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    Advanced sewage treatment plant


    Eco-sensitive phosphate, ammonia and nitrate reduction for nutrient neutral sites

    Designed to reduce Phosphate, Ammonia and Nitrates in environmentally sensitive areas, the Marsh Aqua-Puratine system surpasses standards required by Natural England and environmental regulators.

    Supplied as a complete system, combining the EL and G-APS units, the Marsh Aqua-Puratine is available in capacities catering to sites for up to 50 people. The Aqua-Puratine-G-APS (Intelligent Controlled Dosing System) can be integrated with any sewage treatment plant to enhance effluent discharge quality.

    Enabling nutrient neutral development in environmentally sensitive areas

    Combined effluent standards of TNb 18mg/l, Ptot 0.9mg/l

    Extremely low or undetectable chemical residuals in discharge
    (below 0.0139% of total 24hr processing of the effluent)

    How does it work?

    Marsh’s innovative nutrient removal technology combines the Aqua-Puratine:EL and Aqua-Puratine-G-APS systems, revolutionising wastewater treatment. This integrated approach effectively reduces pollutants and nutrients, ensuring compliance with stringent environmental standards.

    The Aqua-Puratine:EL sewage treatment plant employs a multi-stage process. It initiates with primary settlement, allowing solid particles to settle out. Subsequently, aerobic biological treatment occurs in two biozones filled with specialised biofilm support media. This unique media ensures highly efficient nitrification, reducing ammonia concentrations to a mere 1 mg/l in the final effluent. Additionally, simultaneous nitrification and denitrification processes reduce nitrate levels. This system holds accreditation to EN12566-3 Annex B for systems of up to 50 Population Equivalent (PE) and complies with the UK Forward for BSEN12566-3, demonstrating its reliability and effectiveness.

    Complementing this, the Aqua-Puratine-G-APS introduces controlled chemical dosing for phosphate removal in off-mains sewage treatment plants. It’s designed to match chemical infusion precisely with influent phosphate loads, preventing wasteful overdosing. The Aqua-Puratine-G-APS features two chambers for efficient phosphorus removal and biosolids settling.

    The key to the system’s performance lies in its control and automation. Marsh Controls and Marsh Alarms utilise high-quality aeration and dosing timers, ensuring accurate chemical dosing. Monitoring the pumped outlet from the preceding sewage treatment plant guarantees chemicals are dosed appropriately. In instances of gravity discharge, an intermediate pump chamber ensures precise dosing, even when homeowners are absent.

    This innovative approach stands out from continuous dosing systems, which can lead to increased metal concentrations in effluent. The Aqua-Puratine-G-APS adapts dosing based on inflow, ensuring safety for children, wildlife, and the environment. Moreover, it’s energy-efficient, consuming only 1 kWh per day.

    In summary, Marsh’s nutrient removal technology offers an environmentally friendly solution for wastewater treatment, reducing pollutants and nutrients effectively while adhering to strict regulatory standards.

    Effluent standards

    Effluent standards
    Element Aqua-Puratine:EL
    Efficiency (%)
    Effluent (mg/l)
    Efficiency (%)
    Effluent (mg/l)
    COD 92.2 63 57.6 24
    BOD 95.6 14 75.8 2.0
    TNb 53.5 28 11.5 18
    NH4-N 97.8 1.0 21.1 0.4
    Ptot 28.7 5.4 83.7 0.9
    SS 94.5 21 30.4 14
    Accreditation EN12566-3 test Annex B   EN12566-7 test Annex A  

    Operating principle


    Aqua-Puratine:EL key

    1 Inlet
    2 Primary chamber
    3 Biozone 1
    4 Biozone 2
    5 Air diffusers
    6 Final settlement chamber
    7 Submersible pump
    8 Pumped outlet
    9 Internal recirculation
    10 Access covers
    11 Heavy duty GRP shell

    Aqua-Puratine-G-APS key

    12 Inlet
    13 Advanced chemical dosing system
    14 Primary chamber
    15 Air diffuser
    16 Final settlement chamber
    17 Outlet

    Features and benefits

    Comprehensive nutrient removal
    Marsh’s nutrient removal technology combines Aqua-Puratine:EL and Aqua-Puratine-G-APS, providing a holistic solution for reducing pollutants and nutrients, including ammonia, nitrate, phosphate, BOD, and suspended solids.

    Environmental compliance
    This integrated system ensures compliance with strict environmental standards, making it ideal for areas with ‘Nutrient Neutrality’ designations and tight consent to discharge requirements.

    Multi-stage treatment
    Aqua-Puratine:EL employs a multi-stage process, featuring primary settlement, efficient aerobic biological treatment with specialised biofilm media, and denitrification, all in one system.

    Accredited performance
    The Marsh Aqua-Puratine system is fully tested and certified by PIA (Prüfinstitut für Abwassertechnik) in Aachen, Germany. Aqua-Puratine:EL is accredited to EN12566-3 Annex B for systems up to 50 Population Equivalent (PE), attesting to its reliability and effectiveness.

    Precise chemical dosing
    The Aqua-Puratine-G-APS introduces controlled chemical dosing for phosphate removal, ensuring accurate chemical infusion that matches influent phosphate loads, preventing wasteful overdosing.

    Optimised design
    The Aqua-Puratine-G-APS’s two equally sized chambers optimise phosphorus removal and biosolids settling.

    The Aqua-Puratine-G-APS consumes only 1 kWh per day, contributing to energy savings.

    Reduced environmental impact
    By adjusting dosing based on inflow and avoiding continuous dosing, the system minimises metal concentrations in effluent, ensuring safety for the environment, wildlife, and children.

    GSM/3G/4G monitoring
    All Aqua-Puratine:EL and Aqua-Puratine Aqua-Puratine-G-APS combinations feature monitoring alarms to notify Marsh and homeowners in case of faults, ensuring timely maintenance and system integrity.

    Enhanced materials and fire safety
    Marsh glass reinforced plastic (GRP) materials outperform competitors, showing a remarkable 40% increase in strength through rigorous impact testing. Additionally, successful material fire resistance testing meets EN ISO 11925-2:2010 standards.

    Technical downloads for architects, engineers, consultants and specifiers including BIM files (RFA and IFC), DWG CAD files


    Marsh Aqua-Puratine


    Marsh Aqua-Puratine ‘EL certificate’


    Marsh Aqua-Puratine ‘G-APS certificate’


    Installation/technical manual