Yuejin Wu

Controlling nitrogen migration through micro-nano networks

Nitrogen fertilizer unabsorbed by crops eventually discharges into the environment through runoff, leaching and volatilization, resulting in three-dimensional (3D) pollution spanning from underground into space. Here we describe an approach for controlling nitrogen loss, developed using loss control fertilizer (LCF) prepared by adding modified natural nanoclay (attapulgite) to traditional fertilizer. In the aqueous phase, LCF self-assembles to form 3D micro/nano networks via hydrogen bonds and other weak interactions, obtaining a higher nitrogen spatial scale so that it is retained by a soil filtering layer. Thus nitrogen loss is reduced and sufficient nutrition for crops is supplied, while the pollution risk of the fertilizer is substantially lowered. As such, self-fabrication of nano-material was used to manipulate the nitrogen spatial scale, which provides a novel and promising approach for the research and control of the migration of other micro-scaled pollutants in environmental medium.

Controlling enironmental pollution by application of inartificial nano material

Nano technology and nano material were widely applied to solve the problem of water pollution. It is known that on their way forward, people are bound to run into lakes eutrophication in the world, owing to pollution source not being controlled. Among all pollution sources, agricultual widespread pollution, such as fertilizers nutrient to wash away, and inner pollution in the lake, such total nitrogen and phosphorin, COD and algae, have yet not to find effective controlling their methods. Recent advances in research on application of nano material have opened new areas of study in the field of the lakes eutrophication prevent and treatment, using magnetic or no-magnetic nano materials. Nano materials which were pretreated by modification of chemistry treatments could self-assemble a micro-nano network in aqueous phase. Pollutant micro molecules were banded around the micro-nano network by hydrogen bond, Van Der Waals force and viscous force, to enlaarge their spacial scale comparing with that of water molecule, so that they could easily be separated from water. Fertilizer-lose-control technology has been invented by micro-nano network structure of the nutrient which is blocked by soil filtration. The magnetic separation of water-algae technology was invented by adding magnetic material into mico-nano network materials. Both of these technologies are been engineered and industrialization. The output of controlled releasing fertilizer-lose-control agent reached 2×104 tonnes per year, magnetic flocculating agent was 5000 tonnes per year.