Related Experiment Video
Updated: Jan 27, 2026

Mesocosm-Scale Constructed Wetland Design for Wastewater Treatment
Published on: May 2, 2025
Does rice straw application reduce N2O emissions from surface flow constructed wetlands for swine wastewater
Shunan Zhang1, Feng Liu1, Pei Luo1
1Key Laboratory of Agro-ecological Processes in Subtropical Regions, Changsha Research Station for Agricultural & Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, PR China.
Abstract:
Rice straw was applied often as a carbon source to improve nitrogen removal; however, few studies have considered the effect of rice straw on nitrous oxide (N2O) emission during nitrogen removal in constructed wetlands (CWs). We constructed eighteen combined systems, consisting of rice straw ponds and surface flow CWs to investigate the effect of rice straw application on N2O emission in three strengths of swine wastewater treatments. The results showed rice straw (RS) treatment increased 131.5% of N2O emission factor from low strength CWs, but decreased 37.2-43.7% of N2O emission factors for medium and high strengths compared with no rice straw (NRS) treatment. The RS application led to an average 10.7% increase in the potential denitrification rate, and simultaneously enhanced gene abundances of the total bacteria (16S rRNA), ammonia-oxidising archaea, ammonia-oxidising bacteria, nitrate reductase, and N2O reductase (nosZ) for all strengths CWs. The multiple regression model revealed N2O emissions were strongly related to water temperature, nitrate, chemical oxygen demand, and denitrification genes. The proportion of nosZ gene abundance in 16S rRNA was higher in RS (0.7-1.3%) than NRS (0.4-0.9%) for medium and high strengths, while an opposite trend was observed for low strength. The discrepancy was responsible for increasing or decreasing N2O emission by RS application among different strengths. These findings indicated the effectiveness of RS application to control N2O emissions from the surface flow CWs was related to the pollution level of wastewater.
More Related Videos
09:49Use of a Battery of Chemical and Ecotoxicological Methods for the Assessment of the Efficacy of Wastewater Treatment Processes to Remove Estrogenic Potency
Published on: September 11, 2016
08:18Design and Use of a Full Flow Sampling System FFS for the Quantification of Methane Emissions
Published on: June 12, 2016
Related Concept Videos
Emission Spectra
Reducing Line Loss
With a step-up transformer at the source, the voltage is increased, thereby reducing the current in the transmission lines since power loss in...
Positron Emission Tomography
One of the main requirements of a PET scan is a positron-emitting radioisotope, which is produced in a cyclotron and then attached to a substance used by the part of the body...
Methods of reducing fever
Pharmacological Methods of Reducing Fever:
Local Anesthetics: Clinical Application as Surface, Infiltration, and Conduction Block Anesthesia
Atomic Emission Spectroscopy: Lab