chapter 2 rev

<p>Solids, odor, temperature, color</p> Signup and view all the answers

<p>Chlorides</p> Signup and view all the answers

<p>pH &lt; 7</p> Signup and view all the answers

<p>Zoogloea</p> Signup and view all the answers

<p>Causing dangerous diseases</p> Signup and view all the answers

<p>BOD5</p> Signup and view all the answers

<p>Carbon dioxide</p> Signup and view all the answers

<p>6.5 to 8.5</p> Signup and view all the answers

<p>Nitrosomonas</p> Signup and view all the answers

<p>Nitrogen</p> Signup and view all the answers

<p>Coliform bacteria</p> Signup and view all the answers

<p>Affecting the biological process</p> Signup and view all the answers

<p>The amount of oxygen needed to oxidize the organic carbon to carbon dioxide and other end products</p> Signup and view all the answers

<p>By subtracting TSS from TS</p> Signup and view all the answers

<p>Turbidity</p> Signup and view all the answers

<p>By drying at 105ºC and burning at 550ºC</p> Signup and view all the answers

<p>Organic matter in wastewater</p> Signup and view all the answers

<p>Gas production from organic matter or added substances</p> Signup and view all the answers

<p>Using the weight of dry solids and sample volume</p> Signup and view all the answers

<p>Portable H2S meter</p> Signup and view all the answers

<p>Chemical reactions, aquatic life, and bacterial activity</p> Signup and view all the answers

<p>Animals, plants, and human activities</p> Signup and view all the answers

<p>Algae or industrial colors</p> Signup and view all the answers

<p>BOD and COD</p> Signup and view all the answers

<p>Using the weight of volatile solids and sample volume</p> Signup and view all the answers

<p>Total solids</p> Signup and view all the answers

<p>Suspended solids</p> Signup and view all the answers

<p>Floatable solids</p> Signup and view all the answers

<p>Organic (volatile) solids</p> Signup and view all the answers

<p>Quantifying the amount of organic matter in the wastewater</p> Signup and view all the answers

<p>6.5 to 8.5</p> Signup and view all the answers

<p>Nitrogen</p> Signup and view all the answers

<p>Chlorides</p> Signup and view all the answers

<p>E-Coli (Echerichia Coli)</p> Signup and view all the answers

<p>Zoogloea</p> Signup and view all the answers

<p>Nitrosomonas</p> Signup and view all the answers

<p>BOD5 (Biochemical Oxygen Demand)</p> Signup and view all the answers

<p>CBOD5 (Carbonaceous BOD)</p> Signup and view all the answers

<p>The amount of oxygen needed to oxidize the organic carbon to carbon dioxide</p> Signup and view all the answers

<p>Causing dangerous diseases</p> Signup and view all the answers

<p>Toxicity</p> Signup and view all the answers

<p>By drying at 105ºC and burning at 550ºC</p> Signup and view all the answers

<p>Using instruments like Portable H2S meter</p> Signup and view all the answers

<p>BOD and COD</p> Signup and view all the answers

<p>Turbidity</p> Signup and view all the answers

<p>By subtracting TSS from TS</p> Signup and view all the answers

<p>Chemical reactions, aquatic life, and bacterial activity</p> Signup and view all the answers

<p>Animals, plants, and human activities</p> Signup and view all the answers

<p>BOD</p> Signup and view all the answers

<p>Corrosion and environmental impact</p> Signup and view all the answers

<p>Portable H2S meter</p> Signup and view all the answers

<p>Nitrogen</p> Signup and view all the answers

<p>Infectious diseases</p> Signup and view all the answers

<p>Total solids</p> Signup and view all the answers

<p>Suspended solids</p> Signup and view all the answers

<p>Floatable solids</p> Signup and view all the answers

<p>Suspended solids</p> Signup and view all the answers

<p>By drying at 105ºC and burning at 550ºC</p> Signup and view all the answers

<p>Using instruments like Portable H2S meter</p> Signup and view all the answers

<p>Turbidity</p> Signup and view all the answers

<p>BOD and COD</p> Signup and view all the answers

<p>Potential to cause waterborne diseases</p> Signup and view all the answers

<p>Chemical reactions, aquatic life, and bacterial activity</p> Signup and view all the answers

<p>Animals, plants, and human activities</p> Signup and view all the answers

<p>BOD and COD</p> Signup and view all the answers

<p>Nitrogen</p> Signup and view all the answers

<p>Effect on the biological process</p> Signup and view all the answers

<p>Algae or industrial colors</p> Signup and view all the answers

<p>Biochemical Oxygen Demand (BOD)</p> Signup and view all the answers

<p>Chlorides</p> Signup and view all the answers

<p>Total suspended solids (TSS)</p> Signup and view all the answers

<p>The amount of oxygen needed to oxidize the organic carbon to carbon dioxide and other end products</p> Signup and view all the answers

<p>BOD5</p> Signup and view all the answers

<p>Nitrosomonas</p> Signup and view all the answers

<p>Toxicity</p> Signup and view all the answers

<p>Turbidity</p> Signup and view all the answers

<p>Quantifying the amount of organic matter in the wastewater</p> Signup and view all the answers

<p>Nitrogen</p> Signup and view all the answers

<p>Transmission of dangerous diseases</p> Signup and view all the answers

<p>Olfactometry</p> Signup and view all the answers

<p>Zoogloea</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>The purpose of the TOC method is to measure the organic carbon existing in the wastewater by oxidizing the carbon to carbon dioxide and quantifying the amount of organic matter.</p> Signup and view all the answers

<p>Theoretical Oxygen Demand (ThOD) is the amount of oxygen needed to oxidize organic carbon to carbon dioxide and other end products. It can be computed if the chemical formula of the organic matter is known.</p> Signup and view all the answers

<p>The main inorganic materials of concern in wastewater treatment are chlorides, nitrogen, phosphorus, sulfur, toxic inorganic compounds (e.g., copper, lead, silver, chromium, arsenic, boron), and heavy metals (e.g., nickel, manganese, lead, chromium, cadmium, zinc, copper, iron, mercury).</p> Signup and view all the answers

<p>pH is an important quality parameter in both natural waters and wastewaters. It affects the biological and chemical wastewater treatment processes, and water and wastewater can be classified as neutral, alkaline, or acidic based on pH.</p> Signup and view all the answers

<p>The main groups of microorganisms found in wastewater are bacteria, fungi, algae, protozoa, viruses, and pathogenic microorganisms.</p> Signup and view all the answers

<p>Important types of bacteria in wastewater treatment include Zoogloea (helps in the formation of flocs), Sphaerotilus natuns (causes sludge bulking), Acinetobacter (stores and releases phosphate), Nitrosomonas (transforms NH4 into NO2), Nitrobacter (transforms NO2- to NO3-), and Pseudomonas (reduces NO3 to N2).</p> Signup and view all the answers

<p>Fungi are important in decomposing organic matter, while algae can be useful in oxidation ponds but can also cause taste and odor problems when decayed.</p> Signup and view all the answers

<p>Viruses are a major hazard to public health and can cause dangerous diseases. Pathogenic organisms, including bacteria, viruses, protozoa, and helminths, are of concern in wastewater treatment.</p> Signup and view all the answers

<p>The most common effluent parameters regulated in wastewater treatment standards are BOD5 (biochemical oxygen demand), TSS (total suspended solids), pH, and CBOD5 (carbonaceous BOD).</p> Signup and view all the answers

<p>A BOD/COD ratio of &gt; 0.5 indicates that wastewater is easily treated by biological processes, while a ratio of 0.3 &lt; BOD/COD &lt; 0.5 suggests that biological treatment is possible but may require acclimatization of biomass. A BOD/COD ratio of &lt; 0.3 makes biological treatment difficult without pre-treatment.</p> Signup and view all the answers

<p>Environmental engineers need to understand the physical, chemical, and biological characteristics of municipal wastewater, including the presence of organic and inorganic materials, microorganisms, and potential hazards such as heavy metals and pathogenic organisms.</p> Signup and view all the answers

<p>The method to measure volatile suspended solids in mg/L is by using the weight of volatile solids and sample volume in wastewater.</p> Signup and view all the answers

<p>Dissolved solids (DS) can be determined by subtracting TSS from TS, or by drying the filtrate at 103-105ºC in wastewater.</p> Signup and view all the answers

<p>Instruments like Portable $H_2S$ meter can be used to measure odor in wastewater.</p> Signup and view all the answers

<p>Wastewater temperature affects chemical reactions, aquatic life, and bacterial activity.</p> Signup and view all the answers

<p>Turbidity is a measure of water's light-transmitting properties in wastewater.</p> Signup and view all the answers

<p>Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) can be used to measure the biodegradability of pollutants in wastewater.</p> Signup and view all the answers

<p>Organic matter in wastewater comes from animals, plants, and human activities.</p> Signup and view all the answers

<p>Suspended solids can be calculated in mg/L using the weight of dry solids and sample volume in wastewater.</p> Signup and view all the answers

<p>Odor in wastewater is caused by gas production from organic matter or added substances.</p> Signup and view all the answers

<p>Volatile solids (VS) can be determined by drying at 105ºC and burning at 550ºC in wastewater.</p> Signup and view all the answers

<p>Wastewater color changes from light brownish gray to dark gray or black with time, and may turn pink due to algae or industrial colors.</p> Signup and view all the answers

<p>Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) provide an indication of the biodegradability of pollutants in wastewater.</p> Signup and view all the answers

<p>The main types of physical characteristics of wastewater include solids, odor, temperature, and color.</p> Signup and view all the answers

<p>The different types of solids found in wastewater include dissolved, suspended, settleable, floatable, colloidal, organic (volatile), and inorganic solids (fixed).</p> Signup and view all the answers

<p>Total solids in wastewater are all the matter that remains as residue upon evaporation at $103^{\circ}C$ to $105^{\circ}C$.</p> Signup and view all the answers

<p>Suspended solids in wastewater are those solids that are not dissolved and can be separated out by filtration.</p> Signup and view all the answers

<p>The physical characteristics of wastewater include solids, odor, temperature, and color.</p> Signup and view all the answers

<p>Total solids are all the matter that remains as residue upon evaporation at 103$^{\circ}$C to 105$^{\circ}$C.</p> Signup and view all the answers

<p>The common types of solids found in wastewater are dissolved, suspended, settleable, floatable, colloidal, organic (volatile), and inorganic solids (fixed).</p> Signup and view all the answers

<p>Settleable solids in wastewater are those suspended solids that settle, and they are also called grit or sludge.</p> Signup and view all the answers

<p>Dissolved solids (DS) can be determined by subtracting TSS from TS, or by drying the filtrate at 103-105ºC.</p> Signup and view all the answers

<p>Volatile solids (VS) can be determined by drying at 105ºC and burning at 550ºC.</p> Signup and view all the answers

<p>Suspended solids can be calculated in mg/L using the weight of dry solids and sample volume.</p> Signup and view all the answers

<p>Volatile suspended solids can be calculated in mg/L using the weight of volatile solids and sample volume.</p> Signup and view all the answers

<p>Turbidity is a measure of water's light-transmitting properties.</p> Signup and view all the answers

<p>Wastewater color changes from light brownish gray to dark gray or black with time, and may turn pink due to algae or industrial colors.</p> Signup and view all the answers

<p>Odor in wastewater is caused by gas production from organic matter or added substances, and can be measured with instruments like Portable $H_2S$ meter.</p> Signup and view all the answers

<p>BOD and COD provide an indication of the biodegradability of pollutants in wastewater.</p> Signup and view all the answers

<p>Wastewater temperature affects chemical reactions, aquatic life, and bacterial activity.</p> Signup and view all the answers

<p>Organic matter in wastewater comes from animals, plants, and human activities, and can be measured using BOD and COD.</p> Signup and view all the answers

<p>Total organic carbon (TOC) method measures the organic carbon existing in wastewater by oxidizing it to carbon dioxide and then quantifying the amount of organic matter.</p> Signup and view all the answers

<p>Total solids in wastewater are all the matter that remains as residue upon evaporation at 103°C to 105°C.</p> Signup and view all the answers

<p>The main types of solids found in wastewater are dissolved solids (pass through a fine mesh filter), suspended solids (not dissolved in wastewater), floatable solids (suspended solids that float), settleable solids (suspended solids that settle), colloidal solids, organic (volatile) solids, and inorganic (fixed) solids.</p> Signup and view all the answers

<p>Wastewater is normally 99.9 percent water and 0.1 percent solids.</p> Signup and view all the answers

<p>Total solids in wastewater are all the matter that remains as residue upon evaporation at 103°C to 105°C.</p> Signup and view all the answers

<p>The characteristics detected using physical senses include odor, temperature, and color.</p> Signup and view all the answers

<p>The Total Organic Carbon (TOC) method measures the organic carbon existing in the wastewater by injecting a sample of the WW in a special device in which the carbon is oxidized to carbon dioxide, then carbon dioxide is measured and used to quantify the amount of organic matter in the WW. This method is only used for small concentrations of organic matter. Its purpose is to quantify the amount of organic matter in the wastewater.</p> Signup and view all the answers

<p>Theoretical Oxygen Demand (ThOD) is the amount of oxygen needed to oxidize the organic carbon in the wastewater to carbon dioxide and other end products. It can be computed if the chemical formula of the organic matter existing in the wastewater is known.</p> Signup and view all the answers

<p>The main inorganic materials of concern in wastewater treatment are chlorides, nitrogen, phosphorus, sulfur, toxic inorganic compounds (such as copper, lead, silver, chromium, arsenic, boron), and heavy metals (nickel, manganese, lead, chromium, cadmium, zinc, copper, iron, mercury). These materials can affect the biological process in high concentrations and are essential for various biological and chemical processes.</p> Signup and view all the answers

<p>The hydrogen-ion concentration, pH, is an important quality parameter in both natural waters and wastewaters. It is a very important factor in the biological and chemical wastewater treatment. Water and wastewater can be classified as neutral (pH = 7), alkaline (pH &gt; 7), or acidic (pH &lt; 7). For treated effluents discharged to the environment, the allowable pH range usually varies from 6.5 to 8.5.</p> Signup and view all the answers

<p>The main groups of microorganisms found in wastewater are bacteria, fungi, algae, protozoa, viruses, and pathogenic microorganisms. These microorganisms play significant roles in the biological processes of wastewater treatment, including decomposition of organic matter, nutrient cycling, and indicator functions for the presence of pathogens.</p> Signup and view all the answers

<p>The types of bacteria found in wastewater treatment include spheroid, curved rod, spiral, and filamentous bacteria. Some important bacteria, such as Zoogloea, Sphaerotilus natuns, Acinetobacter, Nitrosomonas, Nitrobacter, and Pseudomonas, play significant roles in processes like flocculation, sludge bulking, nutrient storage and release, ammonia and nitrate transformations, and nitrate reduction in treatment works.</p> Signup and view all the answers

<p>Fungi and algae are important in decomposing organic matter to simple forms and are also useful in oxidation ponds. Protozoa feed on bacteria and help in the purification of treated wastewater. However, some protozoa are pathogenic.</p> Signup and view all the answers

<p>The main categories of pathogens found in wastewater are bacteria, viruses, protozoa, and helminths. These pathogens pose significant health hazards and must be controlled to ensure the safety of water and wastewater for various purposes.</p> Signup and view all the answers

<p>The most common WWT standards set for the secondary treatment effluent include parameters such as BOD5 (Biochemical Oxygen Demand), TSS (Total Suspended Solids), pH, and CBOD5 (Carbonaceous BOD from organic compounds and oxidation of inorganic compounds such as ferrous iron).</p> Signup and view all the answers

<p>The interrelationships of constituents in different types of wastewater represent the changes in the BOD/COD ratio, which indicate the ease of biological treatment. A BOD/COD ratio &gt; 0.5 signifies wastewater that is easily treated by biological processes, while a BOD/COD ratio &lt; 0.3 indicates biological treatment is difficult without pre-treatment.</p> Signup and view all the answers

<p>The characteristics of municipal wastewater include physical, chemical, and biological components. These characteristics can be detected using various methods, including sensory evaluation, chemical analysis, and biological assessments.</p> Signup and view all the answers

<p>Nitrogen and phosphorus are major nutrients of importance in wastewater treatment. Their removal is essential to prevent eutrophication and ensure the ecological balance of aquatic environments.</p> Signup and view all the answers

<p>The physical characteristics of wastewater include solids, odor, temperature, and color. Examples of each type of physical characteristic are: Solids (dissolved, suspended, settleable, floatable, colloidal, organic, inorganic), Odor, Temperature, and Color.</p> Signup and view all the answers

<p>The different types of solids found in wastewater are categorized as dissolved, suspended, settleable, floatable, colloidal, organic (volatile), and inorganic (fixed) solids.</p> Signup and view all the answers

<p>Total solids in wastewater are all the matter that remains as residue upon evaporation at $103^{\circ}C$ to $105^{\circ}C$. Suspended solids are those solids that are not dissolved in wastewater.</p> Signup and view all the answers

<p>Wastewater temperature affects chemical reactions, aquatic life, and bacterial activity. The main types of physical characteristics of wastewater are solids, odor, temperature, and color.</p> Signup and view all the answers

<p>The main inorganic materials of concern in wastewater treatment are chlorides, nitrogen, phosphorus, sulfur, toxic inorganic compounds (such as copper, lead, silver, chromium, arsenic, boron), and heavy metals (including nickel, manganese, lead, chromium, cadmium, zinc, copper, iron, mercury). High concentrations of chlorides indicate that the water body has been used for waste disposal, which affects the biological process. Nitrogen and phosphorus are essential nutrients, with nitrogen being important for the growth of microorganisms, plants, and animals, and phosphorus being essential for the growth of algae and other biological organisms. Sulfur is necessary for the synthesis of proteins, while toxic inorganic compounds and heavy metals can have detrimental effects on the environment and human health.</p> Signup and view all the answers

<p>The hydrogen-ion concentration (pH) is an important quality parameter in both natural waters and wastewaters. It plays a crucial role in the biological and chemical wastewater treatment processes. Water and wastewater can be classified as neutral (pH = 7), alkaline (pH &gt; 7), or acidic (pH &lt; 7). The allowable pH range for treated effluents discharged to the environment usually varies from 6.5 to 8.5.</p> Signup and view all the answers

<p>The main groups of microorganisms found in wastewater treatment are bacteria, fungi, algae, protozoa, viruses, and pathogenic microorganisms. Bacteria play various roles, with different types such as spheroid, curved rod, spiral, and filamentous bacteria. Some important bacteria include Zoogloea, which helps in the formation of flocs in aeration tanks, and Nitrosomonas and Nitrobacter, which are involved in the transformation of nitrogen compounds. Fungi are important in decomposing organic matter, while algae can have both positive and negative effects. Protozoa feed on bacteria and help in the purification of treated wastewater. Viruses are a major hazard to public health, and pathogenic microorganisms pose risks to human health and the environment.</p> Signup and view all the answers

<p>The main effluent parameters for which WWT standards are set for the secondary treatment effluent include BOD5 (Biochemical Oxygen Demand), TSS (Total Suspended Solids), pH, and CBOD5 (Carbonaceous Biochemical Oxygen Demand).</p> Signup and view all the answers

<p>The interrelationships of constituents in different types of wastewater based on the BOD/COD ratio are as follows: BOD/COD &gt; 0.5 indicates that the wastewater is easily treated by biological processes. 0.3 &lt; BOD/COD &lt; 0.5 suggests that biological treatment is possible, but there may be the probable presence of inhibitors and the need for biomass acclimatization. BOD/COD &lt; 0.3 indicates that biological treatment is difficult without pre-treatment.</p> Signup and view all the answers

<p>The main purpose of the Total Organic Carbon (TOC) method in wastewater treatment is to measure the organic carbon existing in the wastewater by oxidizing a sample to carbon dioxide, which is then measured and used to quantify the amount of organic matter present. This method is suitable for small concentrations of organic matter.</p> Signup and view all the answers

<p>Municipal wastewater contains a variety of organic and inorganic constituents, including organic matter, inorganic materials, and microorganisms. It also exhibits specific physical and chemical properties, such as turbidity, color, pH, and nutrient content.</p> Signup and view all the answers

<p>The ThOD can be computed as the amount of oxygen needed to oxidize the organic carbon in the wastewater to carbon dioxide and other end products. This calculation requires knowledge of the chemical formula of the organic matter present in the wastewater.</p> Signup and view all the answers

<p>Fungi and algae play important roles in wastewater treatment. Fungi are essential for decomposing organic matter to simpler forms, contributing to the breakdown of pollutants. Algae can have both positive and negative effects, as they are useful in oxidation ponds but can also cause taste and odor problems when decayed.</p> Signup and view all the answers

<p>The main categories of pathogens in wastewater are bacteria, viruses, protozoa, and helminths. These pathogens pose risks to public health and the environment, leading to the spread of waterborne diseases and the contamination of water bodies.</p> Signup and view all the answers

<p>The standards for the removal of nitrogen and phosphorus (N,P) are not included in the secondary treatment effluent standards because nitrogen and phosphorus require tertiary treatment. This is due to the complexity and specific methods needed to effectively remove these nutrients from wastewater.</p> Signup and view all the answers

<p>The main constituents used to measure the quality of wastewater effluent are BOD5, TSS, pH, and CBOD5. These parameters are important indicators of the organic and inorganic pollution levels, the presence of pathogens, and the overall effectiveness of the wastewater treatment process.</p> Signup and view all the answers

<p>The physical characteristics of wastewater include solids, odor, temperature, and color. Solids in wastewater can be categorized as dissolved, suspended, settleable, floatable, colloidal, organic, and inorganic solids. The most common types of solids are dissolved, suspended, settleable, floatable, colloidal, organic (volatile), and inorganic solids (fixed).</p> Signup and view all the answers

<p>Wastewater is normally 99.9 percent water and 0.1 percent solids. The main types of solids found in wastewater are dissolved, suspended, settleable, floatable, colloidal, organic (volatile), and inorganic solids (fixed).</p> Signup and view all the answers

<p>Total solids refer to all the matter that remains as residue upon evaporation at 103$^\circ$C to 105$^\circ$C in wastewater.</p> Signup and view all the answers

<p>Suspended solids are those solids that are not dissolved in wastewater. An example of suspended solids is grit or sludge, which are solids that settle in the wastewater.</p> Signup and view all the answers

<p>Volatile suspended solids (VSS) in wastewater can be determined by drying the sample at $105^{\circ}C$ and then burning it at $550^{\circ}C$, with the difference in mass before and after burning representing the VSS content.</p> Signup and view all the answers

<p>Odor in wastewater is caused by gas production from organic matter or added substances, and can be measured with instruments like Portable $H_2S$ meter.</p> Signup and view all the answers

<p>Dissolved solids (DS) in wastewater can be determined by subtracting total suspended solids (TSS) from total solids (TS), or by drying the filtrate at $103-105^{\circ}C$.</p> Signup and view all the answers

<p>Wastewater temperature affects chemical reactions, aquatic life, and bacterial activity.</p> Signup and view all the answers

<p>Turbidity in wastewater is a measure of water's light-transmitting properties, which can be measured using a turbidimeter.</p> Signup and view all the answers

<p>Organic matter in wastewater comes from animals, plants, and human activities.</p> Signup and view all the answers

<p>The biodegradability of pollutants in wastewater can be indicated using biological oxygen demand (BOD) and chemical oxygen demand (COD).</p> Signup and view all the answers

<p>Wastewater color changes from light brownish gray to dark gray or black with time, and may turn pink due to algae or industrial colors.</p> Signup and view all the answers

<p>BOD and COD provide an indication of the biodegradability of pollutants in wastewater, as they measure the amount of oxygen required for the biological and chemical oxidation of organic matter.</p> Signup and view all the answers

<p>The main inorganic materials of concern in wastewater treatment can have various effects on the environment and treatment processes, such as altering pH, contributing to nutrient imbalances, and causing toxicity to aquatic life.</p> Signup and view all the answers

<p>Total and volatile suspended solids (TSS and VSS) in wastewater can be measured using the mass and volume of residue and sample, and by drying and burning the samples at specific temperatures to determine the solid content.</p> Signup and view all the answers

<p>Odor measurement in wastewater treatment is important for assessing the presence of harmful gases and substances, as well as for ensuring the safety and comfort of workers and the surrounding environment.</p> Signup and view all the answers

<p>The method for measuring total organic carbon (TOC) in wastewater involves injecting a sample into a special device where the organic carbon is oxidized to carbon dioxide, which is then measured to quantify the amount of organic matter. This method is limited to small concentrations of organic matter.</p> Signup and view all the answers

<p>The theoretical oxygen demand (ThOD) is the amount of oxygen needed to oxidize the organic carbon in wastewater to carbon dioxide and other end products. It can be computed if the chemical formula of the organic matter is known.</p> Signup and view all the answers

<p>The main inorganic materials of concern in wastewater treatment are chlorides, nitrogen, phosphorus, sulfur, toxic inorganic compounds (such as copper, lead, silver, chromium, arsenic, boron), and heavy metals (nickel, manganese, lead, chromium, cadmium, zinc, copper, iron, mercury). These materials can affect biological processes, act as major nutrients, and have toxic effects on aquatic life.</p> Signup and view all the answers

<p>The pH of water and wastewater is classified as neutral (pH = 7), alkaline (pH &gt; 7), or acidic (pH &lt; 7). The pH is an important factor in biological and chemical wastewater treatment, and the allowable pH range for treated effluents discharged to the environment usually varies from 6.5 to 8.5.</p> Signup and view all the answers

<p>The environmental engineer should have considerable knowledge of the principal groups of microorganisms found in wastewater, pathogenic organisms, indicator organisms, methods used to count microorganisms, and methods to evaluate the toxicity of treated wastewater.</p> Signup and view all the answers

<p>The main groups of microorganisms found in wastewater treatment are bacteria, fungi, algae, protozoa, viruses, and pathogenic microorganisms. These microorganisms play important roles in processes such as nutrient transformation, organic matter decomposition, floc formation, and pathogen removal.</p> Signup and view all the answers

<p>Coliform bacteria, such as E-Coli, serve as indicators for the presence of pathogens. Fungi are important in decomposing organic matter, and algae can have both positive effects (useful in oxidation ponds) and negative effects (causing taste and odor problems when decayed) in wastewater treatment.</p> Signup and view all the answers

<p>The main effluent parameters for which wastewater treatment standards are set for the secondary treatment effluent are BOD5 (biochemical oxygen demand), TSS (total suspended solids), pH, and CBOD5 (carbonaceous BOD from organic compounds and oxidation of inorganic compounds).</p> Signup and view all the answers

<p>The interrelationships of constituents in different types of wastewater can be characterized by the BOD/COD ratio, which indicates the treatability of the wastewater by biological processes, the presence of inhibitors, and the difficulty of biological treatment without pre-treatment.</p> Signup and view all the answers

<p>The limitations of total and volatile suspended solids (TSS and VSS) measurements in mg/L for wastewater treatment include the need for proper sample preparation and handling, accurate determination of residue mass and sample volume, and potential errors in the analysis process.</p> Signup and view all the answers

<p>Wastewater treatment standards set the requirements for effluent parameters to protect the environment and public health. Tertiary treatment is needed for nitrogen and phosphorus removal because their standards are not included in the secondary treatment effluent standards, and these nutrients require additional treatment processes.</p> Signup and view all the answers

<p>The main categories of pathogens in wastewater are bacteria, viruses, protozoa, and helminths. They are significant because they pose public health risks and require specific treatment and control measures to prevent the spread of waterborne diseases.</p> Signup and view all the answers