Wiley Wastewater Quality Monitoring and Treatment_3 doc

JWBK117-1.2 JWBK117-Quevauviller October 10, 2006 20:9 Char Count= 0 24 Sampling Assistance on-line devices is increasing, the great majority of wastewater quality measurements is carried out in the laboratory, after sampling. Thus, before considering analytical methods for wastewater quality monitoring, based on either standard or alterna- tive procedures, the sampling step must be considered because of its importance as a source of potential errors. With the aim of getting a representative volume of effluent, sampling has to face a lot of specific constraints related to wastewater char- acteristics. Thus, wastewater sampling is difficult, considering the heterogeneity and variability of effluents, and moreover the evolution of samples during transportation from sampling site to laboratory, related to sample aging. 1.2.1.1 Heterogeneity As for water, there are several types of wastewater. All types are characterized by their composition heterogeneity. A wastewater is composed of water, carrying a lot of suspended solids and dissolved substances which were not present originally (the pollutants). Wastewater types depend on the nature and concentration of solids and pollutants. The most frequent type is urban wastewater, mixing municipal wastewater and industrial ones. The composition of municipal wastewater is rather well known and does not vary a lot from one human being to another or one town to another. Typical compositions of urban wastewater have been published (Muttamara, 1996; Metcalf and Eddy, 2003; Degr´emont, 2005). The concentration of total suspended solids (TSS) varies from 200 to 600 mg/l, the volatile suspended solids from 200 to 600 mg/l, the biological oxygen demand (BOD) from 100 to 500 mg/l, the chemical oxygen demand (COD) from 200 to 1200 mg/l, the total organic carbon (TOC) from 50 to 300 mg/l, the total nitrogen from 50 to 100 mg/l, and the total phosphorous from 10 to 20 mg/l. These values can be decreased in the case of combined sewer (effect of dilution of rainfall) or increased, depending on the proportion and nature of industrial wastewater collected in the urban area. Thus, the heterogeneity is related to thediversity of soluble pollutants’ nature, and increased when considering emergent pollutants, but also to the nonsoluble fractions distribution: colloids, supra-colloids and settleable suspensions. Table 1.2.1 presents the size distribution of particulates and the coarse chemical composition of the soluble fraction. The composition of industrial wastewaters is obviously related to the industrial activity (Eckenfleder, 2001; Metcalf and Eddy, 2003; Degr´emont, 2005), but above all, to the existence of environmental equipments (e.g. wastewater treatment plant) and investments (e.g. recycling process). Contrary to wastewater of domestic origin, which increases with number of inhabitants, industrial loads are more and more controlled and reduced under regulatory pressure. However, some problems remain for industrial discharges in urban sewers, when the industrial fraction of wastewater is dominant, leading to toxic effect and increasing the heterogeneity. JWBK117-1.2 JWBK117-Quevauviller October 10, 2006 20:9 Char Count= 0 Wastewater Monitoring Constraints 25 Table 1.2.1 Dispersion characteristics of the main fractions of wastewater. (Adapted from Sophonsiri and Morgenroth, 2004) Standard Results Fraction Min. Max. Mean deviation RSD (%) calculated from Settleable (%) (>100 μm) 7 45 26.3 13.2 50 8 studies Supra-colloidal (%) (1–100 μm) 12 50 27.4 12.1 44 9 studies Colloidal (%) (0.1–1 μm) 7 48 15.6 12.6 81 9 studies Soluble (%) (<0.1 μm) 9 64 37.2 17.4 47 10 studies Composition COD (mg/l) 203 967 496 292 59 7 studies Protein (% COD) 8 31 19.3 9.1 47 8 studies Carbohydrate (% COD) 6 18 11.3 4.6 40 9 studies Lipid (% COD) 7 82 33.2 28.1 87 6 studies Unidentified (% COD) 8 78 51.4 26.0 51 7 studies 1.2.1.2 Variability Wastewater variability is due to its composition, changing along the sewer system under the influence of several factors (see Chapter 2.1) and with the mixing of efflu- ents of different origin (municipal and industrial). For an industrial sewer network, the wastewater composition varies from downstream units or workshops to treat- ment plant, with a decrease in variability under homogenisation effects of mixing and storage tanks. Another variability factor is time, the wastewater production be- ing generally less during the night for domestic activities, or during weekends and holidays for some industries. For all fractions and chemical compound groups of Table 1.2.1, the variability, expressed as the residual standard deviation (RSD), is around 50 %, except for the colloid fraction and for lipids. It should be noted that, for the soluble fraction, half of the chemical compounds are not actually identified. The variability can also be estimated from nonparametric measurement like UV absorption spectra, giving qualitative information on the global composition of wastewater (linked to UV absorbing substances). This approach will be explained in Chapter 4.2 on industrial wastewater and discharges. The heterogeneity and variability of wastewater quality must betaken into account when a monitoring programme is planned. 1.2.1.3 Sampling Ageing As in sewers, wastewater composition can vary very quickly when sampled. This phenomenon, known as sample ageing, occurs under the influence of at least JWBK117-1.2 JWBK117-Quevauviller October 10, 2006 20:9 Char Count= 0 26 Sampling Assistance three factors: r Firstly, as a heterogeneous medium, agitated in a sewer, suspended solids settle rapidly in the sampling flask modifying the distribution of the fraction size by flocculation, adsorption, etc. r The second factor is of a chemical nature, with reactions of reduction, complex- ation, modification of acidic–basic equilibria, etc., occurring when the depletion of dissolved oxygen leads to anaerobic conditions and to variation of redox po- tential and pH. For example, the adsorption of surfactants on suspended solids, is responsible, in raw or physico-chemically treated wastewater, for colloidal frac- tion aggregation and, thus, for the increase of suspended solids (Baur`es et al., 2004). r The third factor is probably the most important with the biodegradation effect by microorganisms present in wastewater (coming from domestic waste). The consequence is principally a degradation of organic matter, under aerobic or anaerobic conditions, as it is the case in sewers. This will be explained in Chap- ter 2.1. Finally, sample ageing occurs even if the samples are refrigerated (in this case the kinetic of sample evolution is slowed down) and can lead to 20 % variation for some parameters (COD, TSS) in a few hours (Baur`es et al., 2004). This implies that samples must be transported to the laboratory for analysis as soon as possible after sampling. 1.2.2 MAIN PROCEDURES FOR WASTEWATER QUALITY MONITORING 1.2.2.1 Sampling Wastewater sampling is generally performed by one of two methods; grab (manual or spot) sampling or automatic (sequential or composite) sampling. The first method is simple, cheap and largely used, whilst the second is better for monitoring relevance, considering the heterogeneity andvariability ofwastewater. The choiceof a sampling procedure is related to the sampling objective, regulatory requirements, measuring treatment plan efficiency, sewer management, knowledge. Grab sampling is useful for detecting fluctuation in composition, and discharge of pollutants, especially in industrial effluent and storm-sewage investigations (Muttamara, 1996; Metcalf and Eddy, 2003), and automatic sampling is preferred for all other purposes (regulatory, time variation, mass balance, etc.). In any case, the measurement of flow rate during sampling is strongly recommended for pollution loads calculation. JWBK117-1.2 JWBK117-Quevauviller October 10, 2006 20:9 Char Count= 0 Main Procedures for Wastewater Quality Monitoring 27 Grab sampling Grab sampling is like a snapshot, giving instantaneously a volume of wastewater in one point. The reliability of measurement and analysis carried out from a grab sample is thus limited to the compositionofwastewaterforagivencontrolpointat one moment. Nevertheless, grab sampling is extensively used for water and wastewater quality monitoring, and can beveryuseful for rapid informationon a ‘slug’ discharge, intermittently flows, short term variations checking or analysis or very unstable constituents (phenols, cyanides, volatile organic compounds) (WEF, 1996). It can be thus complementary to composite sampling. However, even if the grab sampling procedure seems to be simple, several recommendations have to be made, namely the following: r use of clean and adapted flasks, depending on the analysis to be made; r choose a sampling site with a homogeneous section preventing wastewater quality variability (as for flow measurement); r pay attention for sludge, biofilm or sediment on bottom or sides of sampling site; r be aware to not modify the sample composition just after sampling; r do not agitate before dissolved oxygen on site measurement or fill up the flask for laboratory measurement; r use relevant conservation procedure(s) depending on analysis; r always note the sampling conditions of air temperature and time. Thus grab sampling is not so easy to do, and cannot be carried out by untrained people. Automatic sampling For wastewater quality monitoring, an automatic sample is generally preferred be- cause of the time variability of effluents. Automatic sampling can principally be performed using sequential or integrated mode, depending on time or volume. r Even if it is the simplest form of automatic sampling, because no other devices are needed other than the automatic sampler, the sequential mode can be carried out several ways. The first one is the full sequential sampling mode with sampling at regular time intervals of a given volume collected in one flask. After one sample, the distributing system moves inside the sampler in order to fill the next flask, i.e. several flasks are placed into the sampler (generally 24 or 12), correspond- ing to hourly or bi-hourly samples. The composite sequential sampling mode is JWBK117-1.2 JWBK117-Quevauviller October 10, 2006 20:9 Char Count= 0 28 Sampling Assistance preferred, when a higher sampling frequency is needed, with the collection of equal volume sub-samples at regular time intervals. A selected volume is sampled with a given frequency (e.g. 200 ml every 15 min) and samples are collected in a same flask of large volume (e.g. 20 l) for a single daily composite sample or in several flasks for hourly or bi-hourly composite samples. In this last case, the collection system of the automatic sampler is constituted of 12 or 24 flasks of 1 or 0.5 l, each corresponding to a period of time of 2 or 1 h, if the sampling period is one full day. This technique is used if the daily variation of effluent charac- teristics has to be known and is obviously more representative than several grab samples. r The integrated sampling mode is selected when the knowledge of the daily load has to be known. Instead of sequential samples of fixed volume, taken at regular intervals over a period of 24 h, the volume of each sample is proportional to the mean flow rate of a given time interval. Thus a flow meter, generally a device measuring the height of the water table in a control section where the relation height/flow is known, has to be installed and coupled with the automatic sampler. Samples are collected in a single container in order to have a sample representative of the average of the daily composition of wastewater and the pollution load is calculated as the product of a given parameter by the mean value of flow rate during 24 h. If the evolution of composition and load has to be known, samples are collected, as for hourly or bi-hourly sequential sampling, in 24 or 12 flasks. In this case, the daily load can thus be calculated as the sum of hourly or bi-hourly loads. Sometimes, the volume of samples remains constant, but the time interval is automatically adjusted, inversely proportional to the flow rate (e.g. 200 ml are sampled every 10 m 3 ). The use of two composite sampling during 24 h, at the inlet and outlet of a wastewater treatment plant, is the most common way to determine the average efficiency of the plant. In practice The urban wastewater treatment European Directive (Council Directive of 21 May 1991) indicates in Annex I-D that flow-proportional or time-based 24-h samples shall be collected at the same well-defined point in the outlet and if necessary in the inlet of the treatment plant in order to monitor compliance with the requirements for discharged wastewater laid down in this Directive (see Chapter 1.1). Good interna- tional laboratory practices aiming at minimizing the degradation of samples between collection and analysis shall be applied. The minimum annual number of samples shall be determined according to the size of the treatment plant and be collected at regular intervals during the year: r 2000–9999 p. e.: 12 samples during the first year with four samples in subsequent years, if it can be shown that the water during the first year complies with the JWBK117-1.2 JWBK117-Quevauviller October 10, 2006 20:9 Char Count= 0 Main Procedures for Wastewater Quality Monitoring 29 provisions of the Directive; if one sample of the four fails, 12 samples must be taken in the year that follows. r 10 000–49 999 p.e.: 12 samples. r 50 000 p.e. or over: 24 samples. International standards provide precise information on sampling design (ISO, 1980), sampling techniques (ISO, 1991) and wastewater sampling (ISO, 1992), which is very close to those of other organizations (APHA, 2005). Among the recom- mendations it can be noted that automatic composite sampling must be chosen for sewer systems, considering the variability in wastewater composition and the difficulty to have a representative sample in very variable conditions. Some other practical recommendations can be found in technical literature (WEF, 1996; Seldon, 2004). However, some unstable parameters such as dissolved oxygen, temperature, pH, volatile organic compounds cannot be measured in a composite sample, and a grab one is preferable. The use of grab sampling must be avoided when the objective of sampling is to evaluate the performance of a treatment plant. It can be envisaged for a rapid preliminary diagnosis of a sewer network or assessment impact of treated wastewater discharge in receiving medium. Grab sampling can also be used for the study of combined sewer overflow discharges when an automatic sampler cannot be installed. When a sampling mode is chosen, the precise sampling location(s) must be se- lected. In order to have the more representative sample, the sampling site must correspond to a well mixed area of wastewater, preferably in a linear section of a channel, where the flow is sufficient to prevent settling, by keeping wastewater solids in suspension. Sampling points for wastewater treatment plants are proposed in technical literature (WEF, 1996). If automatic sampling is decided upon, two main techniques can be used. The first one is based on a peristaltic pump (or more rarely piston) the characteristics of which must be sufficient for an isokinetic sampling (aspiration speed close to the velocity of wastewater at the sampling site) and for the hydraulic pressure needed from the sewer up to the sampling system. Another technique based on high vacuum for aspiration gives better results for solids capture but tends to increase the related parameters (total suspended solids and global pollution parameters such as COD). Moreover, the choice of 12 or 24 sampling flasks is important only for the study of the composition variability of wastewater and the measurement of flow rate or volume during sampling is obligatory for loads calculation. 1.2.2.2 Field Measurement Field measurement can be carried out on site, either by automatic instruments (on- line analyser or remote sensors) or by manual systems (handheld instruments or test JWBK117-1.2 JWBK117-Quevauviller October 10, 2006 20:9 Char Count= 0 30 Sampling Assistance kits) and is very useful for some monitoring objectives like process control or early warning (Thomas and Pouet, 2005). Field measurement is complementary to the classical procedure, recommended and even required in official texts for regulation monitoring, based on sampling and laboratory analysis. This approach, obligatory for the measurement of temperature and very often for other basic parameters (dis- solved oxygen, pH, etc.), is increasingly envisaged in order to obtain rapid infor- mation, as is the case for early warning systems (detection of accidental pollution). Unfortunately, the availability of systems for on-site or on-line monitoring is rather limited, if restricted to adapted devices (some instruments, derived from laboratory techniques are too complex and fragile, e.g. chromatographs, to be really useful). However, a relevant control of a treatment process cannot be envisaged without on- line monitoring. Among the commercially available on-line systems, UV analysers [for the rapid estimation of global (TOC, COD, TSS) or specific (nitrate, phenols, anionic surfactants) parameters], specific analysers based on electrochemical analy- sis (e.g. for nutrients) or other principles (TOC meter, hydrocarbons analyser, etc.), are proposed. Chemical or biological colorimetric test kits are also available for a lot of parameters, either mineral or organic. For all these devices, end-users must be aware of the existence of potential interferences. Thus, waiting for the development of reliable and cheap on-site measurement systems, the classical procedure will be preferred for a lot of specific parameters (metallic compounds, emergent pollutants, etc.). 1.2.2.3 Sample Handling The aim of this section is to stress sample preservation, between sampling and analysis; this topic is well covered by standards and technical works (WEF, 1996; ISO, 2003; APHA, 2005). The basic principles for good handling and conservation practices are very simple. First of all, the delay of conservation between sampling and analysis must be as short as possible to prevent sample ageing. After sam- pling, samples must be introduced into wide mouthed polyethylene flasks up to the top. For some parameters, such as hydrocarbons and micro or emergent pollutants, more inert and cleanable material, other plastics or preferably (brown) glass, may be used because of adsorption problems. The volume of flask depends on the an- alytical process and is pr´ecised in the literature (WEF, 1996; ISO, 2003; APHA, 2005). While filling the flask, the raw sample must be gently agitated before being trans- ferred, in order to ensure that suspended solids are collected and to prevent re- oxygenation during transportation. The flasks are then stored at low temperature (4 ◦ C) until analysis. Obviously all information for traceability (location, date, etc.) must be noted while sampling, and flasks carefully identified. For some parameters, preservatives have to be added to the flask (total metallic compounds, BOD, dis- solved oxygen by Winkler titration). For more information on conservation, storage, JWBK117-1.2 JWBK117-Quevauviller October 10, 2006 20:9 Char Count= 0 Interest of Sampling Assistance 31 delay before laboratory analysis, standard recommendations must be considered (ISO, 2003). 1.2.3 INTEREST OF SAMPLING ASSISTANCE For wastewater, sampling is often a routine operation with a given procedure. For a monitoring programme for treatment plant efficiency, the sampling sites are already located (inlet and outlet of a treatment plant), the duration and the frequency fixed (24 h each month), and parameters identical from one sampling campaign to another (for example: temperature,pH, conductivity, BOD, COD,TOC, TSS, nitrogen forms, total phosphorus). However, for objectives other than process efficiency, the design of asampling procedure is sometimes not evident. For theimpact studyof a discharge of treated wastewater in a receiving medium or for the diagnosis of a sewer network, the choice of sampling site is difficult, as well as the other factors (mode, date and duration). This is the reason why sampling assistance has to be envisaged to help the design of specific sampling programmes. Considering that an extensive sampling campaign is not realistic (too complex and too expensive), the first step in sampling assistance is the choice of sampling site and the second one is related to the sampling operations, with adapted on-site complementary measurement for grab or automatic sampling. 1.2.3.1 Choice of Critical Control Points As for natural water, one key point is the design of the monitoring programme, except in the case of a regulatory survey of a wastewater treatment plant where the location (inlet and outlet) and the time period (24 h) are fixed. The study of a sewer network, for example, or of the impact of a treated wastewater discharge, needs to know where to sample. One way to select the sampling points is to apply the Hazard Assessment and Critical Control Points (HACCP) method. If a good knowledge of the sampling area, based on experience and detailed geo- referenced maps and leading to the obvious choice of sampling sites, is not possible, the HACCP method will help for the monitoring programme design. Developed and used for risk analysis and mitigation in the agro-food industry (Council Directive of 14 June 1993), the method is based on seven steps, which can be adapted for wastewater monitoring: (1) Analyse hazards. Identification of potential hazards (biological, chemical, or physical) and monitoring objectives. (2) Identify control points. From the source to the discharge, identification of control points where potential hazard can be controlled or eliminated (e.g. industrial discharge in sewer, see Chapter 4.2). JWBK117-1.2 JWBK117-Quevauviller October 10, 2006 20:9 Char Count= 0 32 Sampling Assistance (3) Establish critical limits. More than critical limits, the choice of parameters and corresponding sampling constraints should be made. (4) Monitor critical control points. Procedures might include determining the efforts for the organization of sampling operations (manpower, methods, tools, and management). (5) Take corrective measures. This point is not crucial for sampling assistance but could be envisaged if sampling sites should be moved (or frequency adjusted) to get more representative information. (6) Establish verification procedures. Procedures include the appliance of best prac- tices for sampling quality control, including a reliable traceability of the final results of the monitoring. (7) Set up record-keeping procedures. Record-keeping is essential and would in- clude records of hazards and problems encountered and their control methods, the monitoring of safety requirements, and actions taken to correct potential problems. Finally, the modified HACCP approach can help in the identification of sampling points and in all sampling operations. 1.2.3.2 Assistance for Grab Sampling Except in the case of ‘historical’ surveillance, where the operator knows where, when and how sampling, the full design of a grab sampling programme is not easy. The spatio-temporal variability ofwastewater composition is a constraint,contrary to sampling locations, very often related to the inlet and outlet of a treatment plant and to the discharge stream of treated wastewater. The main objective being the relevance of the information expected from sample analysis (representativity of sample), the location and the procedure(dateandmethod) should be welldefined.Oncethe critical control points are identified (see above), a simple method derived from natural water sampling (Thomas and Th´eraulaz, 1994) can be applied for the definition of the final grab sampling procedure. In order to estimate the spatio-temporal variability, field measurement of simple parameters is performed during a pre-sampling programme. Grab sampling using either a field portable sampling line (strain, pipe and pump) or a flask fixed at the end of a pole is done at different locations and times, and on-site conductivity measurement and UV absorption spectrum acquisition are carried out. Conductivity characterizes the mineral matrix of wastewater and the UV spectrum gives quantitative and qualitative information on both dissolved organic absorbing substances and on the particulate fractions (suspended solids and colloids). The results can be usedfortheestimation of variability and for the finalchoiceof sampling procedure (precise location and date), depending on the sampling objective. JWBK117-1.2 JWBK117-Quevauviller October 10, 2006 20:9 Char Count= 0 Interest of Sampling Assistance 33 1.2.3.3 Assistance for Automatic Sampling Automatic sampling is very often used for the evaluation of treatment efficiency of a treatment plant. In this case, the sampling programme is defined according to the objectives of the monitoring. The location is easy (inlet and outlet of treatment plant, discharge or mixture) and the sampling starts at one given moment to end generally one day afterwards. In some other applications, automatic sampling is planned for the survey of nonpermanent events, such as the study of overflows or discharge impact on a receiving medium. In order to be sure that sampling is carried out only if, for example, threshold limits are passed for some parameters, the auto- matic sampler can be equipped with a multiprobe for the continuous measurement of given parameters (temperature, pH, dissolved oxygen, conductivity, turbidity). If a value exceeds the limit (alarm status), the sampling period starts and a message is sent to the operator for planning further complementary analysis in the labora- tory. This interesting function is however limited by the measured parameters (no information on organic pollution). In some cases, the sampling container can be automatically drained out and washed for another sampling phase, if the alarm is not validated (some automatic samplers work each day and drain after 24 h, before restarting). An adaptation of this method is available for combined sewer overflows monitor- ing. The automatic sampler starts only when an overflow occurs. This is detected by the measurement of the water table height on the overflow system, giving at the same time an estimation of the discharge volume. The same way can be envisaged for the monitoring of bypass flow to storage tanks in the case of heavy rain, for industrial wastewater. 1.2.3.4 Remote Sensing and Sampling Starting from the previous configuration with physico-chemical measurement de- vices, other sensors can be added such as an optical analyser for the acquisition of UV absorption spectra for the estimation of qualitative and quantitative parameters (see Chapter 1.5). Moreover, a field data logger coupled with a transmission proce- dure (through internet or cellular phone), can be used for the automatic management of the system. If a threshold limit is exceeded, or if a given UV spectrum shape is obtained [corresponding to a (high) polluted state, for example], the operator is warned andcan decideto manually start sampling from the internet or cellular phone. This is very useful because the person–machine interaction includes the validation of the protocol. Moreover, a warning message can be sent before the limit is passed, from the increasing trend of some parameters. Therefore, the operator is able to start remote sampling when he or she decides. This procedure is a simplification of the previous SCADA (supervisory control and data acquisition) system, largely used for more complex industrial environments. [...]... Lanka Standards Institution Standardiseringen i Sverige Swiss Association for Standardisation The Syrian Arab Organisation for Standardisation and Metrology Thai Industrial Standards Institute Trinidad and Tobago Bureau of Standards T¨ rk Standardlari Enstit¨ s¨ u uu Uganda National Bureau of Standards State Committee of Standardisation, Metrology and Certification of Ukraine Directorate of Standardisation... Standardisation Comisi´ n Guatemalteca de Normas o Innovation and Technology Commission Magyar Szabv´ ny¨ gyi Test¨ let a u u Icelandic Council for Standardisation Bureau of Indian Standards Badan Standardisasi Nasional Institute of Standards and Industrial Research of Iran National Standards Authority of Ireland The Standards Institution of Israel Ente Nazionale Italiano di Unificazione Bureau of Standards,... References 1.3.1 INTRODUCTION The monitoring of process effluents and wastewater discharges is required under implementation of the Industrial Pollution Prevention and Control (IPPC) Regulations (96/61/EEC Directive) and the Urban wastewater Treatment Regulations Wastewater Quality Monitoring and Treatment Edited by P Quevauviller, O Thomas and A van der Beken C 2006 John Wiley & Sons, Ltd ISBN: 0-471-49929-3... Intelectual o Bureau of Product Standards Polish Committee for Standardisation Instituto Portuguˆ s da Qualidade e State Committee of the Russian Federation for Standardisation, Metrology and Certification Saudi Arabian Standards Organisation Singapore Productivity and Standards Board Slovak Standards Institution Slovenian Institute for Standardisation South African Bureau of Standards Asociaci´ n Espa˜ ola... Industrial Standards Committee Kenya Bureau of Standards Korean Agency for Technology and Standards State Inspection for Standardisation and Metrology Latvian Standard Lithuanian Standards Board JWBK0117-1.3 JWBK117-Quevauviller October 10, 2006 20:10 Char Count= 0 Definitions and Sources 41 Table 1.3.2 (Continued ) Country Acronym Luxembourg SEE Malaysia Malta Mexico Moldova, Republic of Morocco Netherlands... context Four major types of standards may be cited: r Fundamental standards which concern terminology, metrology, conventions, signs and symbols, etc r Standards which define the characteristics of a product (product standard) or of a specification standard which service (service activities standard) and the performance thresholds to be reached (fitness for use, interface and interchangeability, health,... Normalisation Department of Standards Malaysia Malta Standards Authority Direcci´ n General de Normas o Department of Standardisation and Metrology Service de normalisation industrielle marocaine Nederlands Normalisatie-Instituut Standards New Zealand Direcci´ n de Tecnolog´a, Normalizaci´ n y o ı o Metrolog´a ı Norges Standardiseringsforbund Directorate General for Specifications and Measurements Instituto... Administration of China for Standardisation Instituto Colombiano de Normas T´ cnicas y e Certificaci´ n o Instituto de Normas T´ cnicas de Costa Rica e State Office for Standardisation and Metrology Czech Standards Institute Dansk Standard Instituto Ecuatoriano de Normalizaci´ n o Consejo Nacional de Ciencia y Tecnolog´a ı Quality and Standards Authority of Ethiopia Finnish Standards Association Association... Sophonsiri, C and Morgenroth, E (2004) Chemical composition associated with different particle size fractions in municipal, industrial and agricultural wastewaters, Chemosphere, 55, 691–703 Thomas, O and Th´ raulaz, F (1994) Analytical assistance for water sampling Trends Anal Chem., e 13(9), 344–348 Thomas, O and Pouet, M-F (2005) Wastewater quality monitoring: on line/on site measurement In: The Handbook... appropriate monitoring methodologies, frequency of monitoring, compliance assessment criteria and environmental monitoring The quality of the treated wastewaters must be better than reference values for parameters such as BOD, COD, TSS and even the global nitrogen and total phosphorus These provisions are of great importance but the chosen parameters are not easy to measure without sampling, storage and laboratory . National Standardisation 1 .3. 3 Standard Methods of Main Parameters 1 .3. 3.1 Biological Oxygen Demand 1 .3. 3.2 Chemical Oxygen Demand 1 .3. 3 .3 Total Organic Carbon 1 .3. 3.4 Total Suspended Solids 1 .3. 3.5. 0 1 .3 Standard Methodologies Estelle Dupuit 1 .3. 1 Introduction 1 .3. 2 Definitions and Sources 1 .3. 2.1 Definition 1 .3. 2.2 Sources of International, Regional and National Standardisation 1 .3. 2 .3 National. (96/61/EEC Directive) and the Urban wastewater Treatment Regulations Wastewater Quality Monitoring and Treatment Edited by P. Quevauviller, O. Thomas and A. van der Beken C  2006 John Wiley & Sons,