Treating wastewater seems an easy enough enterprise, considering 99.9% of the runoff material from homes and businesses is pure water with only the remaining 0.1% needing treatment. However that elusive 0.1% can contain components that are either not safe, such as bodily wastes, or contaminated, such as with heavy metals. Industrial chemical supplier Bell Chem has compiled a list of the major chemicals used to treat water and bring it back to safe and/or potable standards.

Treating wastewater occurs in stages, including a mechanical, biological, chemical, and filtration phase. This article will focus solely on the chemicals associated with wastewater treatment along with the roles they play.

Cleaners and antiscalants

Before wastewater is treated, cleaners and antiscalants such as chlorine dioxide, muriatic acid, soda ash, sodium bicarbonate, and chlorine are added to deter mineral salts from clogging filtration membranes.

Precipitates

Toxic metals necessarily need to be removed from any wastewater, and precipitates contain dissolved metals into a larger particulate form, allowing the heavier compilation of waste to sink to the bottom of the tank to be eradicated via filtration. Look to sodium hydroxide or calcium hydroxide for the creation of solid metal hydroxides. 

Precipitates primarily focus on a specific metal, which means several precipitates may be necessary to sequester all metals present, such as the addition of anions to precipitate as aluminum, calcium, or iron salts. 

Coagulants

Aluminum or iron-based coagulants lock smaller particles together similar to precipitates, except their focus is on non-metals. As particles are gathered through a chemical reaction where the negatively charged waste material is attracted to the positively charged coagulants, the combined weight of the flocculated material causes it to slowly sink to the bottom of the tank to be filtered. An organic anionic flocculant expedites the process by sequestering the agglomerated material, and it can also reduce the overall charge in the water as the process is completed.

Oxidizers

An oxidizer, such as sodium bisulfite, sodium hydrosulfite, and ferrous sulfate, moves electrons to the wastewater’s pollutants, which causes the waste material to modify its structure and become less destructive. 

Potable water is also treated via oxidation in the form of hydrogen peroxide and ozone for the removal of pesticides and chlorinated hydrocarbons. A specialty application of oxidation includes the degradation of antibiotics and other drugs as well as the transformation of heavy metal ions into sulfides. 

Ion exchangers

Extreme hard water does not properly clean clothing and often leaves a less-than-pleasing gray discoloration to cloth. Ion exchangers such as positively charged sodium soften water replete with excess calcium and magnesium. Generally ion exchangers are added as dissolved salts.

pH adjusters

Wastewater influent is seldom at the desired stable pH of 7 and must either have added acids to decrease wastewater pH or alkalis to increase the pH. 

Stabilizers

Very similar to oxidation, sludge is treated primarily with chlorine or hydrogen peroxide to impede growth of microbes responsible for odors and poor water quality.

Bell Chem is an industrial chemical supplier based in Longwood, FL (just north of Orlando) with hundreds of products stocked in their 50,000+ square-foot warehouse, including CSANTM sanitation products. You can expect the highest quality products, expedited shipping options for maximum efficiency, and unrivaled personalized customer service. Let our knowledgeable and friendly customer service representatives and accounting staff personalize all your needs by either calling 407-339-BELL (2355) or by sending us an online message.