Standard 300 mL Glass Stoppled BOD Incubation Bottles
Ground-glass stoppered bottles with water-seal flanged rims preventing atmospheric oxygen diffusion.
Civil Engineering / BOD5 Kinetics
FREE TO EXPLORELABORATORY 34 · CIVIL ENGINEERING
Biochemical Oxygen Demand (BOD5) & First-Order Deoxygenation Rate Kinetics
Measure 5-day biochemical oxygen demand (BOD5) of domestic and industrial wastewater, monitor dissolved oxygen depletion kinetics over time, and determine the ultimate carbonaceous BOD (L_0) and deoxygenation rate constant k according to Standard Methods 5210 B. Explore interactive structural mechanics, materials simulation, and civil engineering telemetry.
STRUCTURAL MATERIALS · MECHANICS · GEOTECHNICAL · HYDRAULICS · HIGHWAYS · SURVEYING
Your virtual civil engineering laboratory.
EXERTED OXYGEN DEPLETION BOD5—
CIVIL INFRASTRUCTURE TELEMETRY
Ready to sample with Sample Metric P = 3.0 mL/300mL.
Adjust Sample Metric P, then execute civil engineering measurement.
Civil engineering telemetry is evaluated rigorously using 64-bit IEEE 754 precision. Residuals reflect ordinary least-squares regression across successive observations. Continuous data structures support high-fidelity structural mechanics and geotechnical continuum modeling.
Civil engineering assumptions and boundary condition limits
The civil engineering physical models apply within the specified calibrated operational window (1.0 to 6.0 mL/300mL). Tested on primary municipal sewage effluent. Linearized model relates total oxygen consumption to sample dilution metric P with sensitivity 32.5000 mg/(L·metric) (yielding wastewater BOD5 = 195.0 mg/L).
Laboratory apparatus & testing equipment.
Thermostatic Dark BOD Incubation Chamber
Incubator maintaining 20.0 ± 1.0 °C in total darkness to prevent photosynthetic algae oxygen production.
Luminescent Dissolved Oxygen (LDO) Sensor & Meter
Optical sensor measuring dissolved oxygen to ±0.01 mg/L without consuming oxygen at the probe cap.
Automatic Winkler Chemical Titration System
Standard iodometric sodium thiosulfate titrator with starch indicator for DO calibration checks.
Aerated Nutrient Dilution Water Reservoir
Deionized water saturated with oxygen and spiked with phosphate buffer, MgSO4, CaCl2, and FeCl3 nutrients.
Nitrification Chemical Inhibitor (TCMP)
2-chloro-6-(trichloromethyl)pyridine inhibiting autotrophic nitrifying bacteria oxidation of ammonia.
FOLLOW THE METHOD
A reason behind every step.
Measure 5-day biochemical oxygen demand (BOD5) of domestic and industrial wastewater, monitor dissolved oxygen depletion kinetics over time, and determine the ultimate carbonaceous BOD (L_0) and deoxygenation rate constant k according to Standard Methods 5210 B. Standardized parameter settings: 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 mL/300mL.
01
Nutrient Dilution Water Preparation & Aeration
Aerate deionized water for 24 hours at 20 °C until saturated (DO ≈ 9.0 mg/L); add 1.0 mL each of phosphate buffer, MgSO4, CaCl2, and FeCl3 solutions per liter.
02
Sample Dosing & Nitrification Suppression
Dispense wastewater sample aliquots (1.0, 2.0, 3.0, 4.0, 5.0, and 6.0 mL) into labeled 300 mL BOD bottles; add 10 mg TCMP to suppress nitrification.
03
Bottle Filling & Zero Initial DO Measurement
Carefully siphon aerated dilution water into bottles to overflowing without entraining bubbles; insert optical LDO probe; record initial dissolved oxygen DO_0.
04
Water-Seal Stopper Seating
Insert tapered glass stoppers firmly to displace all air; fill flared neck rim with deionized water; slip plastic cap over rim to prevent evaporation.
05
Five-Day Dark Incubation at 20 °C
Place sealed bottles into thermostatic incubator at 20.0 ± 1.0 °C for exactly 5 days (120 ± 2 hours) in complete darkness.
06
Final DO Measurement & BOD5 Computation
Remove bottles; measure final dissolved oxygen DO_5; verify depletion criteria (depletion ≥ 2.0 mg/L and residual DO ≥ 1.0 mg/L); compute BOD5.
YOUR NOTEBOOK · 0 OBSERVATIONS
Turn measurements into civil engineering insight.
Points are your recorded observations. The solid regression line validates BOD5 Kinetics mathematical scaling.
LINEAR REGRESSION FIT · y = mx + b
BOD = 32.5000 · P
| # | Wastewater Sample Volume Metric P (mL/300mL) | Exerted Oxygen Depletion BOD5 (mg/L) | Wastewater dilution metric P (sample mL / 300 mL bottle) | Exerted 5-day oxygen demand BOD5 (mg/L) | Remove |
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CHECK YOUR UNDERSTANDING
Explain what the civil engineering metrics mean.
The standard temperature and incubation period for the classic BOD test are:
Why is darkness strictly required during BOD bottle incubation?
For a BOD5 test result to be considered statistically valid under Standard Methods, the oxygen depletion must be at least:
The chemical inhibitor TCMP is added to BOD samples specifically to prevent:
THEORY AND STRUCTURAL CONTEXT
Civil engineering background & physical principles.
In civil environmental sanitary engineering, municipal sewage treatment design, and receiving water pollution impact assessments, Biochemical Oxygen Demand (BOD) is the primary bio-chemical parameter quantifying biodegradable organic carbon pollutant loading. Aerobic heterotrophic microorganisms consume dissolved molecular oxygen (DO) to oxidize organic matter into carbon dioxide, water, and new microbial biomass: Organics + O₂ + Nutrients → CO₂ + H₂O + NH₃ + New Cells. Standardized under Standard Methods 5210 B, the classic BOD5 test incubates wastewater samples in airtight 300 mL glass BOD bottles in total darkness at 20.0 ± 1.0 °C for exactly 5 days. Dissolved oxygen is measured initially (DO_0) and after 5 days (DO_5) using the iodometric Winkler method or luminescent dissolved oxygen (LDO) probes. BOD5 is computed as: BOD5 = (DO_0 - DO_5) / P, where P is the decimal volumetric dilution fraction (V_sample / 300 mL). Deoxygenation kinetics follow a first-order rate law: L_t = L_0 · (1 - e^(-k·t)), where L_0 is ultimate carbonaceous oxygen demand, k is the base-e deoxygenation rate constant (typically 0.15 to 0.30 day⁻¹ for municipal sewage at 20 °C), and t is incubation time in days. In this laboratory investigation, domestic wastewater aliquots across dilution metrics from 1.0 to 6.0 mL per 300 mL are analyzed to determine the 5-day oxygen consumption rate, evaluate the deoxygenation rate constant, and calculate raw municipal wastewater BOD5.
BOD = 32.5000 · P
Tested on primary municipal sewage effluent. Linearized model relates total oxygen consumption to sample dilution metric P with sensitivity 32.5000 mg/(L·metric) (yielding wastewater BOD5 = 195.0 mg/L).