Water Supply Midterms

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The process of a seed starting to grow, or the act of causing a seed to start growing

germination

Three basic requirements of agricultural production

soil seed water

Additional requirements of agricultural production

fertilizers, insecticides, sunshine, suitable atmospheric temperature, human labor

most important requirement of agricultural production.

water Signup and view all the answers

The artificial application of water to land for supplementing the naturally available moisture in the root-zone soil for the purpose of agricultural production is

irrigation Signup and view all the answers

Applications of water in soil

supplies moisture, cools the soil, dilutes salt, softens clods, enables fertilizer application, reduces adverse effects of frost, ensures crop success against short-duration droughts Signup and view all the answers

Two categories of irrigation schemes

surface, ground Signup and view all the answers

Use diversion and storage methods and obtain their supplies from rivers.

surface water irrigation scheme Signup and view all the answers

Use open wells, and deep and shallow tube wells to lift water from the water-bearing strata below the earth’s surface

ground water irrigation scheme Signup and view all the answers

Factors to be considered in irrigation systems

surface topography, rainfall characteristics, type of source available, subsoil profile Signup and view all the answers

Traditional Methods of Irrigation

pulley system, chain pump, dhekli, rahat Signup and view all the answers

Also known as Moat. During this method, water is directly collected from the well, using a pulley to irrigate fields.

Pulley system Signup and view all the answers

It consists of two large wheels connected with an endless chain. The bottom wheel is half immersed in the water source. With the turning of the wheel, the connected buckets dip into the water source and bring water. Chain lifts them to the upper wheel where water from the bucket is transferred to the pool.

chain pump Signup and view all the answers

During this system, a rope and bucket is connected to a pole or heavy stick to obtain water from the well. It is also connected to a heavy counterweight at the other end to draw water.

dhekli Signup and view all the answers

During this method, water is drawn from the well through a wheel connected to animals like cows, buffalo, oxen, etc. With the movement of animals, wheels rotate and it draws the water from the well.

rahat Signup and view all the answers

Modern Methods of Irrigation

furrow, basin, sprinkler, drip Signup and view all the answers

is a method of laying out the water channels in such a way where gravity plays the role of providing just enough water for suitable plants to grow. It is usually made by the planned placement of ridges and furrows. It is a kind of surface irrigation system.

furrow irrigation Signup and view all the answers

is the most common form of surface irrigation, particularly in regions with layouts of small fields. If a field is level in all directions, encompassed by a dyke to prevent runoff and provides an undirected flow of water onto the field, it is referred to as basin. (Stauffer & Spuhler 2012)

basin irrigation Signup and view all the answers

Mimic the phenomenon of rain. The pipes carry water to central locations on the farm. Is one of the most efficient irrigation methods to irrigate the uneven land for agriculture.

sprinkler irrigation Signup and view all the answers

we lay plastic pipes in rows near the crops or plants. These pipes have holes in them. The water seeps from these holes drop by drop, hence the name

drip irrigation Signup and view all the answers

Specific Function of Irrigation System

divert water, convey to individual fields, distribute to each field, measure regulating flows Signup and view all the answers

is built at the entry to the irrigation system. Its purpose is to direct water from the original source of supply (lake, river, reservoir etc.) into the irrigation system.

main intake structure Signup and view all the answers

In some cases, the irrigation water source lies below the level of the irrigated fields. Then it must be used to supply water to the irrigation system

pump station Signup and view all the answers

consist of canals transporting the water through the whole irrigation system.

conveyance and distribution system Signup and view all the answers

are required for the control and measurement of the water flow.

canal structures Signup and view all the answers

or ditch, is an open waterway whose purpose is to carry water from one place to another.

open canal Signup and view all the answers

refer to main waterways supplying water to one or more farms.

channels and canals Signup and view all the answers

have smaller dimensions.

field ditches Signup and view all the answers

Canal Characteristics

rectangular, triangular, trapezoidal, circular, parabolic, irregular Signup and view all the answers

are simply dug in the ground and the bank is made up from the removed earth

earthen canal Signup and view all the answers

Earthen canals that are lined with impermeable materials to prevent excessive seepage and growth of weeds

lined canal Signup and view all the answers

four main types of canal structures

erosion control, distribution control, crossing, water measurement Signup and view all the answers

are required to reduce the bottom slope of canals lying on steeply sloping land in order to avoid high velocity of the flow and risk of erosion.

drop structure or chutes Signup and view all the answers

are used to divide or direct the flow of water between two or more canals or ditches.

division boxes Signup and view all the answers

are constructed in the bank of a canal. They divert part of the water from the canal to a smaller one.

turnouts Signup and view all the answers

are used to divert water from the field ditch to the field, it is often necessary to raise the water level in the ditch.

checks Signup and view all the answers

used to carry irrigation water across roads, hillsides and natural depressions.

crossing structure Signup and view all the answers

are used to carry the water across roads.

culvert Signup and view all the answers

is used instead of a culvert when water has to be carried across a road which is at the same level as or below the canal bottom

inverted siphon Signup and view all the answers

its main objective is to permit efficient distribution and application.

water measurement structure Signup and view all the answers

consists of a wall of timber, metal or concrete with an opening with fixed dimensions cut in its edge

weir Signup and view all the answers

consists of a metal or concrete channel structure with three main sections

parshall flume Signup and view all the answers

is similar to the Parshall flume, but has no throat section, only converging and diverging sections

cut-throat flume Signup and view all the answers

is necessary to remove excess water from the irrigated land. This excess water may be e.g. waste water from irrigation or surface runoff from rainfall. It may also include leakage or seepage water from the distribution system.

drainage system Signup and view all the answers

Excess surface water is removed through

shallow open drain Signup and view all the answers

Excess groundwater is removed through

deep open drain or underground pipe Signup and view all the answers

What is the presence of a substance where it should not be or at concentrations above background?

contamination Signup and view all the answers

It is due to the influence or activities of people

pollution Signup and view all the answers

It always creates harmful effects

pollutants Signup and view all the answers

It does not always create harmful effects.

contaminants Signup and view all the answers

“All pollutants are contaminants, but not all contaminants are pollutants.” T or F

true Signup and view all the answers

Common Chemical Pollutants

turbidity, phosphorous, nitrate, DO, BOD, temperature Signup and view all the answers

Parameters of Water

physical, chemical, biological Signup and view all the answers

contaminants that can cause sickness or illness at very low levels or low exposure

acute contaminants Signup and view all the answers

cause sickness or illness only after prolonged exposure to the contaminant in drinking water

chronic contaminants Signup and view all the answers

some common contaminants encountered in water treatment

arsenic, lead, copper, nitrate, manganese, iron Signup and view all the answers

Basic Water Quality Parameters

pH, electrical conductivity, salinity, turbidity, DO, BOD, temperature, CO2, solids, alkalinity and hardness, coliforms Signup and view all the answers

Measured hydrogen ion concentration. Negative log of hydrogen ion concentration. It reflects the acidity or alkalinity of solution

pH Signup and view all the answers

The measure of the ability of water to conduct an electric current and depends upon the number of ions or charged particles in the water, and is measured by passing a current between two electrodes that are placed into a sample water.

conductivity Signup and view all the answers

in measuring this, we consider the concentration of salt dissolved in the water.

salinity Signup and view all the answers

Amount of gaseous oxygen (O2) dissolved in water.

dissolved oxygen Signup and view all the answers

The cloudy or muddy appearance of a naturally clear liquid caused by the suspension of particulate matter.

turbidity Signup and view all the answers

Is the amount of oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample at certain temperature over a specific time period.

biochemical oxygen demand Signup and view all the answers

are caused by volatile substances associated with organic matter, living organisms, and gases

odors Signup and view all the answers

are caused by: ○ Chlorides and sulfates of calcium, magnesium, and sodium ○ Organisms (algae) ○ Industrial Waste

taste Signup and view all the answers

three categories of solids

settleable, suspended, fine or dissolved Signup and view all the answers

are relatively larger and heavier particles that can settle under the influence of gravity within a specified time period

settleable solids Signup and view all the answers

refer to solid particles that are small enough to remain suspended in wastewater without settling.

suspended solids Signup and view all the answers

Particles that are dissolved in water and cannot be removed by physical separation methods.

fine or dissolved solids Signup and view all the answers

Known as “Acid neutralizing capacity of water”. is a measure of the presence of bicarbonate, carbonate, or hydroxide constituents.

alkalinity Signup and view all the answers

is the amount of dissolved calcium and magnesium in the water. Usually expressed as the number of parts per million (ppm).

hardness Signup and view all the answers

they indicate the presence of fecal material and hence the presence of intestinal pathogens.

coliforms Signup and view all the answers

The maximum concentration of a chemical that is allowed in public drinking water systems.

maximum contaminant level Signup and view all the answers

what does NTU mean

nephlometric turbidity unit Signup and view all the answers

MRDL

maximum residual disinfectant level Signup and view all the answers

Water Treatment Processes

softening, coagulation, flocculation, adsorption, settling, filtering, disinfection Signup and view all the answers

One of the problem comes from material that is less than one micrometer (0.001 mm) in size, which is called

colloidal material Signup and view all the answers

The process of decreasing the stability of the colloids in water is called

coagulation Signup and view all the answers

Two opposing forces that impact the removal of colloidal material:

stability factors, instability factors Signup and view all the answers

are those factors that help to keep colloids dispersed.

stability factors Signup and view all the answers

are those factors that contribute to the natural removal of colloids.

instability factors Signup and view all the answers

Most Common Coagulants

aluminum sulfate, sodium aluminate, ferric sulfate, ferrous sulfate, ferric chloride, polyaluminum chloride, cationic polymers Signup and view all the answers

The amount of coagulant which should be added to the water will depend on the

zeta potential Signup and view all the answers

It is a physical process of slowly mixing the coagulated water to increase the probability of particle collision.

flocculation Signup and view all the answers

It is an adhesion of atoms, ions or molecules from a gas, liquid or dissolved solid to a surface. involves its accumulation onto the surface of a solid called the adsorbent.

adsorption Signup and view all the answers

is a solid substance used to remove contaminants from liquid or gas that can harm the environment.

adsorbent Signup and view all the answers

adsorbents

activated carbon, activated alumina, molecular sieves, silica gel Signup and view all the answers

a process of settling that allows the flocculated or coagulated particles to settle by gravity in a sedimentation tank.

sedimentation Signup and view all the answers

A physical process of separating suspended and colloidal particles from water by passing the water through a filter media.

filtration Signup and view all the answers

can consist of silica sand, greensand, anthracite coal, activated carbon, and many other types of media.

filter media Signup and view all the answers

offers high filtration efficiency due to the smaller pore sizes of the membranes.

membrane filtration Signup and view all the answers

Bag or cartridge filters capable off removing giardia and cryptosporidium

membrane cartridge filtration Signup and view all the answers

Membrane filters capable of removing pathogenic organisms larger than 0.1 micrometers in size.

microfiltration Signup and view all the answers

Membrane filters capable of removing pathogenic organisms larger than 0.005 micrometers in size.

ultrafiltration Signup and view all the answers

Membrane filters capable of removing pathogenic organisms and dissolved organic contaminants larger than 0.001 micrometers in size.

nanofiltration Signup and view all the answers

Membrane filters capable of removing pathogenic organisms, dissolved organic, and salts contaminants larger than 0.0001 micrometers in size. Water flows from side that has the highest concentration to the side with the lowest concentration by applied pressure.

reverse osmosis Signup and view all the answers

Water flows from the side that has the lowest concentration to the side that has the highest concentration.

osmosis Signup and view all the answers

Water is clear after the filtration process but still contaminated by microorganisms which must be killed by using disinfectant.

disinfection Signup and view all the answers

boiling water and irradiation with ultraviolet light.

physical disinfection Signup and view all the answers

adding chlorine , bromine, iodine, and ozone to water.

chemical disinfection Signup and view all the answers

Types of Disinfection

physical and chemical Signup and view all the answers

It kills vegetative bacterial cells, but spores, virus, and some protozoa may survive long periods

boiling Signup and view all the answers

is an effective and relatively safe disinfection method, but is relatively expensive and not widely used.

UV radiation Signup and view all the answers

is employed primarily for microbial disinfection.

chlorination Signup and view all the answers

kills microogranisms more effectively

free chlorine Signup and view all the answers

formed when free chlorine reacts with other chemicals in water

combined chlorine Signup and view all the answers

the sum of free and combined chlorine

total chlorine Signup and view all the answers

is the process of removing residual chlorine from disinfected wastewater prior to discharge into the environment.

dechlorination Signup and view all the answers

is a strong oxidant, that produces hydroxyl free radicals that react with organic and inorganic molecules in water to kill microbes.

ozone Signup and view all the answers

To remove hardness (Ca and Mg) in water.

softening Signup and view all the answers

Main supply lines run through the center of the building and sub mains branch off in perpendicular directions.

grid-iron system Signup and view all the answers

Elevated reservoir is centrally located and divided into several distribution area

radial system Signup and view all the answers

are large pipes that carry large quantities of water from the treatment plant and storage tanks into the distribution system.

transmission lines Signup and view all the answers

generally run in straight lines, have few side connections, and aren’t tapped for customer services.

transmission pipes Signup and view all the answers

Connected to transmission mains. transmit flow to distribution mains.

arterial mains Signup and view all the answers

carry water from transmission lines and distribute it throughout a community.

distribution mains Signup and view all the answers

Machine used to convert mechanical energy to fluid energy.

pumps Signup and view all the answers

moves a fluid by repeatedly enclosing a fixed volume and moving it mechanically through the system.

positive displacement pump Signup and view all the answers

add energy to the fluid by accelerating it through the action of a rotating impeller.

rotodynamic and kinetic pump Signup and view all the answers

discharges radially

centrifugal pump Signup and view all the answers

discharges axially

axial-flow pump Signup and view all the answers

radial and axial

mixed-flow pump Signup and view all the answers

type of fitting that allows for regulation, control, and direction of fluids passing through a pipe.

valve Signup and view all the answers

Prevent Backflow

check valve Signup and view all the answers

Prevent water from leaving the pump

foot valve Signup and view all the answers

To stop or start a flow

gate valve Signup and view all the answers

Required at high points to release trap air.

air-relief valve Signup and view all the answers

To keep the dirt from entering the pump

strainer Signup and view all the answers

The total demand for water, which encompasses the amount of water required by the community for various purposes, such as meeting consumer needs, supplying water for fire-fighting, system flushing, and accounting for potential leaks.

water demand Signup and view all the answers

ADD

Average Daily Demand Signup and view all the answers

AAD

Average Annual Demand Signup and view all the answers

MDD

Maximum Day Demand Signup and view all the answers

MMD

Maximum Month Demand Signup and view all the answers

PHD

Peak Hourly Demand Signup and view all the answers

PWD

Peak Weekly Demand Signup and view all the answers

demand per person

per capita Signup and view all the answers

Ratio of the demand to the average day demand

peaking factor Signup and view all the answers

This involves gathering water from multiple sources and allowing sediments found in river or spring water to settle out.

collection chamber Signup and view all the answers

The transportation of water from its source to the treatment facility utilizes various conduits, such as open channels, aqueducts, pipelines, and so on, which are collectively referred to as

transmission mains Signup and view all the answers

are constructed at or below ground level and usually discharge water to the distribution system through pumps.

ground storage reservoir Signup and view all the answers

is useful in the case of fires and emergency conditions. allow the natural force of gravity to produce consistent water pressure throughout the system.

elevated storage tanks Signup and view all the answers

Large column (shaped like a vertical pipe) that can store water. The extra height of it allows it to use gravity in order to maintain proper water pressure.

standpipes Signup and view all the answers

One main pipelines runs through the center of the area. Sub Main lines are divided into several branch.

Dead-End System Signup and view all the answers