ic unit chronic Tab 2-2 Principal constituents of concern in wastewater treatment Suspended solids uspended solids can lead to the development of sludge deposition and anaerobic conditions hen untreated wastewater is discharged in the aquatic environment Biodegradable organics ly of proteins, carbohydrates, and fats. Biodegradable org anics are measured most commonly in terms of BoD and COD. If discharged untreated to the environment their biological stabilization can lead to the depletion of natural oxygen Patho Communicable diseases can be transmitted by the pathogenic organisms that may be present Nutrients Both nitrogen and phosphorus, along with carbon, are essential nutrients for growth. When discharged to the aquatic env ironment, the nutrients can lead to the growth of undesirable aquatic life. When discharged in excessive amount on land, they can also lead to the pollution Priority pollutants rganic and inorganic compounds selected on the basis of their known or suspected carcinogenic ity, metogenicity, teratogen icity or high acute toxicity. Many of these compounds Refractory organics These organics tend to resist conditional methods of wastewater treatment. Typ ical examples include surfactants phenols, and agricultural pesticides Heavy metals Heavy metals are usually added to wastewater from commercial and industr ial activities and may have to be removed if the wastewater is to be reused Dissolved inorganIcs Inorganic constituents such as calcium, sodium, and sulfate are added to the orig inal domestic water supply as a result of water use and may have to be removed if the wastewater is to be There are no universal procedures for sampling: sampling progra st be tailored individually to fit each situation. Special procedures are necessary to handle sampling problems that arise when wastes vary considerably in composition Before a sampling program is undertaken, a detailed sampling protocol must be developed along with a quality assurance project plan( QAPP)(known previously quality assurance/quality control, QA/QC). As a minimum, the following items must be specified in the QAPP. Additional details on the subject of sampling may be found in Standard Methods 1.Sampling plan. Number of sampling locations, number and type of samples, time intervals(.g, real-time and/or time-delayed samples) 2. Sample types and size, Catch or grab samples, composite samples, or integrated samples, separate samples for different analyses(e.g, for metals). Sample size(i.e, volume)required 3. Sample labeling and chain of custody. Sample labels, sample seals, field log book chain of custody record, sample analysis request sheets, sample delivery to the laboratory, receipt and logging of sample, and assignment of sample for analysis 4.Sampling methods. Specific techniques and equipment to be used(e.g, manual, automatic, or sorbent 5. Sampling storage and preservation. Type of containers(e.g, glass or plastic), preservation methods, maximum allowable holding times 6.Sample constituents. A list of the parameters to be measured 7. Analytical methods. A list of the field and laboratory test methods and procedures to be used, and the detection limits for the individual methods If the physical, chemical, and/or biological integrity of the not maintained during interim periods between sample collection and sample analysis, a car performed sampling program will become worthless. Considerable research on the problem of preservation has failed to perfect a universal treatment or method, or to formulate a set of fixed rules applicable to samples of all types Prompt analysis is undoubtedly the most positive assurance against error due to sample deterioration When analytical and testing conditions dictate a lag between collection and analysis, such as when a 24 h composite sample is collected, provisions must be made for preserving samples. Current methods of sample preservation for the analysis of properties subject to deterioration must be used Probable errors due to deterioration of the sample should be noted in reporting analytical data Methods of Analysis The analy ses used to characterize wastewater vary from precise quantitative chemical determinations to 2-32-3 Toxicity TUa,TUc Toxic unit acute,toxic unit chronic Tab 2-2 Principal constituents of concern in wastewater treatment Constituents Reason for importance Suspended solids Suspended solids can lead to the development of sludge deposition and anaerobic conditions when untreated wastewater is discharged in the aquatic environment. Biodegradable organics Composed principally of proteins, carbohydrates, and fats. Biodegradable organics are measured most commonly in terms of BOD and COD. If discharged untreated to the environment their biological stabilization can lead to the depletion of natural oxygen resources and to the development of septic conditions. Pathogens Communicable diseases can be transmitted by the pathogenic organisms that may be present in wastewater. Nutrients Both nitrogen and phosphorus, along with carbon, are essential nutrients for growth. When discharged to the aquatic environment, the nutrients can lead to the growth of undesirable aquatic life. When discharged in excessive amount on land, they can also lead to the pollution of groundwater. Priority pollutants Organic and inorganic compounds selected on the basis of their known or suspected carcinogenicity, metogenicity, teratogenicity or high acute toxicity. Many of these compounds are found in wastewater. Refractory organics These organics tend to resist conditional methods of wastewater treatment. Typical examples include surfactants, phenols, and agricultural pesticides. Heavy metals Heavy metals are usually added to wastewater from commercial and industrial activities and may have to be removed if the wastewater is to be reused. Dissolved inorganics Inorganic constituents such as calcium, sodium, and sulfate are added to the original domestic water supply as a result of water use and may have to be removed if the wastewater is to be reused. There are no universal procedures for sampling; sampling programs must be tailored individually to fit each situation. Special procedures are necessary to handle sampling problems that arise when wastes vary considerably in composition. Before a sampling program is undertaken, a detailed sampling protocol must be developed along with a quality assurance project plan (QAPP) (known previously quality assurance/quality control, QA/QC). As a minimum, the following items must be specified in the QAPP. Additional details on the subject of sampling may be found in Standard Methods. 1.Sampling plan. Number of sampling locations, number and type of samples, time intervals (e.g., real-time and/or time-delayed samples). 2.Sample types and size, Catch or grab samples, composite samples, or integrated samples, separate samples for different analyses (e.g., for metals). Sample size (i.e., volume) required. 3.Sample labeling and chain of custody. Sample labels, sample seals, field log book, chain of custody record, sample analysis request sheets, sample delivery to the laboratory, receipt and logging of sample, and assignment of sample for analysis. 4.Sampling methods. Specific techniques and equipment to be used (e.g., manual, automatic, or sorbent sampling). 5.Sampling storage and preservation. Type of containers (e.g., glass or plastic), preservation methods, maximum allowable holding times. 6.Sample constituents. A list of the parameters to be measured. 7.Analytical methods. A list of the field and laboratory test methods and procedures to be used, and the detection limits for the individual methods. If the physical, chemical, and/or biological integrity of the samples is not maintained during interim periods between sample collection and sample analysis, a carefully performed sampling program will become worthless. Considerable research on the problem of sample preservation has failed to perfect a universal treatment or method, or to formulate a set of fixed rules applicable to samples of all types. Prompt analysis is undoubtedly the most positive assurance against error due to sample deterioration. When analytical and testing conditions dictate a lag between collection and analysis, such as when a 24 h composite sample is collected, provisions must be made for preserving samples. Current methods of sample preservation for the analysis of properties subject to deterioration must be used. Probable errors due to deterioration of the sample should be noted in reporting analytical data. Methods of Analysis The analyses used to characterize wastewater vary from precise quantitative chemical determinations to