Development And Application Of Phase Material Of DGT For Heavy Metals Extraction Technology

Heavy metals hazardous in soil mainly depends on the content of available, and Diffusive gradients in thin-films technology is one of the most available methods for heavy metal extraction in recent years. But Chelex-100 as combination of DGT with the presence of expensive,poor performance for heavy metals dissociation and long time dissociation. The shortcomings severely restrict its application. Thus, in considering of diminished performance, easy preparation,cost-effective re-premise sieve with completely independent intellectual property rights of DGT binder phase materia 1 to replace Chelex-100, it is important for DGT from laboratory applications to standardize large-scale promotion.This paper based on a lot of early work and screening to obtain DTPA intercalated double hydroxides (Mg-Al-DTPA-LDHs) as the backbone of the new DGT binding phase, and the preparation of the Mg-Al-DTPA-LDHS-DGT (hereinafter referred to DTAP-LDHs-DGT or new DGT), based on a lot of test for new DGT, its practical application is studied. The main results are as follows:1. Compared with Chelex-100-DGT, DTPA-LDHS-DGT is non-toxic, easy preparation, full fast dissociation, easy prepare film.cost-effective, low background pollution and other advantages, more suitable for general laboratory preparation and application.2. Use of DTPA-LDHS-DGT for extraction of soil cadmium (Cd), nickel (Ni) available content,results showed:DTPA-LDHS-DGT storage time should be between 1-4 days for the test soil, as Chelex-100-DGT,for one day can get satisfactory results, soil porosity had a significant effect on the new DGT extraction of heavy metal content, but as a factors to consider heavy metal content of available into the soil during the calculation, the impact not obvious. New DGT is sensitive with diffusion phase thickness and soil heavy metal extraction agent. Relevant research need to be strengthened.3.Use of DTPA-LDHS-DGT explore soil cadmium (Cd), nickel (Ni) efective content in aging process, the results show that in aging 120 days achieve balance, and the new DGT efficiently situ indicate different soil heavy metals Cd, Ni available content changes and differences in aging process, and soil environmental factors on the change of heavy metals in active form has a unique role to reveal.4.Combined with changing the thickness of the new DGT diffusion phase, innovative research in different soils and heavy metals Cd, Ni kinetics feature in aging process,analyzes of heavy metals effective state component (plasma state and organic easily dissociated state) changes and the variation of dissociation kinetics coefficient K-1 in aging process.5. Greenhouse tests showed that there is a significant linear correlation between the new DGT extracted soil heavy metals Cd, Ni content of available with canola uptake.Low and high absorption rape varieties with Cd correlation respectively 0.85**,0.98**, correlation with Ni respectively 0.93**,0.92**,and the relationship is superior to other heavy metals extraction method.Experimental results show that the new development combined phase of DGT has good usability and promotion, but due to time constraints, further promote the use of experiments should be further strengthened.