The field of wastewater treatment engineering is primarily focused within the civil engineering discipline. Wastewater treatment refers to the processes used to remove solid, chemical, and biological materials from wastewater before returning it to the primary water source. Wastewater is defined as water received by the water treatment facility from sewers and storm drains. Additionally, some industries have internal processes used to remove harmful products before returning the wastewater to the community’s water treatment plant.
Every civil engineering program has at least one course in wastewater treatment methodologies. There are three primary methods that have widespread usage: filtration, chemical treatment, and natural processes. The selection of the methodology used, implementation, and ongoing testing of this process is primarily the responsibility of the water treatment facility staff.
The filtration method of wastewater treatment engineering is one of the oldest methods of wastewater treatment. In this method, stones of incrementally decreasing sizes are used to filter solid materials out of the water. The water is then run through a series of filters that are increasingly small, so that all particles that are visible to the eye are removed. Although this method is used widely around the world, each location requires wastewater treatment engineering specialists to design and implement the system for maximum effectiveness.
Treatment of wastewater with chemicals is a controversial topic in North America and parts of Europe. There is increasing concern that the chemicals used have long-term health consequences for both humans and the local environment. Although it is generally acknowledged that chemical treatment is necessary to reduce the spread of diseases, many wastewater treatment engineering firms are dedicated to finding alternative processes that reduce the need for harsh chemicals.
Natural processes are difficult to incorporate into wastewater treatment plants, as these techniques are typically the utilization of naturally formed waterfalls, rocky formations, or other methods to treat the wastewater. In general, these techniques are only suitable for very small communities, such as rural villages of fewer than 250 people. When a community creates a significant level of wastewater, the impact on the natural environment is too severe to allow the continued use of these techniques.
The treatment of solid waste sludge is a recurring issue in wastewater treatment engineering. In general this material is pushed through several processes until it becomes solid. At this point, it is disposed of as a biohazardous material. Alternative methods are being explored, as the current methods are very resource intensive.