Cassava starch wastewater treatment
According to statistics, the cassava starch industry discharges about 240 - 300 million m3 of wastewater into the environment/year. Cassava starch processing wastewater includes organic components such as starch, protein, cellulose, pectin, and sugar in fresh cassava tubers, which are the cause of high pollution to the wastewater stream of cassava starch factories. Based on the cassava starch processing process, wastewater can be divided into 2 streams: Waste stream 1: is wastewater after being sprayed into the cassava washing wheel to remove dirt and cassava peel. This type of wastewater has a low flow rate (about 2m3 of wastewater/ton of cassava), mainly containing substances that can settle quickly (cassava peel, soil, sand, ...). Therefore, this type of wastewater can pass through the screen, settle and then recycle the water in the washing stage. The part retained in the screen (cassava peel) after drying is used as fuel in production households. Waste stream 2: is wastewater discharged during the cassava filtering process, this type of wastewater has a large flow rate (10m3 of wastewater/ton of cassava), has a high organic matter content, high suspended matter content, low pH, high cyanide content, sour smell, and opaque white color. These parameters are expressed through the suspended solids content SS, nutrients containing N, P, biological oxygen demand indicators BOD, chemical demand COD,... with very high concentrations. How harmful is tapioca starch wastewater to the environment? pH
Origin of cassava starch wastewater
The pH of wastewater is too low, which will cause the self-cleaning ability of the receiving water source to be lost because the microorganisms naturally present in the water will inhibit their growth. In addition, when wastewater is acidic, it will be corrosive, causing an imbalance in cell metabolism, inhibiting the normal development of life processes.
Tapioca starch wastewater has a high organic content, when discharged into water sources, it will cause a decrease in the concentration of dissolved oxygen in the water because microorganisms use dissolved oxygen to decompose organic substances. Oxygen concentration below 50% saturation can affect the development of shrimp and fish. Reduced dissolved oxygen not only depletes aquatic resources but also reduces the self-cleaning ability of water sources, affecting the quality of water supplied for domestic and industrial use. BOD5 is related to determining the level of pollution of biodegradable components in wastewater and COD indicates the level of pollution of organic and inorganic substances contained in industrial wastewater. Pollution of organic substances leads to a decrease in the concentration of dissolved oxygen in water. Reduced dissolved oxygen will seriously affect the aquatic system, especially the microorganism system. When anaerobic decomposition occurs with a BOD5 content that is too high, it will cause a foul odor to the water source and kill the aquatic system, pollute the surrounding air and spread over a wide area by the wind.
High suspended matter content
Suspended solids make water cloudy or discolored, not only losing its aesthetic appearance but also reducing the depth of the illuminated water layer, affecting the photosynthesis of aquatic plants. On the other hand, when the sediment settles to the bottom of the water, it will cause anaerobic decomposition, causing a foul odor.
High nutrient content
High concentrations of N, P in water will cause eutrophication of water sources, affecting aquatic organisms in the water source, negatively affecting tourism and affecting the quality of water supply.
Biological wastewater treatment
Tapioca starch wastewater has a very high organic content, a large suspended solid content, with such wastewater characteristics, anaerobic methods should be used for treatment. However, the wastewater after anaerobic treatment needs to be treated by aerobic methods... to meet QCVN before being discharged into the receiving source.
Biogas tank:
Wastewater from starch processing will be led to the Biogas tank to treat organic compounds with high pollution concentrations, reducing pressure on the following works. Here, anaerobic microorganisms will decompose organic substances in wastewater into simple inorganic substances such as CH4, CO2, H2S. In this process, biogas is recovered to fuel the mold, run the boiler, cook, and generate electricity.
Organic substances →CH4 + CO2 +H2 + NH3 + H2S + new cells
When restarting the system, we can add anaerobic microorganisms to the biogas tank to increase the number of anaerobic microorganisms. Reduce COD, BOD, TSS of wastewater with high COD concentration. Increase the stability of the anaerobic system and the amount of methane.
Anoxic tank:
Wastewater after being regulated in terms of flow and waste concentration is pumped with a stable flow into the anoxic tank. Here, the process of reducing nitrogen into NO3- into gaseous nitrogen is carried out to achieve the permitted nitrogen standard.
The biological denitrification process involves the biological oxidation of many organic substances in wastewater using NO3- or NO2- as electron acceptors instead of oxygen, in conditions of no oxygen or limited DO (less than 2mg/l).
This process is carried out by a group of nitrifying bacteria that account for about 70-80% of the bacterial mass (activated sludge). The denitrification rate ranges from about 0.04 to 0.42g N-NO3-/g MLVSS. day, the larger the F/M ratio, the higher the reduction rate.
The tank is equipped with a submerged mixer to increase the contact of the biological sludge with the wastewater, thereby increasing the treatment efficiency.
NO3- → NO2- → NO → N2O (g) → N2
When restarting the system, Biofix Ammonia microorganisms must be added to promote the nitrogen treatment process in the anaerobic tank
Aeroten tank:
Wastewater after anaerobic treatment is led into the "Aerotank" to thoroughly treat organic substances. In the aerotank, the aerobic biological process takes place thanks to the microbial system maintained by the air blower. The amount of air supplied to the tank is for the purpose of: providing oxygen for aerobic microorganisms to convert dissolved organic substances into water and CO2. Mixing the wastewater and activated sludge evenly creates conditions for microorganisms to have good contact with the substrates that need to be treated. Releases gases that inhibit the life processes of microorganisms, these gases are produced during the process of microorganisms decomposing pollutants. Positively affects the reproduction process of microorganisms. The aerobic process is based on the principle that aerobic microorganisms decompose organic substances in the presence of dissolved oxygen according to the following equation:
Here, aerobic microorganisms (activated sludge) will decompose the remaining organic substances in wastewater into simple inorganic substances such as CO2, H2O,...
Bài viết liên quan
BioFix Fresh hosted the Seminar "Biological Era in Accommodation" in Da Nang.
Seminar "Biological Era" organized by BioFix Fresh in Da Nang with biological solutions in the accommodation service industry, towards sustainable development.
09-04-2025
BioFix Fresh attends VITAS' 25th anniversary celebration
BioFix Fresh attended the 25th anniversary celebration of VITAS, contributing microbiological solutions for wastewater treatment in the textile industry, and developing with businesses.
19-12-2024
5 effective ways to handle excess grease, simple to implement
In the article, BioFix Fresh guides 5 effective ways to handle grease, simple to apply to avoid clogging drain pipes, protecting the environment.
08-12-2024
Effective and cost-effective solutions for grease disposal in restaurants
Causes and consequences of grease blockage in restaurants. Highly effective and cost-effective solutions for grease disposal in restaurants.
08-12-2024
Effective grease treatment solutions for hotels and resorts
What are the consequences of waste grease on the wastewater treatment system of hotels and resorts? What is the optimal grease treatment solution for hotels and resorts today?
08-12-2024
Effective low-cost grease treatment solution for restaurants
Grease blockages in restaurants cause business disruption. BioFix Fresh will suggest effective grease removal solutions for restaurants.
08-12-2024
Suggestions for effective methods of treating grease in wastewater
Find out the causes of grease formation in wastewater. Measures to treat grease in wastewater are highly effective and are widely applied today.
08-12-2024
Summary of effective and thorough fat treatment methods
Is your drainage system clogged with grease giving you a headache? Check out these effective and thorough grease removal methods that are commonly used.
14-11-2024
Grease-treating microorganisms - effective treatment of clogged pipes
Learn about grease-treating microorganisms - the most effective solution for unclogging pipes today. Suggest some microbial preparations that are highly effective in treating grease.
14-10-2024
The most effective way to compost manure
Manure is an organic fertilizer from livestock and poultry manure, often mixed with straw. This fertilizer helps improve soil fertility, provide nutrients for plants, and improve soil structure.
26-07-2024
What is SVI? The role of SVI in wastewater treatment
What is SVI? SVI is the sludge volume index commonly used to measure the characteristics of a mixture of sludge and water or activated sludge (unit is milliliters/gram).
26-07-2024
What is a septic tank? Why periodically add probiotics to a septic tank?
Septic tanks are places that contain solid waste (such as feces, urine, grease, and some other organic waste, etc.) and this waste will be decomposed in the septic tank into liquid form.
26-07-2024
Wastewater treatment technologies
Scientists have found many advanced wastewater treatment technologies. Applicable to many different types of wastewater.
26-07-2024
What is anaerobic biotechnology? How does it work?
Anaerobic biotechnology is a method of using anaerobic microorganisms and facultative microorganisms to decompose organic and inorganic substances in wastewater.
26-07-2024
Cassava starch wastewater treatment
Cassava starch processing wastewater is rich in organic compounds, causing high pollution in starch factory effluents.
25-07-2024
Impact of excess oil and grease on the wastewater treatment system
Fats, oils and grease from cooking (vegetable oil, meat, milk) enter the drain through the sink, solidifying and causing blockages, broken drains and wastewater treatment problems.
25-07-2024
Operating principle of microbial fat treatment
The habit of pouring grease and leftover food directly into the sink repeatedly every day causes excess grease under the drain pipe to increase, combined with leftover food to clog the drain pipe.
25-07-2024
Water Indicator Microorganisms
Water indicator microorganisms, such as E. coli, are used to detect pollution and assess water quality, protecting public health.
25-07-2024
Bio powder turns dirty water into clean water in just a few minutes
Three-quarters of the world is covered with water, but less than 1% of it is usable water.Did you know that the percentage of "clean water" we use every day will decrease?
25-07-2024
Recycle organic waste into a source of fertilizer
Recycling organic waste into fertilizer reduces waste, creates natural nutrients, and minimizes chemical fertilizer use, benefiting health and the environment.
25-07-2024
What are the benefits of manure? Why is it necessary to compost before fertilizing?
Manure is an agricultural by-product from livestock, poultry, and processing activities, providing essential nutrients for plants.
25-07-2024
Aerobic Annealing Process and Factors Affecting Aerobic Annealing
Aerobic composting occurs in oxygen-rich conditions, where microorganisms decompose organic matter.
25-07-2024
Air conditioner cleaning tablets - Solution to deal with air conditioner blockage and odor
After a long time of use, air conditioners often emit unpleasant odors along with water blockage. Increase the possibility of respiratory infections.
20-07-2024
Aerobic and anaerobic composting methods
Anaerobic composting is a decomposition process that occurs using microorganisms that do not require oxygen to survive.
20-07-2024
BENEFITS OF COMPOSTING WITH MICROBIOLOGICAL ENZYMES
Manure, organic waste, sewage sludge,... are organic wastes rich in nutrients, bringing many benefits to plants and helping to improve the soil.
20-07-2024
Why is it said that biological measures are better than other measures?
What is the cause of clogged drain pipes that cause the sink to become clogged and the wastewater cannot drain?
20-07-2024
COMPREHENSIVE ENVIRONMENTAL SOLUTIONS FOR BUILDINGS
The characteristic of those buildings is that they are places where a large number of people gather, so the amount of garbage, waste and wastewater is also large.
20-07-2024
How to unclog grease pipes in the sink
Did you know that fat and grease will solidify after pouring it down the sink??
20-07-2024
RECIRCULATION OF BIOLOGICAL SLUDGE IN PAPER INDUSTRY IN PRODUCTION
With rapid growth, waste control in the paper production process is a challenge for managers…
20-07-2024
Impact of sludge on the environment and human health
After waste, sludge treatment is also a challenge for Vietnamese cities today.
20-07-2024