Hach BODTrak II Biochemical Oxygen Demand Analyzer

Overview

The Hach BODTrak II is a laboratory-grade biochemical oxygen demand (BOD) analyzer engineered for precision, regulatory compliance, and operational efficiency in water quality laboratories. It employs the manometric (pressure-difference) measurement principle—fully aligned with Standard Methods 5210B and ASTM D5210—to quantify the amount of dissolved oxygen consumed by aerobic microorganisms during the biodegradation of organic matter in aqueous samples over a defined incubation period (typically 5 days, though real-time monitoring supports shorter assessments). Unlike traditional dilution-and-seed methods, the BODTrak II eliminates manual titrations, reagent handling, and volumetric transfers. Instead, it seals each sample in a calibrated 473 mL BOD bottle fitted with a KOH-saturated absorbent pad to chemically remove CO₂; as microbes consume dissolved oxygen, the resulting pressure drop in the headspace is detected by a high-stability piezoresistive sensor. This pressure change is linearly correlated to oxygen consumption and converted directly into BOD concentration (mg/L O₂) using embedded calibration coefficients traceable to NIST standards.

Key Features

• Six independent, parallel measurement channels—enabling simultaneous analysis of up to six samples without cross-contamination or timing interference
• Real-time graphical display showing dynamic BOD accumulation curves with interactive cursor for precise time-point interrogation (e.g., BOD₂, BOD₃, BOD₅)
• Integrated microprocessor-controlled temperature regulation maintaining 20 °C ±0.5 °C across all channels—critical for adherence to ISO 5815-1 and EPA Method 405.1
• Automatic data logging at user-selectable intervals (1–60 minutes); stores 480 time-stamped data points per sample for full audit trail reconstruction
• Self-calibrating pressure transducer with zero-drift compensation—ensuring long-term stability without routine field recalibration
• Auto-shutdown after completion of incubation cycle; configurable alarm thresholds for abnormal pressure trends or temperature excursions
• Compact benchtop footprint (28.9 × 26.0 × 9.8 cm) designed for space-constrained QC labs and mobile environmental testing units

Sample Compatibility & Compliance

The BODTrak II accommodates standard 473 mL glass BOD bottles conforming to ASTM D888 and APHA specifications. It is validated for use with municipal wastewater, industrial effluents (including high-BOD food processing and pulp/paper discharges), surface water, groundwater, and treated drinking water sources. All measurements comply with U.S. EPA approved methods (40 CFR Part 136), ISO 5815-1:2019, and EN 1899-1. The instrument’s data integrity architecture supports GLP and GMP environments: timestamps, operator IDs, and method parameters are embedded in each data file, satisfying FDA 21 CFR Part 11 requirements when paired with Hach’s compliant LIMS integration tools.

Software & Data Management

Data export is supported via USB 2.0 interface to CSV or Excel-compatible formats. Optional Hach LabStation software provides advanced curve-fitting (first-order kinetic modeling), batch reporting, statistical control charting (X-bar/R), and automated report generation compliant with ISO/IEC 17025 documentation requirements. Audit logs record all configuration changes, calibration events, and user logins—retained for ≥18 months per internal memory buffer. No cloud dependency: all processing occurs locally on-device to ensure data sovereignty and cybersecurity alignment with NIST SP 800-53 controls.

Applications

• Regulatory compliance monitoring for NPDES permits and wastewater discharge reporting
• Process optimization in activated sludge, MBR, and SBR treatment plants
• Environmental impact assessment (EIA) baseline and post-intervention sampling
• Academic research on biodegradability kinetics, microbial community activity, and inhibitor screening
• Quality assurance for reclaimed water reuse programs and irrigation water safety protocols
• Third-party certification labs serving ISO 14001 and ISO 22000 audited facilities

FAQ

Does the BODTrak II require seeding for low-microbe samples such as chlorinated effluents or drinking water?
Yes—per Standard Methods 5210B, nitrification-inhibited or low-biomass samples must be inoculated with a standardized seed culture (e.g., Hach 2125909 or equivalent). The instrument does not auto-detect seeding necessity; this remains a methodological responsibility of the analyst.
Can the BODTrak II measure BOD beyond 5 days?
Yes—incubation duration is fully programmable from 24 hours to 14 days. Extended periods support evaluation of slowly degradable compounds (e.g., lignin, certain pharmaceuticals) under controlled 20 °C conditions.
Is the pressure sensor field-replaceable?
No—the sensor is hermetically sealed within the instrument’s manifold assembly and qualified as a non-user-serviceable component. Calibration and verification are performed via certified reference gas challenges during annual service.
How is temperature uniformity verified across all six channels?
Each channel includes an individual PT100 RTD sensor; firmware performs continuous inter-channel delta checks and triggers visual alerts if deviation exceeds ±0.5 °C—documented in the system diagnostic log.
Does the instrument meet USP requirements for purified water BOD testing?
While USP specifies a 5-day incubation at 20–25 °C, the BODTrak II’s fixed 20 °C operation satisfies the lower bound and delivers superior thermal stability versus ambient-incubated methods—making it suitable for compendial testing when validated per USP .