HUANKONG ZHK6250 Automated BOD Analyzer

Overview

The HUANKONG ZHK6250 Automated BOD Analyzer is a fully integrated, laboratory-grade instrument engineered for precise and reproducible determination of Biochemical Oxygen Demand (BOD₅) in surface water, domestic wastewater, and industrial effluents. It operates on the microbial electrode method — a standardized electrochemical approach where immobilized microorganisms consume dissolved oxygen (DO) in proportion to biodegradable organic content, generating a measurable current signal correlated to BOD concentration. Unlike traditional dilution-based manometric or Winkler titration methods, the microbial electrode technique enables rapid, continuous, and real-time monitoring without manual sample handling post-inoculation. The system complies with Chinese Environmental Protection Standard HJ 505–2009, which specifies requirements for BOD₅ measurement methodology, incubation conditions (20 ± 1 °C, dark, 5 days ± 4 h), and data reporting formats. Its architecture supports full traceability, audit-ready operation, and alignment with GLP-compliant laboratory workflows.

Key Features

• Fully automated workflow: Integrated preparation of dilution water, sample dilution, DO saturation, temperature-controlled incubation, electrode calibration, measurement, and report generation — all executed without operator intervention.
• Dual-zone thermostatic incubation system: Two independent PID-controlled temperature modules maintain stable 20 °C across both measurement and incubation chambers; active cooling and heating ensure ±0.2 °C stability under variable ambient conditions.
• High-capacity sample handling: 60 positions for active measurement and up to 132 positions for offline incubation, enabling batch processing of large-volume monitoring programs.
• YSI-certified electrochemical DO sensor (optional luminescent DO probe): Factory-calibrated, temperature/pressure/salinity-compensated, with automatic zero and span calibration cycles prior to each analysis.
• Precision fluidics: High-accuracy syringe pumps dispense reagents, diluent, and inoculum with ≤0.5% volumetric repeatability; spray-jet cleaning mechanism prevents cross-contamination between runs.
• Intelligent safety monitoring: Real-time diagnostics include open-lid detection, cap-drop alert, robotic arm collision sensing, temperature sensor redundancy, reagent line occlusion warning, and low-reagent level notification.
• Remote operation capability: Web-enabled workstation software supports secure mobile access via authenticated TLS-encrypted interface for status monitoring and protocol initiation.

Sample Compatibility & Compliance

The ZHK6250 accommodates undiluted, diluted, inoculated, and non-inoculated samples per ASTM D5210–18 and ISO 5815–1:2019 guidelines for BOD testing. It accepts standard 60 mL or 300 mL BOD bottles with septum-sealed caps, compatible with common nutrient buffer and nitrification inhibitor formulations. All operational parameters — including incubation duration, temperature setpoint, dilution factor, and electrode response time — are programmable and logged with timestamped metadata. The system meets requirements for regulatory submission under China’s MEP Order No. 48 and supports data integrity practices aligned with FDA 21 CFR Part 11 when configured with electronic signature and audit trail modules.

Software & Data Management

The embedded Windows-based workstation software provides role-based user access control (administrator, analyst, reviewer), configurable method templates, and automated PDF report generation compliant with ISO/IEC 17025 documentation standards. Raw sensor signals, calibration logs, environmental chamber readings, and mechanical actuator statuses are stored in encrypted SQLite databases with daily backup export options. Audit trails record all parameter changes, login events, and result modifications with user ID and timestamp. Export formats include CSV, XML, and LIMS-compatible ASTM E1384 structured data files.

Applications

• Regulatory compliance testing for municipal wastewater treatment plants (WWTPs) discharging to receiving waters.
• Industrial pretreatment verification for textile, food processing, pharmaceutical, and chemical manufacturing facilities.
• Environmental impact assessment (EIA) studies requiring high-throughput BOD screening of multiple sampling points.
• Research laboratories investigating biodegradability kinetics of novel organic compounds or wastewater treatment efficiency.
• Academic teaching labs demonstrating standardized BOD methodology with minimized hands-on procedural variability.

FAQ

What BOD measurement principle does the ZHK6250 employ?

It utilizes the microbial electrode method, where a biofilm of aerobic bacteria consumes oxygen proportional to biodegradable organics, producing an electrochemical signal linearly related to BOD concentration.
Does the instrument support unattended multi-day operation?

Yes — it performs fully autonomous 5-day incubations with continuous temperature monitoring, periodic electrode recalibration, and end-point validation before final calculation.
Can the system handle samples with high turbidity or suspended solids?

It is compatible with filtered or centrifuged samples per HJ 505–2009; particulate interference is mitigated through integrated filtration options and adaptive signal processing algorithms.
Is method validation documentation available for regulatory audits?

Comprehensive IQ/OQ documentation, performance verification reports, and traceable calibration certificates are provided upon installation and annually thereafter.
How is data security ensured during remote access?

All remote sessions use TLS 1.2+ encryption, two-factor authentication, session timeout enforcement, and segregated network VLAN deployment options.