แชร์ บทความ
Maintaining stable ORP levels also plays a special role in the correct functionality of our bodies as metabolism relies on a precise mechanism of interrelated redox systems. In the past decades, there has been a growing concern about the use of antioxidants to achieve a better quality of living. One example of this is of water that exhibits a less oxidant nature than that of normal tap water. The demand for this specialized water has grown in recent years for use in beverages, food, bathing, artificial body fluids, cosmetics, skincare products, and other purposes [4].
Easily measuring ORP values in real-life applications
1 พ.ค. 2023
Article
Oxidation-reduction potential (ORP), also known as redox potential, affects many of our daily routines such as simply opening the tap of a faucet. ORP (expressed in millivolts, mV) is a measure of the tendency of a chemical species to acquire electrons from (or lose electrons to) an electrode and thereby be reduced or oxidized, respectively [1]. This parameter can be used to predict the states of chemical species in various sample matrices, monitor water quality, control fermentation processes, and optimize wastewater treatment to prevent releasing higher concentrations of substances than regulation limits allow. The measurement of ORP values is an ongoing operation in many industrial sectors that require the improvement of the currently available instrumentation to facilitate their processes.
ORP importance in the realm of water chlorination
A public health emergency arose in 1854 when more than 600 people died within a month as the result of a cholera outbreak in an area barely half a kilometer in diameter in London. John Snow, an English physician, talked to the local residents and created a map illustrating the occurrences of cholera in the area. He identified the outbreak’s source as the public water pump that supplied drinking water from a well contaminated with excrement. By removing the pump’s handle, the contaminated well was prevented from further use, and the outbreak was ended. Due to his research, John Snow became one of the founders of modern epidemiology, and as a result the importance of water treatment for human consumption started to grow.
Truck with water purification apparatus to provide clean drinking water for troops during wartime (World War I). It has been more than a century since the first mobile water purifiers were invented. They continue to supply clean water for inhabitants of developing countries and disaster areas as well as military personnel and workers in remote locations.
Drinking water quality is clearly a critical public health concern. If the quality of water from public wells and fountains cannot be relied upon, then how is it possible to offer germ-free drinking water for thousands (or millions) of people in cities? On the other hand, what about rural or wilderness areas where clean water is not always readily accessible? The answer to these questions lies in the process of water treatment by chlorination.
In its elemental form, chlorine (Cl2) is a toxic gas. When added to water, Cl2 causes alterations in bacterial cell walls, destroying proteins and DNA contained within. This is the mechanism by which chlorine kills microorganisms – it affects their vital functions until they die, rendering them incapable of spreading diseases. By adding chlorine to disinfect municipal water systems, the risk of catching contagious cholera, typhus, dysentery, and polio are minimized.
Chlorination of water can be done by using elemental chlorine gas, though it is much safer to use liquid sodium hypochlorite or solid calcium hypochlorite. These compounds chlorinate water by generating residual «free chlorine» that attacks disease-causing germs and makes the chlorine disinfection process more versatile and user-friendly.
You may wonder, since chlorine is a toxic element, is there any method to control how much of it is added to the water? Oxidation-reduction potential (ORP) measurement offers a reliable solution to this matter.
