Effects of biochar produced from distiller grains on agronomic performances of sorghum(Sorghum bicolor L.)and greenhouse gas emissions from soil

Aromatic liquor breweries produce massive distiller grains containing a high percentage of rice husks that necessitate harmless treatment and resource utilization.These husk-rich distiller grains can be pyrolyzed in the Ni-based catalyst system at a relatively low temperature(480?C)into combustible gas,which is used in liquor distillation,and biochar(BDG)with high mineral nutrients and good surface properties.A 3-year field experiment(2018-2020)was established to understand the effects of BDG on sorghum agronomic performances and greenhouse gas emissions from the soil.The results showed that BDG had higher mineral nutrient(N,P,K,and S)contents,larger cation exchange capacity,and better surface structure than those prepared using the traditional method at 400 and 600℃.Compared with sole chemical fertilizer(CF),the combination of CF and BDG(CF+BDG)increased sorghum nutrient(N,P,and K)uptake,yield,fertilizer use efficiency,and economic benefit.Cumulative CO_(2) emission from the soil changed little between with and without BDG,indicating the microbial stability of BDG.The effective adsorption of NH_(3) or NH_(4)+by BDG upon N application may reduce N loss through NH_(3) and N_(2)O emissions and increase the efficiency of fertilizer N use.Cumulative CH_(4) emission ranged from 32.45 to 44.86 g ha-1,which could be overlooked as a greenhouse gas in the sorghum field.Moreover,CF+BDG significantly decreased NH3 and N_(2)O emissions for the production of each unit of sorghum grains and the CO_(2) emission from the land for the production of a certain amount of sorghum grains.Therefore,CF+BDG exhibited better agronomic and environmental performances in sorghum cultivation.

Characterization and prediction of tailpipe ammonia emissions from in-use China 5/6 light-duty gasoline vehicles

On-road tailpipe ammonia (NH3) emissions contribute to urban secondary organic aerosol formation and have direct or indirect adverse impacts on the environment and human health. To understand the tailpipe NH3 emission characteristics, we performed comprehensive chassis dynamometer measurements of NH3 emission from two China 5 and two China 6 light-duty gasoline vehicles (LDGVs) equipped with three-way catalytic converters (TWCs). The results showed that the distance-based emission factors (EFs) were 12.72 ± 2.68 and 3.18 ± 1.37 mg/km for China 5 and China 6 LDGVs, respectively. Upgrades in emission standards were associated with a reduction in tailpipe NH3 emission. In addition, high NH3 EFs were observed during the engine warm-up period in cold-start cases owing to the intensive emissions of incomplete combustion products and suitable catalytic temperature in the TWCs. Notably, based on the instantaneous NH3 emission rate, distinct NH3–emitting events were detected under high/extra high velocity or rapid acceleration. Furthermore, NH3 emission rates correlated well with engine speed, vehicle specific power, and modified combustion efficiency, which were more easily accessible. These strong correlations were applied to reproduce NH3 emissions from China 5/6 LDGVs. The predicted NH3 EFs under different dynamometer and real-world cycles agreed well with existing measurement and prediction results, revealing that the NH3 EFs of LDGVs in urban routes were within 8.55–11.62 mg/km. The results presented here substantially contribute to improving the NH3 emission inventory for LDGVs and predicting on-road NH3 emissions in China.

The Status of Ammonia(NH_3) Emissions and Achievements of Emissions Reduction Technology in Farmland Ecosystems

NH3 is one of the leading causes of grey haze, and one of the main causes of serious ecological imbalances that result in environmental problems such as acid rain and air quality deterioration. At present, excessive fertilizer application greatly intensifies NH3 emissions intensity on farmland. In order to understand status and achievements of research on farmland NH3 emissions, the literature of farmland NH3 emission-related studies was retrieved from SCl journals and the Chinese science citation database. These are summarized with respect to the research progress on NH3 emission factors and emission reduction technologies. The future research direction of field NH3 emission and emission reduction technology need to strengthen the field observation on different soil environment and crop types, and understand the effect of NH3 emission on fertilizer application period and the proportion, temperature and organic fertilizer management in farmland mainly. The research results can provide more information about the factors that influence NH3 emissions. This study offers theoretical guidance and support directed at mitigating farmland NH3 emissions in the future.

Gases emissions estimation and analysis by using carbon dioxide balance method in natural-ventilated dairy cow barns

Contaminated gases emissions from livestock industry are becoming one of the most significant contributors to the increasingly serious environmental pollution.To find a way to reduce gases emissions,it is essential to reveal the factors that can affect the gases emissions.In this study,the concentrations of typical gases(including ammonia(NH_(3)),carbon dioxide(CO_(2)),hydrogen sulfide(H_(2)S),and sulfur dioxide(SO_(2)))generated from naturally-ventilated dairy cow barns were detected through the sample-data method in Tianjin,northern China.Indoor environmental conditions,such as temperature(T)and relative humidity(RH),were measured simultaneously.After applying the carbon dioxide mass balance method,ammonia,hydrogen sulfide and sulfur dioxide emissions were determined.The correlation analysis and regression analysis between the climate condition and gas emissions were conducted to assess the data collected in dairy cow barns during the whole study period.There was a significant relationship between environmental conditions and gas emissions.NH3,H2S and SO_(2) emissions from the building are in the range of 0.98-2.36 g/LU·h,0-0.034 g/LU·h,and 0-0.069 g/LU·h,respectively.The numerical analysis shows that the NH3 emission is highly correlated with the temperature and relative humidity.The ventilation rate shows a positive correlation with all the three gases.