Natural or Chemical Coagulation
What is Coagulation?
Coagulation refers to a process of treating contaminated water. It involves the addition of chemicals or natural products to water, which changes the physical state of dissolved and suspended solid particles in the water, facilitating their removal by sedimentation or flocculation.
The Working Principle of Coagulation
In its original form, water contains a wide variety of small particles that possess certain charges in them. Very naturally, the particles with the same charges repel each other and refuse to settle down and hence are suspended into a colloid. Coagulation water treatment exert on these charged particles and assist them to aggregate so that they can be easily removed from the treated water.
Natural Coagulation
Natural polyelectrolytes of plant origin has long been used, generally in the form of powder or paste, to treat water clouded with sediments. Although quite a lot of seed can be used in preparing a natural coagulant, it has been found that Moringa Oleifera is the best natural coagulant yet and can extensively be used in place of its chemical equivalent Alum.
A very simple natural coagulate can be prepared by kernels of dried M. oleifera seeds that are thoroughly pounded in a mortar to produce a somewhat pasty powder and a 2% suspension prepared with distilled water.
Chemical Coagulation
The chemicals used in wastewater treatment include alum, ferric chloride, ferric sulfate, ferrous sulfate, and lime. These chemicals react with the harder-to-settle down particles and introduce positive charges that destabilize the negative charges of the particulates. As a result, these particles combining into a settled form can be easily removed by sedimentation or flocculation where polymers adsorb onto the particulates, causing them to combine together into clumps "flocs."
Chemical coagulants can be classified into two types - primary coagulants and coagulant aids. Coagulant aids are chemicals that are additionally added after the primary coagulant to produce a stronger and more settleable floc. These chemicals can also help reduce the amount of primary coagulant needed and the amount of sludge produced during the treatment process.
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is continually depleting with its increasing demand. Key reasons that account for the growing demand of water.