A novel ambipolar-resin membrane for extracting soil nutrients

作者：Men, Yu-ying; He, Li-yuan^*; Zhang, Ai-qun; Theng, Benny K. G.; Liu, Hua-bo; Guo, Zai-hua

来源：Journal of Plant Nutrition and Soil Science, 2010, 173(2): 198-206.

DOI：10.1002/jpln.200700367

• ion-exchange resin
• membrane synthesis
• ion competition
• HCI desorption
• adsorption time
• soil nutrient extraction

We have synthesized a novel ambipolar membrane for the simple, rapid, and simultaneous extraction of key nutrients from soil. The membrane was made by adding an anion- and a cation-exchange resin to a polyvinyl alcohol hydrogel in the presence of glutaraldehyde as a cross-linking agent. The synthetic membrane was efficient in adsorbing (extracting) NO3-, PO33-, K+, Ca2+, and Mg2+ ions from soil simultaneously. The ion-adsorption capacity of the membrane was related to the soil nutrient status, duration of membrane-soil contact, and soil water content. The importance of these factors followed the order: soil nutrient status > contact time > soil water content. Adsorption by the membrane of NO3- and Mg-2(+) ions from soil leveled off after 48 h of membrane-soil contact but uptake of Ca2+, PO33-, and K+ ions required a longer contact time for equilibrium to be established. When the soil water content exceeds 55% w/w, this factor ceased to influence ion adsorption by the ambipolar-resin membrane. The synthetic membrane is potentially useful for the in situ assessment of the nutrient requirement of certain crops at a given point in time.

• 出版日期2010-4
• 单位湖北省科技信息研究院; 华中农业大学