Introduction
A COD analyzer is an instrument used to measure the chemical oxygen demand (COD) of water and wastewater, which is a measure of the amount of oxygen required to oxidize the organic and inorganic substances in the water, and it is an important parameter for assessing the pollution load of wastewater, and it is used in environmental monitoring, wastewater treatment, and industry. The COD is measured by the oxidation of the sample with a strong oxidizing agent, typically potassium dichromate, in an acidic medium at a high temperature, and the amount of the oxidant consumed, which is related to the amount of oxidizable substances, is measured, and the COD is calculated and expressed in milligrams of oxygen per liter; the COD analyzer automates this determination, using the standard dichromate method or a microwave or photometric method, and it digests the sample in sealed tubes with the reagent, measures the color change or the consumption of the oxidant, and calculates the COD, and it provides rapid and accurate results, with features such as automatic digestion, photometric measurement, and data management. COD analyzers are used for monitoring the COD of influent and effluent in wastewater treatment plants, for compliance with discharge regulations, for assessing the pollution load of industrial wastewater, for monitoring rivers and lakes, for process control, for research, and for many other applications, in environmental laboratories, in industry, and in water treatment facilities, and they are available as benchtop instruments and online analyzers, with various measurement ranges. With their measurement of organic pollution, COD analyzers are essential for water quality monitoring.
COD Analyzer LCDA-T2014
Analyzer provides a measuring range of 0 to 10mg/L with indication error of ≤5%. It features an external digestion device for precise and stable temperature ensuring accuracy of test r...
COD Analyzer LCDA-T2013
Analyzer measures Chemical Oxygen Demand in water samples within a range of 0 to 10mg/L with ≤2% repeatability. Features water bath pot for temperature control which improves repeatabi...
COD Analyzer LCDA-T2012
Analyzer operates with a measuring range of 0 to 10mg/L with repeatability of ≤3%. Utilizes water bath followed by colorimetric measurement for batch processing of up to 20 samples per...
COD Analyzer LCDA-T2021
Analyzer utilizes colorimetric detection for automated measurement of up to 12 samples per batch. It features separate measurement and digestion device. It provides excellent measuremen...
COD Analyzer LCDA-T2020
Analyzer has measuring range of 5 to 2000mg/L. It has separate digestion device, with digestion period of 15min for measurement of 20 samples per batch. It utilizes sealed catalytic dig...
Portable COD Analyzer LCDA-T2010
Portable Analyzer features a compact benchtop design with a measurement range of 10 to 10,000 mg/L. It supports up to 7-point calibration and includes a restore function to revert to fac...
COD Analyzer LCDA-T2011
Analyzer is a benchtop design that offers a measuring range of 10 to 10000mg/L. It features a 7-inch high-resolution touch screen with a user-friendly graphical interface. The Analyzer ...
COD Analyzer LCDA-T2010
Analyzer features a compact, bench-top design with a measurement range of 0.0 to 1500 mg/L. It employs the dichromate colorimetric method as its measuring principle, renowned for its se...
Standards
ISO 15705:2002-Water quality-Determination of the chemical oxygen demand index (ST-COD)-Small-scale sealed-tube method
Complies with the above standards, but is not limited to them.
Features
1. COD analyzer for measuring chemical oxygen demand in water and wastewater samples.
2. Automated or semi-automated COD measurement using dichromate or alternative oxidation methods.
3. Suitable for environmental monitoring, wastewater treatment, industrial effluent, water and research labs.
4. Includes digestion unit, photometric detector, reagent system, autosampler, controller and manual.
5. Supports COD measurement for water quality monitoring, wastewater compliance and process control.
FAQ
Q1: What testing scenarios is this analyzer mainly applied to?
A: The COD (chemical oxygen demand) analyzer is used in environmental monitoring, wastewater treatment plants, industrial effluent monitoring, drinking water testing, surface water monitoring, groundwater testing, agricultural runoff monitoring and research to measure the chemical oxygen demand (the amount of oxygen required to oxidize all organic and oxidizable inorganic matter in a water sample) as an indicator of organic pollution load in water and wastewater, using automated or semi-automated digestion and photometric detection for high-throughput, reproducible COD analysis. It supports wastewater treatment plant influent/effluent monitoring (COD is a key parameter for wastewater treatment plant operation and regulatory compliance - measures treatment efficiency, monitors effluent quality for discharge permits), industrial effluent monitoring (manufacturing, food processing, chemical, pharmaceutical, textile, pulp and paper - COD monitoring for discharge compliance and process control), environmental water quality monitoring (rivers, lakes, reservoirs, coastal waters - COD as an organic pollution indicator, long-term water quality trend monitoring), drinking water source monitoring (COD in source water, treatment plant monitoring), groundwater contamination assessment (leachate, landfill, industrial site contamination), agricultural runoff monitoring (fertilizer, pesticide, organic matter runoff), and research laboratory COD analysis. COD is one of the most widely measured water quality parameters globally, used for regulatory compliance, treatment plant operation, and environmental assessment. The automated COD analyzer provides high-throughput, reproducible results with reduced manual labor and reagent handling compared to traditional manual reflux titration methods.
Q2: What standards does the analyzer comply with?
A: The COD analyzer follows relevant ISO, ASTM, EPA and GB/T standards for COD measurement, including ISO 6060 (water quality - determination of chemical oxygen demand), ISO 15705 (COD by sealed tube method), ASTM D1252 (COD in water), EPA 410.4 (COD by automated colorimetry, semi-automated), EPA 5220 (COD in Standard Methods), and relevant GB/T standards including GB 11914 (COD in water - dichromate method) and HJ/T 399 (COD by fast digestion-spectrophotometric method). The hardware complies with IEC 61010 safety standards. Calibration should use certified COD standard solutions (potassium hydrogen phthalate - KHP, traceable to international standards). For regulatory use, verify the method is approved by the relevant regulatory authority (EPA, EU, MEE/Ministry of Ecology and Environment in China). Users should verify the specific standard and method for their application (dichromate method is the standard reference method; alternative methods like permanganate index (CODMn) are used for less polluted waters, but are different parameters).
Q3: What is the warranty period for the whole analyzer and key components?
A: The whole COD analyzer is covered by a 12-month warranty. The digestion unit (heating block/reactor), photometric detector, reagent delivery system, autosampler, controller, display and housing are covered, while digestion tubes/vials, reagents (dichromate, sulfuric acid, catalyst), calibration standards, lamps, filters and fuses are consumables or accessories. Damage from improper use, reagent spillage/corrosion (sulfuric acid is highly corrosive), digestion unit damage or unauthorized repair is excluded. Extended service contracts may be available for this environmental monitoring equipment. Photometric lamp may have separate lifespan/warranty terms.
Q4: Is this device difficult to operate? Is professional training required?
A: Operation requires trained laboratory personnel familiar with COD analysis, water quality testing, reagent handling (corrosive reagents - dichromate and sulfuric acid) and regulatory requirements. We provide operation manuals, training and application support. Proper sample collection and preservation (collect in glass bottles, add sulfuric acid to pH < 2 for preservation, analyze within 28 days per standard, or 7 days for unpreserved), sample preparation (homogenization for samples with suspended solids, dilution for high-COD samples, chloride interference correction for high-chloride samples - chloride is oxidized by dichromate and causes positive interference; use mercuric sulfate to complex chloride, or use chloride correction), reagent handling (dichromate is toxic and carcinogenic - hexavalent chromium; sulfuric acid is highly corrosive; handle with proper PPE, fume hood, and waste disposal), digestion (proper temperature 148-150 degrees C, time 2 hours for standard method or 15 minutes for fast method), photometric measurement (proper wavelength 600 nm for Cr3+ or 440 nm for Cr6+, blank correction), calibration (KHP standard calibration curve), quality control (blanks, duplicates, spikes, reference materials), and regulatory documentation are important for accurate, compliant COD analysis.
Q5: What is the typical lead-time for order delivery?
A: Standard models require 7-30 working days. In-stock units can ship within 3-7 working days. Custom configurations or large built-to-order systems may require additional time, and we confirm the exact schedule before order confirmation.
Q6: Is regular calibration required? What is the recommended calibration cycle?
A: Calibration with certified KHP standard solutions recommended per batch or per day (for automated analyzers, calibration curve verified per batch). Routine quality control with a check standard per batch (verify calibration accuracy). Photometric wavelength and absorbance verification every 3-6 months. Digestion temperature verification every 3-6 months (use calibrated thermometer - proper digestion temperature is critical for complete oxidation). Reagent lot verification per new reagent batch (blank and standard check). Full analyzer performance verification annually. Lamp and optical system checked. Autosampler and reagent delivery system maintained per schedule. For regulatory use, follow applicable calibration schedules and maintain calibration records.
Q7: Are supporting consumables universal?
A: Digestion tubes/vials (glass, with caps - for sealed tube method), reagents (dichromate solution, sulfuric acid-silver sulfate catalyst solution, mercuric sulfate for chloride complexing), calibration standards (KHP - potassium hydrogen phthalate), chloride correction reagents, photometric lamps/filters, sample vials, caps, cleaning supplies and fuses are available from laboratory/water testing suppliers, though reagent formulation and tube type may be proprietary for some automated systems. Long-term consumable cost includes reagents (per test cost - dichromate and sulfuric acid are the primary ongoing costs; reagent cost per test is moderate), digestion tubes (reusable glass tubes or disposable vials), and calibration standards. Hazardous waste disposal cost (chromium waste - hexavalent chromium is hazardous and requires proper disposal per regulations) should be considered.
Q8: Can I customize parameters or supporting accessories?
A: Customization includes automation level (manual digestion + manual photometry, semi-automated, fully automated with autosampler and reagent dispensing), sample throughput (number of samples per batch/hour), digestion method (standard 2-hour reflux, fast 15-minute sealed tube, alternative methods like UV/persulfate oxidation for online monitoring), measurement range (low range 0-150 mg/L, high range 0-1500/15000 mg/L - select based on sample type; wastewater typically high range, surface water typically low range), chloride correction capability (for high-chloride samples like seawater, brine, industrial effluent), data logging, connectivity (USB, Ethernet, LIMS), software features (calibration curves, QC, reports, regulatory compliance), printer, language and accessories. Additional digestion tubes, reagents, standards and accessories can be ordered separately. Custom orders extend delivery lead-time.
Q9: Does the purchase include on-site installation and commissioning service?
A: Standard delivery includes the COD analyzer and accessories with an operation manual. On-site installation, calibration and training are not included for standard orders but can be arranged at additional cost (recommended for automated systems and regulatory compliance). Remote guidance is provided.
Q10: What types of samples are compatible with this equipment?
A: The COD analyzer measures chemical oxygen demand in water samples including wastewater (domestic sewage, industrial wastewater, treatment plant influent/effluent, septic tank effluent, landfill leachate), surface water (rivers, lakes, reservoirs, streams, coastal water, estuaries), groundwater (wells, aquifers, monitoring wells at contaminated sites), drinking water (source water, treatment plant water, finished water - typically low COD), industrial process water (cooling water, boiler water, process effluent), stormwater and runoff (urban runoff, agricultural runoff, construction site runoff), and other aqueous samples within the COD concentration range, chloride content, suspended solids and matrix specification. Different sample types require specific handling: wastewater (high COD range typically 100-10000+ mg/L - use high-range method; may contain high suspended solids - homogenize before sampling; may contain high chloride from industrial sources - use chloride correction; may contain toxic compounds that inhibit digestion - verify digestion efficiency with spikes), surface water (low to moderate COD typically 5-100 mg/L - use low-range method; may contain algae and organic matter - filter or homogenize per method; seasonal variation), groundwater (typically low COD < 10 mg/L for clean groundwater; contaminated groundwater may have higher COD from organic pollutants - use low-range method; may contain volatile organics - preserve and analyze promptly), drinking water (very low COD < 5 mg/L - COD may not be the best parameter for drinking water; permanganate index (CODMn) is more commonly used for drinking water in some standards; use very low-range method if COD is required), industrial effluent (highly variable depending on industry - food processing high COD from sugars/fats/proteins; chemical industry variable; textile industry high COD from dyes; pulp and paper high COD from lignin; may contain compounds that are difficult to oxidize (e.g., some aromatics, chlorinated organics) - verify with spikes; may contain high chloride from brine or process water - chloride correction essential). IMPORTANT LIMITATIONS: COD measures all oxidizable matter, including both organic and some inorganic compounds (sulfide, sulfite, ferrous iron, nitrite can be oxidized and contribute to COD - these are not organic pollutants but cause positive interference; if present, account for or remove them); COD does not distinguish between biodegradable and non-biodegradable organic matter (BOD - biochemical oxygen demand - measures biodegradable portion; COD/BOD ratio indicates biodegradability - high ratio means mostly non-biodegradable); the dichromate method uses toxic hexavalent chromium and corrosive sulfuric acid (environmental and safety concerns - proper PPE, fume hood, hazardous waste disposal required; some regions restrict or tax chromium waste); chloride interference is a major limitation (chloride is oxidized by dichromate, causing positive interference - mercuric sulfate is used to complex chloride, but mercuric sulfate is also toxic; for very high chloride samples > 2000 mg/L, special methods or corrections are needed; seawater has ~19000 mg/L chloride and requires special handling); volatile organic compounds may be lost during sample handling and digestion (use sealed tube method to minimize loss; for highly volatile samples, consider TOC - total organic carbon - as an alternative). Users should follow the specific test method (ISO 6060, ASTM D1252, EPA 410.4/5220, GB 11914, HJ/T 399) for sample collection, preservation, preparation, digestion and measurement, select appropriate measurement range based on expected COD (dilute high-COD samples to bring into range - use dilution water with low COD blank; record dilution factor), handle chloride interference (add mercuric sulfate to complex chloride - ratio HgSO4:Cl = 10:1 by weight; for chloride > 2000 mg/L, use special correction or alternative method; verify chloride concentration first with a chloride test), include quality control per batch (method blank - verifies reagent purity and contamination; duplicate - verifies precision; matrix spike - verifies recovery and matrix effects; certified reference material - verifies accuracy; digestion efficiency check - spike with known organic standard like KHP or glucose to verify complete oxidation), report results with method, range, dilution factor, chloride correction and units (mg/L O2) specified, and for regulatory compliance, use an approved method and maintain proper documentation. The analyzer should be placed in a fume hood or well-ventilated area (digestion of dichromate and sulfuric acid produces corrosive and toxic fumes - especially when adding sulfuric acid to aqueous samples, exothermic reaction can cause splashing; use proper PPE: lab coat, safety goggles, acid-resistant gloves; handle sulfuric acid carefully - always add acid to water, not water to acid). The digestion unit should be on a stable, acid-resistant surface (acid spills can damage surfaces and equipment; have acid neutralizer (sodium bicarbonate) available for spills). Reagent storage should be proper (sulfuric acid in corrosive cabinet, dichromate in toxic reagent cabinet, separate from incompatible chemicals; mercuric sulfate in toxic cabinet). Waste management is critical (chromium waste - both hexavalent Cr6+ (reagent) and trivalent Cr3+ (product) are hazardous; collect all chromium-containing waste (digestion solution, rinsate, spills) in a labeled hazardous waste container; do not pour down the drain; dispose through licensed hazardous waste vendor per regulations; consider reducing Cr6+ to Cr3+ before disposal if required by local regulations). The digestion tubes/vials should be properly cleaned (chromium residue can contaminate subsequent samples - clean with acid wash and rinse thoroughly; disposable vials eliminate cleaning but generate more waste). For online/process COD monitoring (continuous monitoring at wastewater plants or industrial outfalls), consider an online COD analyzer (different from laboratory analyzer - uses UV absorption or alternative oxidation methods, no dichromate, designed for continuous unattended operation; laboratory analyzers are for discrete sample analysis). The analyzer should be calibrated and maintained per manufacturer schedule for consistent, accurate results (reagent delivery system can clog or drift - check and clean per schedule; digestion temperature can drift - verify with calibrated thermometer; photometric system can drift - verify with absorbance standards).
Tips: For more details, quotes and customized solutions, please contact us anytime. We’re always ready to serve you professionally.