertilizer and advanced fertilizer by water to increasing the production. Recently, therefore, the researchs on regulation and control on water and fertilizer attract agricultural workers'attention. Among them, the relationship between Super Absorbent Resin(Water Retaining Agent)and fertilizer is one of research subjects.From examinations, we research on the reciprocity between PAM,PAAS and ammonium ion, and make the following conclusions:1. In water, NH₄⁺ has remarkable influence on SARs'water absorbent rate, which will be prominently decrease with the concentration increasing. There is a remarkable power function relationship between SARs'relative water absorbent rate and NH₄⁺ concentration.2. The influence extent of the NH₄⁺ on SARs'relative absorbing percentage is almost the same as that of K+, but far less than that of Ca2+. In the same ionic strength, the NH₄⁺-K+ coexistence system is less influential over SARs'relative water absorbent rate than NH₄⁺ or K+ individual system do. However, the NH₄⁺-Ca2+ coexistent system is less influential over SARs'relative water absorbent rate than Ca2+ sole system do and more influental than NH₄⁺ individual system. Therefore, in the NH₄⁺,K+,Ca2+ individual solute and NH₄⁺-K+,NH₄⁺- Ca2+ coexistent system , the influence extent over the SARs'relative water absorbent rate is step up through NH₄⁺-K+, NH₄⁺,K+, NH₄⁺-Ca2+ and then Ca2+.3. Although NH₄⁺ can obviously reduce the water absorbent rate of the SARs in water, the SARs can also largely absorption and fixation the NH₄⁺ which while absorbing water, and the amount of NH₄⁺ which is grasped rapidly increase along with the the increase of the concentration of NH₄⁺. Which rule can be showed by Freundlich absorption and fixation model and linear absorption and fixation model.4. In different solution systems, if NH₄⁺ concentration is the same, the adsorbed and fixed quantity of SARs to NH₄⁺ is difference. While in the same ionic strength, NH₄⁺-K⁺ or the NH₄⁺-Ca²⁺ coexistence system is advantageous to the NH₄⁺ adsorbed and fixed. In the K⁺ sole system, NH₄⁺-K+ and NH₄⁺-Ca²⁺ system, the adsorbed and fixed quantity of SARs step up through NH₄⁺, NH₄⁺-Ca²⁺, and then NH₄⁺-K⁺.5. It's similar between dynamics curve of adsorption water isotherm and dynamics curve of adsorption of NH₄⁺ of SARs in different solution systems, both of which can be simulated by Elovich equation. There are big differences in water absorbing speed in various concentration NH₄⁺ solution. The higher concentration, the slower absorbing, but the faster NH₄⁺ adsorbed and fixed. Generally, It can reach adsorbed and fixed balance in 90 minutes.6. Absorbed ammonium (nitrogen) gel is very fast in desorption ( release) in water, and can reach the balance in about 1 hour. Then it no longer desorption. However, if replace desorption solution, Absorbed ammonium (nitrogen) gel can continue to desorption till to reach the new balance. There is big difference in release rule for gel with different NH₄⁺ concentration solution. For example, gel with low nitrogen desorptionis fast,while gel with high nitrogen is slow. Under replace desorption solution condition, the desorption rule can be showed by liner model and the latter one can be showed by Elovich model. It's need 4-8 days for 80% nutrient release.7. When absorbed ammonium (nitrogen) gel desorption in water, the absorption can be recovered, and the water absorbent rate can even surpass the original one. The desorption of KCl is obviously bigger than that in the water.8. We can increase the adsorbed and fixed function of NH₄⁺ through put SARs in soil, and decrease the eluviation lose of nitrogen。9. With comparison of the two resins, the influence of NH₄⁺ over PAA water absorbent rate is more than PAM. PAA has a big adsorbed and fixed quantity on NH₄⁺. However, there is no relationship between absorbed ammonium (nitrogen) gel NH₄⁺ speed and the type of resins.