Biological denitrification methods are divided into heterotrophic and autotrophic denitrification based on the organic or inorganic nature of the carbon source utilized by bacteria.
Autotrophic denitrification refers to the process where autotrophic denitrifying bacteria (certain chemolithoautotrophic microorganisms) use inorganic carbon (CO2, HCO3-, CO32-) as a carbon source, and mainly use inorganic substances (S, S2-, H2, Fe, Fe2+, NH4+, etc.) as electron donors for the reduction of nitrate nitrogen, reducing NO3--N in nitrogen-contaminated water to N2.
Autotrophic denitrification has broad application prospects in the field of advanced and extreme nitrogen removal from wastewater, mainly due to the multiple advantages of autotrophic denitrification technology, which include:
The problems with Traditional Denitrification
INFORMATION
Carbon source breakthrough
Due to the addition of a carbon source, The effluent COD is higher than the influent COD.
To address this issue, one approach is to increase the retention time, Another method is to add a nitrification tank after the denitrification process.
These two methods clearly increase both the investment and operational costs,and All heterotrophic denitrification processes have this problem.
Hazardous chemicals
Some carbon sources are classified as hazardous chemicals, such as methanol,
which require appropriate qualifications for transportation, storage, and usage.
Special handling is also necessary for the corresponding dosing equipment.
During use, they may affect the health of employees and pose significant safety risks.
High sludge production
During the operation of autotrophic denitrification for nitrogen removal, there is a high production of sludge.
Taking a filter bed as an example, backwashing is required daily. The issues associated with high sludge production
include the impact of frequent backwashing on microorganisms, the electricity consumption caused by frequent backwashing,
and the sludge disposal required as a result.
High labor intensity
If a solid carbon source is used, after preparation, a dedicated dosing system is required,
along with substantial labor. If a liquid carbon source is used, due to the concentration of the chemical,
the transportation costs are very high, leading to excessive overall investment in the carbon source and high operational expenses.
Autotrophic Denitrification
INFORMATION
Addressing the shortcomings of traditional carbon sources.
1. Autotrophic, completely eliminates the carbon source breakthrough issue, no need for additional structures at the backend.
2. No need for a dosing room, the filter material itself serves as the carbon source, saving on investment and space.
3. No need for manual dosing, significantly reduces labor intensity, saving time and effort.
4. Reduced backwashing frequency, less backwash sludge, achieving lower energy consumption.
5. Non-hazardous chemicals, no concerns about storage and safety issues.
Sulfur-based Autotrophic Denitrification Filter Media Product Features
1.A variety of particle sizes and formulations to choose from, suitable for multiple application scenarios;
2.Special filter material for constructed wetlands significantly reduces system clogging;
3.Wear-resistant, soak-proof, not easily crushed, the product is solid and reliable;
4.In-situ retrofitting of heterotrophic filter beds does not affect the original design treatment effect;
5.Can be applied in deep bed, Dn type, integrated equipment, and other various processes.
1.The table above shows a typical autotrophic denitrification Tn removal chart;
2.Typical denitrification loading is 0.3-0.6 kgNO3--N/m3d;
3.The intensity of water washing is the same as for heterotrophic systems, while the intensity of air washing is half that of heterotrophic systems;
4.The backwashing frequency is a quarter of that for heterotrophic systems.
Product Features
INFORMATION
How to create products through autotrophic denitrification is of utmost importance. After continuous efforts,
we have successfully produced autotrophic denitrification products in the form of filter media.Its main features are as follows:
1.Filling particle size: 3-6mm
2.Appearance: Spherical or ellipsoidal with hollow micro-holes
3.Bulk density: ≈1.15 t/m³
4.Consumption ratio: 1gNOX-N ≤ 3g filter material
5.Mud content ≤0.5%
6.Hydrochloric acid solubility ≤0.5%
7.K60 ≤ 1.45
8.Sphericity ≥ 0.9
9.The product is non-hazardous chemical, "Identification of Hazardous Chemicals" report
The water quality requirements are as follows:
1.Influent nitrate nitrogen concentration: 10~100 mg/L
2.Alkalinity: Denitrification amount × 4.5 mg/L
3.Water temperature: 12-35 ℃
4.SS (Suspended Solids): ≤ 30 mg/L
5.Dissolved oxygen: No requirement
6.COD (Chemical Oxygen Demand): Low
7.pH: Neutral or slightly alkaline
8.TP (Total Phosphorus): Phosphate (as P) ≥ 0.1 mg/L
Project Cases
INFORMATION
Municipal Wastewater
1.Changyi Wastewater Treatment Plant in Shandong, China, municipal sewage, treatment capacity of 60,000 tons/day.
2.The total nitrogen design requirement is 20mg/L, treated to 12mg/L, with half heterotrophic and half autotrophic.
3.A deep-bed filter form is adopted, filled with autotrophic denitrification filter material.
4.The volume of the autotrophic filter material is 820m³, with a retention time of 39 minutes.
5.The plant has been in operation for 2 years, with an average influent total nitrogen of 13.2mg/L and an average effluent total nitrogen of 3.39mg/L.
6.The average denitrification load is 0.49.
Municipal Wastewater
1.Xi'an Wastewater Treatment Plant in Shaanxi, China, municipal wastewater, treatment capacity of 80,000 tons/day.
2.The total nitrogen design requirement is 20mg/L, treated down to 15mg/L.
3.A deep-bed filter form is adopted, filled with autotrophic denitrification filter material.
4.The retention time is 35 minutes, with a designed denitrification load of 0.3.
5.The plant has been in operation for 3 years, with an average influent total nitrogen of 18.2mg/L and an average effluent total nitrogen of 12.6mg/L.
6.The average denitrification load is 0.38.
Chemical Wastewater
1.Binzhou Wastewater Treatment Plant in Shandong, China, chemical wastewater, treatment capacity of 30,000 tons/day.
2.The total nitrogen design requirement is for a denitrification amount greater than 10mg/L.
3.A deep-bed filter form is used, filled with autotrophic denitrification filter material.
4.The retention time is 50 minutes, with a designed denitrification load of 0.25-0.5.
5.The plant has been in operation for 1.5 years, with an average influent total nitrogen of 47.29mg/L and an average effluent total nitrogen of 2.19mg/L.
Municipal Wastewater
1.Wastewater treatment plant at a petrochemical factory in China, petrochemical wastewater, treatment capacity of 6,000 tons/day.
2.The total nitrogen design requirement is to reduce from 100mg/L to below 14mg/L.
3.DN (Denitrification) filter form is used, filled with 1536m³ of autotrophic denitrification filter material.
4.The retention time is 6 hours, with a designed denitrification load of 0.33.
5.The plant has been in operation for 1.5 years, with an average influent total nitrogen of 57.26mg/L and an average effluent total nitrogen of 6.03mg/L.
About US
INFORMATION
At present, autotrophic denitrification technology has a wide range of applications in China,
mainly in the form of autotrophic denitrification filter media. The filter media is laid out in filter tanks to achieve the removal of nitrate nitrogen.
The technical difficulty of autotrophic denitrification lies in how to form a robust filter media that not only ensures sufficient biofilm attachment space
for microorganisms but also serves as an electron donor. In recent years, the autotrophic denitrification filter media has become very mature in China.
We are the first manufacturer in China to successfully produce autotrophic denitrification filter media. Currently, we have a broad range of application
achievements and detailed application data. In order to better serve environmental management, we hope to cooperate with international wastewater treatment
suppliers to apply autotrophic denitrification technology globally. We welcome everyone to contact us for cooperation.
Contact Us：
Phone:+8613581689526 Mr.Kou
E-mail：business@supersadn.com
Tel:+8613581689526
E-mail：kchjiang@gmail.com
We-Chat：+8613581689526
