1、Nitrogen removal from wastewater: A comprehensive review of biological

Considering the information gap, the present study provides a comprehensive review of the mechanisms and efficiency of the following BNR based wastewater treatment technologies: (a) biological nitrogen fixation; (b) conventional N/DN process; (c) PN/ANAMMOX process; (d) SNAD process.

2、Advancements and Future Perspectives in Biological Nitrogen and

These technologies integrate resource recovery into wastewater treatment while simultaneously removing N and P. By employing methods such as crystallization and chemical precipitation within the reactor during the treatment process, these methods effectively collect resources from wastewater.

3、Nitrifying bacteria for the remediation of organic nitrogen

For this reason, this research focuses on harnessing the capabilities of nitrifying bacteria to denitrify organic nitrogen compounds in water, exploring various bacterial strains, their functions, and their ability to obtain sources of carbon.

4、Biological nitrogen removal from low carbon wastewater

Bioelectrochemical processes are limited by low kinetics and complicated process configuration. In sum, anammox-mediated processes represent the best alternative to nitrification/denitrification for nitrogen removal in low- and high-strength wastewaters.

A Comprehensive Review on Wastewater Nitrogen Removal and Its Recovery

Discharging large amounts of domestic and industrial wastewater drastically increases the reactive nitrogen content in aquatic ecosystems, which causes severe ecological stress and biodiversity loss.

What is the Best Biological Process for Nitrogen Removal: When and Why?

ABSTRACT: Many different aerobic and anaerobic biological processes and treatment schemes are available for transforming organics and/or removing nitrogen from domestic wastewaters.

Biological Nutrient Removal Processes and Costs

Total effluent nitrogen comprises ammonia, nitrate, particulate organic nitrogen, and soluble organic nitrogen. The biological processes that primarily remove nitrogen are nitrification and denitrification (Jeyanayagam, 2005).

The nitrogen cycle and mitigation strategies for nitrogen loss during

Adding biochar, zeolite, and microbial incubation can mitigate nitrogen loss. Composting is a promising technology to decompose organic waste into humus-like high-quality compost, which can be used as organic fertilizer.

Technologies for biological removal and recovery of nitrogen from

In this review, we present an overview of various technologies of biological nitrogen removal including nitrification, denitrification, anaerobic ammonium oxidation (anammox), as well as bioelectrochemical systems and microalgal growth for nitrogen recovery.

New directions in biological nitrogen removal and recovery from

Microbial electrochemical cells are good for energy efficient recovery. The ideal system utilizes several approaches and plays to the strength of each. This review summarizes strategies for biological nitrogen removal (BNR) and recovery from wastewater.

Biochemical methods are commonly used in agriculture to remove organic nitrogen fertilizers. These methods primarily include physical, chemical, and biological approaches. Below is an overview of the basic principles, operational steps, and key considerations for each method.

1. Physical Methods

Physical methods separate organic nitrogen fertilizers from inorganic ones through mechanical or natural processes. Common techniques include weathering, leaching, and crushing.

(1) Weathering Method

• Principle: Expose organic nitrogen fertilizers to air, allowing oxidation and decomposition through contact with oxygen.
• Application: Suitable for small-scale farms or home gardens. Enhanced air circulation accelerates weathering.
• Advantages: Energy-saving (no heating required).
• Disadvantages: Time-consuming.

(2) Leaching Method

• Principle: Dissolve organic nitrogen fertilizers in water and drain them via irrigation systems.
• Application: Effective for large-scale farms or irrigated fields. Adjust water volume and frequency to control nutrient loss.
• Advantages: Efficiently reduces nitrogen loss.
• Disadvantages: Requires investment in irrigation infrastructure.

(3) Crushing Method

• Principle: Break organic nitrogen fertilizers into smaller particles using machinery to improve soil absorption.
• Application: Suitable for large farms. Achieved using crushers or grinders.
• Advantages: Increases fertilizer utilization rates.
• Disadvantages: High energy consumption and equipment costs.

2. Chemical Methods

Chemical methods use reactions to separate organic nitrogen. Common techniques include lime precipitation, ammonium sulfate precipitation, and calcium chloride precipitation.

(1) Lime Precipitation Method

• Principle: Add lime (CaO) to convert organic nitrogen into ammonia gas, forming calcium carbonate precipitate.
• Application: Suitable for small-scale farms or home gardens. Apply lime powder directly.
• Advantages: Rapid nitrogen removal.
• Disadvantages: Environmental impact; requires careful waste residue handling.

(2) Ammonium Sulfate Precipitation Method

• Principle: Add ammonium sulfate (NH₄HSO₄) to release ammonia gas and form ammonium sulfate precipitate.
• Application: Used in large-scale agriculture. Apply ammonium sulfate powder.
• Advantages: Effective nitrogen removal.
• Disadvantages: Consumes ammonium sulfate; may harm soil health.

(3) Calcium Chloride Precipitation Method

• Principle: Add calcium chloride (CaCl₂) to convert organic nitrogen into ammonia gas, forming calcium hydroxide precipitate.
• Application: Suitable for small-scale farms or home gardens. Apply calcium chloride powder.
• Advantages: Efficient nitrogen removal.
• Disadvantages: Environmental risks; requires safe waste management.

3. Biological Methods

Biological methods leverage microorganisms to remove organic nitrogen. Common approaches include composting and microbial inoculant fermentation.

(1) Composting Method

• Principle: Mix organic nitrogen fertilizers with other organic matter and ferment via microbial action to produce compost.
• Application: Suitable for small-scale farms or home gardens. DIY composting is feasible.
• Advantages: Recycles organic matter; reduces pollution.
• Disadvantages: Time-consuming fermentation process.

(2) Microbial Inoculants Fermentation Method

• Principle: Use specific microbial inoculants to convert organic nitrogen into fertilizers.
• Application: Suitable for large-scale agriculture. Requires purchased inoculants.
• Advantages: Fast nitrogen removal.
• Disadvantages: Cost of inoculants; potential environmental impact.

Biochemical methods are effective for removing organic nitrogen fertilizers. The choice of method depends on context, balancing safety, environmental protection, and efficiency. Proper implementation ensures optimal results while minimizing ecological risks.