Processing septage water at wastewater treatment plants poses several challenges. Septage receiving refers to the wastewater generated from the on-site treatment of septage, which is a mixture of solid and liquid waste from septic tanks, portable toilets, or industrial businesses. If you receive septage at your water facility, chances are you have experienced an overloaded plant, increased grit and grease or process upsets. In this blog, we will explore the difficulties faced by wastewater treatment plants when dealing with septage receival water and discuss potential solutions to mitigate these challenges.
Challenges in Processing Septage
Water resource facilities who are considering accepting septage have many things to consider for planning, design, and processing the highly concentrated water. This is a list of the most common challenges with accepting septage water at your wastewater treatment facility.
High organic content: Septage receival water often contains a high concentration of organic matter. This increases the biochemical oxygen demand (BOD), which can strain the biological treatment processes at wastewater treatment plants, leading to reduced treatment efficiency and increased operating costs.
Variable composition: The composition of septage receival water can vary significantly depending on the sources and local conditions. The composition from a septic truck will be completely different than an industrial user. This variability makes it challenging to design and optimize your treatment process, as different compositions may require different treatment techniques and process adjustments.
Solids and grit: Septage receival water often contains a significant number of solids and grit, such as sand, gravel, plastic, rags and other non-organic material. Grit can cause abrasion and clogging in the treatment system, leading to increased maintenance and decreased overall plant efficiency.
Pathogenic microorganisms: Septage can contain various pathogenic microorganisms, including bacteria, viruses, and parasites. Treating and disinfecting these organisms requires specialized treatment protocols and technologies to ensure public health and safety.
Solutions to Overcome Difficulties
To address the difficulties associated with processing septage receival water, wastewater treatment plants can implement the following solutions. Our team is partnered with various manufacturers who offer septage receival solutions:
1. Pre-Treatment Screening: Installing effective screening systems at the entry of the treatment plant can help remove large debris, solids, and grit. This reduces the strain on downstream processes and minimizes maintenance requirements.
Fluidyne is an innovator through the development of products like the Hydro-Grit™ grit vortex separation. Fluidyne has supplied wastewater process equipment and technology for over 40 years with hundreds of installations throughout the world.
Fluidyne High Efficiency Hydro-Grit™
Fluidyne’s Hydro-Grit™ grit vortex system removes sand and inorganic material before the wastewater treatment process. Historically one of our most popular and effective products, the high efficiency Hydro-Grit™ offers the same advantages as the standard Hydro-Grit™ with improved grit removal efficiencies. Performance data through the high-efficiency unit has shown 95% removal of all grit 74 micron and larger.
Fluidyne Grit Classifier
The Hydro-Grit™ Classifier is designed for the separation, dewatering and removal of settleable inorganic material typically at the inlet/headworks of a municipal or industrial wastewater treatment plant.
Picture source: http://www.fluidynecorp.com/grit-removal/grit-classifier.aspx
2. Enhanced Biological Treatment: Implementing advanced biological treatment processes, such as membrane bioreactors (MBRs) or moving bed biofilm reactors (MBBRs), can improve the overall treatment efficiency and reduce the impact of high BOD levels. These systems provide better control over the treatment process and can handle fluctuations in organic loading.
Aquapoint manufacturers a variety of natural fixed-film biological treatment processes that easily fit into a small footprint and require little maintenance.
Picture source: AquaPoint - Advanced Wastewater Treatment Systems & Services
Bioclere™ OH is a two-stage hybrid biological treatment process integrating an AquaCELLTM moving bed biofilm reactor (MBBR) with a BioclereTM high-rate trickling filter. The high-rate productivity and oxygen transfer efficiency of the MBBR combined with the polishing and clarification capability of the Bioclere makes Bioclere-OH ideal for high-performance nitrification and denitrification applications. BOD/COD removal and partial nitrification are accomplished in the first stage MBBR by heterotrophic organisms allowing a robust population of nitrifying autotrophic organisms to colonize the trickling filter media bed and accomplish complete ammonia-N removal. Bioclere-OH is a fixed-film technology offering process stability, small footprint, minimal process control requirements and high-quality effluent.
3. Dewatering: Implementing a dewatering process, such as a screw press, can effectively handle septic sludge, which increases the safety and cleanliness of the water resource facility.
Process Wastewater Technologies LLC (PWTech) was formed in December, 2006 as the residual manufacturer of wastewater and combined sewer overflow (CSO) products. PWTech has a rich heritage in the storm water, wastewater, CSO, and SSO treatment industry.
The PWTech Volute Dewatering Press is an innovative sludge dewatering product that offers many advantages over conventional sludge management methods. The Volute Dewatering Press is patented worldwide and is manufactured in the United States.
The key to the process is the unique dewatering drum design. This drum is able to achieve both thickening and pressing (dewatering) of the sludge in a single, compact operation. It can take sludge as dilute as 0.1% solids, directly from a biological process, such as an oxidation ditch, and produce a cake of over 25% solids. The PWTech® Volute Dewatering Press has been installed to handle a wide range of sludges, such as potable water sludges (including alum, ferric, and PAC sludges).
Picture source: PWTech.us
Dewatering and Septage Receival:
Livingston County Septage Receiving Station in Michigan experienced continual issues with their dewatering equipment. We interviewed Paul Nygaard, President of ICS Group, to learn about the septage receiving stations issues and the path they took to becoming more efficient.
What was the main issue at Livingston that caused them to upgrade the dewatering technology?
PN - "Livingston had an existing press that did not work. At the time we talked to the team, the dewatering equipment was not even a year old and was having issues. It was running continuously, 24/7. This caused a lot of issues with the team to keep it running and producing the right percentage of sludge cake."
Why did Livingston choose the PWTech Volute Dewatering Press?
PN - "The team at Livingston was interested in the PWTech Volute Dewatering Press and chose to pilot the technology at the facility on their unique sludge. After a successful pilot, Livingston placed an order for the technology."
How has the PWTech Volute Dewatering Press installation helped the efficiency at the facility?
PN - "The facility has reduced their operating hours and the PWTech Volute Dewatering Press is running less than the old machine which makes it more efficient, reducing man power, lower operating time - which lowers O&M. The new press is also providing better cake capture."
What is the biggest benefit of using the PWTech Volute Dewatering Press in a septage receival station?
PN - "The biggest benefit of the dewatering press is with one step, they are able to take less than 1% solids and creating 35% cake solids in a one step process."
Processing septage receival water at wastewater treatment plants presents several challenges. However, with the right technologies, treatment processes, and regular monitoring, these difficulties can be overcome.
Conducting regular monitoring of the septage receival water, including its physical, chemical, and biological characteristics, allows treatment plants to identify any changes or issues promptly. Implementing process optimization strategies based on the monitoring results ensures the treatment system remains efficient and effective.
By identifying appropriate solutions, treatment plants can ensure the efficient and safe treatment of septage receival water, contributing to the overall sustainability of wastewater management systems.