Measurement of Respiration Activity (AT4)

Respiration Activity Testing (AT4)
At our Ecotechnology Laboratory, we perform AT4 testing using accredited methods to measure the biological activity and biodegradability of waste.

Biological Activity of Waste

We determine AT4 by measuring oxygen consumption over a four-day period. This allows us to evaluate the biological activity of waste materials and determine whether they are suitable for further treatment or landfill disposal in accordance with the Landfill Regulation (Official Gazette 4/2023) and other laws.

Why Testing Matters

AT4 testing plays an important role in:

  • Waste classification, particularly for mechanically and biologically treated waste,
  • Evaluating suitable disposal or recovery methods,
  • Demonstrating legal compliance, including the Landfill Regulation (Official Gazette 4/2023),
  • Planning composting and biological treatment processes.
LANDFILL REGULATION

OUR ADVANTAGE

Our laboratory uses accredited testing methods to deliver accurate assessments of biological activity and provide a reliable basis for safe and compliant waste management.

If you need AT4 testing or would like additional information about the interpretation and application of results, feel free to contact us!

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Laboratory services

Laboratory services

Uzorkovanje otpada, otpadnih materijala i nusproizvoda

Sampling of waste materials and by-products

Uzorkovanje otpadnih voda

Wastewater sampling

Uzorkovanje mulja

Sludge sampling

Ispitivanje neugodnih mirisa metodom perjanice

Odor testing

Measuring the composition of landfill gases

Morphological analysis of waste

Determining biogas / biomethane potential

Determining the biodegradability of waste

Determination of respiratory activity (AT4)

Determination of aerobic bacterial activity (RDRI)

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1. REAL SAMPLE COLLECTION

We collect representative field samples directly at client facilities and analyze them in our accredited laboratory in accordance with recognized standards. Our laboratory testing includes physical, chemical, and biological parameters required to define design input values, including load variability and seasonal or operational fluctuations. These data form the foundation for reliable scaling solutions and technology development.

2. DEVELOPMENT OF TECHNICAL SOLUTIONS

Based on the assessment of existing conditions and laboratory results, we develop technical solutions tailored to each client’s requirements. When designing solutions, we consider plant capacity, influent characteristics, discharge requirements (public sewer systems or natural receiving waters), and circular economy principles. To support detailed process development, our laboratory is equipped with reactors, measuring instruments, and pilot-scale systems that allow us to simulate real operating conditions. Through pilot testing, we evaluate process efficiency, optimize operating parameters, and validate treatment concepts before full-scale implementation. This approach significantly reduces investment and operational risk while ensuring long-term sustainability of the selected solution. We also place strong emphasis on optimizing energy, chemical, and resource consumption while minimizing the plant’s environmental footprint throughout its lifecycle.

3. ENGINEERING DESIGN AND PERMITTING

Our multidisciplinary engineering team prepares complete project documentation, from conceptual designs and feasibility studies to detailed engineering documentation and permit applications. All documentation is developed in accordance with current legislation, technical regulations, and applicable standards while maintaining close coordination with clients and regulatory authorities.

4. PLANT ENGINEERING AND INSTALLATION – Complete turnkey plant implementation proposal, including detailed design documentation and commissioning services

We deliver turnkey treatment plants tailored to each client’s needs. Our services include detailed engineering design, equipment procurement and delivery, site organization, installation of process and electrical equipment, and integration of automation and control systems. The final stage includes functional testing and preparation for plant commissioning.

5. CONSTRUCTION SUPERVISION

We provide professional technical supervision during construction to ensure full compliance with project documentation, technical standards, and contractual requirements. We monitor construction quality, installed equipment, and adherence to project timelines.

6. PLANT COMMISSIONING AND STAFF TRAINING

After construction and functional testing are complete, we perform staged commissioning with continuous monitoring of process parameters and adjustment of operating conditions. We also prepare operational manuals and provide professional staff training to ensure safe, efficient, and long-term stable plant operation.

7. POST-CONSTRUCTION TESTING

After project completion, we perform functional and other tests to verify that the treatment plant achieves the required operational parameters and effluent quality.

8. PLANT SERVICE AND MAINTENANCE

We provide preventive and corrective maintenance, scheduled service inspections, and 24/7/365 technical support. Our systematic maintenance approach extends equipment lifespan, minimizes downtime risk, and ensures high operational efficiency.

9. PLANT MONITORING AND OPERATIONAL CONTROL

We implement SCADA and PLC automation and control systems that enable continuous plant monitoring, analysis of key process parameters, and rapid response to operational deviations or fluctuations in wastewater flow and loading. We place particular emphasis on reducing energy, chemical, and labor consumption.

10. PLANT OPTIMIZATION AND RECONSTRUCTION

We perform technical assessments of existing systems to identify capacity limitations, energy losses, and operational inefficiencies. Based on our findings, we recommend retrofits, upgrades, and modernization of technological process lines to improve efficiency, ensure compliance with new regulatory requirements, and extend plant service life.