Justin - Waste Water

Dewatering

• Handling and disposing of sludge is complex because it is heavy and often consists of toxic chemicals
• A firm dry cake indicates good filter performance
• Successful gravity filter operation relies on suspended solids concentration, even dispersal of wastewater, filtration rate, and media age
• Pressure filtration is a unit process used for sludge dewatering

Flow

• Parshall Flumes are used to measure flow
• A manometer is not an example of a flow measuring device
• Venturi Meters measure flow delivered to a treatment plant
• Weirs are a reliable type of wastewater flow measuring device
• Wastewater flow measurements are used to establish the level of pollutants discharged for mass-based discharge standards
• A rotameter measures flows of treated, or untreated wastewater containing high solids or TSS
• The head on a wastewater flow measuring flume is monitored by a venturi meter

Instrumentation

• Conductivity probes are used to maintain, repair, and troubleshoot solvent/solute solutions, electrical circuits, and water/polymer systems
• A PLC controls when acid or caustic is added to a tank
• Floats and level probes ensure motors start/stop at correct liquid levels; it is also necessary to test for alarms
• Check pH probe wiring if pH chart is fixed at 7
• If the alarms continue to trigger , check the wire for Tank 2 first as that tank pH is at 5.00 and later in the process at 10.5
• Reagent level and reagent pump prime should be checked if all tanks read the same pH
• Always clean pH probes before calibration
• A slow pH probe response can be caused by a coated bulb
• pH can be monitored continuously for wastewater characteristics
• Digital meters offer easier reading than analog meters
• Check the sensor if a pH recorder indicates 10.0 when a pH of 8.0 is desired, and adding acid doesn't change the pH

Metals

• Sulfide precipitation is less expensive than hydroxide precipitation for metal removal
• Drag-out refers to plating solution carried over into the rinse tank
• Sodium hypochlorite is a common compound for oxidation
• Cyanide converts to nitrogen and carbon dioxide during treatment
• Hexavalent chromium is toxic to the environment
• A reducing agent treats chromium
• Hydroxide is used for chemical precipitation of metal wastes
• Hydrogen cyanide is released if cyanide solutions reach an acidic pH
• Metal finishing wastes undergo chemical treatment because contaminants resist biological treatment and are toxic.
• Metal finishing industries commonly use chemical precipitation as treatment to recover metals or reduce the volume of sludge
• Wastewater from metal finishing and plating facilities results via production and wash water
• Samples for heavy metal analyses are preserved by adding nitric acid
• Labs and hospitals are sources of radioactive wastes in a treatment plan
• Chlorine is used as an oxidizing agent in the treatment of cyanide
• Zinc and chrome hydroxide treatment demands pH control
• A waste stream indicates metal finishing and plating wastes by the presence of toxicity
• Precious metals are recovered via hydroxide precipitation
• Nitric acid is an example of pickling acid
• Hydroxide precipitation is a cost-effective treatment for many metals
• Metal finishing industries wastewater may contain cyanide wastes or high TSS
• A standard chrome treatment process: change the pH and add chemicals to reduce chrome from hexavalent to trivalent, causing chrome hydroxide precipitation. The pH range in the first step is between 7 and 9
• Adding chlorine is typically the first step when treating chromium waste in the physical-chemical treatment of chromium waste from a plating operation
• Bleach is added in removing cyanide in metal waste streams
• Hydrogen peroxide is an oxidizing agent that is used to treat industrial wastewater
• pH adjustment is a common first step in treating chromium, cyanide, and other industrial wastes
• Sodium Metabisulfite is used as a reducing agent
• Metal-plating industries use ion exchange for by-product recovery
• CN is the symbol for cyanide
• Neutralizing metal plating wastes proves complicated as they vary in flow rate, free acid, caustic content, and metal salt concentrations
• Adjusting pH to less than 12 preserves samples collected for cyanide analysis
• Oxidation-reduction reactions demand chemical oxidizers

Operation & Maintenance

• Procedures for shutting down/starting up industrial waste treatment vary with safety procedures and influent flow rates
• PVC pipe resists bacteria, sunlight, and chlorinated hydrocarbon solvents, but will not hold up against concentrate acids
• Identification is the first task when performing corrective maintenance
• Industry uses recovery as a preliminary practice to reduce the volume of industrial wastes
• Plugging is a problem commonly encountered when using lime slurry
• A faulty drive chain can indicate no wastewater flowing through a micro screen

Physical Chemistry

• Sludges are produced by coagulation and flocculation in industrial wastewater pretreatment systems
• Flocculation follows coagulation in physical-chemical treatment
• Sulfide precipitation yields less sludge during chemical precipitation processes than traditional alternatives
• A major objection to chemical precipitation processes for industrial waste treatment is the quantity of sludge produced
• The optimum pH must be determined experimentally for coagulation to treat industrial waste
• The most accepted testing procedure for coagulants and determining optimal coagulation is the jar test
• A jerky or inoperable sludge collector denotes a misaligned baffle
• Quicklime will produce the least amount of sludge when treating the same wastewater stream
• Modifying the manufacturing process reduces the amount of water requiring treatment

Pre-Treatment

• Coagulation is the first step in a typical wastewater pretreatment process

Chemical Considerations

• Carbon dioxide is considered an acid
• Alkalinity neutralizes acids and absorbs hydrogen ions with sufficient pH depression
• The lowest pH has the highest hydrogen ion concentration
• A pH of 8 has a concentration that is 10 times more alkaline than a pH of 7
• Waste streams with a pH of 9.8 are basic
• Buffers in wastewater treatment minimize hydrogen ion concentration
• Slaking is a process of adding water to quicklime
• To neutralize a waste stream with a pH of 10.6 add sulfuric acid
• pH meters measure hydrogen ion concentration
• Sodium hydroxide may be utilized for pH adjustment

Pumps & Valves

• Lime slurry mixing equipment and pumps ought to be always kept clean because lime slurry is sticky, and material will gum and stick
• The purpose of maintenance record keeping program is to help plan to replace parts
• Motors of 100 horsepower or less should not be started more than hourly
• To prevent a loos in prime, begin all positive displacement pumps with the discharge valve closed
• Centrifugal pumps include an impeller
• Pump maintenance includes checking the operating temperature of the bearing and preventing water seals around the packing glands
• A lantern ring allows water to enter packing
• A gear pump is a positive displacement pump
• Before priming a positive displacement pump, close the suction valve
• Butterfly valves control throttling flow
• Long-term pump shutdown requires disconnecting power with lockout and shutting all suction/water seal/discharge lines and drain the pump
• Stuffing boxes are easy-to-rebuild but leak, compared to mechanical seals
• Never throttle a pump with the suction valve
• Cavitation results from an air leak on the pump's suction side
• Check valves prevent water in the discharge line from flowing back when being used in connection with centrifugal pumps
• Diaphram pumps represent the most reliable type of metering pump
• When beginning a positive displacement sludge pump, the suction valve should be open and the discharge valve closed
• When a high head pump sounds like it is pumping rocks, restrict intake
• If an electrical motor fails to operate, push the reset
• Place water seal rings in line with the water seal pipe hole in the stuffing box when repacking a centrifugal pump
• Reverse flow may be due to improper rotation in a centrifugal pump
• A pump discharges the same volume from each stroke when called a positive displacement pump
• Incorrect steps during operation may include polishing the stem with emery cloth when packing modern gate valves
• Should not grease pump when running
• A peristaltic pump is a type of positive displacement pump
• The water supplied to the water seal on a packed pump should be greater than 5 to 100 PSI relative to the liquid being pumped
• Too-tight packing would be the cause for a pump to draw unnecessarily high amperage
• To comply with safety regulation, all pump couplings must be guarded
• The following precautions must be taken before attempting to maintain or repair a surface aerator: Secure the head assembly before starting to work and Testing the atmosphere for toxic and explosive gases
• Gate valves have rising stems

Regulations

• Substances that harm municipal sanitary wastewater collection systems cannot be discharged
• Most monthly operational reports should be saved for 3 years
• Alarm systems at wastewater treatment facilities in Massachusetts require biannual testing
• At a grade 4 wastewater treatment facility the chief operator must be a grade 4 and the assistant chief must be a grade 1
• Unregulated industrial waste discharge to a municipal wastewater treatment plant might include:Anaerobic digester upset leading to improved plant performance
• The process to treat conventional wastes at a POTW is considered complex
• A level 3 plant needs the chief at a grade 4 and assistant chief operator grade 3
• DEP (Department of Environmental Protection) determines wastewater treatment plant grades when a grade cannot be found.
• Industrial wastewater treatment operators need to know the sources/quantities of waste to identify problems caused by industrial discharges.
• Temperature is a pollutant that is compatible with POTW operation.
• A representative of the Division of Water Pollution Control can inspect a wastewater treatment facility at all reasonable times
• Standard methods for the Examination of Water and Wastewater is the state-specified reference for conducting laboratory analysis at treatment facilities
• Categorical regulations apply to specific industrial groups

Considerations For Treatment Systems

• Equalization is not a detrimental effect that industrial waste waters may have on a POTW (publicly owned treatment works)
• Advantage of biological treatment processes is that the microorganisms adjust quickly to influent temperature
• An operational strategy when toxic waste is discovered in the influent reduces the cost due to damage to equipment/fines
• A staffing plan should be updated every 2 years

Safety

• Pure methane gas, has no odor
• Major injuries in industrial wastewater treatment result from Spills/Falls
• Spilled polymer is a slipping hazard
• When someone suffers physical or emotional shock, telephone for help and talk calmly until help arrives
• The three things necessary for fire are ignition, fuel, and oxidizer
• The following is NOT a route of entry for hazardous chemicals: Inclusion
• If concentrated sulfuric acid is spilled on an arm, rinse with water for at least 15 minutes
• An SDS must be available in an emergency involving a chemical
• Hydrogen gas has a vapor density less than 1
• OSHA states humans should not work in an atmosphere with less than 19.5% level of oxygen than
• While waiting for help to arrive, keep a conscious injured person warm and calm
• Duties of an attendant during a confined space entry do not include entering the space to help an entrant in an emergency
• A lockout procedure ensures electrical and mechanical equipment are de-energized during maintenance
• One the most important factor to keep in mind about treatment plant safety is the proper training of employees
• One of the safest ways to handle emergencies is to plan ahead for it
• Corrosive chemicals include bases
• Breathing becomes difficult when a SCBA (self-contained breathing apparatus) cylinder is running low on air
• The only currently accepted procedures to control bleeding is direct pressure
• First to secure scene and then call fire department and police after a pumps station explodes and four workers are missing
• LEL meters detect explosive gases
• Chewing gum should not affect the fit of respiratory protection equipment
• Spilled polymer will make the floor slippery and can be cleaned up using an inert polymer
• SDS: safety data sheet
• A poor safety program has no assignment or responsibility
• Methane and hydrogen sulfide are only two gases of concern to the IWTO (industrial waste treatment operator)
• A poor safety program has no assignment or responsibility
• According to RCRA, toxicity, Ignitability, corrosivity, and reactivity , indicate that the waste is hazardous
• Disaster planning should reduce confusion in the event of a disaster
• Wastewater operators are responsible for being informed of the chemical hazards for the chemicals used
• Ventilation is the best preventative measure against oxygen deficiency or explosions
• Gases whose vapor density exceeds one in density will tend to gather at floor level or in trenches in turn displacing oxygen
• The main purpose of a confined space entry permit is to ensure the use of safety precautions and safe procedures

Special Processes

• If the sludge blanket in a DAF (Dissolved Air Flotation) Unit builds up, solids can pass under the effluent baffle into the discharge
• Ion exchange removes inorganic dissolved solids from waste streams
• Brewery wastes readily biodegrade in trickling filters
• With a dissolved air floatation clarifier, the thickened sludge leaves at the top
• In a plate and frame press filtering process, the filtrate decreases as the cake builds up between the plates
• Lemella Clarifier benefits over conventional sedimentation tanks: A smaller foot print
• Activated carbon in industrial wastewater treatment removes organic chemicals
• Coconut shells manufacture activated carbon
• Reverse osmosis desalinates water
• Air stripping as a physical unit process is used for industrial use to remove volatile organic chemicals
• Exceeding the feed limit to a centrifuge's will increase centrate solids

Continued Special Processes

• One disadvantage of of ion exchange processes is they may require dilution to prevent attack on resins
• Electrodialysis treats wastewater from electroplating facilities
• Ion exchange removes/recovers metallic ions
• Epoxy or resin lines activated carbon steel pressure containers to prevent corrosion
• COD, not coliform, is collected in an effluent sample, and analyzed daily, to determine if the screens in an activated carbon column are doing an efficent job
• Sedimentation is a common and reliable method of wastewater treatment
• Dialysis does not rely on particle size
• Activated carbon can remove phenols
• Activated sludge treats industrial wastewater pollutants, COD
• Evaporation can achieve volume reduction of wastewater from a plastics manufacturing plant

Testing

• Sulfides, dissolved gasses, and metal concentration are tested using grab samples
• Automatic sampling equipment is difficult to operate because of it requiring cleaning and calibration
• Representative samples must be preserved with ice while being transported
• Jar testing determines coagulant and polymer dose
• A representative sample mirrors overall conditions, but is not a composite sample
• NPDES permit contains information for proper sampling locations
• Samples are preserved at or below 6 degrees Celsius to minimize bacterial activity
• A jar test determines the most economical coagulation dosages
• Samples preserved in basic pH include sulfides
• For accurate pH measurements of effluent from a waste treatment plant, analyze the sample immediately
• A poor sampling point may contain a hazardous atmosphere
• Composite samples mirror the overall conditions and are based on flow and/or time
• Maintenance of automatic sampler is necessary to achieve accurate results and may demand mechanical and electronic skills
• The sample was properly analyzed in a "chain of custody" to legally prove that has occurred
• Color and Sulfide may interfere with the analysis of phenols

Streams

• Domestic wastewater (not cooling water, mining operations, or plating wastes) contains significant quantities of organic material
• Industries discharging hexavalent chrome include pharmaceutical manufacturing
• Any chemicals used in an industrial facility can end up in the waste treatment system
• Wastes are most likely to include chlorinated solvents from a textile manufacturer
• Products spilled on the ground can be a source of pollutants in storm water runoff
• Wastewater generated from papermaking processes includes spent sulfite liquid, FOG, spent organic solvents, and heavy metals

Math

• Concentrations of contaminants (pollutants) are typically measured in Mg/L in the wastewater industry
• 4 PPM converts to 4 mg/L
• 45 feet of water pressure converts to 19.5 psi
• If a gallon of paint will cover 250 sq. ft., then 22 gallons of paint are needed to cover the inside walls and the bottom of a cylindrical tank 75 feet in diameter with sidewalls 10 ft. high
• A 25,000-gallon waste storage tank ought to release the wastewater at the rate of 35 g.p.m ensuring the most uniform discharge over the discharge period of 12 hours
• Set a chemical feed pump at 197/milliliters / min, as it should deliver 75/Gallons per day
• The weight of a 30,000-gallon tank full of dry chemical with a specific gravity of 1.35 is 337,770 lbs
• An industrial waste flow of 0.075 MGD demands a lbs/day setting of 5.3 lbs, assuming its dose of chlorine is 8.5mg/L
• 14,680/gallons: volume of a cylindrical tank that is 10 feet in diameter and 25 feet in height
• Given that a read pump reads 23 psi, its discharge pressure measures 53 feet in feet
• The influent COD measures 285mg/L and the effluent COD = 96mg/L.
• This measures to approximately 66% removal of COD material
• pH is 7.3: average (of 5 data points) from the above information
• The rectangular tank will require 14/gallons, assuming its measurements are 10 feet high by 20 feet wide by 40 feet long
• MGD is typically how flow is recorded in wastewater treatment plans
• With measurements being: diameter of 45 inches, height of 18 inches, the entire surface area to be painted for an uncovered, free-standing cylindrical tank measuring 424/sq. ft.
• At 10/ft. on each side (cubic), weight of wastewater calculates as ~62.4/lbs.
• With 350/Gal of Sodium(Metabisulfite) as total volume, calculate the height of a cylindrical tank (Diameter = 4/ft.) as 3.7/ft.
• Lbs/hr equals 0.42 if industrial flow measures15000/GPD and assumes chlorine as 805/mg/L
• Measurements are (influent TSS = 285/mg/L) while (effluent TSS = 96/MG/L): % TSS removal through use of a LAMELLA-Clarifler = 66%
• At 4 feet tall / 6 feet long / ~ 48" or 3.3 ft, calculate cubic inches of wastewater that a rectangular tank can hold 138,240/in(power of 3.)
• If lab numbers come as 150 mg/L, its calculation is 0.0012 lb/gal
• A concentration of parts per million with Cyanide comes as 1.5 ppm
• A facility discharging 5000 gallons containing 5 lb. Of TPH calculates to be 120 ppm
• If the Scale is 1" = 10' for planning, a chemical room measured to be 1.5" X to the power of 1.75" equals 1,200 square feet
• Lb./Min measures to (0.58), calculate the flow rate of (SO) which measures 2,100 per day
• Stream traveling at 1.4 miles per hour: approximately 1.4 mph
• Mass/volume or Mg/L of a substance represents its mass rate of emission
• Approximately 2794 : calculate how many hours would a CFS (Cubic Ft per Second)

Miscellaneous Items

• Teflon containers are useful because these tools DO NOT intermix with or act in response with other substances.
• Ideal pinfloc comes and only occurs when velocity is both to high or too low
• Distilled/R.O. (Reverse Osmosis) water are best used at absorbing spilled oil-based substances
• Etching best reflects when chemicals of toxicity find their way to the wastes themselves
• A testing of the strength of a chemical is done using the (COD) protocol/guideline
• Valve, if cracked equals root problem as to why air will not distribute (for a standard air-flow tool)
• A Broken (Roller) Bearing is most like to cause a drum or wheel which turns on axis is not turning: drum screen
• A (22%) drop represents the rate if wastewater pumping decreased from 450 to 350 (GDP)
• Grease/Oil are well cleaned with: to avoid stopping the flow throughout the sewer lines
• A plating bath, being inherently a acidic tool is: Chromate
• A toxicity that impacts wastes comes from pesticide manufacturing
• Before water is dispatched/pushed into river systems, the first step is to (EQ) Equalize it
• Auto-Generated Samplers as used primarily in the field may be used to record characteristics, however cannot save information from toxic release moments