Question
Follow the below statement and compile a formal reporton the Wastewater treatment. The report should have followingelements: title, table of content, list of tables, executivesummary, introduction, main body, conclusion, recommendation,bibliography and properly numbered pages.
Wastewater Treatment Water Us
Wastewater is used water. It includes substances such as humanwaste, food scraps, oils, soaps and chemicals. In homes, thisincludes water from sinks, showers, bathtubs, toilets, washingmachines and dishwashers. Businesses and industries also contributetheir share of used water that must be cleaned.
Why Treat Wastewater?
There are a lot of good reasons why keeping our water clean isan important priority: fisheries, wildlife habitats, recreation andquality of life and health concerns.
If wastewater is not properly treated, then the environment andhuman health can be negatively impacted. These impacts can includeharm to fish and wildlife populations, oxygen depletion, beachclosures and other restrictions on recreational water use,restrictions on fish and shellfish harvesting and contamination ofdrinking water. Some examples of pollutants that can be found inwastewater and the potentially harmful effects these substances canhave on ecosystems and human health:
- Decaying organic matter and debris can use up the dissolvedoxygen in a lake so fish and other aquatic biota cannotsurvive;
- Excessive nutrients, such as phosphorus and nitrogen (includingammonia), can cause eutrophication, or over-fertilization ofreceiving waters, which can be toxic to aquatic organisms, promoteexcessive plant growth, reduce available oxygen, harm spawninggrounds, alter habitat and lead to a decline in certainspecies;
- Chlorine compounds and inorganic chloramines can be toxic toaquatic invertebrates, algae and fish;
Wastewatertreatment
The major aim of wastewater treatment is to remove as much ofthe suspended solids as possible before the remaining water, calledeffluent, is discharged back to the environment. As solid materialdecays, it uses up oxygen, which is needed by the plants andanimals living in the water.
"Primary treatment" removes about 60 percent of suspended solidsfrom wastewater. This treatment also involves aerating (stirringup) the wastewater, to put oxygen back in. Secondary treatmentremoves more than 90 percent of suspended solids.
The use of reclaimed wastewater helps people in twoways:
- Reclaimed water can supply needed water for some purposes
- Reclaimed wastewater frees up fresh water that can be usedsomewhere else, such as for drinking water
Uses of reclaimedwastewater
URBAN USES
Irrigation of public parks, sporting facilities, privategardens, roadsides; Street cleaning; Fire protection systems;Vehicle washing; Toilet flushing; Air conditioners; Dustcontrol.
AGRICULTURAL USES
Food crops not commercially processed; Food crops commerciallyprocessed; Pasture for milking animals; Fodder; Fiber; Seed crops;Ornamental flowers; Orchards etc
RECREATIONAL USES
Golf course irrigation; Recreational impoundments with/withoutpublic access (e.g. fishing, boating, bathing); Aestheticimpoundments without public access; Snowmaking.
ENVIRONMENTAL USES
Aquifer recharge; Wetlands; Marshes; Stream augmentation;Wildlife habitat; Silviculture.
POTABLE (DRINKABLE) USES
Aquifer recharge for drinking water use; Augmentation of surfacedrinking water supplies; Treatment until drinking waterquality.
THE PRIMARY TREATMENT PROCESS
1. Screening
Wastewater entering the treatment plant includes items likewood, rocks, and even dead animals. Unless they are removed, theycould cause problems later in the treatment process. Most of thesematerials are sent to a landfill.
2. Pumping
The wastewater system relies on the force of gravity to movesewage from your home to the treatment plant. Sowastewater-treatment plants are located on low ground, often near ariver into which treated water can be released. If the plant isbuilt above the ground level, the wastewater has to be pumped up tothe aeration tanks (item 3). From here on, gravity takes over tomove the wastewater through the treatment process.
3. Aerating
One of the first steps that a water treatment facility can do isto just shake up the sewage and expose it to air. This causes someof the dissolved gases (such as hydrogen sulfide, which smells likerotten eggs) that taste and smell bad to be released from thewater. Wastewater enters a series of long, parallel concrete tanks.Each tank is divided into two sections. In the first section, airis pumped through the water.
4. Removing sludge
Wastewater then enters the second section or sedimentationtanks. Here, the sludge (the organic portion of the sewage) settlesout of the wastewater and is pumped out of the tanks. Some of thewater is removed in a step called thickening and then the sludge isprocessed in large tanks called digesters.
5. Removing scum
As sludge is settling to the bottom of the sedimentation tanks,lighter materials are floating to the surface. This 'scum' includesgrease, oils, plastics, and soap. Slow-moving rakes skim the scumoff the surface of the wastewater. Scum is thickened and pumped tothe digesters along with the sludge.
6. Killing bacteria
Finally, the wastewater flows into a 'chlorine contact' tank,where the chemical chlorine is added to kill bacteria, which couldpose a health risk, just as is done in swimming pools. The chlorineis mostly eliminated as the bacteria are destroyed, but sometimesit must be neutralized by adding other chemicals. This protectsfish and other marine organisms, which can be harmed by thesmallest amounts of chlorine.
