The Differences Between Wastewater Treatment and Water Treatment
The difference between wastewater and water treatment lies in the types of pollutants that are treated. Wastewater is often untreated and can be returned to the environment after treatment. While this method is more environmentally friendly, it does not remove all contaminants, such as nitrates, from wastewater. Soil bacteria are the most effective way to treat sewage and reuse it. They can break down organic material and remove pesticides.
The differences between these two processes are most apparent in industrial wastewater. While domestic wastewater is relatively easy to treat, industrial wastewater is difficult to deal with. Many pharmaceuticals and personal care products can be toxic to aquatic life. The primary goal of water treatment is to remove suspended solids from the wastewater before further treatment can take place. The final product of this process is called effluent. The solid material that is left behind is called sludge, and it depletes oxygen in the water.
Conventional wastewater treatment is comprised of physical, chemical, and biological processes that remove solids, organic matter, and nutrients from the wastewater. Depending on the type of treatment, there are different degrees of treatment. The most common wastewater treatment is filtration. This process uses the use of bacteria and other microorganisms to destroy harmful pathogens. A generalized wastewater treatment diagram is shown below.
Natural wastewater treatment processes include rapid infiltration and overland flow. These methods use pre-treated wastewater and allow the ground to act as a filter. This method is similar to a septic system, but is more efficient for urban areas. Overland flow is a process used in regions where the ground is nearly impermeable. Water flows down a sloped surface, planted with thick grasses. The plants in these areas remove pollutants.
Lagoons are a type of wastewater treatment that stores waste and discharges it into a water body or soil. In domestic wastewater, the solids settle to the bottom of the lagoon over 6-20 days, and can be easily removed in this method. In both cases, the wastewater treatment process removes most of the contaminants and leaves the remaining water as effluent. But in both cases, the process must be effective to prevent over-infiltration and protect aquatic ecosystems.
The differences between wastewater treatment and water treatment are significant. Both are necessary to keep our communities safe. Secondary treatments remove most of the organic pollutants from the water, and primary treatments are not effective enough to remove all of them. A primary wastewater treatment plant will remove more than 90 percent of suspended solids and bacteria. These two types of wastewater treatment differ in the amount of time they take to achieve this outcome. The process of secondary wastewater treatment is more complicated, but it is the best alternative for most people.