According to the Environmental Protection Agency (EPA), the United States has 23,000 to 75,000 sanitary sewer overflows, on average, every year. Sewer overloading occurs when too much nutrient rich wastewater, created as an industrial byproduct, is passed to the local municipal wastewater treatment plant. Research shows that sewage treatment plants in the U.S release between three billion and ten billion gallons of untreated waste annually. We will discuss how companies can lower their environmental impact by treating their own water below!
According to the Centers for Disease Control and Prevention (CDC), untreated wastewater contains microbes, including harmful viruses and bacteria, which pose a serious risk to human health. Harmful parasites found in wastewater can cause respiratory, digestive, intestinal, and other chronic disorders. Wastewater runoff is also detrimental to the environment as it can cause toxic algae blooms.
The primary goal of wastewater treatment is to prevent disease as well as protect the environment from harmful discharges. Wastewater treatment aims to accelerate natural water purification processes. In today’s article, we will discuss how wastewater can be treated. Read on!
Wastewater Treatment Methods
Wastewater is used water discharged from residential, commercial, and industrial sources. Wastewater treatment aims to remove pollutants, allergens, and contaminants from the used water. That way, we protect and preserve natural water resources. After all, there has been no new gallon of water in the world since the beginning of time, what has changed is significant demand and quality of water due to population and man’s evolution.
Today, treatment facilities employ and run various processes to achieve the desired water quality levels. A typical process involves primary separation, biological treatment, secondary separation of microbes and solids, clarification, and then discharge of clean effluent to the receiving body of water. The three basic treatment methods are physical, biological and chemical treatment. Continue reading!
Physical Water Treatment
Physical water treatment is an effective method that uses racks, screens, clarifiers, and filters to treat wastewater. Many systems pair physical filtration with biological filtration to get the cleanest water.
The treatment involves the removal of substances through physical membranes. The process focuses on the use of physical barriers to separate contaminants from wastewater.
Bear in mind that physical treatment does not alter the biological and chemical structure of the target substances. However, it may change the physical state of the target substances. For instance, wastewater undergoes physical changes during the vaporization and filtration stages.
Sedimentation, flotation, absorption, and barriers, including racks, screens, bed filters, and membranes, are standard methods used in physical wastewater treatment. Let us now briefly discuss the physical wastewater treatment methods we engineer and install for our clients.
Screening is an initial and essential stage of any wastewater treatment system that removes largely non-biodegradable floating solids, such as plastics, papers, wood, and other larger materials. These substances frequently enter the wastewater, leading to complications.
Therefore, screening removes these substances to prevent damages to the downstream plant and equipment from pipe blockages. Our company uses different screening methods, like fine or coarse screening, depending on the conditions and requirements.
Many companies use a grit chamber, or a sedimentation basin, to remove different materials, including sand, soil, coffee grounds, and eggs shells from wastewater that can clog different water channels.
Besides, some water treatment plants use skimmers to remove fat and grease from wastewater. The process involves passing the sewage through the small tank, allowing the skimmers to collect the fat and grease content present on the surface.
Flotation is another physical wastewater treatment method. It involves treating industrial wastewater to remove oil, grease, fat content, and suspended solids from sewage. Dissolved air flotation units or DAFs help remove contaminants for many industries including: Food and Beverage, Chemical, Oil & Gas, and many more.
Flow equalization is an effective and reliable technique used in wastewater treatment to improve the entire process. Not only does flow equalization streamline parameters like the flow, pollutant levels, and temperature, but it also reduces the risk of downstream effects of these parameters.
Clarifiers play a crucial role in removing heavier solids before the wastewater undergoes biological treatment. The process involves eliminating sludge solids through settling and separation. Our company uses clarifiers before the biological treatment to reduce biological oxygen demands (BOD) levels. That way, we streamline the process by managing higher loading rates and retention time for the water.
Biological Water Treatment
Our company specializes in biological wastewater treatment, an advanced, cutting-edge method that uses microorganisms, including bacteria, to clean water. We use natural processes to decompose organic substances by employing biological and biochemistry-based technologies.
Besides, biological treatment of wastewater relies on tiny organisms and microbes to break down organic waste via cellular processes. Research shows that wastewater contains organic materials like protein, fat, carbohydrates, urea, surfactants, and volatile organic compounds (VOCs).
In addition, wastewater contains organic matter from garbage, partially digested foods, wastes, heavy metals, toxins, and pathogens. The primary objective of biological treatment is to use a sophisticated system to decompose organic material and clean water.
Thus, the natural-like system makes the biological treatment more reliable, efficient, and economical than chemical and mechanical treatment options. That’s why our company focuses more on physical and biological wastewater treatment methods.
Remember, biological water treatment is a secondary process to remove substances and material remaining after the DAFs treatment, which is a primary process that involves the removal of sediments, oils, fat, and grease from wastewater.
Anaerobic Wastewater Treatment
Anaerobic wastewater treatment uses bacteria to break down biological oxygen demand, chemical oxygen demand, and other organic compounds without using oxygen. Because the process does not require adding air to the reactors, it significantly reduces the system’s operational costs.
Aerobic Wastewater Treatment
Unlike an anaerobic system, aerobic wastewater treatment involves adding air or oxygen to the wastewater reactor to reduce BOD and COD levels. Sometimes, our company uses anaerobic and aerobic systems in conjunction to further improve the process.
The purpose is to remove nutrients by polishing wastewater streams accurately. Aerobic wastewater systems are resilient to different temperature levels, making them more effective and reliable. Common aerobic systems are moving bed biofilm reactors (MBBR), activated sludge, lagoons, aerobic membrane bioreactors, and sequencing batch reactors.
The reuse of treated wastewater is an excellent way to reduce water scarcity issues worldwide. Not only does wastewater treatment minimize the risk of human diseases, but it also prevents the release of toxic waste/substances into the ecosystem.