CONSULTATION ON WASTEWATER TREATMENT SOLUTION FOR FRESH NOODLE PRODUCTION

A. INTRODUCTION

1. Current status of the system needing treatment:

- System capacity: 100 m³/day.

- Aerobic biomass tank: 60 m³.

- The system has been operational and requires additional biomass cultivation.

- The system does not meet the QCVN 40:2011/BTNMT standards for industrial wastewater. The wastewater has a slight sour odor, the treated water's color is not as good as initially, and the indicators for BOD, COD, TSS, and total nitrogen exceed the standards.

Wastewater Composition Table:

 

2. System Treatment Technology: AO Technology – Anoxic combined with Aerobic.

3. Customer Requirements: Achieve QCVN 40:2011/BTNMT standards at the outlet, address the sour odor in wastewater, improve water color, and treat BOD, COD, TSS, and total nitrogen.

 

B. WASTEWATER CHARACTERISTICS:

- Wastewater from cleaning production equipment such as machinery, rice mills, extruders, flour filter fabrics, floor and surface cleaning, etc., contains significant amounts of detergents.

- Wastewater generated from production processes is milky white and contains a lot of starch, minerals, vitamins, and suspended solids. These pollutants hinder natural filtration processes, leading to anaerobic processes over time, causing unpleasant odors and affecting the color of the wastewater.

- However, very few production facilities install wastewater treatment systems, always discharging directly into the environment, leading to prolonged accumulation of untreated pollutants affecting groundwater, creating unpleasant odors, and causing environmental pollution.

The wastewater from noodle production is mainly biodegradable organic matter, with BOD5, COD, and nitrogen levels exceeding discharge standards.

Aerobic Tank: In this tank, BOD removal and ammonia conversion to nitrate occur.

Nitrification occurs here where ammonia (NH3, NH4+) is converted to nitrite (NO2) and then to nitrate (NO3) by two groups of bacteria, Nitrosomonas and Nitrobacter:

* Nitrosomonas bacteria: convert ammonia to nitrite. This nitrite formation stage is referred to as the NO2- 

NH4+ + 3/2 O2 → NO2- + H2O + 2H+ + energy

* Nitrobacter bacteria: Convert nitrite to nitrate. The nitrate formation stage is referred to as the NO3- 

NO2- + ½ O2 →  NO3- + energy

The BOD content in wastewater will be treated with the help of aerobic microorganisms. BOD removal efficiency can reach 85-90%.

Organic matter + Aerobic microorganisms + O2 → CO2 + H2O + New biomass

Anoxic Tank: This tank is responsible for converting nitrate to nitrogen. Anoxic microorganisms absorb nutrients and convert nitrate to free nitrogen. Combining the wastewater with recirculating flow makes the denitrification process more effective. The conversion process to N2 occurs as follows:

- Step 1 Convert nitrate to nitrite:

6 + 2CH3OH → 6 + 2CO2 + 4H2O

- Step 2 Convert nitrite to N2:

6 + 3CH3OH → 3N2 + 3CO2 + 3H2O + 6OH- + 3O2

 

C. SPECIALIZED MICROORGANISMS USED IN WASTEWATER

1.  BIOCLEAN ACF SC MARINE

Bioclean ACF-SC Marine is a liquid used for wastewater with high CELLULOSE content that is difficult to decompose, suitable for wastewater types such as coconut residue, noodle production, livestock wastewater, etc.

• Helps reduce BOD, COD, and TSS.
• Breaks down difficult-to-decompose cellulose.
• Improves wastewater color and reduces odor after treatment.
• Enhances the performance of wastewater treatment systems with high fiber content, sludge, and cellulose.

2.  BIOCLEAN ACF NA

BioClean ACF NA: is a powder containing two groups of bacteria, Nitrosomonas and Nitrobacter, which help convert ammonia to nitrite and nitrite to nitrate.

Applications:

• Treating ammonia for urban wastewater treatment plants, industrial wastewater, and biological ponds.
• Nitrification processes, starting a new system or restarting after a long period, using wastewater with high nitrogen concentrations exceeding thresholds.
• Ensuring stable nitrification processes in the system.
• Supporting nitrification and denitrification processes in the system.

3. Calculation of Appropriate Microorganism Dosage

BIOCLEAN ACF – SC MARINE

+ Initial dosage: 30 - 60ppm/week.

+ Maintenance dosage: 10 – 30ppm/week.

BIOCLEAN ACF NA

+ Initial dosage: 10 - 20ppm/week.

+ Maintenance: 5 – 15ppm/week.

*1ppm = 1ml/1m³ tank = 1g/1m tank

*Notes:

- The above dosages may vary depending on the pollution level of the system.

- It is recommended to divide the dosage within a week into 2 – 3 applications to optimize microbial activity in the system.

- Maintain microbial dosage for subsequent weeks to ensure optimal system performance.

*** ACF SC MARINE, ACF NA , when used together for both anoxic and aerobic biological clusters, provide the most effective solution to enhance BOD, COD, and TSS treatment, high total nitrogen treatment, improve water color, and control odors, and handle cellulose and starch in wastewater, ensuring that the discharge meets the permissible wastewater standards.

 

4. Microorganism cultivation guidelines

* Method 1: Biomass cultivation

Bioclean ACF SC-Marine and Bioclean ACF NA

Preparation:

- 1 suitable aeration tank, aquarium air pump for dissolving air into water.

- Activation process:

Mix the microorganisms in the ratio: microbial solution: molasses: water as 1:1:8 (1 liter of microbial solution + 1 liter of molasses + 8 liters of clean water).

Aerate for 12-14 hours, then pour the aerated microbial solution directly into the aerobic tank.

* Method 2: Mix with clean water as per the above ratio and add directly into the system

Note: It is advisable to divide the microbial dosage into 2 – 3 applications for optimal system performance.

 

5. System cultivation

- Ensure the system operates stably before starting microorganism cultivation.

- During operation, monitor the sludge volume after 30 minutes daily and observe the sludge and supernatant ratio to ensure that the sludge volume is 20-35%.

- Maintain microbial dosage for the following months with a maintenance dose for weeks 2-3-4 at a frequency of once a week.

 

In addition to environmental management, Biotech Vietnam also provides products for aquaculture and agriculture. For more information, please visit our website: https://www.biotechvietnam.org/

 

BIOTECH VIETNAM

11/11A Nguyen Van Mai Street, Ward 4, Tan Binh District, HCMC

Hotline: 0914.811.441