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1、Hach Wastewater CoursePrimary Author: Bob DabkowskiContributing Author: Mark HatfieldI.AbstractThis course is devoted to the Hach Municipal Wastewater Applications Guide. In this course we will discuss the history of wastewater treatment as well as typical wastewater treatment plants and the benefit
2、s of instrumentation. Next we will examine advanced treatment such as nutrient removal, nitrogen removal and phosphorus removal. Finally we will talk about tertiary treatment, for example, mixed-media filtration or denitrification filters.II.ObjectivesThis course is designed to familiarize the user
3、with wastewater issues and its history. The user will learn about a typical wastewater treatment plant and the benefits to using instrumentation as well as advanced treatment methods for nitrogen and phosphorus removal. Finally the user will learn about tertiary treatment such as mixed-media filtrat
4、ion, denitrification filters and membrane filtration.III.Keywords and DefinitionsTake a glance through this list and be sure to read carefully any terms or abbreviations with which you are not familiar.BOD (biochemical oxygen demand): This is a measure of the approximate quantity of oxygen that will
5、 be required to biologically stabilize the organic matter present in the water.Clarifier: A tank used to remove solids by gravity, to remove colloidal solids by coagulation, and to remove floating oil and scum through skimming.COD: Chemical oxygen demand.Denitrification: The process of reducing nitr
6、ate and nitrite, highly oxidized forms of nitrogen available for consumption by many groups of organisms, into gaseous nitrogen, which is far less accessible to life forms but makes up the bulk of our atmosphere. It can be thought of as the opposite of nitrogen fixation, which converts gaseous nitro
7、gen into a more biologically available form. The process is performed by heterotrophic bacteria (such as Paracoccus denitrificans, Thiobacillus denitrificans, and various pseudomonads) from all main proteolytic groups.DO: Dissolved oxygen, or the amount of oxygen gas dissolved in water. Typically ex
8、pressed in mg/L.LDO: Luminescent dissolved oxygen. The LDO analyzers described in this course measure DO concentration using optical and fluorescent means.Turbidity: a measure of the relative clarity of water. Turbidity is related to suspended particles in water but does not directly measure them. R
9、ather, turbidity measures the scattering effect such particles have on light.Turbidimeter: An instrument that measures the turbidity of water. The device usually consists of at least one light source and one detector, commonly arranged perpendicular to one another.ORP: Oxidation Reduction Potential,
10、 or the potential for a molecule, atom, or ion to gain or lose electrons.pH: A measurement of the relative acidity of an aqueous solution. pH is related to the molar concentration of Hydrogen ions (H+) in solution.Acid: Any substance that increases the concentration of hydrogen ions (H+) in solution
11、.Base: Any substance that increases the concentration of hydroxide ions (OH-) in solution.Return Activated Sludge (RAS): RAS describes the sludge returning from a clarifier back into the mixed liquor of an aeration basin or ditch.Sludge: the collection of heavy organic and inorganic solid material r
12、emoved from sewage.Sequencing Batch Reactors (SBR): Industrial processing tanks for the treatment of wastewater. SBR reactors treat waste water such as sewage or output from anaerobic digesters or mechanical biological treatment facilities in batches. Oxygen is bubbled through the waste water to red
13、uce biochemical oxygen demand (BOD) and Chemical oxygen demand (COD) to make suitable for discharge into sewers or for use on land.IV.HistoryThe need for a safe and effective method for handling the wastes generated by humans is as old as man himself. Early public systems in the Western world for de
14、aling with municipal wastewater are believed to exist at least as early as in the time of the ancient Greeks. These early systems consisted largely of simple open trench sewers constructed so waters used for bathing, cleaning, and cooking could be channeled to and contained in specific areas. More e
15、laborate systems of freshwater aqueducts and sewer collection systems existed by the time of the ancient Romans.In todays world, the collection and handling of our wastewater is closely regulated. In the U.S., the United States Environmental Protection Agency (US EPA) is tasked with monitoring both
16、our drinking water and wastewater systems. EPA enforces federal clean water and safe drinking water laws, provides support for municipal wastewater treatment plants, and takes part in pollution prevention efforts aimed at protecting watersheds and sources of drinking water. The Agency carries out both regulatory and voluntary programs to fulfill its mission to protect the nations
