One source of Cl\({}^{-}\) pollution is discharged water from domestic sewage and modern industries [5, 6, 7]. These industries include the soap industry, salt industry, alkali industry, leather- and fur-processing industry, pickled food industry, and so on. Another source of Cl\({}^{-}\) pollution is the development of new energy and new materials. For example, chloride ion batteries have high theoretical capacity and discharge platforms; they have been reported as one of the potential technologies which could replace lithium-ion batteries used in cars [8]. However, new chloride contamination may occur during battery recycling. Chloride is a compound widely used in industrial and agricultural production and human life, but excessive use will also put strain on the environment and ecology. Therefore, chlorine ion detection is particularly important. On the www.baiten.cn (accessed on 16 November 2021) patent website, a search with the keywords \"Chloride ion detection\" produces results that show that, in China, there are more than 30 related patents from 2007 to 2015, while there are more than 100 related patents from 2016 to now. It can be seen that people have gradually attached importance to the detection of Cl\({}^{-}\) pollution. China's national drinking water sanitation standard [9] stipulates that the Cl\({}^{-}\) content in drinking water should be less than 250 mg/L. If wastewater containing high levels of Cl\({}^{-}\) is directly discharged into the environment, the water quality will decrease, the aquatic organisms and plants in the ecological environment will be threatened, the life and health of terrestrial animals, plants, and human beings will be directly or indirectly affected, and industrial production will be seriously affected. The main hazards of Cl\({}^{-}\) are as follows: (1) Soil, water, and air: Heavy content of Cl\({}^{-}\) influences the soil structure and decreases the retention capacity and the porewater pH of soil [10,11]. Cl\({}^{-}\) may reduce the self-purification process of water. [PERSON] et al. found that a 1% increase in Cl\({}^{-}\) in impervious surfaces promoted an increase in conductivity by 15 \(\mu\)S/cm from 1986 to 2010 in 12 watersheds in Maryland's Upper Piedmont [12]. [PERSON] et al. found that heavy Cl\({}^{-}\) influences air quality when it is aerosolized at not more than PM2.5 concentrations [13]. (2) Animals and plants: The increase in Cl\({}^{-}\) content in water reduces the self-purification processes of water and decreases the biodiversity of aquatic animals and plants [1]. Excessive potassium chloride in water will hinder the growth of tobacco, and even promote its death in serious cases [14]. High concentrations of Cl\({}^{-}\) have also deteriorated vegetation near the roads [15]. (3) Human health: High concentrations of Cl\({}^{-}\) can make water taste salty or bitter [16,17]. Excessive intake will cause diseases such as weakened immunity, hypertension, arteriosclerosis, cerebral infarction, etc. [18, 19, 20]. A severely reduced Cl\({}^{-}\) intake can have negative impacts such as chronic heart failure, chronic kidney disease, liver cirrhosis, and so on [21, 22, 23, 24]. (4) Construction and building trades: Very elevated Cl\({}^{-}\) levels in cement raw materials will reduce the strength of concrete, corrode steel bars, affect the durability of the whole building, and severely affect project quality [25, 26, 27]. (5) Industrial equipment: In industrial production, Cl\({}^{-}\) will corrode stainless steel equipment (such as reinforced concrete, petroleum and chemical production equipment, power plants, and some high-purity water and gas systems), preferentially adsorb oxygen atoms on the metal surface, and form soluble metal Cl\({}^{-}\) with metal ions, leading to metal corrosion, causing economic losses, and even threatening the safety of operators [19,28]. (6) Chemical oxygen demand analysis: Cl\({}^{-}\) will disturb the chemical oxygen demand analysis [29].