Carbon. Carbon. Carbon parameters: Carbon

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Eustacia Ward
6 years ago
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1 Carbon Carbon Carbon The main task of a wastewater treatment plant is to reduce the total organic load of wastewater in addition to all the progress made in nitrogen and phosphate elimination. Organic compounds consist mainly of the elements carbon and hydrogen. The cleaning process converts them to carbon dioxide and water while consuming oxygen. Carbon parameters: A measure for the total organically bound carbon DOC: Dissolved organic share of TOC Contains all substances that can be solubilized by chemical oxidation. It is at the same time the conventional parameter for the calculation of wastewater charges BOD: Contains only the compounds that can be oxidated microbiologically 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 measurements are not identical and that the measured values therefore can not be equal. Analysis procedures For an analytical online determination, all these parameters require complex procedures for digestion and the corresponding instrumentation. The (spectral absorption coefficient) is a parameter that can be determined more easily. Many organic compounds have characteristical UV absorption spectrums. The intensity of the light attenuation can, therefore, be correlated with the organic load. This correlation is significant in measuring media with low variations of composition concerning color, solids and their DOC/BOD/ 57

COD measurement in the laboratory In-situ measurement Sampling Using spectrometer sensors Digestion Measurement Result Individual measurement => time-delayed, suitable for monitoring Continuous

For each substance, a different correlation factor concerning the carbon content applies. Measuring at only one wavelength, e.g. at 254 nm for the 254, can often show the load only inadequately especially if the matrix changes.

2 COD measurement in the laboratory In-situ measurement Sampling Using spectrometer sensors Digestion Measurement Result Individual measurement => time-delayed, suitable for monitoring Continuous measurement => fast response time, suitable for control strategies 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 wavelength, e.g. at 254 nm for the 254, can often show the load only inadequately especially if the matrix changes. 58 Spectral Online Sensors The CarboVis and NiCaVis sensors measure the total spectrum range from ultraviolet to long wave visible light ( nm; UV-VIS sensors) or in the ultraviolet range ( 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 longtime 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 measurements, 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 userspecific calibration. The result is then displayed directly as, e.g. mg/l TOC Absorption NO 2 + NO 3 UV sensors COD UV-VIS sensors Turbidity Wave length (nm) Example spectrum of UV-VIS sensor

Carbon Applications The most important measuring points of wastewater treatment Plants for COD measurements are the inlet and outlet.

With a CarboVis installed there (possibly with integrated total suspended solids measurement), the cleaning performance of this plant can be monitored well.

Or NiCaVis NI triple sensor, which determines the carbon content, nitrate and nitrite.

3 Carbon Applications The most important measuring points of wastewater treatment 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 (possibly 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 determines the carbon content, nitrate and nitrite. Measuring principle UV-VIS 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 continued 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 technology. 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. Messprinzip 1 Light source UV-VIS General setup of spectral sensor 21 Lichtquelle Sender of the optical system 23 Sendeoptik Measuring gap between the measurement windows 34 Messspalt Receiver of zwischen the optical den system Fenstern 45 Empfangsoptik Detector 56 Detektor Measuring beam 67 Messstrahl Reference beam 78 Referenzstrahl Connector for the optional compressed air cleaning system TITANIUM Q UALI TY DOC/BOD/ 59

NEW CarboVis /NiCaVis High measurement reliability Low operating costs Simple handling Maximum durability In-situ measurement of COD and suspended solids (optional) The chemical-free spectral

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.

4 NEW CarboVis /NiCaVis High measurement reliability Low operating costs Simple handling Maximum durability 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. Excellent measurement repeatability and zero point and longterm stability. 100 % symmetrical optics, measurement and reference 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 interferences; calculate these automatically or apply these for compensation. 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 Wave length (nm) High-tech materials such as titanium and peek ensure an easy use in almost all media, even corrosive media. Absorption NO 2 + NO 3 UV sensors COD UV-VIS sensors Turbidity TITANIUM Q UALI TY 60

5 CarboVis /NiCaVis Technical Data CarboVis /NiCaVis Measuring Principle Applications Measuring Ranges in Standard Solution (potassium-hydrogenphtalate) Measuring Ranges TSS (Option) Ordering Information UV-VIS sensors CarboVis CarboVis 701 IQ CarboVis 701 IQ TS CarboVis 705 IQ CarboVis 705 IQ TS UV-VIS sensors NiCaVis NiCaVis 705 IQ UV sensors NiCaVis NiCaVis 701 IQ NI NiCaVis 705 IQ NI Spectral measurement in the UV-VIS range ( nm) / UV range of nm CarboVis 705 IQ CarboVis 701 IQ NiCaVis 705 IQ NiCaVis 701 IQ NI NiCaVis 705 IQ NI mg/l mg/l /m Inlet: mg/l TSS Effluent: mg/l TSS inlet, Biological Tank, mg/l mg/l /m Inlet: 0 15 g/l TSS Effluent: g/l TSS mg/l mg/l /m mg/l Materials Housing: Titanium , 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 x 2.36 in. (802 x 59.9 mm, length x diameter) Weight Approx lb (4 kg) Guaranty 2 years for defects of quality : inlet, Biological Tank, NO 2 -N: mg/l mg/l mg/l (IQ order separately) Optical COD/TOC/DOC/BOD or probe, with spectral processing of the UV-VIS range, for in-situ measurement in inlet, BNR part and of municipal wastewater treatment plants, with integrated ultrasonic cleaning. Optical COD/TOC/DOC/BOD/ and TSS probe, with spectral processing of the UV-VIS range, for in-situ measurement in inlet, BNR part and of municipal wastewater treatment plants, with integrated ultrasonic cleaning. Optical COD/TOC/DOC/BOD or probe, with spectral processing of the UV-VIS range, for in-situ measurement in of municipal wastewater treatment plants, with integrated ultrasonic cleaning. Optical COD/TOC/DOC/BOD/ and TSS probe, with spectral processing of the UV-VIS range, for in-situ measurement in of municipal wastewater treatment plants, with integrated ultrasonic cleaning. (IQ order separately) Optical nitrate and COD/TOC/DOC/BOD/ probe, with spectral processing of the UV-VIS range, for in-situ measurement in of municipal wastewater treatment plants, with integrated ultrasonic cleaning. (IQ order separately) UV sensor for the measurement of nitrate, nitrite, CODtotal, CODsoluble, TOC, BOD, DOC, total, soluble and UVT254 in inlet, BNR part and of municipal wastewater treatment plants. UV sensor for the measurement of nitrate, nitrite, CODtotal, CODsoluble, TOC, BOD, DOC, total, soluble and UVT254 in the of municipal wastewater treatment plants. NO 2 -N: mg/l mg/l mg/l Accessories for additional compressed air cleaning system (optional) Cleaning Air Box Cleaning air box with compressor, 230 VAC with air-filter MIQ/CHV PLUS Valve module for automatic cleaning by compressed air; controlled directly via the IQ Sensor Net Bus DIQ/CHV Valve module for the automatic compressed air cleaning for System 182; accessible by means of an DIQ/S 182 relay SET/AP Compressed air cleaning set: 15 m compressed air tubing incl. fittings, additional modules and components must be ordered separately IP 68 2 Year Guaranty Accessories see page 128. DOC/BOD/ 61

Online Wastewater Process Monitoring

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