Carbon analysis cod toc bod sensor-wtw
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The document discusses various methods for measuring organic carbon levels in wastewater, including parameters like TOC, DOC, COD, and BOD. It describes WTW spectral sensors called CarboVis and NiCaVis that can continuously and non-destructively measure COD, TOC, and other parameters by analyzing the full UV-visible light spectrum absorbed by samples. The sensors offer high measurement reliability and simplicity compared to traditional lab methods. Key applications are monitoring organic loads at wastewater treatment plant inlets and outlets.
Carbon analysis cod toc bod sensor-wtw
- 1. For information visit www.WTW.com for a customer care center near you Sludge level Phosphate Carbon: COD/TOC/ DOC/BOD/SAC Nitrogen Turbidity/ Suspended Solids Conductivity pH/ORP Dissolved Oxygen Parameter section C a r b o n C a r b o n The main task of a wastewater treatment plant is to reduce the total organic load of wastewater in addition to all the prog- ress made in nitrogen and phosphate elimination. Organic compounds consist mainly of the elements carbon and hydro- gen. The cleaning process converts them to carbon dioxide and water while consuming oxygen. Carbon parameters To measure the organic load of water, the parameters TOC, DOC, COD or BOD are used. The differences in these parameters (marginal column) show that these measure- ments are not identical and that the measured values there- fore can not be equal. Analysis procedures For an analytical online determination, all these parameters require complex procedures for digestion and the corre- sponding instrumentation. SAC The SAC (spectral absorption coefficient) is a parameter that can be determined more easily. Many organic com- pounds have characteristical UV absorption spectrums. The intensity of the light attenuation can, therefore, be corre- lated with the organic load. This correlation is significant in measuring media with low variations of composition concerning color, solids and their C a r b o n p a r a m e t e r s : TOC: A measure for the total organically bound carbon DOC: Dissolved organic share of TOC COD: Contains all substances that can be solubilized by chemical oxidation. It is at the same time the con- ventional parameter for the calculation of wastewa- ter charges BOD: Contains only the compounds that can be oxidated microbiologically C a r b o n 57
- 2. For information visit www.WTW.com for a customer care center near you optical characteristics. Wastewater, however, contains many substances with completely different optical characteristics. For each substance, a different correlation factor concerning the carbon content applies. Measuring at only one wave- length, e.g. at 254 nm for the SAC254, can often show the load only inadequately – especially if the matrix changes. Spectral Online Sensors The CarboVis® and NiCaVis® sensors measure the total spectrum range from ultraviolet to long wave visible light (200-720 nm; UV-VIS sensors) or in the ultraviolet range (200- 390 nm; UV sensors). The measured values are determined from the high information content of the spectral data. The calculation is based on methods and characteristics that were achieved from a multitude of measurements and long- time analyses. The user can, therefore, select algorithms that are adapted to the measuring site (inlet, Biological Tank, outlet) having a high correlation with the basic parameter COD. The spectral procedure has an additional advantage: the turbidity of the test sample, which affects optical measure- ments, is optimally compensated over a wide wavelength range. Moreover, the spectral measurement provides an optimal compensation of the influence of existing nitrate and nitrite for the COD measurement. The determined measurement result is displayed directly as mg/l COD. A known correlation between this basic parameter COD and one of the related carbon para meters (TOC, DOC or BOD, to be selected) can be set by means of a user- specific calibration. The result is then displayed directly as, e.g. mg/l TOC. COD measurement in the laboratory I n - s i t u m e a s u r e m e n t Individual measurement => time-delayed, suitable for monitoring Continuous measurement = fast response time, suitable for control strategies Using spectrometer sensors 200 720 390 Absorption SAC Wave length (nm) Turbidity COD NO3 NO2 + UV sensors UV-VIS sensors Example spectrum of UV-VIS sensor Sampling Digestion Measurement Result 58
- 3. Q UALITY T I TANIU M For information visit www.WTW.com for a customer care center near you Sludge level Phosphate Carbon: COD/TOC/ DOC/BOD/SAC Nitrogen Turbidity/ Suspended Solids Conductivity pH/ORP Dissolved Oxygen Parameter section C a r b o n Applications The most important measuring points of wastewater treat- ment Plants for COD measurements are the inlet and outlet. To determine the incoming load of the plant, a CarboVis® sensor is positioned in the inlet. The load found in the outlet of the plant is low. With a “CarboVis®” installed there (pos- sibly with integrated total suspended solids measurement), the cleaning performance of this plant can be monitored well. The NiCaVis® combination sensor is also suitable for the outlet. It measures the carbon content as well as the nitrate concentration. Or NiCaVis® NI triple sensor, which determi- nes the carbon content, nitrate and nitrite. Clean measuring windows - a prerequisite for reliable optical measurements Fouling on the measuring windows can easily simulate high concentrations in COD measurement systems. Once the dirt has settled on the measurement windows, the conti- nued build-up of dirt particles will progress at increasing speed. Especially the use in treatment plants with strong fouling problem from the growth of microorganisms or the deposit of dirt on the measurement windows presents a real challenge to the optical online measurement techno- logy. The integrated, permanently operating ultrasonic cleaning of the measurement windows, which is integrated in all spectral WTW sensors as a standard very effectively and gently prevents the growth of all types of dirt/fauling from the start. This guarantees a permanently reliable online measurement. M e s s p r i n z i p U V- V I S 1 Lichtquelle 2 Sendeoptik 3 Messspalt zwischen den Fenstern 4 Empfangsoptik 5 Detektor 6 Messstrahl 7 Referenzstrahl M e a s u r i n g p r i n c i p l e U V- V I S 1 Light source 2 Sender of the optical system 3 Measuring gap between the measurement windows 4 Receiver of the optical system 5 Detector 6 Measuring beam 7 Reference beam 8 Connector for the optional compressed air cleaning system General setup of spectral sensor 59
- 4. Q UALITY T I TANIU M For information visit www.WTW.com for a customer care center near you • Excellent measurement repeata- bility and zero point and long- term stability. 100 % symmetrical optics, measurement and refe- rence channel are identical in design, which provides excellent referencing. • No interference in the COD measurement by nitrate, nitrite and turbidity/suspended solids. Evaluating the entire measured spectrum from 200 to 720 nm provide recognition of interfe- rences; calculate these automa- tically or apply these for com- pensation. Simple to use • Due to the built-in ultrasonic cleaning system, a very long maintenance-free operation is possible. Accumulation of dirt and biofilm formation is gently but very effectively prevented in this manner. Maximum durability • High-tech materials such as titanium and peek ensure an easy use in almost all media, even corrosive media. In-situ measurement of COD and suspended solids (optional) The chemical-free spectral measurement allows a precise determination of the COD and nitrate level. High measuring reliability • Wide dynamic range and high measurement accuracy. Automatic adjustment of the number of flashes to the current sample matrix, similar to an exposure measurement in cameras ensure optimal modulations of the detector. C a r b o V i s ® / N i C a Vi s ® • High measurement reliability • Low operating costs • Simple handling • Maximum durability 200 720 390 Absorption SAC Wave length (nm) Turbidity COD NO3 NO2 + UV sensors UV-VIS sensors N E W 60
- 5. For information visit www.WTW.com for a customer care center near you Sludge level Phosphate Carbon: COD/TOC/ DOC/BOD/SAC Nitrogen Turbidity/ Suspended Solids Conductivity pH/ORP Dissolved Oxygen Parameter section O r d e r i n g I n f o r m a t i o n UV-VIS sensors CarboVis® Supplied with multifunctional slide and Shock-Absorption-Rings, without connection cable (SACIQ order separately) Order No. CarboVis® 701 IQ Optical COD/TOC/DOC/BOD or SAC probe, with spectral processing of the UV-VIS range, for in-situ measurement in inlet, BNR part and effluent of municipal wastewater treatment plants, with integrated ultrasonic cleaning. 481 048 CarboVis® 701 IQ TS Double sensor Optical COD/TOC/DOC/BOD/SAC and TSS probe, with spectral processing of the UV-VIS range, for in-situ measurement in inlet, BNR part and effluent of municipal wastewater treatment plants, with integrated ultrasonic cleaning. 481 049 CarboVis® 705 IQ Optical COD/TOC/DOC/BOD or SAC probe, with spectral processing of the UV-VIS range, for in-situ measurement in effluent of municipal wastewater treatment plants, with integrated ultrasonic cleaning. 481 050 CarboVis® 705 IQ TS Double sensor Optical COD/TOC/DOC/BOD/SAC and TSS probe, with spectral processing of the UV-VIS range, for in-situ measurement in effluent of municipal wastewater treatment plants, with integrated ultrasonic cleaning. 481 051 UV-VIS sensors NiCaVis® Supplied with multifunctional slide and Shock-Absorption-Rings, without connection cable (SACIQ order separately) Order No. NiCaVis® 705 IQ Double sensor Optical nitrate and COD/TOC/DOC/BOD/SAC probe, with spectral processing of the UV-VIS range, for in-situ measurement in effluent of municipal wastewater treatment plants, with integrated ultrasonic cleaning. 481 052 UV sensors NiCaVis® Supplied with multifunctional slide and Shock-Absorption-Rings, without connection cable (SACIQ order separately) Order No. NiCaVis® 701 IQ NI UV sensor for the measurement of nitrate, nitrite, CODtotal, CODsoluble, TOC, BOD, DOC, SACtotal, SACsoluble and UVT254 in inlet, BNR part and effluent of municipal wastewater treatment plants. 481 054 NiCaVis® 705 IQ NI UV sensor for the measurement of nitrate, nitrite, CODtotal, CODsoluble, TOC, BOD, DOC, SACtotal, SACsoluble and UVT254 in the effluent of municipal wastewater treatment plants. 481 055 Accessories for additional compressed air cleaning system (optional) Order No. Cleaning Air Box Cleaning air box with compressor, 230 VAC with air-filter 480 019 MIQ/CHV PLUS Valve module for automatic cleaning by compressed air; controlled directly via the IQ Sensor Net Bus 480 018 DIQ/CHV Valve module for the automatic compressed air cleaning for System 182; accessible by means of an DIQ/S 182 relay 472 007 SET/AP Compressed air cleaning set: 15 m compressed air tubing incl. fittings, additional modules and components must be ordered separately 481 075 Te c h n i c a l D a t a C a r b o V i s ® / N i C a V i s ® Measuring Principle Spectral measurement in the UV-VIS range (200 - 720 nm) / UV range of 200 - 390 nm CarboVis® 705 IQ CarboVis® 701 IQ NiCaVis® 705 IQ NiCaVis® 701 IQ NI NiCaVis® 705 IQ NI Applications Municipal wastewater: effluent Municipal wastewater: inlet, Biological Tank, effluent Municipal wastewater: effluent Municipal wastewater: effluent: inlet, Biological Tank, effluent Municipal wastewater: effluent Measuring Ranges in Standard Solution (potassium-hydrogenphtalate) COD: 0.1 … 800.0 mg/l TOC: 1 … 500.0 mg/l SAC: 0.1 … 600.0 1/m COD: 0.5 … 4000.0 mg/l TOC: 5 … 2500.0 mg/l SAC: 0.5 … 3000.0 1/m COD: 0.1 … 800.0 mg/l TOC: 1 … 500.0 mg/l SAC: 0.1 … 600.0 1/m NO3-N: 0.01 … 25.00 mg/l NO2-N: 0.1 … 25 mg/l NO3-N: 0.1 … 100 mg/l COD: 0.5 … 4000.0 mg/l NO2-N: 0.01 … 5 mg/l NO3-N: 0.01 … 25 mg/l COD: 0.1 … 800 mg/l Measuring Ranges TSS (Option) Inlet: 0 … 3000 mg/l TSS Effluent: 0.0 … 900.0 mg/l TSS Inlet: 0 … 15 g/l TSS Effluent: 0 … 4.5 g/l TSS — — — Materials Housing: Titanium 3.7035, PEEK Window: Sapphire glass Pressure Resistance ≤1 bar Ambient Conditions Operating temperature: 32 °F … 113 °F (0 °C … + 45 °C) Storage temperature: 14 °F … 122 °F (– 10 °C … + 50 °C) Flow Velocity ≤ 3 m/s pH Range pH 4 … pH 12 Salt Content of Medium 5000 mg/l (Chloride) Dimensions 31.57 x 2.36 in. (802 x 59.9 mm, length x diameter) Weight Approx. 8.82 lb (4 kg) Guaranty 2 years for defects of quality Accessories see page 128. IP 68 2 Year Guaranty C a r b o V i s ® / N i C a V i s ® 61