Rapid and efficient device and method for extracting micro-plastics in soil

Abstract

The invention relates to a rapid and efficient device and method for extracting micro-plastic in soil. The rapid and efficient device is characterized by comprising a mud washing barrel, a screen set,a circulating pump, a circulating pipeline and a micro-plastic collector; the method specifically comprises the following steps: S1, soil pretreatment; s2, flotation of soil; s3, collecting particulate matters; s4, extracting the micro-plastic; s5, post-treatment of the micro-plastic; the mixed solution is used for pretreatment so as to destroy the structure of soil aggregate and improve the flotation separation effect; water, a NaCl saturated solution and a 1.8 g / L sodium iodide solution are sequentially used for gradient flotation, and the recovery rate is increased by 5.5%-11.8% compared with three times of repeated flotation of a single flotation agent; fine-grained soil or bottom mud is washed away, oversize particles are taken for extraction treatment, the extraction time can be shortened, the particle settling performance is greatly improved, meanwhile, the use amount of sodium iodide is reduced, and the cost is greatly reduced; tests prove that the extraction effect can be improved by 30%; 1000g of soil or bottom mud can be treated at most, and the problem of sampling errors is solved.

Description

technical field [0001] The invention relates to the technical field of soil microplastic detection, in particular to a fast and efficient extraction device and method for microplastics in soil. Background technique [0002] In the existing technology, for the extraction and treatment of microplastics in the soil, it is used to weigh about 100-200g of soil or sediment samples, add 1.8g / L sodium iodide extractant to the scale line, about 300-400ml , After fully stirring, let it stand until the sedimentation is completed. According to the different sedimentation speeds of the medium, it takes about 12 to 24 hours, and then collect the supernatant, and repeat this step two to three times. Pass the collected supernatant through a 100-micron sieve, collect the solid particles on the sieve, and then perform purification treatment. Finally, the microplastics are qualitatively and quantitatively checked by visual inspection, microscope inspection, and instrument inspection. [0003]...

AI Technical Summary

Problems solved by technology

[0004] 1) Because the soil or sediment particles are fine and difficult to settle, it is time-consuming; 2) The demand for sodium iodide is large, and about 2000g of sodium iodide is required for three extractions, which is expensive and costly; 3) The fine soil or sediment particles will also Attaching or wrapping microplastic particles makes it difficult to achieve the ideal extraction effect; 4) The amount of processed samples is small; the distribution of microplastics in the soil medium is very uneven, and the true content of microplastics in the soil cannot be fully reflected by sampling 100-200g

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