Monthly Archives: August 2021

How to Build an Industrial Sewage Treatment Plant

To build an industrial sewage treatment plant, you first must address what industrial sewage is. It’s wastewater produced in an industrial setting.

Water treatment plants handle different types of wastewater. You have domestic sewage that contains residential toilet water and gray water (water from showers, baths, washing machines, etc.) from houses and apartments. There’s storm sewage that is the rainwater and snowmelt that goes into drains found on the street. Finally, you have industrial sewage, which is the used water from manufacturing plants and factories.

Industrial sewage often contains higher levels of chemicals and pollutants than domestic sewage or storm runoff. It can be the wastewater created while manufacturing batteries, refining petroleum, and making paper in paper mills. This type of wastewater must be handled appropriately to ensure that it’s clean enough to send back to bodies of water or be reused in the businesses that use the water.

Industrial wastewater often contains heavy metals, food waste, inorganic materials like rubber and metal shavings, microplastics, radionuclides, and many toxins. For this reason, you must treat it appropriately. None of those should be returning to drinking water storage tanks, rivers, lakes, etc. The treatment plant must be designed to treat industrial sewage.

Many sewage treatment plants in residential settings are ill-equipped to handle industrial wastewater. It makes it harder to properly treat the water and damages equipment, leading to expensive repairs and downtime. An industrial business owner has to stop and think of the impact on the local wastewater district. As a result, companies consider building their own onsite treatment plants to pretreat water before it goes to the sewers.

The Steps Involved in Industrial Sewage Treatment

As water leaves your machines and buildings, where it goes depends on your setup. You may need to build an onsite industrial sewage treatment plant. If your city wants you to do the first stages of treatment before releasing your wastewater to the sewers, it’s important to understand what equipment is needed.

You might prefer to put in a small wastewater treatment plant on your grounds and reuse the water. That lowers your water bill and helps the environment. Denmark’s Carlsberg Brewery came up with a plan to use at least 90% of the wastewater the brewery uses and to create biogas to produce energy the plant needs. The goal is to reach zero water waste within the decade. It’s an ambitious, respectful goal that starts with an industrial wastewater system that covers these steps.

#1 – Screening

As wastewater enters a wastewater treatment plant, the solids must be removed. If they’re left in, they can clog lines and damage equipment in downstream processes. Don’t let your plant’s efficiency tank because of damage or clogs.

With the use of open screw pumps, you don’t need pre-screening. Move the wastewater into the open screw pumps for screening and grit removal. Once there, additional screw pumps keep the sewage flowing to primary clarification tanks.

Lakeside Equipment’s Raptor equipment screens and washes solids. From there, they are compacted and dewatered. As they’re made from stainless steel, they’re ideal for use in industrial sewage processes. Choose from rotary strainer screens, rake bar screens, rotating drums, micro strainers, and fine screens. This allows you to choose the best screen for the job.

#2 – Primary Clarification and Grit Removal

Once the wastewater is screened, it goes through the primary clarification process. Some plants also need to install grit removal systems. Clarification moves the wastewater and helps remove any additional solids that have settled in the wastewater.

You might choose a peripheral feed with a surface skimmer that pushes floating solids into a trough where the solids are removed. A Spiraflo clarifier holds solids in a sludge blanket that travels towards a center hopper for removal. Lakeside also has the Spiravac that pushes the solids to the sides where they get trapped between a skirt and wall and end up falling into a settling area.

Not all industrial wastewater treatment plants need grit removal systems, but some do. These systems remove fine grit like coffee grounds, bone fragments, eggshells, etc. You’d want to put in grit collection systems if you run a meat processing plant, a plastic extrusion company where microplastics make their way into the wastewater. Another example is a chicken farm where you’ll have seeds and eggshells getting into the wastewater.

#3 – Aeration

Aeration stirs up the wastewater to add oxygen to the mix. The oxygen feeds the microorganisms that help digest some of the contaminants remaining in wastewater. You don’t want any small particles of waste material to settle at this point. By continually stirring up the water, nothing can settle.

Magna Rotor Aerators have fiberglass rotor covers to eliminate spray. That will keep odors down and protect workers from wastewater droplets. Plus, the covers can trap heat from escaping in the cooler months. The aeration blades are stainless steel, which helps prevent corrosion.

#4 – Secondary Clarification

The water is getting pretty clean at this point, so wastewater goes into secondary clarification. The process is the same as you’d find in the primary clarification process. The remaining particles are negatively charged after the other processes. They’ll bond, which makes it easy for the clarifiers to remove these remaining particles.

#5 – Disinfection

Now it’s time to disinfect the treated water. Industrial wastewater carries a lot of contaminants like lead, chemical cleaning agents, cyanides, etc. Disinfection is required to remove them. UV disinfection is one option. Using UV lighting is an environmentally friendly method for disinfection without relying on chemicals like chlorine.

Chlorine and chlorine products are the first choice in industrial wastewater treatment. In addition to disinfecting the wastewater, chlorine also removes ammonia, kills any remaining organic materials, and oxidizes iron, hydrogen sulfide, manganese, and organic matter. Chlorine is cost-effective, but it has to be removed before the wastewater moves back into a lake, stream, or other body of water.

Other Wastewater Treatment Equipment That Benefits Your Plant

Are there other wastewater equipment and tools you should incorporate in your design? A SharpBNR is a process control system that allows you to fine-tune your equipment along the way. You can monitor readings and adjust aeration as needed. With this system, you maximize efficiency. If you have a SCADA system, you can monitor your wastewater treatment processes from anywhere.

The type of equipment you choose will lower your operating costs and effectively clean the water. Calhoun, Georgia, is home to several manufacturers of flooring, which leads to very corrosive wastewater. Lakeside Equipment helped the city build a sewage treatment plant designed for industrial wastewater by using open screw pumps with stainless steel tubes that withstand the corrosive materials.

Manufacturing plants, food processing companies, and other factories have two goals when it comes to industrial wastewater treatment. They want energy-saving designs that keep costs low, but they also want a water treatment system that properly cleans the water. Meet your budgetary goals and get a system that does exactly what you expect. Give us a call to discuss your industrial sewage treatment plant. Our team of specialists is happy to help design a system to your specifications that’s going to last.

Most Effective Commercial Sewage Lift Station Design

An effective commercial sewage lift station design has to match your industry’s needs. Often, it’s a pump system put in to move sewage to the sewers, but there’s a problem. The sewer line is at a higher elevation than the pipes leaving the business. For example, a hotel may have dozens of bathrooms with wastewater going to the lowest elevation, often a basement wet well, and then out to the nearby sewer.

When you have wastewater at a lower elevation that needs to travel to a higher elevation, the best solution is a sewage lift station. The lift station needs to be designed to meet needs and efficiently move the sewage along its route. You don’t want clogs to create issues. How do you determine what is the most effective commercial sewage lift station design?

Factors to Consider

When choosing your commercial sewage lift station design, what should you consider? These are the key points to consider when designing the lift station.

#1- Flow Capacity

Start with the flow capacity. You’re going to have peaks where more wastewater is leaving than usual. If you own an office building, toilets and sinks will get more use during office hours. At night, the flow decreases. You have to play your sewage lift station to match the peak flow rates. Leaving some extra room for the unexpected is a smart idea.

Flow capacity is calculated by going over all of the fixtures in the commercial building or area. You have to look at the max load for each of those fixtures. If you have 20 toilets and each toilet flush sends five gallons of water to the sewage lift station, there’s the chance that you’ll get 100 gallons of wastewater hitting the lift station at once. Add sinks, dishwashers, washing machines, etc. to that figure. While it’s unlikely they’d all run simultaneously, it’s better to plan accordingly than have a lift station that isn’t prepared for the peak flow rate.

#2 – Force Main

You now have the peak flow rate. You have to take that and consider the velocity of the force main, which is the pressurized pipe that handles the sewer pump’s discharge. You want to keep that velocity to two to five feet per second. This is important as it keeps solids from settling without creating head loss. It also helps you decide the minimum pipe size to prevent clogging of the force main.

Force main pressure may have the velocity change rapidly. If that happens, you end up with a rapid increase in water pressure known as water hammer. Water hammer can damage valves and lead to costly repairs. Making sure the water pressure on valves and other components is within the correct psi range is essential for force main pressure.

#3 – System Head

Head loss occurs when there is friction in pipes or components like the elbows. Friction can make it harder for a pump to cool down, resulting in unnecessary wear and tear. You want to avoid head loss. To do this, you want to plan for the system head curve. If you make the pipe length and elbows too small, it can lead to head loss. If you consider the vertical lift that the wastewater must be able to travel, you keep wear and tear to a minimum and reduce the need for unexpected maintenance.

#4 – Wet Well

All of the commercial wastewater may collect in a covered wet well. That wet well collects the wastewater that needs to be pumped to the sewer lines. Knowing the right size for this wet well is also essential. In the Water Pollution Control Federation’s manual, rules state sewer pumps shouldn’t run less than 5 minutes or more than 30 minutes. Your wet well needs to be large enough so that the pump falls within these discharge rates.

#5 – Area Regulations

Towns, cities, and municipalities all have regulations you must follow. These regulations are in place to prevent wastewater from overloading a wastewater treatment plant, which increases the risk of raw sewage going into bodies of water before there is enough time to treat it. You don’t want to design a lift station that increases flow so much that it impacts the effectiveness of downstream lift stations.

You may be required to design a sewage lift station that accommodates several decades of use. That means planning for growth and expansion, which also benefits you because you have a system that will not need replacing in a few years. You save money on future expansions and improvements.

#6 – The Site

You have to choose a site that considers the impact on the environment. If you’re building a commercial sewage lift station near a wetland, you could cause harm. Any flooding would also impact your lift station. You need to be near a power supply, have a site that drains well, and be located in an area where the odors won’t cause issues with residents. If there may be issues with the smell, you need to consider odor control in your design.

Types of Sewage Lift Stations

A typical sewage lift station has a wet well with a pump and piping. The pump pushes wastewater uphill to the gravity sewer manhole. Wastewater travels into the wet well for the pump to push out when the water level is high enough.

Submersible pumps are one option. The pump sits on the floor of the wet well. The impellers draw the wastewater through the pump and into the piping, heading to the sewer. A screw pump is an alternative that suits many commercial facilities’ needs due to the lift, low maintenance requirements, and efficiency.

Why Choose Screw Pumps?

Screw pumps are the best choice for moving large volumes of sewage from a commercial area, while keeping an eye on maintenance costs, downtime, and efficiency. You have two choices for screw pumps: enclosed or open.

An enclosed screw pump sits within a tube. Lakeside Equipment has two types: Type C or Type S. Type C screw pumps use a rotating tube, while Type S has a stationary tube. Here are the benefits of enclosed screw pumps.

  • Designed for drop-in replacement
  • No grouting or trough is required, shortening the time needed for installation and lowering costs
  • Type C inclines up to 45 degrees and is up to 10% more efficient than an open screw pump
  • Type S inclines range from 22 to 40 degrees and is able to pivot

An open screw pump is the opposite. The exposed screws sit in a concrete or steel trough and can be installed at angles of 22 to 40 degrees. Here are a few facts to know about open screw pumps:

  • Hydraulic lift of up to 50 feet
  • Move as little as 90 gallons per minute to as much as 55,000 gallons per minute
  • Permanently lubricated roller bearings to reduce maintenance
  • Pre-screening is not necessary thanks to the non-clogging design
  • Slow operating speeds with variable pumping capacities
  • Up to 75% efficient
  • Wet well is not required

What’s most important when it comes to a commercial sewage lift station? You want a practical design that gets the job done without requiring a lot of maintenance or wear. A lot goes into a commercial sewage lift station, and it’s not always something you can design on your own. It’s best to call an expert.

Lakeside Equipment’s screw pumps meet and exceed your goals. We’ve been designing screw pumps since the 1960s and have the experience you need for fuss-free operation and extreme efficiency. Call our experts at 630-837-5640.