Ga Wastewater Class 2

Gor pH meters. a pH of 7 corresponds to how many millivolts?

0

High-rate activated sludge processes typically have a mean cell residence time of?

1 to 5 days

You conducted a jar testing on one liter samples of sludge. The best results came from the jar that received 26mL of 0.5 percent polymer solution. What is the polymer concentration in this jar?

130 mg/L

An ideal carbon to nitrogen ratio for composting sludge is __________

30:1

What is the maximum safe level of ammonia a worker can be exposed to during an 8-hour workday?

50 ppm

Which of the following chemicals is commonly used for chemical phosphorus removal?

Aluminum Sulfate

Which of the following chemicals is used to precipitate phosphorus from wastewater

Aluminum Sulfate

NH3

Ammonia

In typical domestic wastewater, what are the typical percent removals of BOD and TSS during primary treatment?

BOD: 20-35 TSS 50-75

Slime slakers convert quicklime(CaO) to __________

Calcium Hydroxide

Impellers are a component of ______ pumps

Centrifugal

Solid-bowl describes which type of dewatering equipment?

Centrifuges

A chemical commonly used for controlling hydrogen sulfide and its odors is __________?

Chlorine

Oxidation Reduction Potential (ORP) is most often associated with _______.

Chlorine Control

Which of the following thickening processes mixes incoming sludge with a pressurized recycle stream as it enters the thickener?

Dissolved Air Flotation Thickener (DAF)

The First indicator of a high organic load coming into an activated sludge process is a decease in ________.

Dissolved Oxygen

As a last resort, what situation might require an operator to chlorinate the RAS?

Excessive Filamentous Organsisms

Which of the following chemicals would be used to aid in precipitating phosphorus?

Ferric Chloride

What condition/situation might require an operator to chlorinate the RAS?

Filamentous Organisms

Rotary drum screens are typically classified as _________

Fine screens

Breakpoint Chlorination

Free Chlorine + Combined Chlorine = Total Chlorine

Which of the following units is used for the final washing and dewatering of grit?

Grit Classifiers

Starch Solution(Reagent)

Indicator

Most often the WAS rate for an activated sludge process is based on _______.

MRCT or SRT

The precise amount of polymer used to settle sludge in a thickener is termed the _____.

Optimal Dosage

The lack of acid preservation and digestion of a filtered phosphorus sample will measure only ________

Orthophosphate

The microorganisms typically involved in the activated sludge treatment are bacteria and metazoa such as?

Rotifers

The process of adding water to quicklime is termed________

Slaking

Which of the following is true of the pressure dewatering zone in the belt filter press?

Sludge passes from the low-pressure zone created by large-diameter rollers to the high-pressure zone created by small-diameter rollers

NaOH

Sodium Hydroxide (caustic soda)

The differential speed of of a centrifuge results in ___________.

Solids being transported from the feed zone to the beach

The last step to starting a gravity belt thickener is _________.

Starting polymer and sludge feed pumps

________ can be used to break the emulsion when using emulsion-type polymers.

Static Mixers

Normal Sodium Thiosulfate(Reagent)

Stock Solution/Chloroform is added in order to decrease bacterial decontamination

Most of the major odorous gases contain which element?

Sulfur (S)

An operator notices that some of the secondary clarifiers have rafts of sludge floating on the liquid surface of the clarifiers. What is the problem?

The sludge is not being removed quickly enough from the clarifiers, causing denitrification to occur in the tanks

Normal Sodium Thiosulfate(Reagent)

Titrant. Prepared from 0.1 Normal solution above.

Which of the following influent constituents cannot be removed through bioflocculation?

Total Dissolved Solids

Potassium Bi-lodate or Potassium Dichromate(Reagent)

Used to standardize the Sodium Thiosulfate

What type of unit removes grit from wastewater?

Vortex Separator

a cation typically used to precipitate phosphorus from wastewater is

aluminum

In an electrical circuit an ________ is used to measure current.

ammeter

Which type of bacteria use chemically bound oxygen?

anoxic

In general biological sludges require __________ polymer for coagulation and flocculation.

cationic

If your calculated F:M value is significantly higher than your target, which of the following actions could help to correct the situation.

decrease the wasting rate

How does an increase in effluent water temperature impact chlorine disinfection?

demand increases; residual decreases

If an activated sludge is not settling or compacting well there may be _____________________

excessive filamentous organisms

The most common type of wastewater treatment pond used is the ______ pond.

facultative

The hydraulic loading rate to a trickling filter is based on

flow to the filter and surface area of the filter

Typically the presence of light, stiff, billowy foam on the surface of an aeration tank is an indication of _______________.

high F:M ratio

Dominance of flagellates in your mixed liquor indicate?

high F:M, low SRT

The target SRT is 12 days. Currently, the MLSS concentration is 2800 mg/L. Tourist season begins this weekend and the influent BOD load is expected to increase by 25% in the next few days. What should the operator do to maintain the SRT?

increase the wasting rate

Excessive organic material is being removed from a grit system. This situation can be corrected by

increasing the velocity

The air-to-solids ration for a DAF unit is always

less than one

In anaerobic digestion, what explosive gas is formed?

methane

Which two compounds are formed during nitrification?

nitrate and nitrite

Which of the following is a probable cause for excessive sloughing in a rotational biological contactor?

pH below 5.0

If there is insufficient alkalinity in your wastewater initially, the _____ of an aerobic digester tends to _____ over time

pH, decrease

The purpose of a turnbuckle on the stay rod on a trickling filter is to ________.

permit the adjusting and leveling of the distributer arm

Sludge cake is moved through a multiple-heart furnace by an action called?

rabbing

Potassium Iodine(KI)(Reagent)

reacts with the chlorine

Grit is washed in order to _______.

remove organic matter

H2SO4

sulfuric acid

MLVSS is used for SOUR testing rather than MLSS because

the MLVSS does not include inert solids

Acetic Acid(Reagent)

to lower the pH to between 3-4

The bioassay test measures the ________ of a plant's effluent sample

toxicity

The first step in shutting down a centrifuge is to?

turn of the feed sludge

The primary indicator of an upset in your anaerobic digester is _________

volatile acids increase