The links that generate wastewater in the food industry mainly include the following aspects:
Raw material cleaning: When cleaning raw materials such as vegetables, fruits, meat, and seafood, a large amount of wastewater containing mud, pesticide residues, and microorganisms will be generated. For example, the wastewater generated by vegetable processing plants every day when washing vegetables can reach hundreds of tons, and the content of suspended matter far exceeds the normal water body standard.
Processing process: In different links of food processing, such as cutting, mixing, cooking, and pickling, wastewater containing rich organic matter, oil, food additives, etc. will be generated. For example, the cooking wastewater in meat processing contains a large amount of fat, protein, and salt, and the chemical oxygen demand (COD) can reach 3000-8000mg/L.
Cooling process: After the food is heat-treated such as baking, boiling, frying, and sterilization, water is needed for cooling, thereby generating wastewater. These wastewaters may contain impurities and chemicals generated during the heat treatment process.
Cleaning and floor washing: Wastewater used to clean processing equipment, containers, floors and workshops, containing detergents and food residues. These wastewaters need to be centrally treated through the wastewater treatment system.
Packaging process: Wastewater generated when water is used to clean and rinse packaging containers or materials during the food packaging process.
Characteristics of food industry wastewater include:
High organic matter content: Food processing wastewater contains a large amount of biodegradable organic matter such as protein, sugar, oil, organic acid, etc. For example, the COD of meat processing wastewater can reach 1000-3000mg/L, and the COD of beer wastewater is around 1000-2000mg/L.
Large fluctuations in water quality and water volume: Affected by the seasonality, periodicity and changes in processing technology of food processing production, the quality and quantity of wastewater will vary greatly in different seasons and time periods. For example, the wastewater output in the peak season of fruit processing is large, while it is significantly reduced in the off-season.
High suspended matter: The wastewater contains suspended matter such as raw material residues and microbial cells. For example, starch processing wastewater contains a large amount of starch particles and fibers.
Complex ingredients: In addition to the main ingredients, it may also contain food additives, pigments, salt and other substances. For example, pickled food wastewater contains high concentrations of salt, which will affect the growth and treatment effect of microorganisms.
The main components of food industry wastewater can be summarized into the following five categories, with specific characteristics and sources as follows:
1. Composition of main pollutants
Suspended matter
Includes floating matter (such as vegetable leaves, fruit peels, minced meat, poultry feathers) and suspended particles (such as oil, protein, starch, colloids). This type of pollutant mainly comes from the physical separation of raw material cleaning and production processes.
Organic matter
Characterized by high concentrations of COD (chemical oxygen demand), it comes from underutilized raw materials (such as fats, sugars, proteins) and processing by-products. For example:
Starch wastewater (high B/C ratio, good biodegradability)
Dairy wastewater (COD can reach more than 5000mg/L).
Nutrients
Include ammonia nitrogen, total nitrogen, total phosphorus, etc., which are mainly introduced by raw material decomposition and processing additives (such as preservatives). For example, the ammonia nitrogen concentration in meat processing wastewater is relatively high.
Soluble substances
Such as salt, acid, alkali, sugar, etc., are particularly prominent in pickled food wastewater (such as salt inhibits the activity of ordinary microorganisms).
Pathogenic bacteria and harmful substances
Animal wastewater (such as slaughter wastewater) may carry pathogens, blood, etc., and requires special treatment.
Characteristics and hazards of wastewater in the food industry
Perishability: Organic pollutants can easily lead to eutrophication of water bodies and cause the death of aquatic organisms.
Treatment challenges: High-salt wastewater (such as pickled) requires halophilic bacteria treatment, and high-concentration COD wastewater requires “anaerobic-aerobic” combined process.
Core conclusion: The complexity of food wastewater components is directly related to the type of processing, and it is necessary to select a combination of pretreatment (such as oil separation, flotation) and biochemical treatment (such as UASB, activated sludge method) processes.
The main indicators of wastewater testing in the food industry include the following categories:
Physical indicators:
Temperature: reflects the temperature characteristics of wastewater.
Color and chromaticity: measures the color depth of wastewater.
Smell and taste: evaluates the smell and taste of wastewater.
Turbidity and transparency: reflects the clarity of wastewater1.
Chemical indicators:
Chemical oxygen demand (COD): measures the content of organic matter in wastewater.
Biochemical oxygen demand (BOD): indicates the content of biodegradable organic matter in wastewater.
Total organic carbon (TOC): evaluates the total amount of organic matter in wastewater.
Suspended solids (SS): measures suspended solids in wastewater.
Volatile suspended solids (VSS): evaluates the organic components in suspended solids.
Heavy metals: such as mercury, cadmium, lead, chromium, etc., evaluate the content of heavy metals in wastewater. Plant nutrients: such as nitrogen and phosphorus, to assess the eutrophication of wastewater.
Sulfide, cyanide: to assess the content of toxic substances in wastewater1.
Biological indicators:
Total bacteria count: to assess the bacterial content in wastewater.
Coliform group: to detect pathogenic microorganisms in wastewater1.
Specific pollutant indicators:
Volatile organic compounds (VOCs): to assess the content of specific organic pollutants.
Polycyclic aromatic hydrocarbons (PAHs): to detect specific pollutants such as polycyclic aromatic hydrocarbons.
Pesticides: to assess pesticide residues in wastewater1.
Other indicators:
Dissolved oxygen (DO): to assess the oxygen content of water bodies, affecting the survival of aquatic organisms.
Ammonia nitrogen (NH3-N) and total nitrogen (TN): to assess the nitrogen content and prevent eutrophication of water bodies. Total phosphorus (TP): Evaluate the phosphorus content and prevent eutrophication of water bodies12.
Lianhua Technology is an innovative environmental protection enterprise specializing in the research and development, production, sales and service solutions of water quality testing instruments. Products are widely used in environmental monitoring systems, scientific research institutes, daily chemical light industry, petrochemical, food processing, brewing, municipal sewage treatment, metallurgical coking, pharmaceutical industry, papermaking, textile printing and dyeing, electroplating, power and other industries and fields.
After more than 40 years of development, Lianhua Technology has branches and offices in 22 regions in China, and has established online and offline omni-channel sales services and a national provincial capital-level marketing and after-sales network, providing customers with Lianhua’s characteristic full-process intimate services for procurement, use, maintenance and matching, and continuously providing customers with more effective, more convenient and safer products and solutions.
This issue brings you the application cases of Lianhua Technology’s LH-3BA (V12) multi-parameter water quality meter in water quality testing in food processing enterprises, so that everyone can have a more comprehensive understanding of the actual application of Lianhua Technology’s water quality testing instruments in various fields for your reference.
Application environment
Wastewater treatment system for food processing enterprises
User needs
Detect water quality indicators such as COD, ammonia nitrogen, total phosphorus, total nitrogen, turbidity, etc. in the influent and various process links, and provide data support for process adjustment, sewage discharge, and sewage recycling.
Solution
The LH-3BA (V12) multi-parameter water quality meter is simple and fast, with accurate measurement values, meeting most of the customer’s indicator detection needs. On-site training of customer laboratory personnel ensures that laboratory personnel can operate the instrument and master the experimental process of each indicator, so that customers can quickly and accurately determine various indicators of water samples in the future. The COD of customer water samples is generally 100-5000mg/L, ammonia nitrogen is 5-50mg/L, total phosphorus is 0.2-10mg/L, and total nitrogen is 5-100mg/L. Therefore, we assisted customers in developing a method for determination by diluting different water samples at different times, as well as an overall detection plan for dilution multiple selection, prediction, and measurement error control. Customers are very satisfied with the accuracy of the instrument’s measurement values, and are very satisfied with our instruments for reducing environmental protection labor costs and expenses for enterprises. During the subsequent use, our engineers will visit regularly and provide customers with services related to instruments and consumables at any time.
On-site display
Instrument introduction
LH-3BA (V12) multi-parameter water quality analyzer is a powerful instrument that can be used not only as a dedicated water quality photometric detection instrument, but also as a professional UV dual-wavelength total nitrogen detection instrument and UV-visible near-infrared spectrophotometer. The instrument has 74 preset measurement modes and 360 curves, including 277 standard curves and 83 fitting curves. It can be flexibly configured according to different detection requirements to meet various water quality detection tasks.
Features
● Meets the Level 2 requirements of “JJG-178 UV, Visible and Near Infrared Spectrophotometer Verification Procedure”;
● Compatible with 10/20/30mm cuvettes and φ16mm tubes for colorimetry, upgraded limit function, improved consistency and accuracy of sample measurement;
● Unique socket-type tungsten lamp/deuterium lamp, lamp replacement without optical debugging, simpler equipment maintenance;
● Professional total nitrogen analyzer, automatic switching of UV dual wavelengths, simple and easy to use, flexible and efficient, good wavelength repeatability, accurate results, direct concentration reading;
●74 preset measurement modes and 360 curves, including 277 standard curves and 83 fitting curves;
●Provided with professional consumables and reagents, the working steps are greatly reduced, and the measurement is simpler and more accurate;
●Adopt imported high-quality holographic grating to further reduce the stray light of the instrument and make the detection more accurate;
●7-inch color touch screen, user-friendly interface design, the instrument can store 12,000 sets of data, and can be freely viewed, supported printing and uploading;
●Can be freely matched with multiple models of digestion equipment according to needs;
Post time: Apr-25-2025
