Relationship between Urban Industrial Land Use Size and Sulfur Dioxide Emissions:Evidence from 294 Cities in China

Although the relationship between the size of urban industrial land use and pollutant emissions has been widely discussed from different perspectives(e.g.,the scale and crowding effects),the results of various studies have revealed positive,negative,and combined impact relationships.However,how the expansion of urban industrial land use affects SO_(2) emissions remains unknown.We need to clarify this relationship in order to facilitate the realization of China’s pollution reduction and emission reduction goals.This study used the panel data from 294 cities spanning from 2011 to 2019 to construct a spatial econometric model.The objective was to explore the correlation between the scale of urban industrial land and sulfur dioxide emissions in China.The results show that a large scale of urban industrial land use corresponds to lower sulfur dioxide emissions per unit of industrial added value.By gaining a deeper understanding of the relationship between the scale of urban industrial land use and sulfur dioxide emissions,policymakers can further reduce pollutant emissions by rationalizing the planning of urban industrial land use and industrial layout.In addition to promoting industrial agglomeration and economies of scale in cities with extensive industrial land use,this strategy can support the development of efficient and environmentally friendly industries in areas with limited industrial land use.Optimizing the technology and encouraging the development of green industries can help reduce environmental pollution and promote sustainable urban development.

Quantification of emission reduction potentials of primary air pollutants from residential solid fuel combustion by adopting cleaner fuels in China

Residential low efficient fuel burning is a major source of many air pollutants produced during incomplete combustions, and household air pollution has been identified as one of the top environmental risk factors. Here we compiled literature-reported emission factors of pollutants including carbon monoxide（CO）, total suspended particles（TSPs）, PM2.5, organic carbon（OC）,elemental carbon（EC） and polycyclic aromatic hydrocarbons（PAHs） for different household energy sources, and quantified the potential for emission reduction by clean fuel adoption. The burning of crop straws, firewood and coal chunks in residential stoves had high emissions per unit fuel mass but lower thermal efficiencies, resulting in high levels of pollution emissions per unit of useful energy, whereas pelletized biofuels and coal briquettes had lower pollutant emissions and higher thermal efficiencies. Briquetting coal may lead to 82%–88% CO, 74%–99%TSP, 73%–76% PM2.5, 64%–98% OC, 92%–99% EC and 80%–83% PAH reductions compared to raw chunk coal. Biomass pelletizing technology would achieve 88%–97% CO, 73%–87% TSP, 79%–88%PM2.5, 94%–96% OC, 91%–99% EC and 63%–96% PAH reduction compared to biomass burning. The adoption of gas fuels（i.e., liquid petroleum gas, natural gas） would achieve significant pollutant reduction, nearly 96% for targeted pollutants. The reduction is related not only to fuel change, but also to the usage of high efficiency stoves.

Achieving air pollutant emission reduction targets with minimum abatement costs:An enterprise-level allocation method with constraints of fairness and feasibility

For achieving air pollutant emission reduction targets,total pollutant amount control is being continuously promoted in China.However,the traditional pattern of pollutant emission reduction allocation regardless of economic cost often results in unreasonable emission reduction pathways,and industrial enterprises as the main implementers have to pay excessively high costs.Therefore,this study adopted economic efficiency as its main consideration,used specific emission reduction measures(ERMs)of industrial enterprises as minimum allocation units,and constructed an enterprise-level pollutant emission reduction allocation(EPERA)model with minimization of the total abatement cost(TAC)as the objective function,and fairness and feasibility as constraints for emission reduction allocation.Taking City M in China as an example,the EPERA model was used to construct a Pareto optimal frontier and obtain the optimal trade-off result.Results showed that under basic and strict emission reduction regulations,the TAC of the optimal trade-off point was reduced by 46.40%and 45.77%,respectively,in comparison with that achieved when only considering fairness,and the Gini coefficient was 0.26 and 0.31,respectively.The abatement target was attained with controllable cost and relatively fair and reasonable allocation.In addition,enterprises allocated different emission reduction quotas under different ERMs had specific characteristics that required targeted optimization of technology and equipment to enable them to achieve optimal emission reduction effects for the same abatement cost.

Air pollutant emissions induced by rural-to-urban migration during China's urbanization(2005-2015)

As the world's most populous country,China has witnessed rapid urbanization in recent decades,with population migration from rural to urban(RU)regions as the major driving force.Due to the large gap between rural and urban consumption and investment level,large-scale RU migration impacts air pollutant emissions and creates extra uncertainties for air quality improvement.Here,we integrated population migration assessment,an environmentally extended inputeoutput model and structural decomposition analysis to evaluate the NOx,SO2 and primary PM2.5 emissions induced by RU migration during China's urbanization from 2005 to 2015.The results show that RU migration increased air pollutant emissions,while the increases in NOx and SO2 emissions peaked in approximately 2010 at 2.4 Mt and 2.2 Mt,accounting for 9.2%and 8.7%of the national emissions,respectively.The primary PM2.5 emissions induced by RU migration also peaked in approximately 2012 at 0.3 Mt,accounting for 2.8%of the national emissions.The indirect emissions embodied in consumption and investment increased,while household direct emissions decreased.The widening gap between urban and rural investment and consumption exerted a major increasing effect on migration-induced emissions;in contrast,the falling emission intensity contributed the most to the decreasing effect benefitting from end-of-pipe control technology applications as well as improving energy efficiency.The peak of air pollutant emissions induced by RU migration indicates that although urbanization currently creates extra environmental pressure in China,it is possible to reconcile urbanization and air quality improvement in the future with updating urbanization and air pollution control policies.

City level CO_(2) and local air pollutants co-control performance evaluation: A case study of 113 key envir on mental protection cities in China

‘Co-control',or synergistically reducing CO_(2)and local air polluta nt emissions,is an important strategy for cities to achieve'low carb on'and'blue sky'simultaneously.However,there were few studies to evaluate and compare the level of co-control of CO_(2) and local air pollutants in cities year.The present study proposed qualitative and quantitative methods to evaluate the level of co-control of CO_(2)and three local air pollutant(SO_(2).NOX,and particulate matter PM)emissions in key environmental protection cities in China over two periods(2012-2015 and 2015-2018).Statistical analysis found that,though three local air pollutant emissions positively correlated with CO_(2) emission,no significantly positive correlation was found between local air pollutants emission reductions and CO_(2) emission reductions,indicating that co-control effects were poor in general.By using the co-control effect coordinate system,qualitative evaluation showed that less than half of the sample cities could achieve co-control of the total amount of CO_(2) and local air pollutants.By employing the indicator of emission reduction equivalence(EReq),quantitative evaluation showed that the co-control level of the sample cities improved in 2015-2018 compared with 2012-2015.Further regression analysis showed that,reducing coal consumption and economic development significantly enhanced the co-control performance of the observed cities.The present case study proved that the proposed methods for evaluation and comparison of the city co-control performance works well,and can be used in other countries and regions to promote global cities racing to carbon and local air pollutants co-control.

The R&D of Flue Gas Pollutants Deep-Removal Technology for Coal-fired Power Plants

The flue gas pollutants deep-removal technology(DRT) focusing on PM2.5removal is the prime method of further reducing pollutants emission from coal-fired power plants. In view of the four key technological challenges in developing the DRT, studies were conducted on a series of purification technologies and the DRT was developed and successfully applied in 660 MW and 1000 MW coal-fired units. This paper analyzes the application results of the demonstration project, and proposes a roadmap for the follow-up researches and optimizations.