PRETREATMENT EQUIPMENTS
Chemical Dosing Systems
In water treatment, chemical dosing systems play a crucial role in maintaining water quality.
Water disinfection with chemicals is considered safe because only small, managed amounts of chemicals are added to the untreated water (just enough to kill bacteria and other microorganisms). However, most forms of chemical water disinfection react with naturally occurring organic matter to produce disinfection by products, which (according to the Centers for Disease Control) may have dangerous health effects, including cancer.
There are many types of Dosing Systems some of them are:
Coagulation & Flocculation /Chemical Precipitation
Pretreatment removes physical, chemical, contaminants and suspended solids. This procedure begins with a series of mixing reactors, usually one or two, that add particular chemicals to remove any finer particles from the water by combining them into heavier particles that settle out. Coagulation is charging neutralization of finely divided and colloidal impurities in water into masses that can be filtered. In addition, particles have negative electrical charges, which cause them to repel each other and resist adhering together. Coagulation, therefore, involves neutralizing the negative charges and providing a nucleus for the suspended particles to adhere. Flocculation is the bridging together of coagulated particles. Chemical precipitation is a process in which chemicals react with dissolved minerals in water to form a relatively insoluble reaction product. Precipitation procedures are used to reduce dissolved hardness, alkalinity and silica, etc.
Chlorine Dosing System
A chlorine dosing system is a method of disinfecting water by introducing chlorine into the water supply. Chlorine is a widely used disinfectant that effectively kills or inactivates bacteria, viruses and other microorganisms present in water, helping to address problems of water supply and waterborne diseases. The chlorine dosing system is particularly important in areas where water conditions may be compromised, leading to contamination and the risk of bacterial infection.
SMBS Dosing System
Sodium Metabisulfite (SMBS) dosing is essential because chlorine is highly reactive and can damage the RO Membranes, which can reduce the efficiency of the RO plant.
SMBS is a common form of pretreatment for reverse osmosis systems and works in removing free chlorine, including being used as a biostatic. SMBS is preferred to be used for larger water treatment systems than other chemical reducing agents such as carbon filters and sulfur dioxide due to its advantage of reducing the chance of bacteria growth than produces biological fouling.
pH Correction System
pH dosing systems, also known as pH control systems, are highly automated devices capable of measuring, adjusting and monitoring a range of water properties. These systems are widely used in commercial and industrial applications, including waste and recycling water applications. A pH dosing system is a process that involves correcting the water’s pH level in order for it to reach an acceptable level within regulations for safe disposal with minimal harm to the environment.
Antiscalant Dosing System
Antiscalant is a crucial component in water treatment, especially for reverse osmosis (RO) systems. Antiscalant chemicals are used to prevent the scaling & fouling of the RO membranes. The Antiscalant dosing should be done before reaching the RO Membranes to break up sulfate precipitates, calcium carbonate, silica and other mineral fouling.
As antiscalant reduces membrane fouling more effectively than any other pretreatment, it is the preferred method for water systems.
Clarifiers, Clariflocculators
At APK we design, all capacities of Clarifiers, Clarifloculators as per customer requirement to remove suspended solids, turbidity, colloidal particles and heavy metals from water by coagulation and settling method. High Rate Solids Contact Clarifier is used in applications, where the inlet solids load is variable and if the solids are fine.
A Clariflocculator is a large circular tank combining flocculation and clarification in a single unit. It has two concentric tanks where the inner tank serves as a flocculation basin, and the outer tank acts as a clarifier. Flocculation is the pretreatment of water before sending it for further purification. This is a necessary process for treating water with high levels of TSS and other contaminants. Clariflocculators are used for primary and secondary clarification.
Dissolved Air Flotation
At APK we design, Dissolved Air Flotation (DAF) to clarifies wastewaters & water by the removal of suspended matter such as oil or solids. The removal is achieved by dissolving air in the water or wastewater under pressure and then releasing the air at atmospheric pressure in a flotation tank . The released air forms tiny bubbles which adhere to the suspended matter, causing the suspended matter to float to the surface of the water where it may then be removed by a skimming device.
Dissolved Air Flotation is very widely used in treating the industrial waste water effluents from oil refineries, petrochemical and chemical plants, natural gas processing plants, paper mills, general water treatment and similar industrial facilities.
Tube Settler
Tube settlers which are also known as plate settlers or lamella clarifiers, are used in waste water treatment plants to settle out suspended solids. Tube settlers and parallel plates increase the settling capacity of circular clarifiers and/or rectangular sedimentation basins by reducing the vertical distance a floc particle must settle before agglomerating to form larger particles.
Tube settlers are designed to provide as much settling surface as possible but at the same time they must prevent channel clogging. They are made of light weight PVC, tube settlers can be easily supported with minimal structures.
Multimedia Filters
At APK we design Multimedia Filter in Stainless Steel, MSEP, MSRL & FRP material from capacity 50 LPH to as per customer requirement to efficiently remove suspended impurities and turbidity from water. They consist of carefully graded anthracite, sand and garnet layers, offering a reliable way to maintain water clarity. Anthracite is the lightest filtration media per unit volume, followed by sand and then garnet.
Multimedia Filters are used as the primary or secondary filtration stage in drinking water treatment to remove a wider range of particle sizes and types than sand filters, including small particles and organic matter. Lakes, rivers and streams are protected from contaminants by using media filters. Multimedia filters are used in ETP & STP Plant also.
Activated Carbon Filter
At APK we design Activated Carbon Filter in Stainless Steel, MSEP, MSRL & FRP material from capacity 50 LPH to as per customer requirement. Activated Carbon Filters effectively remove residual chlorine, odours, color and colloidal impurities from water to a large extent.
Carbon beds should be backwashed to help remove trapped silt, prevent packing and head loss and to remove carbon fines produced by friction between granules.
