Introduction

Arsenic is a toxic element that can be found in natural water sources. Exposure to arsenic can cause serious health risks, including cancer and skin lesions. To ensure safe drinking water, water treatment plants employ various methods to filter and remove arsenic. In this article, we will explore how water treatment plants filter arsenic from water.

Arsenic removal technologies

There are several technologies employed by water treatment plants to remove arsenic from water. These include coagulation/filtration, ion exchange, activated alumina, reverse osmosis, and adsorption. Each of these technologies has its pros and cons, but the most commonly used methods for arsenic removal are coagulation/filtration and adsorption.

The coagulation/filtration method

The coagulation/filtration method involves adding chemicals to the water to turn arsenic into a solid, then passing it through a filter to remove it from the water. This method is highly effective, but it does require careful monitoring of the chemical dosage levels to ensure that the arsenic is properly removed. The filter used in this method is usually composed of sand or activated carbon, which effectively trap the solid arsenic particles. The coagulation/filtration method is commonly used in large-scale water treatment plants and is highly effective in removing both arsenic and other inorganic contaminants from the water.

The adsorption method

The adsorption method involves using a material to bind with arsenic in the water, causing it to separate from the water and be removed. The material can be activated carbon or other materials, such as granular ferric hydroxide or iron oxide. The adsorption method is highly effective in removing arsenic from water, and it is often used in small-scale water treatment systems, such as point-of-use devices. This method is highly efficient, requiring minimal maintenance, and has a lower cost compared to other arsenic removal technologies.

Conclusion

In conclusion, arsenic can be a serious health hazard when not removed from water sources. Water treatment plants use a variety of methods to remove arsenic, including coagulation/filtration and adsorption. Both of these methods are highly effective and have been extensively used in large-scale and small-scale water treatment systems. With the appropriate technologies in place, safe drinking water can be ensured, even from natural sources that contain arsenic.