Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
73 Cards in this Set
- Front
- Back
|
Occurs when the discharge of wastes impairs water quality or disturbs the natural ecological balance |
Water Pollution |
|
|
Direct from sewer outfalls or industrial discharges |
Point Sources |
|
|
Indirect from air pollution, or agricultural or urban runoff |
Nonpoint sources |
|
|
A complex mixture containing water together with organic and inorganic contaminants, both suspended and dissolved |
Municipal Wastewater (Sewage) |
|
|
Provides an ideal environment for many microbes, primarily bacteria, plus some viruses and protozoa |
Microorganisms |
|
|
The residue after the liquid portion in wastewater has been evaporated and the remainder dried to a constant weight at 103 deg. Celcius |
Solids |
|
|
Constituents of Sewage |
Microorganisms Solids Organics Inorganics |
|
|
Microorganisms |
Bacteriak diseases Viral disease Protozoan-caused disease |
|
|
Bacterial diseases |
Cholera Typhoid Tuberculosis |
|
|
Viral disease |
Hepatitis |
|
|
Protozoan cause disease |
Dysentery |
|
|
Most useful categories |
Ss and vs Suspended solids and volatile suspended solids |
|
|
Used to measure wastewater strength and process performance |
Ss and bod Suspended solids and biochemical oxygen demand |
|
|
Indicates organic content of raw waste and measures active microbial population in biological processes |
Vss Volatile suspended solid |
|
|
Common inorganic constituents of wastewater |
Chlorides and sulfates Nitrogen and phosporus Carbonates and bicarbonates Toxic substances Other parameters such as dissolved gas and H+ concentration |
|
|
Normally present in water and from human wastes |
Chloride and Sulfates |
|
|
From human wastes; additional P from detergents |
Nitrogen and Phosphorus |
|
|
Normally present as calcium and magnesium salts |
Carbonates and bicarbonates |
|
|
Arsenic, cyanide, heavy metals; may come from industrial wastes |
Toxical substances |
|
|
How many percent of organic matter in domestic sewage are proteins and carvohydrates |
90% |
|
|
Measurements if Organic Matter |
TOC (total organic carbon) COD (chemical oxygen demand) BOD (biochemical oxygen demand) |
|
|
Amount of CO2, produced when organic carbon is oxidized by a strong oxidizer |
TOC |
|
|
Amount of O2 needed to chemically oxidize organics present |
COD |
|
|
Amount of O2 required by microorganisms to biologically degrade organic matter in wastewater |
BOD |
|
|
Excreted wasted from humans |
Sanitary Sewage |
|
|
Wastewater from residential areas |
Domestic Sewage |
|
|
Municipal wastewater equation |
Municipal wastewater = sanitary sewage + domestic sewage + liquid wastes from commercial and industrial establishments |
|
|
Is determined from water use, with assumptions for groundwater filtration, storm wate, etc. |
Quantity of wastewater |
|
|
Wastewater from industries; includes employee's sanitary wastes, process wastes from manufacturing; volume or strength is often compared to that of domestic sewage in terms of population equivalent |
Industrial wastewater |
|
|
Runoff from rainfall, snowmelt, streetwashing; less contaminated than municipal; reciebed little or no treatment |
Stormwater |
|
|
Pollution of Recieving Water |
Effects of Pollutants Water Quality Requirements Need for Pollution Control |
|
|
A public health concern when sewage reaches recieving waters used fir water supplies or recreation |
Pathogens |
|
|
Metabollic activity by bacteria requiring oxygen may reduce the normal dissolved oxygen |
Organic Matter |
|
|
Unsightly deposits, odorous sludge banks, and reduced sunlight penetration through the water |
Solids |
|
|
N and P promote plant aand algal growth, cause eutrophication, detrimental aesthetic effect on lakes.. |
Nutrients |
|
|
Acids, caustics, cyanide, arsenic... |
Toxic and Hazardous Substances |
|
|
Effects of Pollutants |
Pathogens Organic Matter Solids Nutrients Toxic and Hazardous Substances |
|
|
Aesthetically objectionable, limit light penetration and reduce DO |
Color |
|
|
Same effects with color; from pulp and paper mill wastes |
Foam |
|
|
Potential for recovery; increase oxygen utilization rate, reduce DO levels; increases chances for aquatic animals to develop diseases |
Heat/Thermal Discharge |
|
|
Fiah and other organism can also be killed by |
Thermal Shock |
|
|
Other Pollutants |
Color Foam Heat/Thermal discharge |
|
|
The principal concern for treatment of domestic wastes |
Public Health |
|
|
To remove or modify contaminants detrimental to human healthand /or environment |
Principles of Wastewater TREATMENT |
|
|
Contaminants are generally removed from wastewater in order of increasing difficulty |
Principles of Wastewater Treatment |
|
|
Principles of Wastewater Treatment |
Primary Treatment Secondary Treatment Disinfection |
|
|
Primary Treatment |
Screening and grit removal Primary settling(physical) |
|
|
Secondary Treatment |
Aerobic Oxidation(biological) Final settling(physical) |
|
|
Disinfection |
Chlorination(chemical) |
|
|
The most common physical process for removing ss from wastewater |
Gravity settling |
|
|
Sand particles >_ 0.2mm |
Grit |
|
|
Clarifying raw settled solids |
Raw or primary sludge |
|
|
Settled floc |
Biological, activated or secondary sludge |
|
|
These can serve most organic constituenta |
Substrate |
|
|
Chemical process for industrial wastewater |
Oxidation Reduction Precipitation Neutralization |
|
|
Chemical processes for municipal wastewater |
Precipitation Disinfection |
|
|
The least expensive and most often used disinfectant |
Chlorine |
|
|
Chlorinated organics |
Trihalomethanes |
|
|
Capable of causing cancer |
Carcinogens |
|
|
Land Based Treatment Methods |
Slow-rate infiltration systems(spray irrigation) Rapid infiltration systems(for highly permeable soils) Overland flow(water is pretreated then applied to fairly impervious land) |
|
|
Impoundment Systems |
Wetlands Oxidation Ponds Aerated lagoons |
|
|
Water is pretreated then applied to fairly impervious land |
Overland Flow |
|
|
Another name for wetlands |
Aquaculture |
|
|
A shallow earthen basin 1-2 m deep |
Oxidation ponds |
|
|
Another name for oxidation ponds |
Stabilization ponds |
|
|
Saves money, Reduces water shortage, Increases water supply |
Water Efficiency= sustainable water use |
|
|
water use efficiency |
Water Conservation |
|
|
can temporarily relieve pressure on water sources |
short-term water restrictions during a water shortage |
|
|
involves a combination of retrofits, new watersaving appliances, maintenance of infrastructure, and a collective water conservation ethic focused on resource use, allocation, and protection |
lasting water conservation |
|
|
a systematic survey of all water-using fixtures, appliances, equipment, and practices at a facility ; basis of a water use efficiency improvement plan |
Water Audit |
|
|
Water Audit Procedures |
Residential Commercial and Institutional |
|
|
the non-physical or “paper” losses that occur in utility operations due to meter inaccuracies, billing system data errors and unauthorized consumption - water that is consumed but is not properly measured, accounted or paid for |
Apparent losses |
|
|
the physical losses of water from the distribution system, including leakage and storage overflows - water that is extracted and treated, yet never reaches beneficial use |
Real Losses |
