One of the primary stages in sewage treatment is the removal of suspended solids and colloidal particles. Coagulants, such as aluminum sulfate (alum) or ferric chloride, are added to the wastewater to promote the aggregation of these particles. This process, known as coagulation, helps to form larger particles or flocs that can be easily removed through sedimentation or filtration. Subsequently, flocculants, which may be organic polymers, are introduced to further enhance the aggregation process, making it easier for these larger flocs to settle out of the water.
APIs can be derived from various sources, including natural substances, synthetic processes, and biotechnological methods. For example, aspirin, a widely used drug for pain relief and anti-inflammatory purposes, is a synthetic API that mimics compounds found in the bark of willow trees. Conversely, some APIs, such as penicillin, are derived from naturally occurring organisms like fungi.