WASTEWATER ENGINEERING

1ST SET

FWPA

Federal Water Pollution Control Act

CAFO

Concentrated Animal Feeding Operation

Concentrated Animal Feeding Operation

facilities where animals are fed and confined for 45 days or more in any 12- consecutive month period, and where crops, vegetation, forage growth, or postharvest residues are not grown or sustained in a feedlot or facility.

Non-point Source

examples are agricultural and urban runoff

Non-point Source

also called diffuse sources

Point sources

Occur when harmful substances are emitted directly into a body of water from a pipeline or sewer.

Point sources

examples are domestic sewage and industrial wastes

Point sources

stationary locations such as an effluent pipe.

Load

Refers to the mass flux of a pollutant and is expressed as mass per unit time

NPDES

National Pollutant Discharge Elimination System

Conventional pollutants

Toxic pollutants

Non- conventional pollutants

Clean Water Act of USA categorized pollutants into three categories namely:

SEWAGE

it is the liquid (spent water) conveyed by a sewer

Domestic Sewage

Also known as sanitary sewage

Domestic Sewage

-          the one that originates in the sanitary conveniences of a dwelling, residences, commercial institutional and similar facilities.

Industrial wastewater

i.e. waste from industrial process such as brewing, dyeing, etc.)

Storm sewage

Liquid flowing in sewers during or following a period rainfall and resulting from precipitation runoff

Inflow

-          Is water discharged into sewer pipes or service pipe connection from sources such as roof leaders etc.

Infiltration

-          is the groundwater entering sewers and building connections through defective joints and broken or cracked pipe and manholes.

INFILTRATION/ INFLOW

Extraneous flows in sewers

Infiltration

-          Water entering a sewer system, including sewer service connections, from the ground through such means as defective pipes, pipe joints, connections or manhole walls.

Steady inflow

-          Type of inflow that is steady and is identified and measured along with infiltration.

Steady inflow

o   Examples are water discharged from cellar and foundation drains, cooling water discharges and drains form springs and swampy areas.

Direct inflow

Those type of inflow that have a direct storm water runoff connection to the sanitary sewer and cause an almost immediate increase in wastewater flows

Direct inflow

o   Ex: water from roof leaders, yard and areaway drains, manhole covers and combined sewers.

Total inflow

-          The sum of the direct inflow at any point in the system plus any flow discharged from the system upstream thru overflows, pumping stations bypasses and the likes.

Delayed inflow

-          Storm water that may require several days or more to drain thru the sewer system. Example discharge of sump pumps from cellar drainage.

Black water

-          Is a domestic wastewater comprising toilet waters only.

Grey water

-          Is a waste flow originating from kitchen, bath, shower and laundry excluding toilet wastes.

Stale sewage

-          Has a pronounced odor of hydrogen sulfide (H2S), dark gray and occasionally contains recognizable solids.

Biosolids

semi-solid by-products that are rich in nutrients, formed after separation and treatment of solid during the wastewater treatment process

Biosolids

This is sewage sludge that has been treated to reduce disease-causing pathogens, thus becoming suitable for beneficial reuse

Infiltration

The flow of water from the surface into the ground or into a wastewater system.

Infiltration

occurs when groundwater seeps into sewer pipes through cracks, leaky pipe joints, and deteriorated manholes

Waste Activated Sludge (WAS):

A type of sludge that is produced in the treatment of wastewater and that contains a high concentration of organic matter.

anaerobic digestion or thermal drying

WAS is often treated and stabilized through processes such as _______ or_______

Grit

Heavy inorganic solids, such as sand, gravel, eggshells, or metal filings

Pathogen

A disease-causing microorganism, such as a bacterium or virus.

Direct Flow

Those inflow types create an almost immediate rise in wastewater flows and have a direct relationship between the sanitary sewer and stormwater runoff.

Direct Flow

Roof leaders, yard and areaway drain, manhole covers, cross-connections from catch basins and storm drains, and combined sewers are examples of potential sources.

Combined Sewer

A sewer that carries both sanitary wastewater and stormwater runoff.

Settleability

the quality or state of being able to settle or be settle

Settleability (30, 60)

A process control test used to gauge how well the activated sludge settles. The settled sludge volume (SSV) and the sludge volume index are calculated using readings taken between ___ and ___ minutes (SVI).

Nitrogenous oxygen demand (NOD)

a quantitative measure of the amount of dissolved oxygen required for the biological oxidation of nitrogenous material, for example, nitrogen in ammonia, and organic nitrogen in waste water

Anoxic

conditions where dissolved oxygen is absent or extremely low, but nitrate or nitrite (bound oxygen) is present to serve as an electron acceptor for microorganisms.

Inorganic

not being or consisting of living material, or of chemical substances, containing no carbon or only small amounts of carbon

Nutrients

substances that provide necessary nourishment for sustaining life and growth

Detention Time

This is the estimated amount of time water will stay in a tank at a specific flow rate.

Septic

refers to the anaerobic bacterial environment that develops in the tank which decomposes or mineralizes the waste discharged into the tank

Chemical Oxygen Demand (COD)

a measure of the amount of oxygen required to chemically oxidise organic substances in water such as ammonia or nitrate, in applications such as lakes, rivers or wastewater which have been contaminated by domestic or industrial waste. It is used to provide an indication of the level of pollution in a water course, especially after a water treatment process.

carbonaceous biochemical oxygen demand (CBOD)

measures dissolved oxygen depletion only from carbonaceous sources. When applied to wastewater, CBOD measures the potential of wastewater to deplete the oxygen level in the receiving water

Advanced Wastewater Treatment

Treatment technology to produce an extremely high-quality discharge.

Advanced Wastewater Treatment

this treatment uses a combination of physical, chemical and biological processes to eliminate pollutants like suspended solids, organic matter, nitrogen, and phosphorus, making the water safe for reuse or environmental discharge

mg/L

unit that expresses the concentration of a substance in water, indicating the amount of solute in milligrams contained in one liter of water

Activated Sludge

A method of treating water through biology that is frequently employed in municipal wastewater treatment facilities

Activated Sludge

an aerobic biological process that uses microorganisms like bacteria and protozoa combined with oxygen (aeration) to treat municipal and industrial wastewater

Daily Discharge

daily measurement of pollutants or substances released into the environment by a facility, requiring regular testing and reporting under environmental regulations.

Hospital wastewater flow

the movement and characteristics of the complex mixture of liquids from healthcare facilities that are typically collected and treated before discharge.

Very Fine Screens

these have openings of 0.2 to 1.5mm and are placed after coarse or fine screens can reduce suspended solids to levels near those achieved by primary clarification

Anaerobic

Refers to an environment that lacks oxygen

anaerobic processes

involve the breakdown of organic matter in the absence of oxygen.

screening

the first physical preliminary step that removes large solid objects and debris, such as rags, sticks, and plastics, from incoming wastewater using bar screens or mesh filters

continuous belt

receives influent wastewater in an enclosed tank, where filtration occurs as the belt rises from the water. the solid residue is then conveyed above the tank liquid level, where they are washed off with spray water then dewatered using a screen auger

Dissolved oxygen (DO)

a measure of how much oxygen is dissolved in the water, and the amount of oxygen available to living aquatic organisms

Return Activated Sludge (RAS)

Sludge that is returned to an earlier stage of a wastewater treatment

grit removal

the process used to remove sand, silt and grit from water. this generally involves using sedimentation technologies prior to primary treatment in municipal WWTPs and the removed grit is generally disposed in landfills

Comminution

The process of reducing the size of particles in water

Comminution

the reduction of solid materials from one average particle size to a smaller average particle size, by crushing, grinding, cutting, vibrating or other processes

Biochemical Oxygen Demand (BOD)

measures the amount of oxygen consumed by microorganisms to decompose organic matter in a water sample, indicating organic pollution levels

Sludge

The semi-solid material that is left over after the treatment of sewage. It contains organic matter, nutrients, and other contaminants that need to be removed or processed before it can be safely disposed of or used as a fertilizer.

Biosolids

This is sewage sludge that has been treated to reduce disease-causing pathogens, thus becoming suitable for beneficial reuse

Grab Sample

An individual sample collected at a randomly selected time

Grab Sample

method of collecting a water sample at a specific point in time and space. it is a technique that is often used to measure water quality

Settled Sludge Volume (SSV)

The volume (in percent) occupied by an activated sludge sample after 30 to 60 minutes of settling; normally written as SSV with a subscript to indicate the time of the reading used for calculation (SSV60 or SSV30).

Settled Sludge Volume (SSV)

it measures the volume of sludge that settles to the bottom of a container after a predetermined time period, providing a practical assessment of the sludge’s density and settling characteristics

organic

carbon-based compounds that are present in the wastewater

sewage

a domestic or industrial wastewater which is discharged into a sewer system

Delayed Inflow

Stormwater takes a few days or longer to pass through the sewage system. Sump pump discharge from cellar drainage and surface water entering ponded areas through manholes slowly falls under this category

wastewater/sewage

the water supply of the community after it has been fouled by a variety of uses

wastewater engineering

branch of environmental engineering in which basic principles of science and engineering are applied to the problem of water pollution control

pathogenic microorganisms

disease-causing microorganisms that dwell in human intestinal tract or that may be present in industrial wastes

heterotrophs

uses organic material as a supply of carbon

autotrophs

requires only carbon dioxide to supply their carbon needs

phototrophs

rely only on sun for energy

chemotrophs

extract energy from organic/inorganic oxidation/retox reactions

organotrophs

uses organic materials for energy

lithotrophs

oxidize organic compounds

obligate aerobes

microorganisms that must have oxygen as a terminal electron acceptor

obligate anaerobes

cant survive in the presence of oxygen

obligate anaerobes

can’t use oxygen as terminal electron acceptor

facultative anaerobes

can use oxygen as the terminal electron acceptor, under certain conditions can also grow in the absence of oxygen

Psychrophiles

bacteria grow best below 20C

Mesophiles

bacteria grow best between 25 to 40C

Thermophiles

bacteria grow best between 45 to 60C

Stenothermophiles

bacteria grow best above 60C