Arsenic exists in nature. It is a silver-gray, shiny, blocky solid that is hard and brittle. Many compounds containing arsenic are easily soluble in water. What kind of wastewater is likely to be contaminated by arsenic? If so, how should it be dealt with? This article, together with Hangzhou Modi, explores some knowledge about arsenic pollution in sewage.
Although there are trace amounts of arsenic in normal human tissues, it does not cause harm to the human body. Once it exceeds the body’s tolerance, the consequences would be unimaginable! For instance, just like when we eat, there won’t be any problem if we eat in moderation. However, if we eat beyond the capacity of our stomach, it may cause discomfort at best, and in severe cases, it can even damage our stomach. Therefore, it is very important to do a good job in the treatment and monitoring of arsenic in wastewater!
Inorganic arsenic is one form of arsenic, and arsenic mostly exists in sedimentary or igneous rocks in the form of inorganic arsenic compounds. Arsenic is present in wastewater discharged from industrial or mineral development, and it is also present in pesticides and herbicides used in agriculture. Inorganic arsenic exists in wastewater in the form of arsenate ions and nitrite ions, and then through dissolved oxygen, nitrite is oxidized into arsenate (which has relatively low toxicity). Arsenic acid and arsenates are present in many industries, such as in industrial wastewater discharged from leather, chemical, dye, glassware, metallurgy, petroleum refining and other industries.
So how should we deal with this arsenic? Ensure that it does not exceed the standard. The conventional treatment methods are to precipitate with lime or sulfides, and also use the hydroxides of iron and aluminum for precipitation. These methods can effectively remove arsenic from wastewater during the process of transmission flocculation in wastewater treatment. In addition, activated carbon or bauxite adsorption and ion exchange can also be utilized, which has a very good effect on the removal of arsenic from wastewater.
The treatment of arsenic content in wastewater through biochemical methods is constantly improving. The activated sludge process has a fast arsenic removal speed, capable of removing about 80% of arsenic within just half an hour, and reaching a balanced state within one hour.
The above has discussed how to remove arsenic from wastewater. However, to know exactly how much arsenic is in the wastewater and whether it exceeds the standard, it is necessary to conduct real-time detection of the arsenic content in the water through a water quality monitor. Of course, the monitoring instruments used to detect different pollutants are not qualified. The arsenic pollution mentioned in this article can be monitored by the T8000-As Online Arsenic Analyzer for water, thereby determining whether the arsenic in the water meets the relevant standards.
