Environment & Wastewater
Increasing water demand and wastewater volumes due to global urbanization and industrialization have made wastewater management a critical area from both environmental and economic perspectives. In this context, wastewater treatment plants are transforming into “wastewater refineries” where energy, water, and materials are recovered, rather than merely disposing of waste.
Increasing water demand and wastewater volumes due to global urbanization and industrialization have made wastewater management a critical area from both environmental and economic perspectives. In this context, wastewater treatment plants are transforming into “wastewater refineries” where energy, water, and materials are recovered, rather than merely disposing of waste. New generation biological, physicochemical, and mechanical technologies, along with process optimization — particularly sludge management and dewatering — reduce investment and operating costs while enhancing environmental functionality. This article focuses on technological trends, application areas, and performance criteria, based on international literature, the Turkish regulatory framework, and industry practices, with a focus on the decanter centrifuges and comprehensive dewatering solutions offered by Polat Makina.
Today, many countries around the world are experiencing water shortages due to increasing pressure on water resources. Due to the rapidly growing global population, urbanization, changes in production and consumption habits, and the resulting increase in demand for water, it is estimated that by 2030, existing practices will face a 40% gap between potential demand and available water resources (World Bank, 2022). Furthermore, chronic water scarcity, hydrological uncertainty, imbalances in global water distribution, and extreme weather events (floods and droughts) linked to climate change are emerging as one of the greatest threats to global prosperity and stability. The impact of water scarcity and drought on increasing vulnerability and impoverishment is also growing.
Investments in wastewater infrastructure in Turkey and the EU region are increasing in the context of strengthening water efficiency and environmental standards. Turkey’s water and wastewater strategies for the 2020–2025 period aim to increase the number of wastewater treatment plants, encourage energy and material recovery, and ensure the financial sustainability of wastewater management. This framework directly increases the demand for high-efficiency dewatering technologies and process optimization in plants.
2. “New Generation” Technologies and Processes in the Wastewater Sector
2.1 Advanced Biological Processes: MBR, AnMBR, PN/Anammox
Membrane Bioreactor (MBR) technologies offer high-quality effluent, a smaller footprint, and intensive processing advantages; in recent years, improvements in membrane performance and operating costs have made it a mature technology. Anaerobic MBR (AnMBR) and Anammox-based processes stand out due to their energy efficiency, low carbon footprint, and effectiveness in nitrogen removal. These technologies have the potential to convert organic matter into energy (biogas) while reducing energy consumption.
2.2 Advanced Oxidation and Physicochemical Solutions
Advanced oxidation processes such as UV/H₂O₂, photocatalysis, and ozonation are effective in breaking down difficult organic pollutants (e.g., trace micropollutants); their use as complementary processes in industrial wastewater is increasing. These processes can be integrated following biological treatment or in a manner that supports the biological process.
2.3 Electrocoagulation
Electrical precipitation methods enable the effective removal of suspended solids and emulsified oils by reducing chemical usage in some industrial wastewater; they are particularly advantageous in facilities where chemical costs and chemical storage are problematic.
2.4 Smart Monitoring, IoT, and Artificial Intelligence (Process Optimization)
Control strategies that optimize energy usage and chemical dosages are becoming widespread thanks to field sensors, cloud-based SCADA integrations, and predictive models. Machine learning-based predictive maintenance reduces downtime for critical equipment such as centrifuges, increasing energy efficiency and service continuity.
2.5 Sludge Management and Dehydration Technologies
The costs of sludge transportation, stabilization, and volume reduction are decisive factors in plant operation. In this regard, decanter centrifuges are high-tech systems and are preferred in the industry. Their flexible operating capacity and ability to provide automatic optimization are also reasons for their preference. Decanter centrifuges find a wide range of applications due to their effectiveness in achieving high dry solids (DS), flexibility, and suitability for continuous operation.
3. The Role of Decanter Centrifuges: Technical Advantages and Energy-Balance Assessment
Decanter centrifuges are devices that provide high-efficiency solid-liquid separation in a short time and are used in the wastewater chain for both thickening and dewatering purposes. In modern decanters:
Continuous operation, high throughput, and short contact times ensure plant compactness.
Advanced materials, rotor/speed optimization, and scroll geometry enable higher DS and lower chemical dosage.
Energy consumption is a critical parameter; recent studies have shown that energy consumption can be significantly reduced through brake energy recovery systems, parametric optimization, and speed management. (There are reputable studies on decanter energy models and parameter optimization.)
4. Polat Makina Sample Applications and Technology Portfolio
Polat Makina offers decanter centrifuge and separation solutions for industrial and wastewater applications beyond desktop specifications. The company has the capacity to supply both single equipment (decanters) and turnkey dewatering lines — providing businesses with the advantage of a single point of contact for procurement, commissioning, and spare parts/service processes. Furthermore, Polat Makina’s recent launch of the widest spiral diameter decanter (SX-920) manufactured in Turkey is a concrete demonstration of the strengthening of local production capabilities in high-capacity applications. Such high-capacity decanters are particularly preferred in food, olive oil, industrial waste, and municipal sludge applications.
5. Polat Makina Advantages:
Shorter supply chain and maintenance times with local production.
Cost-effectiveness in high-capacity units (such as large-diameter decanters like the SX-920).
Turnkey integration: comprehensive solution including chemical dosing, pumping lines, control panels, and service contracts.
6. Performance Criteria and Selection Guide:
The following main criteria should be considered when selecting a decanter:
Input Characterization: Sludge solids content (g/L or %DS), particle size distribution, and viscosity.
Output Targets: Target DS (%), disposal cost reduction targets, and recovery objectives.
Capacity Range and Continuity: Will it operate continuously or at part-load; how will peak flows be managed.
Energy and Operating Costs: Motor power, drive type (frequency inverter), maintenance cycles. Modern designs offer advantages with speed control and energy recovery.
Service and Spare Parts Availability: Local service network and spare parts access directly impact operational continuity — local manufacturer/supplier brings advantages.
7. Integration: Wastewater Refinery Perspective:
Not just dewatering; integrated approaches (e.g., AnMBR + decanter + gasification/anaerobic digestion + energy production) can positively impact the plant’s net energy balance. For example, while energy independence increases with biogas production, sludge transportation and disposal costs are significantly reduced with effective dehydration. Policy documents in Turkey also encourage the transformation of wastewater facilities into “wastewater refineries” and the recovery of materials/energy — in this context, process integration will become increasingly important.
8. Risks, Operational Challenges, and Recommendations
Risks & challenges:
Feed variability: Industrial fluctuations can alter sludge properties; therefore, process flexibility is important.
Energy cost variability: Centrifuges are high-power equipment; energy optimization is critical.
Membrane fouling (MBR) and mechanical wear (decanter): Requires regular maintenance, filtration pretreatment, and material selection.
Recommendations (to the plant owner/operator):
Regularly characterize the feed and leave a conservative margin in the design.
Evaluate speed control, periodic operation, and recovery solutions for energy optimization.
Support process control with IoT and ML; spare parts and maintenance-prediction models, in particular, increase consistency.
Reduce MTTR (mean-time-to-repair) times for critical equipment by signing service contracts with local suppliers (e.g., Polat Makina).
9. Conclusions & Recommendations
The future of wastewater management will be defined by efficiency, recovery, and sustainability. Decanter centrifuges and integrated dewatering solutions play a key role with their potential to reduce the total cost of sludge management and increase energy efficiency. Domestic manufacturers such as Polat Makina offering high-capacity, turnkey solutions create a significant opportunity for the modernization of wastewater infrastructure in Turkey, both technically and logistically. The domestic separators and decanters produced by Polat Makina separate solids and liquids in dirty water/wastewater. This equipment is suitable for both industrial and municipal water/wastewater separation. Dewatering, another treatment method, involves solutions for dewatering sludge, i.e., reducing the volume of sludge and increasing its dryness ratio. The solutions offered by Polat Makina significantly reduce transportation, storage, and disposal costs. With Wastewater Engineering & Project Design studies, infrastructure and equipment suitable for the facility’s process, flow rate, and wastewater characteristics are planned. Benefits include 3D-supported design, simulation studies, and optimizing equipment performance by previewing it in advance. As another solution, Polat Makina offers customized equipment and processes tailored to customer needs and facility conditions through its R&D processes, developing pinpoint solutions. Polat Makina provides equipment and processes tailored to the needs of different facilities and customers.
Our recommendation to plant investors and operators:
(1) Invest in process integration (aiming for energy and material recovery),
(2) Implement optimization strategies centered on operational data, and
(3) Strengthen maintenance/supply chain security with local partners.