Determining method for trace nickel in high-salinity wastewater

Abstract

The invention provides a determining method for trace nickel in high-salinity wastewater. The determining method comprises the following steps: firstly, taking the high-salinity wastewater containing the trace nickel as a water sample; secondly, adding acid in the water sample for dissolving and then using distilled water to reach constant volume, respectively taking a plurality of parts of water samples with the constant volumes, not adding a nickel standard solution into one water sample, and adding nickel standard solutions of different amounts into other parts to obtain one part of to-be-determined solution and one group of sample solutions with concentration gradient; thirdly, selecting a spectral line for determining nickel to be 231.6nm, and using an inductive coupling plasma emission spectrograph to respectively test the to-be-determined solution and the group of sample solutions to obtain corresponding spectral intensity data; fourthly, using the spectral intensity data of the sample solution to map the addition amount of the nickel standard solution, and fitting to obtain a linear curve; fifthly, calculating the concentration of nickel in the to-be-determined solution according to the linear curve and the spectral intensity data of the to-be-determined solution, and then calculating the concentration of the nickel in the water sample according to the dilution multiple of the water sample. According to the method, the workload can be reduced; the method has the advantages of high determination speed, high accuracy and good precision.

Description

technical field [0001] The invention relates to a method for determining trace nickel in high-salt wastewater, belonging to the technical field of heavy metal detection. Background technique [0002] Nickel (Ni), a silvery-white, hard, ductile, ferromagnetic metallic element that is highly polishable and corrosion-resistant. Nickel is an iron-loving element. Nickel is often used in electroplating because of its good corrosion resistance. Nickel-cadmium batteries contain nickel. It is mainly used in alloys and catalysts, and can be used to make coins, etc. It can be plated on other metals to prevent rust. It is mainly used to make stainless steel and other corrosion-resistant alloys, such as nickel steel, nickel-chromium steel and various non-ferrous metal alloys. Copper-nickel alloys with high nickel content are not easy to corrode. It is also used as a hydrogenation catalyst and used in ceramic products, special chemical containers, electronic circuits, glass green and ...

AI Technical Summary

Problems solved by technology

[0003] While China's nickel industry continues to develop, there are also some problems. For example, most of the nickel ore is of low grade, the proportion of open mining is very small, the recoverable reserves only account for 10% of the total reserves, and the mining and smelting technology is relatively backward; mineral processing Weak acid or weak base medium flotation process is generally adopted, and the beneficiation capacity is 4.3 million tons per year; except for a few large-scale enterprises in China, nickel smelting generally adopts the matte selection smelting technology of fire method, and nickel sulfide anode diaphragm electrolysis and sulfuric acid are mainly used for refining nickel Selective leaching—the electrowinning process still has a certain gap with the world’s advanced technology, so the cost of mining and smelting in China remains high, and a large amount of nickel-containing wastewater and waste residue will be generated during the mining and refining process

Because most of the wastewater treatment process uses lime or other strong alkali to increase the pH value of the water body to precipitate nickel and remove it, the salt content in wastewater discharge is very high, and the discharge index of nickel is generally 0.5mg / L, which is tested in various analysis and detection. Medium salt has caused great interference to the detection of trace nickel, making the detection results greatly deviate from the actual value, and adversely affecting industrial production and emission monitoring

[0004] Plasma spectroscopy has a low detection limit and a wide linear range, but due to the high salt content will cause physical interference and spectral superposition interference on the nickel emission line, it is difficult to directly measure accurately; atomic absorption method has many interference factors, poor stability and reproducibility , high detection limit; spectrophotometry is relatively simple, with fast detection speed and low analysis cost, but the reagents that need to be configured are numerous and perishable, and it is also difficult to eliminate interference from the complex matrix effect of high-salt wastewater; oscillographic polarography is easy to operate Very inconvenient, the same high-salt wastewater will interfere with its test results