Wastewater & Infrastructure

    Sewage Treatment Plant Companies

    STP providers covering packaged, modular, and large-scale sewage treatment for municipalities and compounds.

    96 providers

    This page is a good fit if you need:

    • Reverse Osmosis (RO) or Ion Exchange capabilities
    • Suppliers with asset maintenance & rehabilitation sector experience
    • Providers operating in United Kingdom or Netherlands

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    Showing 1-20 of 96

    96 results from 96 matched providers

    Ecosystems International logo

    Ecosystems International

    Verified
    Indonesia51-200 employees
    83 technologies6 regions

    PT Ecosystems International (PT ESI) was established at Jakarta on 21st November 2006. We are an industrial effluent treatment systems integrator specializing in electrocoagulation (EC), a unique waste water treatment profile. PT ESI has capabilities in designing complete waste water treatment solutions by combining various effluent treatment systems such as the electro-coagulation, biological, chemical processes and membrane filtration, offering its customers a wide and comprehensive range of solutions, tailored to suit their various needs – ranging from basic effluent treatment for discharge to effluent recycling for water reuse. The Company is experienced in handling the design, engineering, procurement, construction and operation of new Effluent Treatment Plants (“ETP”) and possesses expertise in retrofitting existing ETP to increase the flow rate and treatment capability without any major infrastructure increase PT ESI is also a premier waste water treatment service company specializing in handling waste water generated from Exploration (Drilling) and Produced Water. Customers in Indonesia include major Oil & Gas companies such as Pertamina, Exxon, Chevron, Petro-China and Medco. Operations in Indonesia are provided by both mobile and fixed units. At drill sites where waste-water recycling is required, PT ESI supplement these treatment units with skid mounted mobile Reverse Osmosis systems. The technologies and solutions employed by PT ESI are developed in-house and examples of these are its proprietary Trident™ Electro Contaminant Removal (“ECR”) system, the Stage Contaminant Removal (“SCR”) process and Mobile On-Site Waste-Water Treatment (“OWT”) units

    Reverse Osmosis (RO) Systems
    Ultrafiltration (UF) Systems
    Multi-media Filtration (MMF) Systems
    Nanofiltration (NF) Systems
    +62 more
    Brine Consulting logo

    Brine Consulting

    Verified
    Netherlands1-50 employees
    133 technologies6 regions

    BRINE CONSULTING delivers senior-level strategy, technical design, and actionable insight across the full lifecycle of water-related challenges. We support clients with advisory and due diligence, advanced brine management and resource recovery, industrial and municipal water reuse, and MLD/ZLD systems. Our team also leads ESG and climate-resilience strategy, innovation scouting, and international development and PPP advisory. With deep specialization in desalination, brine valorization, circular economy models, and high-impact infrastructure, we help organizations turn water and waste streams into opportunities, providing clear thinking, rapid delivery, and solutions built for real-world results.

    Activated Carbon Filtration
    Reverse Osmosis (RO) Systems
    Ultrafiltration (UF) Systems
    Microfiltration (MF) Systems
    +84 more
    Gi Aqua , Water as a Service logo

    Gi Aqua , Water as a Service

    Verified
    Saudi Arabia51-200 employees
    6 technologies3 regions

    GI WAAS delivers cutting-edge water and wastewater solutions using advanced nanotechnology and zero total discharge solution sets industry standards. Our mission is to provide smart, sustainable, and decentralized treatment systems. We are committed to circular economy principles and reducing environmental impact. Our holistic approach provides comprehensive, tailor-made solutions that are designed to meet the specific needs of each client

    Water-as-a-Service (WaaS) Contracts
    Public-Private Partnerships (PPPs)
    Technology Leasing and Rental Solutions
    Operation of Water & Wastewater Treatment Plants
    +12 more
    Hangzhou Realize Technology Co., LTD. logo

    Hangzhou Realize Technology Co., LTD.

    Verified
    China1-50 employees
    6 technologies1 region

    HANGZHOU REALIZE TECHNOLOGY CO., LTD. is a technology enterprise. The company collaborates with domestic and international universities such as Beijing University of Technology, Tsinghua University, and Berlin University of Technology to address the challenges of enhancing anaerobic efficiency and nitrogen removal in high-ammonia nitrogen wastewater. The core technologies foucs on energy-saving denitrification and enhanced green methane production. These two technologies can increase production efficiency of green methane by 20% and reduce costs of wastewater denitrification by 60%.

    Process Water Treatment
    Wastewater Treatment
    Advanced Treatment Technologies
    Activated Sludge Process
    +7 more
    PNR ITALIA Srl logo

    PNR ITALIA Srl

    Verified
    Italy51-200 employees
    2 technologies5 regions
    19 published assets19 case studies

    We produce a comprehensive range of spraying solutions, encompassing everything from small-scale nozzles to large industrial spraying systems. Our diverse product line includes various types of nozzles tailored to meet the specific requirements of every application and customer need. The company was established in Milan in November 1968, focusing on distributing parts and components for fire protection systems. Over time, we expanded our offerings to include a diverse range of industrial sprayers tailored to various applications. In addition to our distribution and manufacturing of fire protection system components and industrial sprayers, we specialize in designing and producing pneumatic spray nozzles for industrial use and tank washing nozzles. Our product line also encompasses a variety of complementary accessories essential for industrial washing, including filters, spray guns, and hoses. Furthermore, we offer ejectors, blower nozzles, swivel joints, and hose clamps to provide comprehensive solutions for our customers' needs. PNR Italia is part of the Tecomec Group and oversees four other affiliated companies to form PNR Company, a consolidated reality with a significant presence on the market.

    Microfiltration (MF) Systems
    Disinfection Technologies
    Disinfection Chemicals
    Antifoam and Defoaming Agents
    +6 more
    BAISEN TECHNOLOGY CO.,LTD logo

    BAISEN TECHNOLOGY CO.,LTD

    Verified
    China51-200 employees
    9 technologies6 regions

    Our manufacturing plant in Guangdong, China, was established in 2007 and has served various municipal equipment manufacturers in China for nearly 20 years. We have been exporting products for almost 10 years, such as MBBRs, tube settlers, and aerators. The factory is located near Shenzhen Port, making sea freight extremely convenient.

    Multi-media Filtration (MMF) Systems
    Aerobic Digestion
    Anaerobic Digestion
    Process Water Treatment
    +12 more
    Hainan Litree Water Purification Technology Industry Co., Ltd. logo

    Hainan Litree Water Purification Technology Industry Co., Ltd.

    Verified
    China200+ employees
    20 technologies6 regions

    Litree: Pioneering Ultrafiltration for a Water-Secure World Founded in 1992, Litree has dedicated 30+ years to redefining water purification through ultrafiltration (UF) membrane technology—our core expertise and passion立升(Litree). As a global high-tech enterprise rooted in independent innovation, we’ve evolved from a membrane R&D startup to one of the world’s leading water problem solvers, with over 146 core patents and state-of-the-art manufacturing hubs in Haikou and Suzhou, China立升(Litree). Our signature hollow fiber UF membranes are engineered to deliver unmatched performance: 0.01μm precision removes 99.99% of bacteria, viruses, and contaminants while preserving essential minerals—striking the perfect balance between purity and health立升(Litree). This technology powers our diverse solutions, from residential whole-house systems to large-scale municipal projects and industrial wastewater treatment, all designed for sustainability and cost-efficiency. What truly sets us apart is our commitment to making safe water accessible. We’ve completed projects serving 50,000+ residents with centralized purification systems that cut construction costs and footprint by 50% compared to traditional setups—proof that advanced technology can also be affordable. Today, our solutions reach 60+ countries, supporting 3,000+ industrial clients and millions of households worldwide. At Litree, water isn’t just our business—it’s our mission. We believe every drop matters, and we’ll keep pushing boundaries to create a future where clean, safe water is a universal right, not a privilege

    Ultrafiltration (UF) Systems
    Membrane Filtration Technologies
    pH Adjustment and Neutralization
    Disinfection Chemicals
    +63 more
    RCI Aquatech logo

    RCI Aquatech

    Verified
    India1-50 employees
    79 technologies4 regions
    1 published asset1 case studies

    Founded in 2009, formerly known as Red Circle Industries (RCI), RCI Aquatech creates custom wastewater solutions based on end users’ requirements, which allow for optimally chosen components resulting in a solution that meets or exceeds customer needs. RCI Aquatech’s wastewater treatment systems combine necessary process technologies to reach required state and federal discharge limits and comply with local regulations. Our systems focus on removal of pollutants such as heavy metals, greases, suspended solids, oils, high salt content, toxic compounds, phosphates and more. Using chemical-physical treatment (coagulation, flocculation, and sedimentation), biological treatment (aerobic and anaerobic) and wet chemical oxidation (persistent or toxic organics). Our expertise comprises the following technologies:  Filtration & softening systems  Physicochemical treatment (coagulation-flocculation)  Membrane filtration (UF & RO)  Ion exchange  Chemical oxidation  Biological treatment  Zero liquid discharge (ZLD) system

    Activated Carbon Filtration
    Microfiltration (MF) Systems
    Reverse Osmosis (RO) Systems
    Nanofiltration (NF) Systems
    +51 more
    Liquid X logo

    Liquid X

    Verified
    United Arab Emirates1-50 employees
    3 technologies1 region

    Liquid X is a water technology consultancy and commercialization platform focused on accelerating the deployment of next-generation filtration solutions, with a core emphasis on graphene-based water treatment. Founded to address the gap between breakthrough innovation and real-world implementation, Liquid X operates at the intersection of advanced material science, water infrastructure, and market deployment. While significant advances in water technologies exist globally, many remain confined to laboratories or early-stage ventures. Liquid X bridges this gap by identifying, validating, and commercializing high-impact solutions—particularly graphene-based filtration systems—within the GCC and wider MENA region. Our consultancy model is built around a full lifecycle approach: from technology scouting and technical evaluation to pilot design, validation, and scaled deployment. We work with asset owners, governments, and enterprises to translate emerging technologies into practical, site-ready solutions. This includes designing pilot programs with measurable performance metrics, enabling data-driven decision-making, and ensuring that innovations are proven under real operating conditions before scale-up. A key focus of Liquid X is the commercialization of graphene-based water filters. Graphene, a two-dimensional material with exceptional strength, permeability, and adsorption capacity, has the potential to fundamentally transform water treatment. Its nano-scale structure allows precise separation of contaminants while enabling faster water flow and lower energy consumption compared to conventional systems. Through strategic partnerships with innovators, researchers, and manufacturers, Liquid X is actively working to bring graphene filtration technologies from concept to market. These systems are being developed to address some of the most critical water challenges, including the removal of PFAS and emerging contaminants, heavy metals, dissolved solids, and industrial pollutants—while significantly reducing waste and energy intensity associated with traditional technologies such as reverse osmosis. Our role extends beyond technology development. Liquid X supports the full commercialization journey, including: Technical due diligence and performance validation Pilot implementation and third-party verification Integration with existing infrastructure Development of scalable deployment models Coordination with EPC contractors, facility managers, and regulators Ongoing monitoring, compliance, and optimization By operating as a vendor-agnostic platform, we ensure that solutions are selected based on performance, suitability, and long-term value—not vendor bias. The MENA region faces some of the world’s most acute water challenges, including scarcity, high desalination dependence, and rising energy costs. Liquid X is positioned to introduce more efficient, decentralized, and sustainable alternatives through advanced filtration technologies. Graphene-based systems, in particular, offer the potential for lightweight, modular, and energy-efficient treatment solutions that can be deployed at scale across residential, commercial, and industrial applications. At its core, Liquid X is not just a consultancy—it is an enabler of the next generation of water infrastructure. By combining deep regional expertise with global innovation networks, we are helping transform how water is treated, distributed, and consumed. Our mission is to accelerate the transition from legacy, resource-intensive systems to smarter, more sustainable water solutions—unlocking the full potential of graphene and other advanced materials to build a more water-secure future.

    Activated Carbon Filtration
    Nanofiltration (NF) Systems
    Point-of-Use (POU) Filtration Systems
    Ion Exchange Systems
    +10 more
    EC Solutions logo

    EC Solutions

    Verified
    United Arab Emiratesfreelance
    1 technologie6 regions

    EC Solutions is a specialized consultancy focused on electrochemical technologies for water and wastewater treatment. We believe electrochemical processes, and electrocoagulation in particular, are among the most promising technologies in the water sector today. As a rule of thumb, anything that can be treated with conventional coagulation–flocculation can be pretreated with electrocoagulation, without adding chemicals. That means less chemical handling, lower sludge complexity, and more controllable treatment outcomes. We help industries evaluate, pilot, and implement electrocoagulation as a robust pretreatment or core process for color removal, heavy metals, TSS, emulsified oils, and complex industrial effluents. If you’re dealing with a difficult water challenge and want a cleaner, smarter alternative to chemical treatment, EC Solutions is built for that.

    Greywater Recycling Systems
    Industrial Process Water Reuse
    Industrial Wastewater Treatment Plants
    Specialized Wastewater Treatment Plants
    +1 more
    SB

    Savino Barbera

    Italy

    Purification/cleaning, Purification Plants, Technical parts for installation, Desalination equipment, Cooling water treatment

    CC

    Cangzhou Changyuan Fittings Co., Ltd.

    China

    Stainless steel -1 way , 2 way,3 way,4 way faucet

    ECO FRESH CARBON logo

    ECO FRESH CARBON

    India

    Building materials, Filters, Filtration other, Purification/cleaning, Purification methods, Purification Plants Show more

    E(

    Emate (Shanghai) Environmental Technology Inc.

    China

    Professional water-purification manufacturer

    NINGBO H O PURIFICATION TECHNOLOGY CORP., LTD. logo

    NINGBO H O PURIFICATION TECHNOLOGY CORP., LTD.

    China

    carbon block/carbon fiber/microbial barrier

    Pentair logo

    Pentair

    Netherlands

    Global partner in sustainable water solutions

    R-

    Rielli - Kazanci Environmental Technics

    Türkiye

    Rielli Water and Waste Water Treatment Plants

    TA

    TEKNIK ARITMA MÜH.MÜS.HIZ.TAAH.TIC VE SAN.LTD.STI

    Türkiye

    Water, Wastewater and Seawater Treatment Systems

    CORSA logo

    CORSA

    Spain

    Water treatment product manufacturer

    HIDROSALUD logo

    HIDROSALUD

    Spain

    Water Treatment company

    Process Selection and Regulatory Compliance in Municipal Sewage Treatment

    Municipal wastewater treatment plant design is governed by a hierarchy of regulatory requirements that flow from the Clean Water Act through NPDES permit conditions to specific technology-based and water quality-based effluent limits. Technology-based effluent limits (TBELs) establish minimum treatment performance—secondary treatment under 40 CFR Part 133 requires BOD₅ removal to 30 mg/L and TSS to 30 mg/L on a monthly average. Water quality-based effluent limits (WQBELs) may be significantly more stringent based on the assimilative capacity of the receiving water, adding nutrient limits (total nitrogen, total phosphorus), toxicity requirements, and temperature constraints.

    Process selection for secondary treatment typically comes down to activated sludge variants, trickling filters (with or without recirculation), and rotating biological contactors for smaller systems. Extended aeration, sequencing batch reactors (SBR), and membrane bioreactors (MBR) offer advantages in footprint, effluent quality, and operational flexibility. MBR systems produce consistently high-quality effluent suitable for reuse applications and eliminate secondary clarifiers, but their higher energy consumption and membrane replacement costs must be weighed against these advantages over the plant's design life.

    Nutrient removal—biological nitrogen and phosphorus removal—has become a near-universal requirement in new and upgraded municipal plants discharging to nutrient-sensitive water bodies. Biological nutrient removal (BNR) process configurations such as A²/O, four-stage Bardenpho, and UCT (University of Cape Town) process achieve nitrogen and phosphorus removal through carefully staged anaerobic, anoxic, and aerobic zones. Chemical phosphorus removal using alum or ferric chloride supplementation provides insurance against biological process upsets but generates additional chemical sludge. Providers experienced in BNR process optimization are essential for plants operating under tight nutrient permit limits.

    Frequently Asked Questions

    What is the difference between secondary and tertiary sewage treatment?

    Secondary treatment removes dissolved and suspended organics through biological processes—activated sludge, trickling filters, or equivalent—achieving typical effluent quality of BOD₅ below 30 mg/L and TSS below 30 mg/L. Tertiary (or advanced) treatment adds one or more additional process steps to meet more stringent effluent requirements: sand or membrane filtration to reduce TSS further, biological or chemical nutrient removal to reduce nitrogen and phosphorus, and disinfection (UV, chlorination) before discharge. Many NPDES permits for discharges to sensitive water bodies now require tertiary or advanced treatment as a baseline standard.

    How do I determine if my activated sludge plant needs biological nutrient removal upgrades?

    Check your current NPDES permit for total nitrogen (TN) and total phosphorus (TP) effluent limits. If TN limits are below 10 mg/L or TP limits are below 1 mg/L, you likely need a biological nutrient removal configuration. If you are approaching permit renewal in a nutrient-impaired watershed, anticipate that these limits will be applied or tightened. Request a feasibility study from a plant design firm evaluating BNR retrofit options for your existing tankage configuration before committing to a full upgrade design.

    What causes bulking in activated sludge and how is it corrected?

    Bulking—poor sludge settling caused by filamentous bacterial overgrowth—raises the sludge volume index (SVI) above 150–200 mL/g and can cause clarifier overflow and permit violations. Filamentous bulking is typically triggered by low dissolved oxygen in the aeration basin, low F/M ratio (extended SRT), nutrient deficiency, or septic influent. Corrective actions include DO aeration adjustment, selective chlorination of the return activated sludge (RAS) to selectively kill filaments, and process control changes to the SRT. A knowledgeable process engineer should diagnose the filament type microscopically before applying corrective measures, as different filaments respond to different interventions.

    What should I evaluate when selecting a design-build contractor for a new wastewater treatment plant?

    Evaluate the contractor's experience with the specific process configuration you require (activated sludge, MBR, BNR), not just general wastewater construction. Review their commissioning track record—ask specifically how many plants have achieved permit compliance within six months of startup and what the most common commissioning challenges were. Confirm that the contractor's process performance guarantee is backed by a financial bond or retention mechanism, and clarify who is responsible for process optimization during the warranty period if the plant struggles to meet permit limits.

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