Over time, wastewater has the natural ability to treat itself. But as population and industrial activity increases, treatment levels need to be improved before municipal and industrial wastewater can be discharged.
The United Nations Sustainable Development Goals (UN SDGs) set targets for improving water quality, integrated water resource management, water efficiency and restoration of water-related ecosystems.
In the first half of the 20th century, municipal and industrial wastewater was combined and disposed of through a single drain. This process posed a health hazard to humans and marine life and required the separation of municipal and industrial wastewater.
COD Remover
Biochemical oxygen demand (BOD) substances - Industrial and domestic wastes release oxygen-demanding pollutants into the water. These pollutants come from plants and animals used in food processing, paper and leather tanning. Bacteria convert these pollutants into other compounds, but the decomposition process consumes dissolved oxygen used by fish.
Pathogens - Infectious microorganisms or pathogens are a source of waterborne diseases. They may leach into groundwater through industrial activities such as tanning and food processing or through animal waste from pets and livestock.
Eutrophication/Cultural Enrichment - Minerals such as carbon, phosphorus and nitrogen are naturally present in the water and are necessary for adequate nutrition. However, when these substances are released in excess from secondary water treatment plants, they can lead to excessive algae, blocked sunlight and suffocation of marine life.
Inorganic waste - Human and industrial activities release large amounts of inorganic waste into the drainage system, including detergents, household cleaning fluids, heavy metals, pharmaceuticals and pesticides. Some of these are highly toxic even at low concentrations, while others leave an unpleasant odor or taste in the water.
Thermal waste - Wastewater discharged from cooling systems at high temperatures can deplete the water of oxygen.
Industrial Glucose
Treating wastewater is not as simple as it was half a century ago. Growing populations, CWA guidelines, and evolving health and safety-focused EPA regulations have created new challenges for wastewater separation and treatment.
There can be no single universal solution for industrial and municipal wastewater management. Customizing wastewater treatment based on water source, pollutant type, geographic location, budget and technology availability are major challenges. Other challenges include
High Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) - Aerating wastes can promote biological oxidation and produce solid wastes that can be easily removed through filtration and clarification.
High total suspended solids - CWA regulations set limits on total suspended solids (TSS) and total dissolved solids (TDS) in wastewater. tss is often filtered using sand and carbon filtration. tds requires chemical treatment, demineralization or evaporation.
High Nitrate and Phosphate Levels - Nitrate and phosphate enter the wastewater stream through human and animal excreta. It can be treated with IX, RO, clarification, or biological treatment.
Oil and grease - In addition to environmental damage, oil and grease clog waterways and drainage systems. They are often treated with dissolved air flotation (DAF), ultrafiltration (UF), and carbon filtration methods.
Large Discharges - Some industrial and municipal facilities generate large volumes of wastewater and may need to implement zero liquid discharge systems. This allows for the re-adjustment of chemical volumes, recovery of most liquid wastes for reuse, treatment of valuable by-products, and production of dry/solid cakes for disposal.
In addition, many old and dilapidated wastewater collection and treatment facilities need to be improved and maintained to extend their useful life. This requires continued financial and technical investment.
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