click below
click below
Normal Size Small Size show me how
Wastewater Lab
Wastewater Lab Analysis
Question | Answer |
---|---|
The tolerance of Class A glassware | +/– 0.30mL |
The tolerance of Class B glassware | +/– 0.60 or twice that of Class A glassware |
Pipet classified as TC means... | Pipet CONTAINS the graduated amount and entire contents must be used |
Pipet classified as TD means... | Pipet DELIVERS the graduated amount and there will be a small amount remaining in the tip |
At what temperature is laboratory glassware calibrated? | 20°C |
1mL equals how many grams? | 1 |
Water is at its most dense at what temperature? | 4°C |
Volumetric glassware is best suited for what? | Accurate and precise analytical work |
Which glassware is more precise? Class A or Class B | Class A |
When performing a titration with a buret the tip must be... | filled before titration is performed |
Which pipet is usually recognized by the bubble in the center? | Volumetric |
Which pipet will only "transfer" one amount? | Volumetric |
Volumeric flasks are most commonly used for... | Making standards |
Volumeric flasks will measure... | Only one volume |
Graduated cylinders can measure... | Multiple volumes |
When reading a meniscus where should you look? | The bottom of the upward curve |
Glassware used for phosphorous testing should be cleaned with... | Hot, dilute HCL and rinsed well with distilled water |
Laboratory glassware should be cleaned with | Phosphate free liquid detergent and rinsed with distilled water |
Light sensitive chemicals/reagents should be stored in | Amber bottles |
Define Digestion | The heating of a sample in the presence of a strong acid |
Define Distillation | Removing heavy materials from water samples by evaporating and re–condensing the sample |
Define Filtration | Removing materials from samples by passing it through some type of filter material |
Device used to allow samples to cool in the absence of moisture | Desiccator |
What material forms a reverse meniscus? Where should it be read? | Mercury The center of the dome/downward curve |
What is Gravimetric analysis | Technique involving use of a scale |
In colorimetric analysis the more intense the reaction... | The greater the presence of the substance being tested for |
What is Nephelometric Analysis | Measure of turbidity (cloudiness) |
Gravimetric analysis required equipment | Analytical Scale |
Desiccator | Drying oven |
Analytical balances must be calibrated by a service technician... | At least once a year |
Analytical balances/scales should be calibrated with what weights? | NIST Class S and/or ASTM Class 2 |
What does NIST stand for | National Institute of Standards and Technology |
What does ASTM stand for | American Society for Testing and Materials |
Desiccators must contain this | Dessicant |
As a dessicant absorbs moisture it will | Change from blue to pink (assuming it is blue to start) |
Dessicant can be recharged in a | TDS drying oven |
What is Beer–Lamber Law (Beer's Law) | The amount of light absorbed by the sample is proportional to the amount of light absorbing material found in the sample. (darker the intensity = more substance present) |
What is the Visible light spectrum | 400 – 900nm |
Define Titration | The addition of a known concentration (titrant) to a sample to reach a desired endpoint |
Define Reagent | A chemical used in the laboratory to react with a sample or solution |
Chemicals can be ordered in what states? | Solid, liquid, or gaseous forms |
Define Solution | Solute (dry ingredient) –––––––––––––––––––––––––––––––– Solvent (liquid) |
What is a Hydrate chemical | A chemical that has water molecules attached |
What is an Anhydrous chemical | A chemical that has no water attached |
Most widely used grade of chemicals in the laboratory also the minimum grade allowed. | ACS chemicals |
What does ACS stand for | American Chemical Society |
Typical shelf life for reagents stored under proper conditions if no expiration date is listed | One year |
Upon receipt of a reagent or standard the analyst should | Write the date on the bottle and the certificate of analysis (COA) |
What does COA stand for | Certificate of Analysis |
The most common solvent used in water and wastewater labs | Water |
Methods used for water purification | Deionization cartridges, Activated Carbon cartridges, and distillation |
Temperature for conductivity measurement | 25°C |
Best test to check for reagent grade water purity | Conductivity (at 25°C) |
3 temperature scales used in the US | Fahrenheit (mostly for weather) Celsius (typically used in lab) Kelvin (official scientific scale) |
Most commonly used method of temperature measurement | Liquid–in–glass thermometers |
3 types of thermometers | Total Immersion Partial immersion Complete immersion |
What is a Total immersion thermometer | Thermometer immersed to level expected to measure |
What is a Partial immersion thermometer | Thermometer immersed to specified mark |
What is a Complete immersion thermometer | Thermometer 100% immersed |
If the liquid column in a thermometer separates | Place in a dry ice slurry of acetone, toluene or alcohol to contract liquid back into bulb |
Define Matter | Anything that occupies space and has mass |
Define Mass | The amount of matter contained in an object or material |
Define Weight | The measurement of earth's attraction to that body |
Lab thermometers must be calibrated | Yearly, against an NIST or NIST–traceable thermometer |
Define Chemistry | The study of the composition and structure of matter and the changes that matter undergoes |
Define Density | Mass –––––––– Volume |
What unit(s) are Solids & liquids are measured in | gram/cubic centimeter |
What unit(s) Gases are measured in | gram per liter |
Define Specific Gravity | The density compared with that of a standard (solids & liquids – 1g/cm3) (gases – 1.29 g/L) |
What does IBWM stand for | International Bureau of Weights and Measures |
Mass is measured in | Grams (1/1000 of a standard kilogram) |
Volume is measured in | Liters (1 kilogram of water at 4°C) |
1Kg = __ g | 1,000g (1,000 x basic unit) |
1mL = __ L | 0.001L (1/1,000 x basic unit) |
1µg = __ g | 0.000001g (1/1,000,000 of basic unit) |
Define Element | Substance that cannot be broken down into other substances by conventional means |
Define Atom | Smallest particle of an element that has the properties of that element |
Define Atomic nucleus | Center of atom, contains protons and neutrons |
Define Proton | Atomic particle with a positive charge "P+" |
Define Neutron | Atomic particle with no charge "N" (about the same size as the proton) |
Define Electron | Atomic particle with a negative charge "e–" (found outside the nucleus) |
Define Electron shells | Space around the nucleus where electrons are found (divided into different levels) |
Define Atomic number | Used to identify an atom |
Atomic # = | # of Protons in nucleus |
Elemental symbol "Ca" | Calcium |
Elemental symbol "C" | Carbon |
Elemental symbol "Cl" | Chlorine |
Elemental symbol "Fe" | Iron |
Elemental symbol "N" | Nitrogen |
Elemental symbol "O" | Oxygen |
Elemental symbol "P" | Phosphorous |
Elemental symbol "K" | Potassium |
Elemental symbol "Na" | Sodium |
Define Atomic Mass (Weight) | Total weight of an atom Mass = # Protons + # Neutrons |
Define Mole | The unit used to define the amount of substance in a chemical reaction or solution |
Define Molar Mass | The mass in grams of one mole of a substance, directly obtained from an element's atomic mass (i.e. gram–formula mass) |
Define Neutral Atom | Stable atom that possess and equal number of protons (P+) and electrons (e–), rarely found in real life |
Define Cation | Atom with a (+) charge |
Define Anion | Atom with a negative (–) charge |
Define Valence electrons | Outer shell electrons where bonding occurs |
Define Molecule | The smallest unit of a compound, atoms of different elements bonded |
What is a Neutralization Reaction | The reaction between acids and bases, The products are usually salt and water |
What is a Oxidation–Reduction Reaction (Redox) | A reaction that involves an exchange of electrons |
OIL RIG acronym for | Oxidation involves loss Reduction involves gain |
What is an Acid | a substance that readily donates hydrogen ions (H+) to a substance. The (H+) is also known as a proton (The "H" is typically in the front: HCl, H2SO4, HNO3)(The "H" is typically in the front: HCl |
What is a Base | A substance that accepts protons (H+). (The "H" is typically in the back: NaOH, KOH) |
What is the Cadmium Reduction Method | NO3 ––> NO2 |
What is Oxidation | Defined as the addition of oxygen, or the removal of electrons |
What is Reduction | Defined as the removal of oxygen, or the addition of electrons |
Convert 44.5°C to °F | 112°F |
Convert 72°F to °C | 22°C |
Convert 10°C to °F | 50°F |
Convert 35°C to °F | 95°F |
Convert 20°C to °F | 68°F |
Convert 212°F to °C | 100°C |
Convert 32°F to °C | 0°C |
Convert 68°F to °C | 20°C |
Convert 98.6°F to °C | 37°C |
Gram–molecular weight (formula wt) of HCl | 36.46 g/mol |
Gram–molecular weight (formula wt) of NaOH | 40.00 g/mol |
Gram–molecular weight (formula wt) of CaCO3 | 100.09 g/mol |
Gram–molecular weight (formula wt) of H2SO4 | 98.07 g/mol |
How many moles in 46 g of NaCl | 0.79 moles |
How many moles in 410 g of NaOH | 10.25 moles |
How many moles in 712 g of KMnO4 | 4.51 moles |
What is the percent composition of Fluoride in Sodium Fluoride (NaF)? | 45.25% |
What is the percent composition of Oxygen in Sodium Carbonate (Na2CO3)? | 45.29% |
How many grams of NaOH are needed to prepare a 500mL solution of a 5.2 M solution of NaOH? | 104 grams |
How many grams of KMnO4 are needed to prepare 300mL of a 0.5 M solution of KMnO4? | 23.71 grams |
If you dissolve 54 grams of NaCl in 1 Liter of water, what is the molar concentration of the NaCl solution? | 0.92 M |
If 120 grams of Ca(OH)2 is dissolved in 750mL of water, what is the resulting molar concentration of Ca(OH)2? | 2.16 M |
Gram–equivalent weight of HCl | 36.45 grams |
Gram–equivalent weight of H2SO4 | 49.04 grams |
Gram–equivalent weight of NaOH | 40 grams |
Gram–equivalent weight of Na2CO3 | 53 grams |
How many grams of NzOH are required to prepare 500mL of 0.1 N NaOH | 2 grams |
How many grams of H2SO4 are required to prepare 750mL of 1.2N H2SO4 solution? | 44.14 grams |
1.33 specific gravity solution, 48% active. How many mg/L | 637 |
How much of a 0.1N sodium hydroxide titrant do you need to dilute to make 1000mL of a 0.02N sodium hydroxide titrant | 200 mL of 0.1N sodium hydroxide |
How many mL of a 4000NTU Formazin solution needs to be diluted to 200mL to have a 20NTU standard | 1mL of 4000NTU Formazin solution |
On a colorimeter, if the absorbance is 0.000, the % transmittance would be | 100% |
What does FWPCA stand for | Federal Water Pollution Control Act |
What does NPDES stand for | National Pollutant Discharge Elimination System |
What does DMR stand for | Discharge Monitoring Report |
What did the Clean Water Act (CWA) do | Made it unlawful for any person to discharge any pollutant from a point source into navigable waters |
What is Title 40 CFR Part 136 (Code of Federal Regulations) | Federally approved methods for regulatory monitoring; guidelines establishing test procedures for the analysis of pollutants |
Minimum velocity of water coming into the plant in feet per second (fps) | 2.0 fps |
Primary treatment in a plant can remove as much as what % of solids and BOD | 60% of solids and 30% of BOD |
Secondary treatment in a plant must achieve what % removal of original waste concentration | 85% removal |
What are algae, bacteria, ciliates, rotifers | Microorganisms |
Predominant organisms involved in secondary treatment | Bacteria |
To maintain activated sludge... | a portion of the settled solids must be returned to the head of the secondary treatment process |
The wastewater treatment process designed to kill pathogenic bacteria is called | Disinfection |
Primary purpose of the Lab | To provide regulatory required and process control data to regulatory offices and plant |
The first place to look when searching for an approved NPDES test method | Title 40 CFR Part 136 |
When states accept the authority to enforce the wastewater programs for their state | Primacy – Primary Enforcement Responsibility |
Compliance monitoring results must be reported on | Discharge Monitoring Report (DMR) (EPA form 3320) |
Form 3320 must be completed and postmarked to EPD by what date | the 15th of the month following the sampling month |
Who accepts legal responsibility for the reported monitoring data on form 3320 | The person signing the bottom of the form |
What is the federal agency that enforces the Clean Water Act | USEPA |
Amendments made to the Code of Federal Regulations (CFR) is updated daily in what publication | Federal Registry |
What is the LEL in regards to gases (Lethal Exposure Limit) | > 10% |
Where do most errors in the lab occur | Sampling process |
Most common types of samples | Grab and Composite |
What is a Grab sample | Sample representative of the source material at a particular instant of time; collected over a period of time not exceeding 15 minutes |
What is a Composite sample | Sample representative of the average conditions of the flow over a set period of time; obtained by taking a intervals and combining in proportion to the flow number of grab samples at equal |
Automatic samples can be configured in one of two way | Time proportional (most simplistic) Flow proportional (requires flowmeter) |
What is Proportional Compositing | (Instantaneous flow) (Total sample volume) –––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– (Number of portions) (Average flow) |
The ideal location to obtain samples | Where there is good mixing action in the waste stream |
These should be excluded from a sample | Large solids (greater than 1/4 inch in diameter) |
The following are examples of what Cool <= 6°C pH adjustment Dechlorination (sodium thiosulfate) | Common preservation techniques |
The maximum length of time which can pass before a sample is analyzed | Holding time |
Objective of Sampling | To obtain a portion of material small enough to handle but accurately represent the characteristics of the bulk material |
Required sample information | Location of sample collection Date and time of sample collection Type of analyses requested Initials of person collecting the sample Required analysis information |
Required analysis information | Date and time of analysis, Person performing the analysis Analytical procedure used Results |
Record retention for plant samples | At least 3 years |
Record retention for sludge (biosolids) handling | At least 5 years |
If you test it... | You have to report it |
6 items required for flow composited sample collection | Location Date sample collected Time sample collected Person who collected samples Flow of each aliquat (sample) Volume of each aliquat (sample) |
What substance is added to a fecal coliform sample if it contains chlorine? | Sodium thiosulfate |
What is the hold time for a chlorine residual sample? | None – immediate analysis – max time of 15 minutes |
What is the most common sample preservation temperature? | = 6° C |
How is a BOD sample preserved? | = 6° C |
Preservation and hold time for metal analysis | pH <2, HNO3 (nitric acid) 6 months |
Preservation and hold time for chemical (compound)analysis | = 6°C, H2SO4 (sulfuric acid) 28 days |
Preservation and hold time for BOD | = 6° C 48 hours |
Preservation and hold time for solids (TSS, TDS, TS) | = 6°C 7 days |
Preservation and hold time for coliform | < 10°C 8 hours |
Diseases commonly caused by Bacteria in wastewater | Typhoid, Paratyphoid, shigellosis, E. coli, diarrhea, campylobacteriosis, gastroenteritis, cholera, yersiniosis, leptospirosis, salmonellosis |
Diseases commonly caused by Viruses in wastewater | Hepatitis A, polio, viral gastroenteritis, encephalitis, poliomyelitis |
Diseases commonly caused by Parasites in wastewater | Giardiasis, cryptosporidiosis |
Two common Indicator organisms | Total Coliform Fecal Coliform |
Define Bacteria | Microscopic simple celled organisms that lack a nucleus (prokaryotes) |
Define Fecal Coliform | Thermo–tolerant bacteria that grow at 44.5°C (112°F) |
Characteristics Coliform | Ferments lactose Produces Gas Produces Acid |
Membrane filtration – 9222D | Water bath (fecal coliform) |
Membrane filtration – 9222B | Dry incubator (total coliform) |
Two types of bacteriological media | Agar – solid "Jello"–like media Broth – liquid media |
CFU | Colony Forming Units |
Fecal coliform incubation temperature and time | 44.5°C for 24 (+/–) 2 hours |
m–FC media filter | filter with a pore size of 0.45µm (most bacteria will has a size of 0.5–0.8µm) |
Seven–day and monthly fecal coliform average use what calculation | Geometric mean |
Rosalic Acid | Added to media to inhibit the growth of non–fecal coliform bacteria |
What color are fecal coliform colonies | Blue |
Which plates are used for fecal coliform calculations | Plates with 20–60 visible colonies |
MPN | Most Probable Number also called Multiple Tube Method (MTF) |
3 phases of MPN | Phase 1 – Presumptive Phase Phase 2 – Confirmed Phase Phase 3 – Completed Phase |
Presumptive Phase (MPN) | Media indicates target organism MAY be present |
Confirmed Phase (MPN) | Media indicates target organism IS DEFINITELY present |
Completed Phase (MPN) | Microscopic examination of growth on specialized media |
Media used in MPN analyses | Lauryl tryptose broth |
MPN incubation temperature and time | 35 +/– 0.5°C for 24 +/–2 hours |
MPN positive tubes | Fluoresce and have visible gas bubbles |
Confirmed Phase of MPN | Brilliant Green Lactose Bile Broth – Total Coliform incubate at 35 (+/–) 0.5°C |
EC Broth – Fecal Coliform | incubate at 44.5 (+/–) 0.2°C |
Fecal Coliform QC | Analyize Dilution water blank (a.k.a. negative) Analyize Positive (a.k.a. spike) Analyize Duplicates |
3 dilutions used in MPN analyses | 10.0 mL, 1.0 mL, 0.1 mL |
What is the geometric mean for the following? 5, 21, 9, 2, 7 | 6.67 |