Related Experiment Videos
Nitrogen removal from wastewater by a catalytic oxidation method.
T L Huang1, J M Macinnes, K R Cliffe
1Department of Environment and Biotechnology, Refining & Manufacturing Research Center, Chinese Petroleum Corporation, Chia-Yi, Taiwan. huang1@rmrc.gov.tw
Water Research
|May 19, 2001
Summary
This study presents a novel catalytic oxidation method using a hydrophobic platinum on sulfonated divinylbenzene (Pt/SDB) catalyst to effectively remove ammonia from industrial wastewater. Optimal conditions were identified for efficient ammonia conversion to nitrogen and water, minimizing by-product formation.
Area of Science:
- Environmental Chemistry
- Catalysis
- Chemical Engineering
Background:
- Industrial wastewater often contains high concentrations of ammonia at elevated temperatures, posing challenges for conventional biological treatment.
- Direct biological treatment of ammonia-rich, high-temperature wastewater is often infeasible.
- Effective ammonia removal is crucial for environmental protection and water resource management.
Purpose of the Study:
- To develop and evaluate a catalytic oxidation process for removing ammonia from industrial wastewater.
- To investigate the simultaneous stripping and catalytic oxidation of ammonia in a trickle-bed reactor.
- To determine the optimal reaction conditions for ammonia removal and by-product minimization.
Main Methods:
- Utilized a hydrophobic Pt/SDB catalyst in a trickle-bed reactor for simultaneous ammonia stripping and catalytic oxidation.
- Varied temperature and oxygen partial pressure to assess their impact on ammonia removal efficiency.
- Analyzed reaction pathways and quantified by-products such as nitrites and nitrates.
- Monitored the effect of resultant pH on ammonia removal and nitrogen oxide selectivity.
Main Results:
- Higher temperatures and increased oxygen partial pressures significantly enhanced ammonia removal.
- Confirmed a reaction pathway involving ammonia oxidation to nitric oxide, followed by reaction with ammonia to yield nitrogen and water.
- Detected nitrites and nitrates as by-products, formed from nitrogen oxide absorption.
- Achieved maximum ammonia removal and minimum nitrite selectivity near a pH of 7.5 for unbuffered ammonia solutions.
Conclusions:
- The hydrophobic Pt/SDB catalyst in a trickle-bed reactor offers an effective method for treating high-concentration, high-temperature ammonia wastewater.
- Optimizing temperature, oxygen partial pressure, and pH is key to maximizing ammonia removal and minimizing undesirable by-products.
- This catalytic process presents a viable alternative to biological treatment for challenging industrial ammonia waste streams.