Natural organic matter (NOM) can be effectively removed from surface water using methods such as coagulation with coagulants like poly aluminum chloride, adsorption with activated carbon, and advanced oxidation processes. Combining these techniques, such as integrating coagulation with ozonation, can enhance removal efficiency and improve overall water quality.

Coagulation followed by filtration is the most effective and widely used method to remove natural organic matter (NOM) from surface water, often enhanced with activated carbon or advanced oxidation for better results.

Usama Fathy

Removing organic matter from surface waters is an important step in improving water quality and protecting aquatic ecosystems. Organic matter in water, including biological, biochemical, and physical components such as growing plants, dead organic materials, and wastewater, can cause significant problems such as oxygen depletion, eutrophication, and increased proliferation of pathogenic microorganisms. Several methods are used to remove this material from surface waters:

1. Physical Methods

• Filtration: Physical filtration methods, such as the use of sand filters or activated carbon filters, can remove suspended organic matter. These methods are effective at removing larger particles and suspended organic material but do not eliminate dissolved organic substances.
• Mechanical Removal: This method involves the use of mechanical devices such as screens, sieves, or centrifuges to remove larger organic matter and particles from water.

2. Chemical Methods

• Coagulation and Flocculation: These are chemical processes that involve adding chemicals (such as aluminum sulfate or iron salts) to the water to cause small particles of organic matter to aggregate into larger, more easily removable floccules. This method is effective at removing suspended organic matter.
• Chemical Oxidation: In this process, organic substances are broken down by adding chemicals that act as oxidizing agents (e.g., chlorine, ozone, or hydrogen peroxide). This method is particularly effective at removing organic contaminants and pathogens.

3. Biological Methods

• Biological Filtration: Biological filtration uses natural processes such as microorganisms (bacteria, fungi, and others) that break down organic matter. This method is often used in systems such as bioreactors or biofilters, where water passes through filters containing microorganisms that degrade organic contaminants.
• Activated Sludge: This is a biological method used in wastewater treatment plants. In this process, microorganisms break down organic matter in the water, resulting in cleaner water free from organic contaminants.
• Constructed Wetlands and Biological Treatment Systems: This method uses plants and microorganisms to filter organic matter from water. Constructed wetlands with plants such as reed or cattail can effectively absorb organic material and improve water quality.

4. Phytoremediation

• Phytoremediation is a method that uses plants to remove organic substances, nutrients, and other contaminants from surface waters. Certain plants (such as water lilies, reeds, or wild rice) can absorb organic matter from the water and remove it through metabolic processes. This is an environmentally friendly and cost-effective approach, although it has limitations in terms of the volume of water that can be treated.

5. Natural Systems and Constructed Systems

• Constructed Wetlands and Natural Water Treatment Systems: These systems use natural processes such as filtration, absorption, and breakdown of organic matter by microorganisms, plants, and other organisms. These systems are particularly effective for smaller volumes of contaminated water and can be used as a supplement or replacement for chemical and mechanical methods in specific conditions.

6. Integrated Approaches

• Integrated Water Management Systems: Using a combination of the methods listed above (physical, chemical, and biological), the best results can be achieved in removing organic matter. These systems can be applied at different stages of the water treatment process, from initial filtration to final biological or chemical treatment.

Removing organic matter from surface waters can be achieved by combining various methods that depend on specific needs and conditions. In many cases, the best results are achieved through integrated approaches that combine physical, chemical, and biological methods. Additionally, environmentally friendly methods such as phytoremediation and constructed wetlands contribute to sustainable water management and the improvement of surface water quality.