[Treatment Effect of Corncob and Rice Straw Enhanced Subsurface Flow Constructed Wetland on Low C/N Ratio Wastewater].

The lack of carbon sources severely inhibits denitrification in wastewater with a low C/N ratio. Corncob and rice straw were chosen as supplementary carbon sources to bring into the wetland system to supplement the carbon sources needed for denitrification, and the enhancing effects of the two carbon sources on nitrogen removal from the wetland were studied. The cumulative release of carbon was in the order of rice straw[(145.

[Effects of Plastic Film Mulching and Biochar Application on NO Emission from a Vegetable Field].

The aim of this research was to examine the effects of biochar addition (B0:0 t·hm, B20:20 t·hm, and B40:40 t·hm) and mulching (FM:film and NM:no film) on vegetables. The impact of NO emissions in the field was based on the pepper-radish rotation vegetable field system on the farm of Southwest University, using static dark box/gas chromatography to conduct in-situ observations in the field for one year. In this experiment, a total of six treatments were set up, namely NMB0 (CK) and FMB0, NMB20 and FMB20, and NMB40 and FMB40.

[Effects of Hematite and Biochar Addition on Wastewater Treatment Efficiency, Greenhouse Gas Emission, and Microbial Community in Subsurface Flow Constructed Wetland].

The type and structure of the substrate in constructed wetland affects the diversity and abundance of microorganisms, thereby influencing the effect of sewage treatment. In this study, four groups of wetlands were constructed in the greenhouse:blank-constructed wetland (CW0), hematite-constructed wetland (CW1), biochar-constructed wetland (CW2), and hematite+biochar-constructed wetland (CW3), to study the differences in sewage treatment effects, greenhouse gas emissions, and microbial community structures of constructed wetland systems under different filler substrates. The results showed that the addition of hematite or biochar increased the COD removal rate of -0.

[Effect of Ferric-carbon Micro-electrolysis on Greenhouse Gas Emissions from Constructed Wetlands].

As the problem of global warming becomes increasingly serious, the greenhouse gas (GHG) emission reduction measures of constructed wetlands (CWs) have drawn significant attention. Ferric-carbon micro-electrolysis exhibits an excellent effect on wastewater purification as well as the potential to reduce GHG emissions. Therefore, to explore the impact of ferric-carbon micro-electrolysis on GHG emissions from intermittent aeration constructed wetlands, four kinds of different wetlands with different fillers were constructed.

[Wastewater Treatment Effects of Ferric-carbon Micro-electrolysis and Zeolite in Constructed Wetlands].

Ferric-carbon micro-electrolysis fillers and zeolite have been increasingly used as substrates in constructed wetlands due to their good wastewater pollution-removal efficiencies. To explore the effects of different fillers on wastewater treatment in constructed wetlands, four constructed wetlands were examined with vertical subsurface flow areas filled with ferric-carbon micro-electrolysis filler+gravel (CW-A), ferric-carbon micro-electrolysis filler+zeolite (CW-B), zeolite (CW-C), and gravel (CW-D). In addition, intermittent aeration was used to improve the dissolved oxygen (DO) environment.

[Effect of Plastic Film Mulching on Methane and Nitrous Oxide Emissions from the Ridges and Furrows of a Vegetable Field].

Investigate the effects of plastic film mulching on CH and NO emissions from a vegetable field, a one-year field observation was conducted using a static opaque chamber in a pepper-radish cropping system at the Key Field Station for Monitoring of Eco-Environment of Purple Soil of the Ministry of Agriculture of China at Southwest University, Chongqing. Two treatments (conventional and film mulching) were used to study the influence of film mulching on CH and NO emissions. The results showed that mulching significantly increased the annual average soil pH (<0.

[Characteristics of Aerosol Optical Depth in the Urban Area of Beibei and Its Correlation with Particle Concentration].

To understand the atmospheric quality of the Beibei District of Chongqing, using the simultaneous observation data of aerosol optical depth and particulate matter concentration in 2014, we analyzed the characteristics of aerosol optical depth (AOD) in the urban area of Beibei and its correlation with particle concentration. The results showed that the annual average of AOD in Beibei District is 1.46±0.

[Effect of Plastic Film Mulching on Greenhouse Gas Emissions from Rice-Rapeseed Rotation in Cropland].

A field experiment was conducted at the Key Field Station for Monitoring of Eco-Environment of Purple Soil of the Ministry of Agriculture of China at the farm of Southwest University in Chongqing. In the study, static chamber and gas chromatography methods were used to study the effects of plastic film mulching treatment on CO, CH, and NO emissions from rice-rapeseed rotation in situ for one year. A control experiment was also conducted without using the film.

[Effects of Plastic Film Mulching and Nitrogen Fertilizer Application on CH Emissions from a Vegetable Field].

To investigate the effects of plastic film mulching and nitrogen fertilizer application on CH emissions from a vegetable field, static opaque and gas chromatography methods were applied, and field observations of a chili-radish rotation system, from May 2014 to April 2016, were carried out in the Key Field Station for Monitoring of Eco-Environment of Purple Soil of the Ministry of Agriculture of China in the farm of Southwest University in Chongqing. Eight treatments were set up in the field experiment:control routine (no N application and no plastic film mulching) (NN0), control mulching (FN0), low N routine (NN1), low N mulching (FN1), conventional N routine (NN2), conventional N mulching (FN2), high N routine (NN3), and high N mulching (FN3). The characteristics and influencing factors of CH emissions and the changes of soil carbon and nitrogen composition from all treatments were studied.

[Effects of Plastic Film Mulching and Nitrogen Fertilizer Application on NO Emissions from a Vegetable Field].

To investigate the effects of plastic film mulching and nitrogen fertilizer application on NO emissions from a chili-radish rotation system, field observations were conducted from May 2014 to April 2016 in the Key Field Station for Monitoring of Eco-Environment of Purple Soil of the Ministry of Agriculture of China in the farm of Southwest University in Chongqing. Static opaque and gas chromatography was used to determine emissions. Eight treatments were set up in the field experiment:control routine (no N application and no plastic film mulching; NN0), control mulching (FN0), low N routine (NN1), low N mulching (FN1), conventional N routine (NN2), conventional N mulching (FN2), high N routine (NN3), and high N mulching (FN3).

[Effects of the Crop Rotation on Greenhouse Gases from Flooded Paddy Fields].

A field experiment was conducted at the Key Field Station for Monitoring Eco-environment of Purple Soil of the Ministry of Agriculture of China in the farm of Southwest University, Chongqing. The static chamber and gas chromatography method was used to study the effect of the cropping systems on greenhouse gases from rice-fallow (RF), rice-rapeseed rotation (RR), and rice-brussel mustard rotation (RV) cropland for a year. An opaque chamber was used for CH and NO observations and a transparent chamber was utilized for CO observations.

[Mass Concentrations and Size Distributions of Water-soluble Inorganic Ions in Atmospheric Aerosols in Beibei District, Chongqing].

In order to study the concentration and distribution characteristics of water-soluble inorganic ions in aerosol particles of the Beibei district of Chongqing, aerosol samples were collected with an Andersen cascade impactor between March 2014 and February 2015. Water-soluble inorganic ions, including Na, NH, K, Mg, Ca, F, Cl, NO, and SO were determined for different particle sizes (9.00, 5.

[Pollution Characteristics of Organic Carbon and Elemental Carbon in Atmospheric Aerosols in Beibei District, Chongqing].

To study the pollution characteristics of atmospheric carbon aerosols, aerosol samples were collected via a cascade impactor (Andersen) from March 2014 to February 2015 in Beibei District, Chongqing. Organic carbon (OC) and element carbon (EC) were detected using a DRI 2001A carbon analyzer. The results showed that the annual average concentrations of OC and EC in PM were (16.

[Effects of Plastic Film Mulching on Methane and Nitrous Oxide Emissions from a Rice-Rapeseed Crop Rotation].

A field experiment was conducted in the Key Field Station for Monitoring of Eco-Environment of Purple Soil of the Ministry of Agriculture of China in the farm of Southwest University in Chongqing. Static opaque chamber and gas chromatography methods were used to study the effect of plastic film mulching on CH and NO emissions characteristics from a rice-rapeseed crop rotation for one year. The results showed that CH and NO emissions are mainly concentrated in the early stages of the growth of each crop and there is a clear seasonal variation of CH emissions during the rice growing period and NO in the rapeseed growing period.

[Effects of Plastic Film Mulching on Nitrous Oxide Emissions from a Vegetable Field].

Considering the common cropping system (chili-radish rotation) in Southwest China, the objective of this study is to explore the effect of plastic film mulching on NO flux, NO concentrations in the soil profile, soil temperature, and humidity from a vegetable field. The method of the static opaque chamber was used and the experimental period lasted for one year. The results showed that the average flux of NO was 1000.

[Characteristics and Influencing Factors of CH Emissions from the Drawdown Area of the Three Gorges Reservoir].

Five levels (180 m, 175 m, 165 m, 155 m, and 140 m) in a typical drawdown area in Wangjiagou in the Three Gorges Reservoir were selected to study CH emissions from subtropical reservoirs. The experimental period lasted two years from September 2010 to August 2012. The methods of static opaque chambers during the drainage period and floating chambers during flooding period were used in this study.

[Effect of Plastic Film Mulching on Methane Emission from a Vegetable Field].

Using the static opaque chamber method and choosing a chili-radish cropping system, a field experiment, located in the Key Field Station for Monitoring of Eco-Environment of Purple Soil of the Ministry of Agriculture of China in the farm of Southwest University in Chongqing, was conducted for one year. Mulching and non-mulching treatments were set in the field, and the seasonal variation of CH flux and CH concentrations in the soil profile and the seasonal changes in soil moisture and temperature were observed for different treatments to explore the effect of plastic film mulching on soil moisture and temperature. The results showed that plastic film mulching can significantly improve the surface soil temperature during the pepper growing season in spring and summer (<0.

[Change and Influencing Factors of Dissolved Carbon and Dissolved Nitrogen in Water of the Three Gorges Reservoir].

In order to understand the changes of dissolved carbon and dissolved nitrogen in the water of Three Gorges Reservoir,this research was carried out once a week by the bank of Yangtze River in Fuling beach from March 2011 to August 2012,and the variation characteristics of dissolved C,N composition and their source were analyzed.The results showed that the concentration of DOC ranged from 0.64 mg·L to 9.

[Seasonal Variation and Source Analysis of the Water-soluble Inorganic Ions in Fine Particulate Matter in Suzhou].

A total of 87 daily PM samples were collected in the urban area of Suzhou city during 2015, representing spring, summer, autumn, winter, respectively. Mass concentration of PM was analyzed gravimetrically. Water-soluble inorganic ions, including F, Cl, NO, SO, Na, NH, K, Mgand Ca, were determined by ion chromatography.

[Characteristics and Influencing Factors of Soil Microbial Biomass Carbon and Nitrogen in Drawdown Area in the Three Gorges Reservoir].

Taking a typical drawdown area located in Wangjiagou of the Three Gorges Reservoir as the study object, four elevations 180,175,165 and 155 m were selected to explore the effect of water level change on soil microbial biomass carbon (SMBC) and microbial biomass nitrogen (SMBN). Wherein, 175,165 and 155 m elevations located in the fluctuating zone, manifested as short, medium and long-term flooding, respectively; 180 m was used as the control, located on the land and never flooded. Sampling depth in soil samples was 0-20 cm, collected once a week.

[Features and Influencing Factors of NO Emissions from Drawdown Area in the Three Gorges Reservoir].

Three heights (180 m, 175 m and 155 m) located in a typical drawdown area in Wangjiagou of the Three Gorges Reservoir were selected for studying the NO emissions from subtropical reservoirs. The experimental period lasted two years from August 2010 to August 2012. The methods of static opaque chambers during the drainage period and floating chambers during flooding period were adopted in this study.

[Effects of Land Use Type on Soil Microbial Biomass Carbon and Nitrogen in Water-Stable Aggregates in Jinyun Mountain].

In this study, four land use types including subtropical evergreen broad-leaved forest (abbreviation: forest), sloping farmland, orchard and abandoned land were selected to collect soil samples from 0 to 60 cm depth at the same altitude in Jinyun Mountain. Four sizes of large macroaggregates (> 2 mm), small macroaggregates (0.25-2 mm), microaggregates (0.

[Effects of Different Land Uses on Soil Active Organic Carbon and Nitrogen Fractions in Jinyun Mountain].

In this paper, we take Jinyun Mountain where located in Beibei district of Chongqing as the research object and explore the effect of different ways of land use on soil active organic carbon, nitrogen components by collecting the soil samples from 0 to 60 cm depth in subtropical evergreen broad-leaved forest (hereinafter referred to as the forest), abandoned land, orchard, farmland and measuring the content of MBC, MBN, DOC and DON. The research results show that the contents of soil MBC, MBN, DOC, DON are reduced with the increase of soil depth in four types of land using soils. Variance analysis of the single factor shows that four kinds of land uses have no significant difference in the contents of MBC, MBN and DON, but the DOC content of the abandoned land is significantly higher than that of other three kinds.

[Impact of Land Utilization Pattern on Distributing Characters of Labile Organic Carbon in Soil Aggregates in Jinyun Mountain].

Four land utilization patterns were selected for this study in Jinyun mountain, including subtropical evergreen broad-leaved forest (abbreviation: forest), sloping farmland, orchard and abandoned land. Soil samples were taken every 10 cm in the depth of 60 cm soil and proportions of large macroaggregates (> 2 mm), small macroaggregates (0. 25-2 mm), microaggregates (0.

[Impacts of Land Use Changes on Soil Light Fraction and Particulate Organic Carbon and Nitrogen in Jinyun Mountain].

Four land types including the subtropical evergreen broad-leaved forest, sloping farmland, orchard and abandoned land were selected to collect soil samples from 0 to 60 cm depth at the same altitude of sunny slope in the Jinyun Mountain in this study. Soil light fraction organic carbon and nitrogen ( LFOC and LFON), and particulate organic carbon and nitrogen (POC and PON) were determined and the distribution ratios and C/N ratios were calculated. The results showed that the contents of LFOC and LFON decreased significantly by 71.