What Are Trihalomethanes in Water & How to Remove?

Water disinfection is crucial to purifying water and making it free of various contaminants and pathogens. While water disinfection is important, it can lead to the production of harmful byproducts known as trihalomethanes (THMS). Since chlorine is mostly used as a disinfectant, it results in the production of THMS which are potentially dangerous for health.

This blog will explore what are trihalomethanes in water in detail and their health implications, and will also list down the potential solutions to get rid of them.

What Are Trihalomethanes in Water?

Now that you have an overview of what are trihalomethanes in water, let’s learn about their chemical composition and different types.

1. Definition of Trihalomethanes (THMs)

Trihalomethanes

Trihalomethanes are volatile chemical compounds that are formed along with other disinfection byproducts when chlorine reacts with naturally organic matter (algae, decaying plants) in water. When chlorine comes into contact with water, it becomes hypochlorous acid.This acid reacts with organic matter to form trihalomethanes. THMS are colorless and tasteless. They may have a faint chlorine-like odor.

Since 98% of water treatment plants use chlorine as a disinfectant, trihalomethanes are frequently found in the water supply.

2. Common Types of THMs

Trihalomethanes comprise four common types of chemical compounds: chloroform, bromodichloromethane, dibromochloromethane, and bromoform. These compounds are collectively known as TTHMS.

Let’s see what are trihalomethanes in water and their various types.

Chloroform

Chloroform is a type of trihalomethane with the formula CHCL3. It’s a common solvent and is a very volatile, colorless, strong-smelling, dense liquid produced on a large scale as a precursor to refrigerants. It also acts as a powerful general anesthetic and sedative when inhaled or ingested. While it is miscible with many solvents, it is only very slightly soluble in water.

Prolonged exposure to chloroform can harm the eyes, skin, liver, kidneys, and nervous system. It can be toxic if inhaled or swallowed.

Bromodichloromethane

Bromodichloromethane is a type of trihalomethane with the formula CHBrCl2. It is used as a reagent in organic chemistry. Formerly, it was used as a solvent for fats and waxes.

Bromodichloromethane can increase the risk of cancer, pose harm to reproduction and child development, and may cause changes to fetal growth and development when present in quantities higher than 0.06 parts per billion.

Dibromochloromethane

Dibromochloromethane is a type of trihalomethane with the formula CHBr2Cl. It is a colorless to yellow, heavy, and non-flammable compound. Dibromochloromethane has a sweet odor and its small quantities are produced in the ocean by algae.

Dibromochloromethane is used as a laboratory reagent and formerly was used as a flame retardant.

Bromoform

Bromoform is a type of trihalomethane with the chemical formula CHBr3. It is a colorless liquid at room temperature, with a high refractive index and a very high density. Its odor is similar to that of chloroform. Bromoform is used as a laboratory reagent.

How Do Trihalomethanes Get Into Drinking Water?

Trihalomethanes get into drinking water as they are formed as byproducts of chlorine disinfection in water treatment plants.

Detailed Chlorination Process

THMS can form during the process of treating the water for consumption or as part of a wastewater disposal system, as the effluent from a sewage treatment plant is usually chlorinated before it enters a river.

When chlorine and other similar gases enter the water, they become hypochlorous acids. This acid reacts with natural organic matter like algae, forming byproducts known as trihalomethanes.

The amount of THMS in water depends on the amount of organic matter present in water. The higher the organic matter, the higher the THMS formed. For instance, surface water like lakes, reservoirs, rivers, and streams have higher levels of organic matter; hence, they produce more THMS. Groundwater in deeper wells usually has low organic content and, hence, is less likely to form THMS.

Moreover, there are other factors too that influence THM levels in water. These include the dosage of chlorine, water temperature, pH levels, and the amount of time chlorine remains in contact with water.

For example, warmer temperatures and higher pH levels accelerate the chemical reactions, leading to increased THM production. Similarly, longer contact times between chlorine and water allow more THMs to form.

What Do Trihalomethanes Do to the Body?

The presence of trihalomethanes in water is not a good sign as they directly impact health. THMS are carcinogenic, meaning they are known to result in cancer. These effects were first acknowledged in 1974, and in 1979, the US Environmental Protection Agency (EPA) began regulating allowable concentrations of THMs in drinking water, limiting them to 100 parts per billion.

THMS usually enter the body via direct consumption or inhalation. They are inhaled when they evaporate from tap water, especially when showering. Another form of exposure is absorption via the skin when showering, bathing, or swimming.

Trihalomethanes are injurious to health as chloroform, bromodichloromethane, and bromoform have been linked to bladder and colon cancer at relatively low exposure. If they are exposed infrequently, it leads to birth defects, reproductive issues, and damage to the kidneys, liver, and nervous system.

Moreover, trihalomethanes have negative health effects and have been associated with cancer and adverse reproductive outcomes. Exposure to high levels of chloroform inhibits the function of kidney tubules and increases nitrogen in blood urea.

How Do You Remove Trihalomethanes From Drinking Water?

By now, you may have a complete understanding of what are trihalomethanes in water. It’s important to eliminate them from drinking water to prevent health risks. Following are some of the most notable methods to remove THMS from drinking water.

Activated Carbon Filtration: The first method is activated carbon filtration. Carbon filters are mostly used in commercial treatment plants to remove chlorine from water. These are also present in showers to remove chlorine and THMS from water. The carbon filter comprises an activated carbon or charcoal membrane that is highly porous and traps THMS on its surface.

During the process, water passes through the carbon filter and THMS are adsorbed to the carbon filter. As a result, the water becomes free of THMS.

Aeration: Aeration is another method to get rid of THMS. During this procedure, air is introduced into the water, allowing the volatile THMs to evaporate and escape into the air. Aeration is usually carried out in several types of aeration systems, such as an aeration tank.

The efficiency of aeration depends on various factors, such as water temperature, the concentration of THMs, and the specific aeration technique used. Due to this, aeration is suitable for large-scale water treatment facilities due to the equipment and space required.

Alternative Disinfectants: Since chlorine leads to the formation of trihalomethanes, there are alternative methods to purify water. These include chloramine, ozone, and UV radiation. Chloramine is a better alternative to chlorine as it produces fewer THMs and is commonly used in many water treatment plants. Ozone is a powerful oxidant that effectively destroys microorganisms without producing THMs. UV radiation inactivates pathogens without the need for chemical additives, making it a safer option for disinfecting water.
Improved Water Treatment Processes: In addition to using alternatives, it is essential to improve water treatment processes by introducing pre-treatment and post-treatment methods, including coagulation and sedimentation, During the pre-treatment method, chemicals are added into the water that causes organic matter to clump together and settle out of the water, making it easier to remove. Due to low organic matter levels, THM formation is also reduced.

Post-treatment options include the use of granular activated carbon (GAC) filters to adsorb any remaining THMs.

Additionally, controlling factors such as pH levels, and water temperature, and minimizing the contact time between chlorine and water can reduce THM production.

Best Filtration Systems for Trihalomethanes: SimPure T1-400 UV 8 Stage RO System

Reverse osmosis is the best procedure for getting rid of trihalomethanes in drinking water. In that respect, consider the SimPure T1-400 UV 8-Stage RO System, which is specially designed to eliminate THMS from drinking water.

Thanks to its advanced multi-stage filtration process, along with activated carbon and reverse osmosis stages, it effectively adsorbs and filters out THMs, ensuring nearly zero TDS levels.

The SimPure RO System is SGS Test certified and also meets the NSF/ANSI 58 and GB/T 5750 standards. The T1-400 UV filter helps reduce lead by over 96.6%, PFOA by over 98.2%, TDS by over 95%, and fluoride by over 99.7%. In addition, it can also reduce arsenic by over 99.8%, chromium by over 98.7%, nitrate, and barium by over 99.9% respectively. This ensures you and your loved ones get access to clean, pure, and filtered water.

The SimPure RO System also features UV sterilization which further eliminates any remaining contaminants, providing the highest water purity. Moreover, its high capacity (400GPD) and space-saving design make it a top choice for comprehensive water purification.

Conclusion

We hope this blog may have answered your query on what are trihalomethanes in water. Given their health risks and potential implications, it’s essential to employ effective THMS removal methods to ensure clean and pure water. You must monitor your water’s purity to protect your loved ones’ health. Use advanced and effective water filtration methods such as SimPure reverse osmosis systems to get THM-free water at home.