Algae enrichment device and method for detecting heavy metals in water by X-ray fluorescence spectroscopy

Abstract

The invention discloses an algae enrichment device and method for detecting heavy metals in water by X-ray fluorescence spectroscopy. Based on the advantages of strong adsorption characteristics of algae to heavy metals, fast adsorption speed, large adsorption capacity, and high adsorption efficiency, fresh water The green algae in the microalgae is the adsorption material, which can simultaneously adsorb various heavy metals in the water body. The filter membrane is used as the carrier for the heavy metals and algae cells. Through the process of adsorption and suction filtration, a circular thin sample with even distribution of heavy metals is made to realize the water body. Simultaneous, fast, automatic and effective enrichment of two heavy metals. The invention has the characteristics of simple operation, no need for chemical reagents, no secondary pollution, economical and environmental protection, and low operation and maintenance costs. Through enrichment, a round thin sample with uniform distribution of heavy metals can be made, which can effectively remove the interference of the complex matrix of the water body, which is beneficial to Improve the stability and sensitivity of the subsequent X-ray fluorescence spectrometry measurement, and provide a new enrichment method for the fast, real-time and online detection of various heavy metals in water by X-ray fluorescence spectrometry.

Description

technical field [0001] The invention relates to the technical field of enrichment of environmental heavy metal pollutants, in particular to an algae enrichment device and method for detecting heavy metals in water by X-ray fluorescence spectroscopy. Background technique [0002] Water is a natural resource that human beings depend on for survival. my country is not only poor in water resources, but in recent years, with the rapid development of manufacturing, mining, metallurgy, chemical industry and other industries, the problem of heavy metal pollution in my country's water is very prominent, and the pollution rate of the bottom of rivers, lakes and reservoirs is as high as 80.1%. Heavy metals are non-degradable, bioaccumulative, and biotoxic, and can cause cancer, disease, and mutagenesis. Once they are enriched in organisms, they will pose a serious threat to human health and the ecological environment, and cause serious damage to the national economy. huge loss. Rapid...

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Problems solved by technology

[0004] ① When high-energy X-rays directly irradiate water samples, the irradiated area of ​​the sample will cause chemical reactions of some elements due to local heating, resulting in bubbles, precipitation, and even precipitation. Therefore, the X-ray fluorescence intensity produced by the sample is extremely low. Stable and prone to change, which seriously affects the reproducibility and stability of X-ray fluorescence analysis signals, so the accuracy of heavy metal detection is poor

[0005] ② When the X-rays generated by the excitation source directly irradiate the water body sample, the water body has a strong absorption effect on X-rays, resulting in a higher-intensity scattering background, and at the same time, the characteristic X-ray spectral line intensity emitted by the analyzed elements is weak Therefore, the signal-to-noise ratio and sensitivity of heavy metal detection in water are low, and the detection limit of X-ray fluorescence spectrometry cannot meet the detection requirements of heavy metal elements in water bodies in environmental and industrial fields.

[0007] ①The direct titration method is to directly drop the water sample containing heavy metal elements on the filter membrane, and make a thin sample by heating and drying, and then measure the XRF spectrum. However, due to the uneven diffusion of the liquid sample on the filter membrane, the thin sample formed The uniformity of the sample is poor, and the heating process is easy to volatilize and lose toxic heavy metals such as Hg and As, so the repeatability and accuracy of the XRF spectrum measurement results are poor

[0008] ②The electrochemical deposition method deposits the heavy metal cations in the water sample on the surface of the electrode by electrolysis to enrich the heavy metal in the water, but this method requires sophisticated electrochemical equipment, and the actual water application will be limited, and the formed heavy metal thin layer sample The uniformity and repeatability are poor, and the electrode as the main component needs to be replaced and maintained regularly, which is expensive and easy to cause secondary pollution

[0009] ③The precipitation / co-precipitation method adds a precipitant to the water body sample to precipitate the heavy metal elements to be measured and make a thin sample with uniform distribution of heavy metals through solid-liquid separation. However, it is difficult to apply a precipitant to simultaneously enrich multiple When a variety of precipitants need to be added, the solution environment in which multiple heavy metals precipitate simultaneously is difficult to control, so it is difficult to achieve simultaneous precipitation and enrichment of multiple heavy metals in the same solution environment, and the added chemical reagents are likely to cause secondary pollution of the water body. pollution problem

[0010] ④The solid phase extraction method uses solid adsorbents to transfer the heavy metal elements to be measured in the water from the liquid phase to the solid phase. The solid adsorbents generally include activated carbon, carbon nanotubes, graphene, resin, etc., and the cost is relatively high.

In order to improve the adsorption performance of heavy metals, activated carbon, carbon nanotubes and graphene need to be functionalized and modified before use. Before the enrichment of heavy metals in water, the resin needs to be pretreated for a long time, such as drying, crushing, grinding, sieving, expansion and acid soaking. This operation process is also cumbersome and time-consuming

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