Hach BODTrak™ Biochemical Oxygen Demand (BOD) Analyzer

Overview

The Hach BODTrak™ Biochemical Oxygen Demand (BOD) Analyzer is an automated, manometric laboratory instrument engineered for precise and reproducible determination of biochemical oxygen demand in water and wastewater samples. It operates on the well-established pressure-difference principle—measuring the consumption of dissolved oxygen during microbial oxidation of organic matter under controlled aerobic conditions. Unlike conventional dilution-and-inoculation methods requiring manual titration after 5-day incubation, the BODTrak™ system continuously monitors headspace pressure changes in sealed test bottles. As microorganisms metabolize biodegradable organics, O₂ is consumed from the gas phase above the sample; simultaneously, CO₂ produced is chemically absorbed by lithium hydroxide (LiOH) embedded in the bottle cap. This creates a direct, linear correlation between the net pressure drop and the mass of oxygen consumed—enabling real-time calculation and display of BOD concentration (mg/L) without chemical reagents or endpoint titrations.

Key Features

• Manometric measurement with high-resolution pressure transducers calibrated for trace-level O₂ depletion detection (detection limit: 0.05 mg/L)
• Multi-range auto-ranging capability: four selectable full-scale ranges (0–35, 0–70, 0–350, and 0–700 mg/L BOD) to accommodate diverse sample matrices without manual dilution for concentrations ≤700 mg/L
• Six independent test stations enabling parallel analysis of up to six samples per run
• Programmable incubation durations: 5-day, 7-day, or 10-day protocols compliant with standard regulatory timelines (e.g., ASTM D5210, ISO 5815-1, APHA 5210B)
• Automated data acquisition at 15-minute intervals—generating time-series BOD profiles and supporting kinetic assessment of biodegradation rates
• Integrated microprocessor control with LCD interface for real-time display of current BOD value, elapsed time, and remaining incubation period
• Onboard memory storing up to 480 timestamped data points per instrument session
• Robust thermal management ensuring stable 20 °C incubation environment (±0.5 °C), critical for method-compliant BOD testing

Sample Compatibility & Compliance

The BODTrak™ analyzer accommodates standard 473 mL BOD test bottles with integrated LiOH scrubber caps, compatible with both raw and treated municipal, industrial, and surface water samples. Its design conforms to core regulatory frameworks governing BOD analysis: it supports compliance with U.S. EPA Method 405.1 (as referenced in 40 CFR Part 136), ASTM D5210-22 (“Standard Test Method for Determining Anaerobic Biodegradation of Plastic Materials”), and ISO 5815-1:2019 (“Water quality — Determination of biochemical oxygen demand after n days (BOD_n) — Part 1: Dilution and inoculation method”). While the instrument itself does not require GLP/GMP validation out-of-the-box, its audit-ready data logging—including timestamps, range selection, and final reported values—facilitates integration into laboratories operating under ISO/IEC 17025 or FDA 21 CFR Part 11–aligned quality systems when paired with appropriate procedural controls.

Software & Data Management

Data export and long-term archiving are enabled via HachLink™ PC software (Windows-compatible), which establishes USB communication with the instrument. HachLink™ allows users to download complete datasets—including all 15-minute interval readings, final BOD results, incubation settings, and instrument ID—for reporting, trend analysis, and regulatory submission. The software supports CSV and Excel-compatible output formats and permits annotation of sample IDs, operator names, and project metadata. All stored records include immutable timestamps and are retained until manually overwritten—ensuring traceability and alignment with basic data integrity requirements under ALCOA+ principles (Attributable, Legible, Contemporaneous, Original, Accurate).

Applications

• Wastewater treatment plant performance monitoring (influent, effluent, and sludge supernatant BOD tracking)
• Environmental compliance reporting for NPDES and discharge permit renewals
• Research on biodegradability kinetics of emerging contaminants (e.g., pharmaceuticals, surfactants, microplastics)
• Validation of biological treatment efficiency in pilot- and full-scale bioreactors
• Academic and teaching laboratories requiring rapid, hands-on BOD methodology instruction
• Industrial pretreatment verification for food processing, pulp/paper, and textile facilities

FAQ

How does the BODTrak™ eliminate the need for sample dilution in most cases?
It offers four programmable measurement ranges up to 700 mg/L—covering typical municipal wastewater BOD levels without dilution. Only samples exceeding 700 mg/L require pre-dilution per standard practice.
Is temperature control built into the instrument?
Yes—the BODTrak™ incorporates an integrated thermostatically regulated incubation chamber maintaining 20.0 °C ±0.5 °C, eliminating reliance on external water baths or incubators.
Can historical data be retrieved after power loss?
All measurements are non-volatile: 480 data points remain stored in onboard memory even after power interruption or shutdown.
Does the system support multi-day unattended operation?
Absolutely—the instrument autonomously executes user-defined incubation periods (5/7/10 days), logs data every 15 minutes, and halts automatically upon completion without operator intervention.
What consumables are required beyond the test bottles and LiOH caps?
No additional reagents, titrants, or sensors are needed. The pressure transducers are solid-state and maintenance-free over the instrument’s service life.