Air-operated double diaphragm (AODD) pumps are used in various industries, from chemical manufacturing and mining to wastewater treatment, in processes including sludge treatment, filtration of waste products and separating solids from liquids. It is important to understand the wastewater industry to better comprehend how AODD pumps are used in wastewater treatment.
Industrial wastewater treatment encompasses the technologies and procedures used to treat water that has been polluted by an anthropogenic business or manufacturing operation
before its discharge into the environment for reuse.
Most companies generate some wet waste, while recent trends have leaned toward reducing or recovering such trash within the production process. Nevertheless, many businesses continue to depend on procedures that produce domestic wastewater.
Many procedures can remove unwanted byproducts from industrial processes, including industrial wastewater treatment. After treatment, a sanitary sewer or surface water in the environment may receive the treated industrial effluent.
Types of Wastewater Treatment Plants
Water treatment facilities, such as petroleum refineries, chemical and petrochemical plants are standard in most industrial operations to ensure that pollution levels in the municipal wastewater systems meet the requirements for discharge into sewers, rivers, lakes and oceans. Hazardous contaminants such as toxic pollutants, organic compounds and nutrients like ammonia can all be found in wastewater generated by enterprises. A pretreatment system is used by some businesses to remove contaminants
before the sewage is discharged to the sanitary sewer.
The four different types of wastewater treatment plants include:
- sewage treatment plants (STPs)
- effluent treatment plants (ETPs)
- activated sludge plants (ASPs)
- common and combined effluent treatment plants (CETPs)
Sewage Treatment Plants
Waste is removed from wastewater in sewer systems. STPs can be found in large American cities. A facility like this receives sewage waste from residential properties and, on occasion, commercial wastewater. It may also receive precipitation and storm sewer trash. STPs play an important role in protecting the health and safety of communities by removing harmful pollutants from wastewater before it is released into the environment.
The first step in the sewage treatment process is simple filtration. It is sluiced in the settlement basins as it passes through screens. STP tanks and equipment are damaged by debris, so as much of the debris, grit and sand as possible must be removed from the wastewater to prevent undue wear and strain on the machinery. This is called pretreatment because it comes before the more aggressive phases of therapy. Several STPs are referred to as “three-stage” because their wastewater is processed in three distinct stages: primary, secondary and tertiary.
In the secondary stage, aeration and activated sludge processing occurs. A bacteria sludge blanket ultimately settles on the bottom of these next series of tanks. The sludge can be reused in the first stage as the active bacteria will assist with the breakdown of organic matter of incoming sewage. In the final stage, the wastewater flows through sand filters and UV lights to remove fine particulate matter and to neutralize microorganisms.
Effluent Treatment Plants
For municipal and domestic wastewater, sewer systems perform the first stage of treatment. Industrial sewage, on the other hand, is often cleaned at ETPs. ETPs can be useful in trades with a high risk of contaminants in their wastewater, such as pharmaceutical manufacturing and chemical industries. Without proper treatment, plants cannot release these chemical pollutants into the environment. The sewage compositions of different businesses may necessitate the use of different ETPs.
Initial, primary, secondary and tertiary treatments are common in ETPs. Processes used may vary depending on certain factors including the number of suspended solids in the wastewater and the availability of contaminants like metals, industrial chemicals and bacteria.
A typical ETP primary treatment focuses on the extraction of additional solid waste and organic material while secondary treatment aims to remove suspended particles and biodegradable organic matter. Lastly, a tertiary treatment combines physical, chemical and biological techniques to discard any residual solids and contaminants.
Activated Sludge Plants
Sewage treatment facilities and municipal wastewater plants are similar. They use activated sludge to break down biological pollutants in sewage effluent. Activated sludge can also be used in secondary treatment in an STP but has a more important function in an ASP.
Because of the air, the raw sewage becomes a more viscous liquid. The mixture’s biological components then digest most organic debris and pollutants. For the dissolved oxygen to act correctly, the sewage must be blown with air for an extended length of time. When that process is complete, some of the sewage liquor is discharged into a clarifying chamber. Sewage liquor is left to settle in this area, while biological matter sinks to the bottom of the mixture.
This crust of dead bacteria forms on the sewage liquid at the chamber’s top. Clear liquid forms in the center. The facility can discharge it into a soakway or waterway to further treat this water. Since the bacteria found inside the chamber are alive and ready to devour organic materials, activated sludge is a filmy, slimy substance.
Once the activated sludge layer has been created, the plant returns it to the digesting chambers like a typical STP. When fresh, raw sewage enters the tank, bacteria in the activated sludge break down organic debris. Standard STPs vary slightly in composition from ASPs. The principal settlement chamber in most STPs must be cleaned out regularly as these settlement chambers do not produce activated sludge but rather anaerobic sludge, which cannot break down organic materials and must be removed. Anaerobic sludge does not need to be removed from ASPs because they solely deal with activated sludge.
Common & Combined ETPs
Smaller wastewater generators can benefit from CETPs. Processing plants, for example, cannot often afford to operate their ETPs, as many smaller manufacturers and other operations produce wastewater so maintaining and operating these massive, sophisticated structures is beyond their means. CETPs provide an answer. It is possible to treat the effluent of many industrial plants in an industrial zone by pooling their effluent into a single facility. All the small facilities that bring their waste to the plant make up the costs of operating and managing the CETP. Instead of running multiple full-scale plants, they receive clean, compliant effluent.
What Are AODD Pumps?
Positive displacement (PD) pumps are powered by air, such as the AODD. To fill and empty the pumping tanks, diaphragms move in opposite directions. The pump action is created by the diaphragms pumping air in and out of chambers on the opposite side of the diaphragms.
This pump type is used for transfer applications and can manage a wide range of input materials, including solid waste, liquids with high shear and abrasives. As a result of their sturdy design, they are not susceptible to freezing and can be used in low-pressure with variable flow situations.
Wastewater Treatment Applications
Loading/unloading and transfer: Safe handling of hazardous materials
AODD pumps are used for loading, unloading and transferring hazardous waste and chemicals in wastewater treatment processes. They are ideal for injecting substances, from acids to antimicrobials, and function well with municipal wastewater, sewage and many others present throughout this area.
With the help of AODD pumps, transferring chemicals and hazardous materials becomes safer and easier.
Filter press: Sanitize water for reuse, belt press feed, wastewater solids handling
The equipment used for liquid/solid segregation is called a filter press. Filter presses use pressure filtration to separate the liquid from the solid by pumping the solid into the filter press and dewatering it under pressure. Filter presses have proven themselves repeatedly in commercial water supply and wastewater applications. This is a daily separation application for big volumes of different substances. Due to their robust construction and easy maintenance, AODD pumps are used in filter presses.
The AODD pump’s design eliminates the need for electricity, as its functioning is accomplished by using normal compressed air. In particular, high-pressure AODD
pump versions can provide a supply pressure of up to 15 bar (218 pounds per square inch [psi]) required for many filter-press uses. The pumps are constructed of high-density polyethylene, which is nearly twice as resistant to erosion than polypropylene and more durable than iron, aluminum and steel.
As a result, they apply to all kinds of chemical mixtures used in water and wastewater treatment procedures. With the help of the AODD pump filter press process, wastewater can be easily filtered and sanitized along with solid wastewater handling, making the process easier.
Municipal utility: Dewatering, solids handling using a portable pump
Mechanically operated AODD pumps provide a less expensive approach to transferring wastewater and sediments. The mechanical AODD pump provides an inline flow route to effectively pump fluids compared to the frequent twists in standard AODD pumps. With the help of an AODD pump, dewatering wastewater becomes easier and more convenient. Since transferring with AODD pumps is safer for removing and transferring chemicals, it becomes easier to use for filtration, cleaning and purification.
Wastewater: Processing includes neutralization, disposal, chemical spill containment, grit and scum removal
The entering wastewater is first processed by screening types of machinery, which remove rags, wood bits, plastics and grease items. Materials taken are cleansed and pressed before being disposed of in a landfill. In the subsequent step, the settled material, referred to as primary sludge, is removed from the process by circular tanks known as clarifiers.
The material will settle, although at a slightly slower pace than previous steps. The settled material is pumped out of the tank from the bottom using an AODD pump, and the wastewater is pumped out of the tank from the top. Debris that floats to the surface is skimmed off and transported to digesters together with the settled material. To eliminate phosphorus from the water, chemicals are introduced during this process. The effluent is subjected to the necessary treatment, and the contaminants are digested by microorganisms and turned into cell tissue, water and nitrogen due to biological deterioration.
The cleared effluent is polished in this phase by passing through a polyester media with a 10-micron pore size. During routine maintenance, the material caught on the surface of the disc filters is washed with water and transferred to the plant’s main processing area for treatment. With the assistance of AODD pumps, all of this becomes faster and
easier to complete.
Sludge Removal
AODD pumps help manage a diverse variety of items, including thickened/clarified/digested sludge, waste activation or return synthetic wastewater (WAS/RAS) and other organic waste.
The primary sludge that is pressurized from the base of the filtration process and the constant flow of sludge from the aerobic biological/activated sludge system must be treated to reduce the quantity and generate a usable final product. The sludge removal process is easier with the help of an AODD pump. Moreover, AODD pumps make it safer to remove the toxic chemicals without harming the individuals carrying out the process.
The filtration of wastewater and control of waste pollution is frequently oversimplified and misinterpreted. In a model to correct the variety of situations involved, significant preparation is required. This includes safety cleanups of raw sewage, hazardous waste management, industrial cleaning, preventative maintenance and composting.
AODD pumps can be used for a variety of wastewater treatment processes and may be the best option in all these situations.
