What Are the Treatments for River Water?

Rivers have many uses; one of the most important being a source of drinking water. In California, 23 million people rely on the Sacramento-San Joaquin Delta for their drinking water. Treating river water to remove harmful contaminants is essential to improving global health. There are several straight-forward river water treatment methods.

Ozonation

• Ozonation is a common river water treatment. Ozone is a compound with three oxygen atoms, which purifies large-scale water systems. Ozone oxidizes organic compounds and pathogens, causing them to become inactive. Producing commercial ozone requires the conversion of compressed oxygen in the chamber of an ozone generator. This process does not require transportation or storing toxic chemicals. Ozonation is the preferential choice to chlorination as it does not produce unwanted by-products, nor does it remain in the water.

Chlorination

• Chlorination for water purification was a breakthrough in public health. While the chlorination process produces disinfection by-products (DBPs) like trihalomethanes, it is still the most common method for river water treatment, which provides continual protection against microbial re-growth. Chlorine reacts violently with organic chemicals, and requires handling by specialists. Chlorine reacts with ammonia in water to produce chloramines, which also disinfects water for a longer but slower period. Chlorination can combine with ozonation or UV radiation to limit the production of DBPs.

Solar Radiation

• Direct exposure to constant sunlight can remove harmful bacteria and organic pollutants present in water. Contaminated drinking water contributes globally to 6 to 60 billion gastrointestinal cases per year. Sunlight penetrates into water, inactivates microorganisms and breaks down organic compounds without forming toxic byproducts. However, sunlight's intensity decreases as the body of water deepens due to light being scattered by particles in the water, so methods to increase the intensity of light using artificial UV radiation are important.

River Bank Filtration

• River Bank Filtration is a process whereby subsurface water passes through an aquifier, and undergoes a range of purification processes like filtration, biodegradation, sorption and dilution.You can hydraulically connect the aquifier to the river. Although RBF can remove organic pollutants like fecal contamination, a project conducted in India showed the quality of water purified by RBF did not meet drinking quality standards. RBF is can also combine with other treatment methods to improve the quality of water produced.

Aeration

• Aeration is a process that brings water at the bottom of the river to the surface and vice-versa. This allows more atmospheric oxygen into the river water. In the process, toxic gases at the bottom neutralize, and organic compounds oxidize. Anaerobic pathogens at the bottom of the river also oxidize or inactivate by sunlight. There are several commercial aeration systems that you can purchase to treat river water.