Laboratory Procedures

The BOD5 test incubation is:

A BOD5 result is generally considered valid only when:

If a BOD bottle ends with DO below ~1 mg/L, you should:

Carbonaceous BOD (CBOD) uses a nitrification inhibitor to:

Why must BOD dilution water contain nutrients and a buffer?

Glucose-glutamic acid BOD check (a known 300 mg/L standard) typically yields ~198 mg/L; if your lab gets 120 mg/L, suspect:

BOD results are reported in:

A BOD blank (seed-free dilution water incubated) should:

Seeding BOD samples with settled domestic effluent is used to:

When seeding, you must:

Chlorinated samples can give falsely low BOD because chlorine:

Why is BOD5 sometimes performed with multiple dilutions?

BOD5 final results must consider:

The COD test oxidizes organics using:

COD is usually:

Chloride interference in COD is controlled by adding:

COD is most useful when:

A high COD/BOD ratio usually indicates:

Typical COD/BOD ratio for domestic wastewater is roughly:

Which test does NOT involve microorganisms?

Which reagent is added to COD digestion as a catalyst?

TSS is measured using which filter?

What temperature is the TSS filter dried at?

Volatile suspended solids (VSS) are determined by:

Fixed (non-volatile) suspended solids are mostly:

Total Solids (TS) equals:

TDS is determined by:

Settleable solids are reported in:

Settleable solids are measured using:

A TSS result is suspiciously low after a high-flow event; the most likely lab/field issue is:

Standard Methods recommends which best practice for TSS analysis?

Dissolved oxygen (DO) is most commonly measured with:

A DO probe should be calibrated by:

The Winkler method measure DO via:

The azide modification of the Winkler method is used to:

Why must a DO sample be analyzed immediately?

Higher temperature affects DO readings by:

A membrane DO probe membrane fouling typically causes:

A DO reading that suddenly reads max on a membrane probe most likely indicates:

A pH meter must be calibrated with at least how many buffers?

Common pH calibration buffers are:

pH is best defined as:

A neutral solution at 25 °C has a pH of:

pH meters should:

Which buffer would you choose to calibrate before measuring a pH ~6.5 sample?

Erratic pH readings often indicate:

For pH, a grab sample analyzed on-site is recommended because:

Turbidity is reported in:

A turbidimeter measures turbidity by:

Turbidity standards are made from:

Low-turbidity measurements require:

A turbidity rise in final effluent often signals:

Turbidity is a useful in-line surrogate for:

Alkalinity is typically reported as:

Alkalinity titration end-point pH is commonly:

The dominant form of alkalinity in raw wastewater is:

Hardness is most commonly measured by:

Hardness is reported as:

Carbonate (CO₃²⁻) hardness contributes to alkalinity:

Which contributes to 'non-carbonate' hardness?

Alkalinity changes during nitrification because:

Ammonia is commonly analyzed by:

Nitrate is commonly analyzed by:

Total phosphorus (TP) requires:

Orthophosphate (reactive P) is measured:

TKN (Total Kjeldahl Nitrogen) requires:

TKN consists of:

An ion-selective electrode (ISE) for nitrate requires:

Colorimetric nutrient methods are sensitive to:

For nutrient analyses, the type of preservation is typically:

Holding time for ammonia (preserved) is commonly up to:

Fecal coliform compliance is most commonly measured by:

On a membrane-filter coliform plate, you count:

Which is a methodology for coliform analysis using a defined substrate?

Why does chlorine disinfection monitoring use a grab sample analyzed immediately?

An MPN (Most Probable Number) result is:

Which is true about IDEXX Quanti-Tray?

Sterile sampling technique for bacteriology requires:

Bacteriological samples have a very short holding time, commonly:

A grab sample is:

A 24-hour composite sample is typically built from:

For a parameter that changes rapidly (e.g., chlorine residual), the best sample type is a:

For BOD5 and TSS compliance, the typical sample type is a:

Cooling samples to 4 °C during compositing/storage is done to:

Chain-of-custody documents:

Every analytical parameter has:

Sample preservation with acid (H₂SO₄ to pH <2) is used for:

Samples for metals analysis are usually preserved by:

A 'representative' sample is one that:

Why is glassware for nutrient analysis usually acid-washed?

For BOD, the sample temperature should:

A method blank verifies:

A laboratory duplicate checks:

A laboratory-fortified blank (LFB) or known standard checks:

A matrix spike (MS) checks:

Control charts are used to:

Reagent water (Type I/II) is required for nutrient and metals analyses to:

A balance used for TSS/VSS must be:

Calibration verification should be performed:

A sample sent to a reference lab for a duplicate is part of:

Spikes, blanks, and duplicates should be run at a frequency that:

Acids should always be added to water, never water to acid, to:

Reagent-grade solvents and acids require handling using:

SDS files in the lab should be:

An emergency eyewash/safety shower must be:

Mercury and other heavy-metal wastes must be:

Glassware with broken glass should be:

Phenolphthalein alkalinity vs total alkalinity differ by:

A BOD seed source should be:

The IDEXX Colilert test detects E. coli through:

Membrane filter fecal coliform incubation is at:

Fecal coliform reporting units commonly are:

Method Detection Limit (MDL) is:

Reportable results below the MDL are usually:

Relative Percent Difference (RPD) for laboratory duplicates is commonly flagged when it:

A continuing calibration verification (CCV) failing outside acceptance means:

Composite samplers must be:

For TSS, filtering too small a sample volume can cause:

For very turbid samples in TSS, the operator should:

A BOD sample containing residual chlorine should be:

For DO, the sample should be collected:

Alkalinity to pH 4.5 endpoint uses which standard titrant?

Hardness EDTA titration endpoint color change is:

Nitrate by cadmium reduction requires:

TSS/VSS results should be calculated from:

A 'field blank' verifies:

For very low-level nutrient analyses (e.g., TP < 0.1 mg/L), the lab must:

Samples for dissolved metals/orthophosphate are typically:

pH electrodes are stored:

Glass pipettes for trace work are usually:

Chlorine residual by DPD is read:

Lab QA/QC documentation should be: