By Challenge / Contaminant

    Pathogen Removal & Disinfection Companies

    Multi-barrier pathogen removal, filtration, UV, chlorine, ozone, and membranes for bacteria, viruses, and cysts.

    20 providers

    This page is a good fit if you need:

    • Granular Activated Carbon (GAC) Filters or Cartridge Filters capabilities
    • Suppliers with manufacturing sector experience
    • Providers operating in United Kingdom or China
    Providers
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    Ecosystems International logo

    Ecosystems International

    Verified
    Indonesia51-200 employees
    Flat Sheet Microfiltration Units · Hollow Fiber MF Systems · Ceramic Microfiltration Modules +80 more
    apac · china · europe +3 more

    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
    +63 more
    agriculture
    manufacturing
    Devram International logo

    Devram International

    Verified
    India1-50 employees
    Granular Activated Carbon (GAC) Filters · Fixed Bed Activated Carbon Adsorbers · Powdered MOF Adsorbent Systems +19 more
    apac · mea

    DEVRAM INTERNATIONAL, headquartered in Surat, India, is a pioneering enterprise specializing in Snow and Rainwater Management with advanced contamination reduction abilities for storage and artificial groundwater recharge. Established as the commercial wing of Shree Someshwar Education Trust (SSET), DEVRAM INTERNATIONAL is driven by a mission to provide tech-enabled, nature-based solutions that address the world’s most pressing water and climate challenges. The company’s work integrates Integrated Water Resources Management (IWRM) principles and contributes across the source-to-sea water management cycle, ensuring holistic restoration of the global water cycle. Its innovative portfolio includes rainwater harvesting systems, stormwater management, aquifer recharge, artificial glaciers, desert trenches, rooftop water filtration, and green infrastructure models. These interventions directly reduce salinity in soils and aquifers, restore ecological balance, and enhance resilience to droughts, floods, and climate change. As the commercial promoter of the Global Rainwater Management Program (GRMP), DEVRAM INTERNATIONAL advances the vision of GRMP as a Global Common Minimum Program (GCMP) for nations and international bodies. GRMP demonstrates how rainwater and snowwater retention can restore entire natural cycles, while delivering unmatched benefits across the Sustainable Development Goals (SDGs). Alignment with the SDGs • SDG 2 (Zero Hunger): By reducing soil salinity, supporting organic farming, and ensuring water availability for agriculture, GRMP safeguards food security. • SDG 6 (Clean Water & Sanitation): DEVRAM’s recharge structures and contamination reduction technologies guarantee safe, sustainable drinking water for communities. • SDG 7 (Affordable & Clean Energy): By reducing dependency on energy-intensive desalination, GRMP lowers national energy bills and improves hydropower capacity. • SDG 9 (Industry, Innovation & Infrastructure): DEVRAM integrates nature-based water infrastructure with industrial operations, reducing OPEX and water footprints. • SDG 11 (Sustainable Cities & Communities): Through stormwater management and aquifer recharge, GRMP mitigates urban flooding and secures municipal supplies. • SDG 12 (Responsible Consumption & Production): Promotes a circular water economy, reusing wastewater, biogas from organic waste, and aligning with industrial CSR. • SDG 13 (Climate Action): By lowering GHG emissions and cooling local climates through water cycle restoration, GRMP strengthens resilience to global warming. • SDG 14 (Life Below Water): Free-flowing rivers, improved aquaculture, and reduced dam-related aquatic pollution support marine and freshwater ecosystems. • SDG 15 (Life on Land): DEVRAM’s interventions restore wetlands, mangroves, peatlands, and biodiversity-rich ecosystems, addressing land degradation. • SDG 17 (Partnerships for the Goals): The company actively collaborates with UN agencies, governments, World Bank programs, and private investors to scale GRMP globally. Founders and Leadership Dhaval Pandya, Co-Founder of DEVRAM INTERNATIONAL and CEO of SSET, is a globally recognized sustainability leader. He co-developed the Global Rainwater Management Program (GRMP), recognized by the United Nations Global Water Partnership (GWP) and the Government of India. As a Technical Committee Member (WRD03) of the Bureau of Indian Standards (BIS), he contributes to national water policy frameworks. His work is featured in UNCCD IWRM Action Hub and global forums like COP, Stockholm World Water Week, and World Bank SDG reviews. Manalika Pandya, Co-Founder, plays a critical role in embedding social, gender, and educational dimensions into GRMP. Her focus on women empowerment, local capacity building, and community-driven adoption ensures the program’s sustainability at the grassroots. Impact and Recognition DEVRAM INTERNATIONAL has piloted groundbreaking projects such as: Kawas Village (Gujarat, India): A GRMP model village achieving self-reliance in water, organic farming, and biogas, while resolving conflicts with industries. Delhi’s Water Paradox (Figshare Study): Shows how GRMP can solve megacity water crises without costly desalination or dams. GSECL Surat Project: Demonstrates reduced industrial water costs through GRMP recharge planning, aligning profitability with SDG and ESG goals. These projects show GRMP’s potential to reduce industrial and municipal water supply costs by up 60%, avoid massive investments in desalination and dams, and enable nations to achieve water sovereignty. Core Competencies • Rainwater & Snowwater Harvesting • Artificial Groundwater Recharge & Salinity Reduction • Stormwater Management & Urban Flood Control • Transboundary Water Cooperation • IWRM & Source-to-Sea Water Governance • AI-Enabled Hydrological Modelling & Policy Analytics • Environmental Services Restoration (Wetlands, Mangroves, Peatlands) • Circular Economy.

    Activated Carbon Filtration
    Granular Activated Carbon (GAC) Filters
    Multi-media Filtration (MMF) Systems
    +25 more
    manufacturing
    utilities
    Brine Consulting logo

    Brine Consulting

    Verified
    Netherlands1-50 employees
    Mechanical Vapor Recompression (MVR) · Atmospheric Evaporator · Spray Evaporator +130 more
    apac · china · europe +3 more

    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
    +85 more
    manufacturing
    energy-production
    Hainan Litree Water Purification Technology Industry Co., Ltd. logo

    Hainan Litree Water Purification Technology Industry Co., Ltd.

    Verified
    China200+ employees
    Tubular Ultrafiltration Units · Hollow Fiber UF Modules · Flat Sheet UF Membranes +17 more
    apac · china · europe +3 more

    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
    +64 more
    agriculture
    manufacturing
    Liquid X logo

    Liquid X

    Verified
    United Arab Emirates1-50 employees
    Granular Activated Carbon (GAC) Filters · GO–Polymer Composites · Cartridge Filters
    mea

    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
    +11 more
    food-beverages
    hospitality-tourism
    Evergreen Water Solutions logo

    Evergreen Water Solutions

    United Kingdom

    A leading supplier of progressive wastewater treatment systems Evergreen Water Solutions works closely with a number of international engineering companies whose expertise are in scalable wastewater treatment systems and containerised wastewater treatment systems for municipal and industrial application. Evergreen Water Solutions offers a comprehensive engineering service. Our company incorporates initial design and planning, to implementation of projects that are delivered on time and on budget. Our expertise in wastewater treatment covers infrastructure development, package sewage treatment systems and advanced treatment technology for wastewater recycling with the strictest treatment requirements. The goal of Evergreen Water Solutions is to exceed the expectations of our clients, foster long-term relationships, and make a positive impact on the environment and industry standards. Evergreen Water Solutions use innovative products and suppliers to source, design and implement leading environmental water and wastewater treatment products and solutions. All new equipment and suppliers are required to undergo pre-qualification program and a series of acceptances and trials are applied prior to the approval of the vendor. Evergreen Water Solutions’ pre-qualification program guarantees you our clients that the products we source are of the highest standard within the industry, these products along with the expertise within Evergreen Water Solutions ensures that the solution we provide will meet and exceed any expectation you might have.

    Treatment Works Products/Services
    Contractors
    RCI Aquatech logo

    RCI Aquatech

    Verified
    India1-50 employees
    Mechanical Vapor Recompression (MVR) · Multiple Effect Evaporator (MEE) · Atmospheric Evaporator +76 more
    apac · europe · latam +1 more
    1 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
    +52 more
    manufacturing
    chemicals-pharmaceuticals
    EC Solutions logo

    EC Solutions

    Verified
    United Arab Emiratesfreelance
    Conventional EC
    apac · china · europe +3 more

    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
    +2 more
    manufacturing
    food-beverage
    Medio Industries Private Limited logo

    Medio Industries Private Limited

    Verified
    India1-50 employees
    Granular Activated Carbon (GAC) Filters · Ion Exchange · Multimedia Filters +1 more
    mea · apac

    MEDIO is committed to the installation and servicing of water filtration systems and purifiers. Our initial venture into the water filtration industry began with Kent Water Purifiers and later expanded to encompass whole-house filtration systems and, subsequently, commercial ranges. As a company, MEDIO consistently stays abreast of the latest technologies, filtration methodologies, and advanced filtration mediums. This proactive approach has enabled us to build a robust network with multiple sales and service points. We uphold the principle of providing "Value for Money," prioritizing customer requirements. This customer-centric policy has cultivated significant trust, resulting in repeat orders and referral sales. Our continuous investment in training our staff in sales and operations reflects our commitment to achieving the desired work quality. We view quality as a habit and dedicate our utmost efforts to manifest it in both our products and services. Mission: Our goal is to achieve industry leadership in water filtration products by capturing the majority of the Iron removal medium market in India. Additionally, we aim to pioneer the introduction of energy efficient and water-saving filtration products that enhance water quality and minimize wastage.

    energy-production
    manufacturing
    PNR ITALIA Srl logo

    PNR ITALIA Srl

    Verified
    Italy51-200 employees
    Spray Evaporator · Self-cleaning Screen Filters
    apac · europe · latam +2 more
    19 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
    +7 more
    agriculture
    manufacturing
    Amazon Filters Ltd logo

    Amazon Filters Ltd

    United Kingdom

    Founded in 1985, UK-based Amazon Filters Ltd is one of Europe’s leading manufacturers and suppliers of bespoke filtration technology such as filter cartridges and housings. Our comprehensive range of products support critical liquid and gas applications in many industries. With over 40 years of continuous support to municipal water companies, we are ideally placed to solve water quality problems with our bespoke cartridge filtration technology. From small boundary boxes installations to large volume fully containerised system and rentable mobile skids, we can manufacture and supply it all. We offer solutions for: Turbidity Control Metals Removal (iron / manganese) Cryptosporidium removal Chlorine reduction Let us support your AMP 8 commitments: Securing Long Term Resilience Securing Cost Efficiency Securing Confidence and Assurance We operate a range of ISO-accredited Quality Management Systems to ensure excellence in customer service. We provide high quality, reliable products and services that exceed client expectations. We help you worry less about the filtration process so you can focus on what you do best.

    Accreditations
    EMS Industries Ltd logo

    EMS Industries Ltd

    United Kingdom

    EMS are a UK based manufacturer of positive displacement ram pumps and grit removal solutions used traditionally in the wastewater industries but also in the food waste (AD) sector. EMS Industries was established in 1995 and has since grown into a world-renowned name for providing robust, reliable products which have provided our substantial client list with many years of trouble free service. All EMS products are designed, manufactured and tested in our Stoke on Trent operational facilities where we can also offer additional services including spare parts, service and repairs, installation, commissioning, operator training packages and full CAD and 3D modelling services. As a framework provider to some of the major UK utility companies, we ensure that our products meet with all current legislation and continually strive to provide innovative products to the market place.

    Treatment Process Technologies
    Hydro International logo

    Hydro International

    United Kingdom

    Hydro International, a CRH company,  provides advanced products, services and expertise to help municipal, industrial and construction customers to improve their water management processes, increase operational performance and reduce environmental impact. Hydro International can help water companies meet their AMP and environmental obligations, including the reduction of sewer overflows and the Water Industry National Environment Programme (WINEP). Hydro International provides total solutions for Inlet Works, Combined Sewer Overflows (CSOs), Stormwater Management, Flood Warning and Prevention, and Water Resource management, from design to supply and installation through to ongoing preventative maintenance, servicing and emergency repair.  These solutions include: Hydrometric data collection, monitoring analysis and reporting for river level, reservoir, network and weather. Continuous water quality monitoring for compliance with Section 82 of the Environment Act. Water resource analysis and consultancy. Stormwater management solutions, including options for Sustainable Drainage Systems. (SuDS) and Smart Maintenance. CSO event duration monitoring. CSO and storm tank treatment and screening. Passive flow controls for flood prevention schemes, SuDS, CSOs and WwTWs. Inlet works screening and grit removal solutions. Sludge screening. Dropping sewage or water safely from height. Hire, repair and maintenance of inlet works screens and screenings handling equipment

    Networks - Sewerage
    Asset Maintenance & Rehabilitation
    Te-Tech Process Solutions logo

    Te-Tech Process Solutions

    United Kingdom

    Te-Tech Process Solutions is a provider of traditional products and advanced process technologies for water and wastewater treatment. Our products cater for a range of client needs from standardised products to bespoke applications designed to meet the exacting needs of the client’s process. Our in-house capability includes process, mechanical and electrical design, off-site manufacture and assembly, MCC and Control Panel Manufacture and System Integration. Our extended services include digital engineering, service and maintenance, operational support and real time control. Advanced technology and innovation are at the core of our business enabling us to provide high quality, efficient solutions to our clients. Our business is founded upon 4 key areas of expertise: WATER & WASTEWATER TREATMENT Te-Tech deliver established water and wastewater products and processes, including: te-cyc TM: Cyclic activated sludge ‘Macrofloc’ biological wastewater treatment te-saf TM: Packaged submerged aerated filters te-ion TM: Advanced oxidation technology for water and wastewater treatment te-mem TM: Advanced membrane filtration te-mbr TM: Package advanced membrane filtration te-sewpas TM: Airlift sludge removal plant te-uv TM: UV disinfection AUTOMATION CONTROL & TECHNOLOGY Our MCC and control panels are provided into multiple sectors including process and water, marine, oil & gas, energy, nuclear, defence and building services. Our capabilities include: MCCs LV Switchboards Local Control Panels Software System Integration DIGITAL ENGINEERING Te-Tech utilise cutting edge digital technologies to provide innovative solutions to our client’s problems. Our digital engineering services support the whole life cycle of our clients’ assets from conceptual design, through design for manufacture and assembly (DfMA), installation on site, final commissioning, operation and maintenance and decommissioning at the end of the asset’s life. Our in-house software capability provides clients with the visualisation tools to precisely view and interrogate designs in a virtual world to minimise clashes, delays or abortive activities and to ensure that the delivered assets are acceptable to operators in the real world. Our BIM capability ensures our products and technologies create assets that are fit for the future and our virtual reality technology allows our teams and clients to fully immerse themselves in the design, optimisation and operation of our solution prior to manufacturing. Our asset optimisation capability helps clients get the best performance out of their assets, by integrating real time control and using data driven insight we can ensure the sustainability and efficiency of asset performance across its lifecycle. Our virtual environment shows the equipment in operation, with liquids moving and plant turning on/off according to the actual system control philosophy. This is an invaluable tool for HAZOPS, ALM and remote training of operators before the plant is constructed – reducing risk and time on site OFF-SITE MANUFACTURING & ASSEMBLY Te-Tech’s off-site manufacture and assembly capability provides standard products and engineered solutions to the water and wastewater sector, oil and gas and energy industries. Its primary focus is on solutions which are designed for manufacture and assembly DfMA; reducing on site construction time, reducing carbon footprint and minimising risk. At our Southampton based headquarters we have over 1000 sq. metres of internal manufacturing space as well as external areas for assembly and storage of larger materials and manufactured components. We design, manufacture and assemble to a range of different standards including CE/CA marking, EXC2 Structural Steel, BS and ASME welding procedures. Our strength within Te-Tech culminates in our integrated service, offering the complete process solution package, from digital design, automation and control through to off-site manufacture and on site assembly.

    Treatment Process Technologies
    Contractors

    Pathogen Removal in Water Treatment: Log Reduction Targets, CT Values, and Multi-Barrier Design

    Pathogen removal and inactivation in drinking water treatment uses a multi-barrier approach combining physical removal (coagulation, sedimentation, filtration) and chemical or UV inactivation (disinfection). US EPA Surface Water Treatment Rule (SWTR) requires: 3-log (99.9 percent) Giardia removal/inactivation, 4-log (99.99 percent) virus removal/inactivation, and 2-log (99 percent) Cryptosporidium removal (LT2ESWTR). Physical removal credit: conventional treatment (coagulation-sedimentation-filtration) = 2.5-log Giardia, 2.0-log virus, 3.0-log Cryptosporidium credit. Remaining credit must come from disinfection. Direct filtration (no sedimentation) = 2.0-log Giardia, 1.0-log virus, 2.5-log Cryptosporidium. Membrane filtration (UF/MF, direct integrity testing) = 4.0-log Giardia and Cryptosporidium.

    Disinfection CT (concentration times contact time, mg per L times minutes) required for inactivation credits at specific pH and temperature conditions. Free chlorine for 1-log Giardia inactivation (7 degrees C, pH 7.0): CT = 65 mg per L-min; 1-log virus (7 degrees C, pH 7.0): CT = 2 mg per L-min. Free chlorine for 3-log Giardia at pH 7, 15 degrees C: CT approximately 78 mg per L-min; a system with 1.5 mg per L free chlorine and 52-minute contact time achieves this. Cryptosporidium is chlorine-resistant (3-log inactivation requires CT above 7,200 mg per L-min - impractical); UV at 40 mJ per cm2 achieves 3-log Cryptosporidium inactivation (US EPA UVDGM). Ozone for 3-log Cryptosporidium: CT = 5 to 20 mg per L-min depending on temperature.

    UK Drinking Water Inspectorate (DWI) and WHO Guidelines use a different framework for E. coli (less than 0 per 100 mL, absolute standard), Cryptosporidium (Regulations 2000: all surface water treatment works must have a 3 to 6-log reduction standard based on catchment risk assessment under the Cryptosporidium Risk Assessment programme), and Regulation 28 (requiring risk assessment and monitoring for Cryptosporidium and Giardia at all surface water sources). WHO QMRA (Quantitative Microbial Risk Assessment) methodology calculates the required log reduction based on source water pathogen concentration and tolerable disease burden (10 to the -6 disability-adjusted life years (DALYs) per person per year for acceptable risk level).

    Frequently Asked Questions

    What is the most effective disinfectant for drinking water?

    No single disinfectant is best for all pathogens and situations. Chlorine (free): widely used, cost-effective, provides residual in distribution, effective against bacteria and viruses (CT 2 to 10 mg per L-min for 4-log virus); poor against Cryptosporidium (CT 7,200 mg per L-min). Chloramine (combined chlorine): weaker primary disinfectant but more stable residual in distribution (persists for days vs hours for free chlorine); less prone to forming trihalomethanes and haloacetic acids (DBPs). UV (254 nm, 40 mJ per cm2): no DBP formation, effective against Cryptosporidium (3-log), Giardia (3-log), and viruses (4-log); no distribution residual (used at plant, chlorine applied for residual). Ozone: most powerful primary disinfectant, effective against all pathogens, no DBP formation from NOM (but bromate risk if bromide present); no distribution residual. Best practice: multi-disinfectant systems (ozone or UV for primary inactivation, chloramine for distribution residual) provide the broadest pathogen coverage.

    What does 4-log virus removal mean?

    4-log removal means a 99.99 percent reduction in virus concentration, or a 10,000-fold reduction. A source water containing 100 viruses per litre would contain 0.01 viruses per litre (1 virus per 100 litres) after 4-log removal. US EPA SWTR requires 4-log virus removal/inactivation for all public water systems using surface water. Log removal (LRV) is additive across treatment barriers: coagulation-sedimentation-filtration credit 2.0 LRV + chlorination CT providing 2.0 LRV total = 4.0 LRV. Log reduction is measured in challenge testing using MS2 bacteriophage (surrogate for human enteric viruses) with membrane filtration and UV systems certified to specific LRV at worst-case operating conditions. WHO QMRA targets for virus risk: Norovirus from contaminated source water should achieve 6 to 9 LRV to meet 10 to the -6 DALY per person per year risk target depending on source virus load.

    Why is Cryptosporidium difficult to remove from drinking water?

    Cryptosporidium parvum and C. hominis are protozoan parasites with oocysts (infective stage, 4 to 6 micron spheres) that have three properties making them particularly challenging: (1) Chlorine resistance - oocysts have a thick, multi-layered wall that prevents chlorine penetration; at practical water treatment chlorine doses (0.5 to 2 mg per L), Cryptosporidium oocysts survive intact indefinitely; 3-log inactivation requires CT above 7,200 mg per L-min - impractical in drinking water; (2) Small size - at 4 to 6 microns, oocysts can pass through poorly functioning or damaged sand filters but are retained by properly coagulated and settled water followed by filtration; (3) Low infective dose - as few as 10 to 100 oocysts can cause cryptosporidiosis; even 2-log treatment failures can result in public health incidents (Milwaukee 1993: 403,000 people sickened). Effective barriers: coagulation-filtration (3-log physical removal credit), UF/MF membranes (4-log absolute barrier), ozone (5 mg per L-min CT gives 3-log), and UV (40 mJ per cm2 gives 3-log).

    How is disinfection effectiveness monitored at a water treatment plant?

    Disinfection performance monitoring uses multiple measures: (1) CT compliance - continuous measurement of disinfectant residual concentration (amperometric analyser for free chlorine, accuracy plus or minus 0.05 mg per L; UV intensity sensor for UV dose, accuracy plus or minus 5 percent) times hydraulic contact time (calculated from tracer study T10 divided by T, the time for 10 percent of a tracer pulse to appear at the outlet); log-inactivation credit claimed only when CT exceeds the required value for the temperature and pH measured; (2) Turbidity - continuous turbidity monitoring before disinfection (target below 0.3 NTU pre-disinfection per US EPA, below 0.1 NTU per enhanced filtration guidance); high turbidity interferes with UV disinfection (particles shield microorganisms) and chemical disinfection (demand); (3) Microbiological compliance monitoring - daily E. coli samples from treated water, weekly coliform counts, and quarterly Cryptosporidium and Giardia monitoring per site-specific DWI or EPA requirement.

    Case Study·UK water company, upland surface water supply, Wales
    Challenge

    A DWI Cryptosporidium risk assessment rated a surface water source as high risk following the detection of 10 to 80 oocysts per 10 litres during winter flood events. The existing treatment train (coagulation, sedimentation, dual-media filtration, chlorination) could not reliably demonstrate 6-log Cryptosporidium reduction required by the risk assessment outcome, and chlorination alone provided negligible Cryptosporidium inactivation.

    Approach

    A medium-pressure UV system (four UV reactors, 30 MLD each, validated at 40 mJ per cm2 for 3-log Cryptosporidium credit) was installed downstream of filtration. The hydraulic contact model was validated by tracer testing. UV dose monitoring sensors were calibrated against a NIST-traceable reference lamp. Turbidity interlocks prevented UV credit from being claimed when pre-UV turbidity exceeded 0.5 NTU.

    Outcome

    DWI accepted the UV installation as providing 3-log Cryptosporidium inactivation credit, achieving the required 6-log barrier when combined with coagulation-filtration. No Cryptosporidium-related compliance events occurred in the 3 years following commissioning. UV energy consumption was 0.03 kWh per m3, adding 30,000 GBP per year to energy OPEX for the 30 MLD plant.

    Questions to Ask Shortlisted Providers

    1. 1

      What Cryptosporidium risk assessment has been completed and what log reduction target does the DWI require for this site?

      The required LRV determines the treatment barrier needed; the risk assessment framework under Cryptosporidium Regulations 1999 sets site-specific targets that govern UV dose and system design.

    2. 2

      What is the pre-disinfection turbidity and how is it monitored to ensure CT credit is valid?

      High turbidity reduces UV transmittance and chlorine CT credit; interlock logic must prevent credit being claimed outside the validated turbidity range.

    3. 3

      How will CT be calculated and documented for regulatory purposes and what tracer test will validate the hydraulic model?

      Regulatory CT credit requires a validated T10/T baffling factor established by a USEPA or DWI-accepted tracer methodology; this must be re-validated after any hydraulic modification.

    4. 4

      What UV validation protocol was used and what was the validated dose at worst-case UVT and flow?

      UV reactor validation must follow an approved protocol (DVGW W294, USEPA UV Disinfection Guidance Manual, or equivalent); the validated dose at minimum UVT and maximum flow is the credited dose.

    5. 5

      What chlorine residual is targeted at the site boundary and furthest point of the distribution system?

      DWI requires a maintained residual of 0.05 to 0.5 mg per L free chlorine in distribution; the disinfection design must confirm adequate residual at the hydraulically worst-case point.

    What Drives Cost in This Category

    UV system capacity and number of reactors

    Medium-pressure UV reactors for 10 to 50 MLD cost 200,000 to 800,000 GBP each installed; lamp replacement (every 12 to 18 months) adds 10,000 to 50,000 GBP per reactor per cycle.

    Chlorination infrastructure and chemical supply

    Bulk sodium hypochlorite storage and dosing systems cost 50,000 to 250,000 GBP; sodium hypochlorite at current market prices of 0.15 to 0.30 GBP per litre at 12 percent concentration adds 30,000 to 120,000 GBP per year for a 30 MLD plant at 1 mg per L dose.

    CT compliance monitoring instrumentation

    Continuous chlorine analysers (amperometric, 0 to 5 mg per L, 2-stream duty-standby) cost 15,000 to 40,000 GBP per installation point; UV intensity monitors, turbidity analysers, and flow meters add further capital and calibration OPEX.

    DWI approval and independent verification costs

    DWI approval for new disinfection technology requires independent expert review, validated performance data, and ongoing monitoring; total regulatory process adds 50,000 to 150,000 GBP and 6 to 24 months to the project programme.

    Key Regulations & Standards

    Water Supply (Water Quality) Regulations 2016 Schedule 1 (E. coli, Cryptosporidium)

    Require E. coli to be zero per 100 mL in all treated water samples; Cryptosporidium oocysts must be managed through DWI-approved treatment barriers as determined by the Cryptosporidium Risk Assessment programme.

    Cryptosporidium in Water Supplies Regulations 1999 (SI 1999/1524)

    Require risk assessment and monitoring of all surface water sources in England and Wales; treatment standard (log reduction requirement) is set by the DWI-approved risk assessment methodology for each site.

    DWI Guidance on UV Disinfection (2010 and supplements)

    Sets validation requirements for UV reactor credit in English and Welsh water supplies; validated dose at worst-case UVT and flow must be demonstrated using DVGW W294, NWRI/AWWA, or equivalent validated protocol.

    WRAS / DWI Approved Products List (APL)

    All disinfectant chemicals and UV equipment in contact with treated water must appear on the APL or receive individual DWI approval; sodium hypochlorite suppliers must be WRAS-approved.