In wastewater treatment, coagulation and flocculation are employed to separate suspended solids from water. Although the terms coagulation and flocculation are often used interchangeably, or the single term “flocculation” is used to describe both they are, in fact, two distinct processes. Knowing their differences can lead to a better understanding of the clarification and dewatering operations of wastewater treatment.
Coagulation is the destabilization of colloids by neutralizing the forces that keep them apart. Cationic coagulants provide positive electric charges to reduce the negative charge (zeta potential) of the colloids. As a result, the particles collide to form larger particles (flocks). Coagulation, thus, implies the formation of smaller compact aggregates. Rapid mixing is required to disperse the coagulant throughout the liquid.
Figure 1. Coagulation process
Effluents are heterogeneous in nature. Chemical coagulation is an important unit process in water treatment for the removal of turbidity. Its application in water treatment is followed by sedimentation and filtration. Various types of coagulants are being used to condition the water before sedimentation and filtration. The most widely used coagulants are:
- Aluminum sulphate
- Ferrous sulphate
- Sodium Aluminate
- Silicon Derivatives
Antifoams and Defoamers
Unwanted foaming can be problematic in many commercial, manufacturing and industrial process applications, consequently, it requires careful control measures to minimize or eliminate its impact.
To ensure that such systems are well maintained and operate at optimum efficiency it is essential that the correct water conditions are maintained at all times. This can be achieved using carefully selected antifoams and defoamers.
ideal for use in a wide range of process applications including wastewater and effluent treatment, steam generation, cooling water systems, distillation and fermentation processes, food processing, sugar manufacturing, paper and paperboard production, plastics, adhesives and more.
Biocides and Disinfectants
The control of microbiological activity is an important, often safety-critical activity in many commercial, manufacturing and industrial process applications.
It is used in a wide range of commercial cleaning, disinfection, environmental hygiene, and industrial and process water treatment activities where the effective control of microbiological activity in water and on surfaces is essential, if not critical.
There are 2 categories, Oxidizing & Non-oxidizing,
- Calcium hypochlorite/ Sodium hypochlorite
- Sodium bromide
Boiler water treatment chemicals
Industrial boilers and steam-raising plants are used extensively in many commercial, manufacturing and industrial processes.
It is used to manage the problems associated with the use of water including scale formation, metallic corrosion, boiler water carryover, and sludge deposition.
They constitute Alkalinity builders, Condensate Line Protection, Multifunctional treatments, Oxygen scavengers, Scale & Corrosion inhibitors, and Sludge conditioners.
Figure 4. Boiler Water Treatment Chemicals
Closed-circuit treatment chemicals
Closed circuits and closed loops that employ water as a primary medium are used extensively in many commercial, manufacturing, and industrial process activities.
It includes Anti foulants, Specific corrosion inhibitors, Multi-functional scale and corrosion inhibitors, Anti freeze and de icing products for frost protection applications.
Cooling tower pack cleaning chemicals
It allows the insitu cleaning of cooling tower pack components. This high-performance chemical cleaning system is especially useful where it is not practical to remove the tower packing.
Anti foulants
The accumulation of microbiological slimes, biofilm and general bio-fouling in closed-circuit water systems can be problematic. It is used in closed loops and circuit systems that use water as a primary medium. They remove and disperse unwanted microbiological fouling and slimes.
Scale and corrosion inhibitors
The unwanted formation of scale and the detrimental impact of metallic corrosion can be significant issues that affect the operation and maintenance of closed-circuit water systems.
- Phosphate esters
- Phosphoric acid
- Polyacrylic acid