植被生产力反映了陆地生态系统通过光合作用固定的有机碳量.长江流域在我国经济社会发展和生态环境保护中占有重要的战略地位.然而,由于区域尺度植被生产力估算不够精准,导致了目前长江流域植被生产力现状及演变规律不清、关键驱动因子研究不充分的问题.本研究选取最新的日光诱导叶绿素荧光(solar-induced chlorophyll fluorescence,SIF)数据来表征长江流域植被生产力,基于全球陆地数据同化系统(GLDAS v.5)数据集,采用偏最小二乘回归方法,系统辨识了长江流域SIF的时空演变规律,解析了SIF对降水、温度、净辐射变化的响应规律.结果表明:①2001-2020 年,长江流域SIF年均值为(0.25±0.08)mW/(m2·nm·sr),SIF随着纬度的增加呈现显著减少的趋势,随着经度的增加呈现先增加后减少的趋势,汉江流域、鄱阳湖流域、洞庭湖流域SIF均相对较高,金沙江石鼓以上流域和金沙江石鼓以下流域SIF均相对较低.②2001-2020 年长江流域SIF有显著增加的趋势,增加速率为 0.002 mW/(m2·nm·sr·a),乌江流域、宜宾至宜昌段长江干流区间和鄱阳湖流域的SIF增长率均较高,30.34%的金沙江石鼓以上流域和 47.21%的太湖流域SIF存在减少趋势.③降水、温度和净辐射对长江流域SIF变化的贡献度分别为 16.41%±9.59%、49.29%±10.79%和 34.30%±14.99%.研究显示,2001-2020 年长江流域植被生产力有显著增加的趋势,温度对长江流域植被生产力变化起着主导作用.本研究可提高对长江流域植被气候变化适应性的认识,研究成果可为长江流域增汇减排政策的制定及碳中和目标的实现提供科技支撑.
加强新污染物治理是持续改善生态环境质量、切实保障生态环境安全和人民群众身体健康的重要抓手.自《新污染物治理行动方案》发布以来,各地方省级行政区相继发布《新污染物治理工作方案》(简称"《工作方案》"),推进新污染物治理工作.该文从时间历程、重点行业、重点新污染物种类和责任主体等方面出发,分析了我国各省级行政区新污染物治理工作的特点,总结了各省级行政区在标准建立、调查监测、源头减量化和协同治理等方面的工作进展,并展望了未来新污染物治理工作方向.截至2023 年 5 月,我国 31 个省级行政区以及新疆生产建设兵团全部出台《工作方案》,涉及医药制造业、化学原料和化学制品制造业等 19 大类行业.各地区新污染物治理重点行业与其行业产业规模密切相关,以聚焦重点工业园区为重要共性特征.共有 13 个省级行政区的《工作方案》提出重点关注新污染物,分属持久性有机污染物、抗生素、内分泌干扰物和微塑料等.通过计算不同职能部门在省级行政区《工作方案》中的职责分量,揭示了生态环境厅(局)、农业农村厅(局、委员会)、市场监督管理局、卫生健康委员会以及工业和信息化厅(局、委员会)等多部门跨领域协同治理的工作机制.然而,目前新污染物分析监测方法、环境质量和排放标准等仍较为缺乏,区域新污染物环境调查监测尚处于起步阶段,污染源减量化尚在部分行业领域启动,新污染物治理工作与其他生态环境保护规划的协同仍有待加强.未来我国新污染物治理工作可从落实属地责任和职能部门分工、开展区域生态环境联防联控联治、夯实新污染物环境监测体系和风险评估能力以及研发新污染物绿色替代和防控技术等方面进一步深入推进.
国家级经济技术开发区(简称"经开区")是我国改革开放的排头兵,历经近 40 年发展,已成为我国经济发展和落实区域高质量发展战略的重要支撑.本文构建了涵盖经开区整体和个体的绩效评价体系,以资源产出率、污染物排放强度和生态效率指标表征发展绩效,定量分析了经开区发展绩效时序变化和生态效率的空间分异.结果表明:①2007-2017 年,经开区新鲜水耗、4 种常规污染物(COD、NH3-N、SO2、NOx)排放均与经济发展呈相对脱钩.2017 年经开区能源和水资源产出率分别是全国工业能源和水资源产出率的 1.2 和 3.5 倍,COD、SO2、NOx排放强度是全国工业排放强度的 72％、53％、52％.②经开区绝对经济规模两极分化程度不断缓解,对地区经济影响力整体上升.空间分布上,经开区绝对经济规模大的城市从东部沿海进一步拓展到长江流域的中西部地区.③运用数据包络法分析 190 家经开区的生态效率并识别出典型的投入冗余和产出不足,为经开区精准施策奠定基础.全国仅 10％的经开区生态效率为 1,污染物排放、温室气体排放、工业能耗冗余是影响生态效率的主要原因.东部地区经开区生态效率平均值为 0.35,大于中部地区(0.28)和西部地区(0.26).研究显示,不同地区经开区GDP差异较大,未来要加强不同地区经开区协作提高内生动力;为进一步提高经开区生态效率,需结合研究识别出影响生态效率的关键因素,开展针对性提质增效工作.在经开区实施能耗、水耗以及碳排放总量和强度的"双控"行动;同时,在稳定末端治理成效基础上着力强化全过程和系统优化,深化源头降碳减污.
含铬废水的直接排放会对自然环境造成严重危害.为探究零价铁-生物炭材料(Fe0-BC)与Cr(Ⅵ)的反应效能,以木质垃圾与印染行业废铁泥两种亟需处理的固体废物作为原料,在不同温度下通过碳热还原制备Fe0-BC,并将其应用于水中Cr(Ⅵ)的去除.材料表征结果表明,1200℃下制备的Fe0-BC材料(Fe0-BC-1200)性能最佳,其比表面积为105.6 m3/g,孔径为6.23 nm,物相主要由Fe0、Cu0、C以及少量杂质构成,其中Fe0以球状的颗粒形式分散附着在碳的孔结构中,且大小均匀,粒度基本达到纳米级.通过静态试验考察了Fe0-BC材料对Cr(Ⅵ)的去除过程,发现Fe0-BC-1200对Cr(Ⅵ)的去除效果最好,在初始浓度为20 mg/L、初始pH为3.5、投加量为2.5 g/L的条件下,Cr(Ⅵ)的去除率达到95.2％.Cr(Ⅵ)的去除过程符合准二级反应动力学过程和Langmuir等温吸附模型(R2>0.99),最大吸附量为10.71 mg/g.Cr(Ⅵ)的去除是包含吸附、还原以及络合沉淀等共同作用的结果,此外,Cu0的存在有利于催化Fe0的氧化,从而促进Cr(Ⅵ)的去除.研究显示,利用固体废物制备的Fe0-BC材料成本低且对于含Cr(Ⅵ)废水的解毒效果显著,是实现"以废治废"的环境治理新思路.
集中供热是事关国计民生的刚性需求,是能源消费的重要部门,是大气污染物减排的重要着力点.开展面向减污降碳的集中供热结构调整路径分析对我国实现"双碳"目标、建设"美丽中国"具有重要意义.通过构建2020年集中供热碳污耦合排放清单,摸清碳污排放现状;考虑热电联产供热范围以及生物质资源分布,分析拆炉并网、煤改气以及煤改生物质等措施的局限性及碳污减排潜力;结合情景分析,识别碳污减排关键路径,为开展集中供热减污降碳相关工作提供参考.结果表明:①热电联产、燃煤工业锅炉分别是集中供热部门CO2和大气污染物的主要排放源,东北地区及内蒙古自治区是该部门碳污排放的热点区域.燃煤工业锅炉污染控制水平及热效率较低是开展集中供热部门减污降碳的重要切入点.②热电联产供热管网难以全面覆盖35 t/h以下燃煤工业锅炉,超40％的小容量燃煤工业锅炉需要采用其他方式进行综合改造.③生物质能源利用潜力空间差异较大,制约了供热部门低碳化,如华北及东北地区难以满足本区域燃煤工业锅炉生物质改造的能源需求.④加强低碳情景下,2060年集中供热部门SO2、NOx、可过滤细颗粒物、可凝结颗粒物及CO2排放量分别为1.9×105、2.6×105、1.0×104、1.1×105及5.0×108 t,较2020年分别减排75％、66％、90％、66％及58％.研究显示,深入挖掘生物质资源、健全生物质成型燃料产业、推动拆炉并网是实现集中供热部门减污降碳的重要路径.
该研究对四川省攀枝花钒冶炼场地附近钒污染土壤进行了稳定化实验.结果显示:土壤中钒的含量高达1028.56mg/kg.不同添加量下,11种稳定化剂中3％焦磷酸钾、7％磁黄铁矿和7％电石渣的稳定化效果更好,稳定率分别为29.9％、41.4％和72.7％,且稳定化效果随着稳定化时间而提高.稳定化前后的钒形态及土壤性质的分析结果显示土壤中钒的稳定性得到提高.作者进行了复配实验,并使用Design-Expert得到了 5.0％焦磷酸钾、2.7％磁黄铁矿和4.7％电石渣的最优配比,稳定率实测值提高到了 85.9％.
In order to study the control factors of local ozone chemical generation in key regions of China(Beijing-Tianjin-Hebei and surrounding areas,Yangtze River Delta region,Pearl River Delta region,Chengdu-Chongqing region,and Fenhe and Weihe River Plain)in recent years,a comparative analysis was conducted on the composition of volatile organic compounds(VOCs)and their relationship with ozone chemical generation at 8 sites in five key regions using ozone and precursor concentration data from eight representative sites in these regions between 2014 and 2019.The research results indicate that:(1)The VOCs concentrations in the five key regions were mainly composed of alkanes,and the active components were mainly alkenes,oxygenated VOCs,and aromatic hydrocarbons.(2)The case studies in Taian and Chengdu as suburban and urban sites demonstrated that changes in environmental conditions(2℃increase in average temperature,a 20%increase in radiation,or a 20%increase in biogenic source emissions)may have an impact on local ozone generation.However,these factors alone were not enough to change the ozone generation control zones.(3)By using VOCs source analysis technology and Relative Incremental Reactivity method,it was found that anthropogenic sources such as vehicle exhaust,industrial operations,and solvent use were the key VOCs emission sources affecting local ozone chemical generation.In rural or suburban areas(such as Wangdu,Taian and other sites),biogenic VOCs contributed significantly to ozone generation.Therefore,in order to reduce peak concentration of ozone in cities,differentiated precursor emission reduction strategies must be implemented so as to enable effective control on the basis of each city's VOCs emission characteristics and the impact on local ozone generation.Prioritizing the control of anthropogenic VOCs is a crucial measure for effectively controlling summer ozone pollution.
Antibiotic resistance genes(ARGs),as emerging contaminants,pose a huge threat to human health and the ecological environment.It has been confirmed that ARGs can enter livestock and humans through the food chain along with agricultural products,causing greater health risks.However,there is still insufficient systematic research on ARGs in agricultural planting environment.This paper is based on bibliometrics and systematically summarizes the research progress of ARGs in agricultural environment in the past 5 years,and a systematic and in-depth study is performed on the pollution sources,occurrence forms,migration risks,influencing factors and control measures of ARGs.The result showed that there is little research on ARGs in the agricultural environments and a lack of focus.The application of organic fertilizers/manure,irrigation with production and domestic sewage,and the use of disinfectants all contributed to the accumulation of ARGs in agricultural planting environments,becoming an emerging reservoir for the development of antibiotic resistance.In agricultural planting environments,the ARGs mainly existed in intracellular DNA(iDNA),extracellular DNA(eDNA),mobile genetic elements(MGEs),and extracellular polymeric substances(EPS).The widespread distribution of eDNA and stable exchange of EPS facilitated the accumulation of ARGs.The migration risk of ARGs in agricultural planting environments,known as horizontal gene transfer(HGT),is mainly attributed to the processes such as MGE migration,inter-bacterial transfer of iDNA,natural transformation of eDNA,and EPS exchange.These processes are influenced by various factors such as soil physicochemical properties,nutrient elements,antibiotics,and other pollutants under different agricultural land use patterns.Additionally,soil salinization,nutrient and pollutant enrichment in agricultural planting environments can exacerbate the risk of the spread of antibiotic resistance.Currently,composting fermentation and organic carbon addition are the main methods to control the spread of antibiotic resistance,but these methods mainly reduce the production of ARGs by degrading and adsorbing antibiotics,which is insufficient to meet the demand for reducing the accumulation of ARGs in the soil environments.It is recommended to further study the evolutionary characteristics of ARGs in agricultural environments and conduct comprehensive risk assessment.Measures such as source control,nutrient optimization,and pollutant remediation should be taken to enhance soil stability,reduce the bacterial stress caused by changes in antibiotics,pollutants and nutrients,and inhibit the accumulation,migration and diffusion of ARGs in agricultural environment.
In order to study the ozone(O3)pollution and the characteristics and sources of volatile organic pollutants(VOCs)pollution in central China,this study conducted online observations of VOCs in 2022 and investigated their impact on the formation of O3 in Nanyang City,Henan Province.In order to guide more effective ozone and VOCs control in central China,this study conducted a one-year online VOCs monitoring in Nanyang City,a typical city in Central China,in 2022.The period from May to September was defined as the ozone pollution period,and the other months as non-ozone pollution period.The results showed that:(1)The average TVOCs concentration in non-ozone pollution months(32.1×10-9±13.2×10-9)was 65.5%higher than that in ozone pollution months(19.4×10-9±5.9×10-9).However,the concentration of OVOCs in ozone pollution months was 5.3%higher than that in the non-ozone pollution months,indicating that secondary formation may be a significant source of OVOCs in ozone pollution months in Nanyang City.(2)During both observation periods,the OFP of OVOCs accounts for more than 50%,among which formaldehyde(35%),acetaldehyde(10%)and ethylene(9%),m-p-xylene(5%)and toluene(3%)were the most important OFP contributing species.(3)Empirical kinetic model approach(EKMA)and relative incremental reactivity(RIR)calculation revealed that the O3 formation sensitivity was in transitional regime during the ozone pollution months,and O3 production was sensitive to both anthropogenic VOCs(particularly alkene and aromatic hydrocarbons)and NOx.(4)Positive matrix factorization(PMF)analysis identified six sources during the ozone pollution months:gasoline vehicles(29%),solvent use(23%),industrial process emissions(21%),residential emissions(11%),diesel vehicle emissions(10%)and plant emissions(6%).The research shows that during the ozone pollution months,secondary generation was a significant source of OVOCs,while gasoline vehicle emissions were an important contributor to atmospheric VOCs in Nanyang City.
From September 18th-20th,2022,an ozone(O3)pollution episode occurred in Fuzhou.The O3 concentration from 11:00 to 14:00 remained above 160 μg/m³.On September 19th,2022,the daily maximum 8-hour average O3 concentration reached 176 μg/m³.This episode may be related to the offshore O3 transport caused by the northeastern airflow in the periphery of Typhoon'Nanmadol'No.14.Here,based on the concentrations of conventional atmospheric pollutants and VOCs components and meteorological data from September 15th to 21st,2022,combined with the Lagrange particle diffusion model(LPDM),regional air quality model(WRF-CMAQ),and observation-based chemical box model(OBM),we analyzed the process of this O3 pollution episode,quantitatively assessed the contribution of maritime O3 transport and the effect of emission reduction of O3 precursors on O3 pollution,which can provide support for the prevention and control of O3 pollution in Fuzhou under the influence of typhoon systems.The main conclusions are as follows:(1)Based on the ∆Ox(hourly concentration change of photochemistry oxidant)results,under the influence of the northeast wind,the air mass with high O3 concentrations from the offshore was transmitted to the inland of Fuzhou on 19th.The contribution of O3 transmission was about 5-17 μg/m3.From 18:00 to 23:00 on the 19th,the hourly transportation contribution to the Jiulong site reached 6.0 μg/(m3·h).(2)From September 18th to 20th,ozone generation in Fuzhou City gradually shifted from the VOCs and NOx synergistic control area to the VOCs control area.The emission reductions of VOCs and NOx in Fuzhou should be controlled at a ratio of 1∶1 in the early stage of typhoon influence.In the later stage,the emission reduction of VOCs should be increased,and the ratio should be adjusted to 2∶1 to mitigate the impact of uncontrollable factors such as high temperatures and the increased biogenic VOCs emissions on the O3 pollution in pollution days.The study found that better control can be achieved through scientific and dynamic adjustment of NOx and VOCs emission control.
Winter is the most difficult period for the prevention and control of atmospheric PM2.5 pollution.In recent years,Yichang City has adopted appropriate winter prevention measures for air pollution prevention and control,and achieved certain improvement results.In order to study the impact of winter control measures on air quality in Yichang City and the effect of heavy pollution emergency emission reduction during the winter control period,we analyzed the changes in air quality,particulate matter components and source resolution during the winter control period of 2019-2021 in Yichang City using the ambient air quality and component monitoring data of Yichang City,and assessed the effect of heavy pollution emergency control measures during the winter control period of 2021 during three typical heavy pollution periods.The results showed that:(1)The PM2.5 concentration in Yichang City during the winter defense period in 2021 decreased by 4.3%compared with the winter defense periods in 2020 and 2019.(2)The concentrations of NO3-,SO42-,POA and SOA decreased significantly in the 2021 winter defense period compared with the 2019 winter defense period,with the decreases of 11.8%,12.7%,24.4%and 29.6%,respectively.(3)During the winter defense period of 2019-2021,the main sources of PM2.5 in Yichang City were secondary sources(35.85%-55.10%),motor vehicles(13.56%-36.08%),biomass combustion(8.26%-17.15%),industrial sources(4.34%-8.83%),and dust sources(3.78%-7.22%).The contribution of the secondary sources was high,the contribution of motor vehicles showed a decreasing trend year by year.The contribution of both secondary sources and industrial sources increased in the 2021 winter defense period compared with the 2019 winter defense period.(4)WRF-Chem model simulations showed that emergency control measures for three typical heavy pollution periods during the winter prevention period in 2021 reduced PM2.5 concentrations by 4.2%-9.2%.The study shows that scientific winter control measures have made positive contributions to the improvement of air quality in Yichang City.However,at the same time,the compound atmospheric pollution in Yichang City has intensified,making PM2.5 prevention and control more difficult.Precise analysis and research,and scientific pollution prevention and control will be conducive to the sustained and steady improvement of ambient air quality.
In order to obtain the best growth period for rice leaf surface barrier application in the main soil types in Chongqing and improve the efficiency of leaf surface barrier technology in reducing Cd in rice seeds,'Hengfeng Youzhen Simiao'seedling was selected as the test variety in Hechuan District(purple soil)and Qianjiang District(yellow soil),and'Chuge'leaf surface barrier agent(rich Si type)was used for field comparative experiments.The results showed that only at the heading stage(T2)could the Cd content of rice seed(0.151 mg/kg)reduce to below the food safety limit,and only at the tillering stage(T1),tillering stage and heading stage(T3)could the Cd content of rice seed increase.All treatment groups in yellow soil showed the Cd reducing effect on rice seeds,but it was difficult to guarantee the safety of rice seeds(the Cd content of rice seeds was 0.210-0.245 mg/kg).The Cd reducing effect of spraying only at tillering stage(T1)was better than that at heading stage(T2).The soil Fe content is the key to the reduction efficiency of Cd in rice seed applied with leaf surface barrier at different growth stages,and a certain thickness of iron film on the root surface can block the transfer of Cd to the internal and aboveground tissues of rice roots.The yield of rice increased significantly by applying foliar barrier agent.The yield increases of T1-T3 in purple soil area and yellow soil area were 9.90%-12.25%and 5.06%-12.44%,respectively.The research shows that foliar barrier agents should only be applied at heading stage in purple soil area,while at tillering stage and heading stage in yellow soil areas,respectively.However,comprehensive control technology(VIP+n)should be adopted to ensure the safety of rice seeds.In addition,rice roots,stems and leaves have a strong ability to accumulate Cd,so it is recommended to remove rice roots from the field after rice harvest to increase the output flux of heavy metals in farmland soil.
In order to study the spatiotemporal evolution characteristics and main influencing factors of industrial air pollution in key cities in Northwest China,the emissions of industrial SO2,NOx and smoke(powder)dust and social and economic data of 35 cities(study area)in this region from 2016 to 2020 were selected as the basic data sources.Global autocorrelation analysis,cold hot spot analysis and Log-mean Dieldahl Decomposition Model(LMDI)were used for analysis.The results show that:(1)The emissions of industrial air pollutants in the study area showed a downward trend in general,and the cities with high emissions significantly decreased.From 2016 to 2020,industrial SO2,NOx and smoke(powder)dust decreased by 57.08%,33.77%and 9.35%,respectively,which had a big difference from the nation-wide emission efficiency 78.5%,64.5%and 49.3%,respectively.(2)The overall level of spatial agglomeration of industrial pollutants in the research area is relatively low,mostly in a state of low agglomeration to high pollution.But the spatial correlation increased over time,and the Z(I)value of each pollutant in 2020 exceeded 1.96 and passed the significance test of P<0.05,which showed significant spatial autocorrelation.(3)The technology improvements have a significant inhibitory effect on industrial air pollution emissions in the study area.Economic development is always the primary driving factor to promote industrial air pollutant emissions.The effect of industrial structure has a certain impact on industrial air pollution emissions,which should be improved by strictly controlling the new production capacity of the'Two High'industries,updating old equipment and eliminating backward production capacity.Population size effect has little impact on industrial air pollution emissions.The study shows that the spatial spillover of industrial pollution emissions in the study area is not significant,and it is mainly affected by the inhibitory effect of technological improvement and industrial structure effect and the promoting effect of economic development effect.
During the'13th Five Year Plan'period,the overall air quality in the Yangtze River Delta(YRD)region improved,significantly.However,the atmospheric environment situation in the northern area of YRD is still severe.In addition,the frequently occurrence of haze in winter has become a weakness in winning the battle to protest the blue sky.This study focuses on a typical agricultural city in the northern part of YRD region.Local PM2.5 samples were collected manually at the Suzhou Environmental Protection Monitoring Station from December of 2020 to February of 2021,and the chemical components of the samples were analyzed.The results showed that the average PM2.5 concentration in winter was(80±31)μg/m3,and 49%of the sampling days exceeded the standard limit of level Ⅱ(75 μg/m3)of Ambient Air Quality Standards(GB 3095-2012).The seasonal average concentration of water-soluble inorganic ions was(38.6±24.8)μg/m3,accounting for 48%of PM2.5.The average concentration of secondary inorganic ions was(33.8±20.3)μg/m3,accounting for 42%of PM2.5.The average concentration of NH4+ in Suzhou was relatively high,and the emission intensity of NH3 from local agricultural sources may be the key to reducing ion and even PM2.5 concentrations in Suzhou.The seasonal average concentrations of total carbon,organic carbon(OC)and elemental carbon(EC)were(19.0±7.3),(16.3±6.2)and(2.7±1.2)μg/m3,respectively,and OC and EC accounted for 17%and 2.8%of PM2.5,respectively.The seasonal average concentrations of crustal elements and trace inorganic elements were(8.5±7.8)and(0.23±0.11)μg/m3,respectively,accounting for 10.5%and 0.3%of PM2.5,respectively.According to the PMF results,the local atmospheric PM2.5 mainly came from traffic(22%),combustion(21%)and secondary inorganic(21%)sources.In addition,it was also affected by dust(18%),industrial(15%)and fireworks burning(3%)sources.Therefore,it is necessary to strengthen the emission regulations of traffic sources,combustion sources,and secondary inorganic precursors(NOx,SO2 and NH3)to reduce the secondary generation of PM2.5.In addition,it is also essential to increase publicity and control efforts to forbid fireworks during the intensive fireworks period of the Spring Festival to further improve the ambient air quality.
In the context of'dual-carbon'goal,the traditional processes with heterotrophic denitrification as the core technology can no longer meet the demand for low-carbon nitrogen removal.Sulfur-driven autotrophic denitrification(SDAD)has received widespread attention in the field of biological nitrogen removal due to its advantages of efficient nitrogen removal and simultaneous carbon reduction.Based on existing research both domestically and internationally,this paper systematically reviews the latest advancements in SDAD and its derivative technologies,with a focus on process efficiency,microbial metabolism mechanisms,greenhouse gas(N2O)emission reduction mechanisms and engineering applications,and obtained the following conclusions:(1)The SDAD system consists of three types of microorganisms,autotrophic sulfur-oxidizing nitrate-reducing bacteria(a-soNRB),heterotrophic sulfur-oxidizing nitrate-reducing bacteria(h-soNRB),heterotrophic sulfur-oxidizing nitrate-reducing bacteria(h-soNRB),and sulfur disproportionating bacteria(SDB)interacted with each other to complete nitrogen removal.At low sulfide concentration(S2-concentration is 6.25 mmol/L),a-soNRB was the main functional bacterium.When the sulfide concentration increased,a-soNRB and h-soNRB interacted with each other in the system to ensure high process efficiency.(2)In terms of carbon reduction,different operating conditions mainly affect the N2O reductase(Nos)activity to control N2O production.Overall,SDAD plays an important role in the treatment of sulfur-containing wastewater and othercomposite pollutants in practical applications,and the emission of N2O from SDAD under the same operating conditions is only 1/5 of that of the traditional heterotrophic denitrification process,which provides an effective solution for the improvement of the traditional biological denitrification process by providing a high efficiency of denitrification and a significant reduction of carbon emissions at the same time.(3)In terms of engineering applications,the coupling of SDAD with heterotrophic denitrification,anaerobic ammonia oxidation and other processes further expands its application fields,giving full play to the radiation effect of the advantages of SDAD's low-carbon denitrification.Finally,it concludes an outlook on the challenges faced by wastewater denitrification processes with SDAD as the core technology and encourages future research to develop multi-pathway process combinations for different scenarios based on feasibility and environmental friendliness(e.g.anaerobic ammonia oxidation,partial denitrification,sulfur-driven autotrophic denitrification and coupling with nitrate/nitrite-dependent anaerobic methane oxidation),and to further optimize model-based carbon reduction strategies and predict the behavior of novel pollutants,with a view to providing theoretical basis for advancing the field of low-carbon denitrification of wastewater for further development.
The public's satisfaction with air quality is an important indicator of environmental governance achievements.In order to accurately grasp the actual feelings of the Chinese public towards the state of air environment and objectively reflect the progress and problems in air environmental management,an air environmental quality satisfaction index(AEQS)model and an air quality public satisfaction evaluation index system were established based on analytic hierarchy process and comprehensive methods such as questionnaire survey,model construction,entropy method and attitude quantification method.A questionnaire survey on public air quality satisfaction was conducted in 31 provinces,and the AEQS model and evaluation index system were assessed and applied.Our results show that:(1)The reliability and validity tests of the survey data are good,indicating that the index system has a good scientific validity.(2)The national public satisfaction index of air quality is 73.77 points,which reaches a relatively satisfactory level.(3)Air environmental quality satisfaction is not significantly correlated with PM2.5,PM10 concentration and AQI.The public satisfaction index of air quality was most influenced by satisfaction with government management to air quality and satisfaction with government investment in air quality improvement.(4)The analysis of importance-satisfaction of indicators(IPA)indicates that the public satisfaction index of air quality can be improved by the important strategies,such as government supplementing personal travel and health protection information in the disclosure of air quality-related information,reducing personal economic expenditure caused by air pollution,and taking into account the public's daily life when formulating relevant policies.Overall,the AEQS model and evaluation index system have good scientific quality.The satisfaction with the government air quality management and satisfaction with the government investment in air quality improvement are important factors affecting public satisfaction.In the future,China should pay more attention to the impact of air quality management on daily life and the public's economic expenditures to deal with air pollution in the customization of environmental governance policies.
Industrial parks are crucial in the modernization process of the industrial system and have significantly contributed to the attainment of carbon peaking and carbon neutrality goals.To effectively achieve carbon peaking and carbon neutrality,the State Council has released the'Action Plan for Carbon Peaking before 2030'.This plan explicitly emphasizes the need for enhancing the material flow management(MFM)within industrial parks.To aim the efficacy of the MFM in industrial parks,our initial step involves a comprehensive examination of fundamental concept of MFM inside industrial parks.This examination is conducted through a meticulous analysis of a literature review and policy analysis.Subsequently,we propose a roadmap for the MFM within industrial parks,which encompasses the stages of problem definition,system boundary establishment,data collecting,comprehensive assessment,and optimization and adjustment.Finally,an empirical study is undertaken using a representative industrial park as a case study.This case study aims to identify the main challenges faced by industrial parks in strengthening material flow management.Specifically,it focuses on aspects such as the primary entities responsible for MFM and basic data support capacities.Our study reveals that the essence of MFM in industrial parks is to elucidate the intricate interplay between industrial activities and the resource,energy,and environmental systems within the limited physical area of the park.Additionally,our study aims to provide systematic regulatory methods and recommendations for decision-making to improve resource and energy efficiency.Furthermore,it is important to uncover the complex attributes of multi-tiered materials and energy flows in the interconnected network of products,enterprises,and infrastructure.Effective MFM is vital for optimizing the industrial structure and development mode of the park,and will serve as a new competitive advantage for achieving the goals of carbon peaking and carbon neutrality.Our study proposes three strategies to strengthen MFM.Firstly,the proposal calls for the adoption of a systems-oriented approach to park development,with a focus on implementing both top-down and bottom-up approaches to promote the establishment of MFM systems.Secondly,it highlights the importance of improving coordination mechanisms and achieving multi-level collaborative management of material flows involving enterprises,infrastructure,and industrial parks with active participation of multiple stakeholders.Finally,this study advocates the promotion of collaborative efforts and data resources sharing between park management departments and enterprises,thereby facilitating dynamic and sustainable material flow management within the park through intelligent management approaches.
The emissions of greenhouse gases from agricultural ecosystems account for 12%of global anthropogenic greenhouse gas emissions.However,as a prominent agricultural ecosystem,the fate and mechanisms of greenhouse gases(CH4,N2O and CO2)linked with the microorganisms and agricultural emission reduction strategies are still unclear at the soil-water interface in paddy fields.This work discussed the mechanisms and influencing factors of greenhouse gas(CH4,N2O and CO2)production in paddy fields,as well as agricultural management measures to reduce emissions.Researches demonstrated that the greenhouse gas emissions at the water-soil interface in paddy fields were primarily driven by microorganisms.The soil physicochemical properties,such as soil temperature,moisture,and redox potential(Eh),profoundly influenced the composition and processes of microbial communities,thereby affecting greenhouse gas emissions.Agricultural management measures such as effective water regulation,soil nutrient management,and microbial regulation can change the flux of greenhouse gas emissions from the soil.Microbial regulation techniques such as the addition of Bacillus amyloliquefaciens,stimulation of methane-oxidizing bacteria activity,and the exploration of nitrogen-fixing bacteria containing N2O reductase genes have promising potential for greenhouse gas emissions reduction.However,the microbial mechanisms of greenhouse gas emissions from paddy fields currently primarily reply on indoor studies and lack the support of large-scale field data.The relationship between the microbial communities in rice fields and ecosystem functions,as well as the microbial control mechanisms mediated by agricultural management,are topics that have received little attention in the literature.Soil microorganisms play an important regulatory role in reducing greenhouse gas emissions from rice field.They can reduce greenhouse gas emissions by changing soil properties and altering the composition of microbial communities at the water-soil interface.This study provides new perspectives for reducing greenhouse gas emissions from rice fields and provides theoretical support for reducing greenhouse gas emissions from farmland and mitigating global warming.
In order to obtain an in-situ Fenton technique for effective oxidation of total petroleum hydrocarbons(TPH)in soils,the remediation of oil-contaminated soil by in-situ preparation of aggregated iron using fulvic acid(FA)was studied.The study focused on the effects of the aggregated iron groups and non-aggregated iron groups on the oxidation of the two types of oil-contaminated soils(S1,S2)with different textures and soil organic matter(SOM),as well as the mechanism of efficient in-situ oxidation of TPH in the aggregated iron groups.The results showed that:(1)In oil-contaminated S1 and S2 soils(the initial concent of TPH was 16,074.33 mg/kg and 14,528.17 mg/kg in S1 and S2 soils,respectively),the TPH oxidation level was as high as 7,550.32 mg/kg(S1)and 8,747.78 mg/kg(S2)in the aggregated iron group,which were higher than the corresponding values in the non-aggregated iron group Ⅰ(6,364.43 mg/kg,5,730.73 mg/kg).It indicated that the aggregated iron group could remove TPH efficiently from soils.(2)In the S1 and S2 soils,the oxidation rates of medium-chain alkanes(C19-C24)were up to 20%and 22%,and long-chain(C25-C30)alkanes were 23%and 20%in the aggregated iron group,which were higher than the oxidation rates of non-aggregated iron group Ⅰ in S1 soil(17%,18%)and S2 soil(19%,12%),respectively.(3)Electron paramagnetic resonance(EPR)technology showed that the intensity of hydroxyl radicals(·OH)in the aggregated iron group(S1,36.61 a.u;S2,16.06 a.u.)was higher than the corresponding indicators in the non-aggregated iron group Ⅰ(S1,27.78 a.u.;S2,7.11 a.u.),and the hydroxyl radical durations(S1,50 h;S2,55 h)were also higher than the corresponding indexes in the non-aggregated iron group Ⅰ(S1,45 h;S2,40 h).(4)The high contents of FeOOH(S1,503.52;S2,850.01)and α-FeOOH(S1,399.40;S2,769.62)measured by XPS increased the instantaneous strength and yield of·OH in the aggregated iron group.The 3DEEM results confirmed that the standard volume of the fluorescence region of fulvic acid in the aggregated iron group(S1,1,554,047.24 au·nm2;S2,1,110,373.00 au·nm2)was significantly higher than the corresponding values in the non-aggregated iron group(S1,1,100,706.21 au·nm2;S2,716,069.98 au·nm2),indicating that high FA content is beneficial for the aggregation of FeOOH and α-FeOOH in soils.Our study indicated that the aggregated iron group effectively catalyzed the removal of TPH from soils by H2O2,providing an economical and effective method for in-situ chemical oxidation remediation of oil-contaminated soil.
From July to August 2022,the temperature in the Sichuan Basin was 3.63℃higher than that of last year,and the number of ozone pollution days increased significantly compared to previous years.To understand the effects of high temperature on biogenic emissions and O3 generation contribution in the Sichuan Basin,the Model of Emissions of Gases and Aerosols from Nature(MEGAN)was used to estimate the emissions of biogenic volatile organic compounds(BVOCs)in the Sichuan Basin from July to August 2022 based on the meteorological data obtained by Weather Research and Forecasting(WRF)simulations.The spatiotemporal distribution characteristics of BVOCs and chemical species were analyzed.The impact of BVOCs emissions on O3 generation in high temperature weather was quantitatively evaluated by a Community Multi-Scale Air Quality(CMAQ)model.The results showed that:(1)From July to August 2022,BVOCs emissions in the Sichuan Basin were 86.30×104 t,and the emissions of isoprene,methanol and monoterpenes were 42.16×104,17.32×104 and 9.92×104 t,respectively.The BVOCs emission intensities of Chengdu Plain urban agglomeration,South Sichuan urban agglomeration,and Northeast Sichuan urban agglomeration were 3.61,6.55 and 5.00 t/km2,respectively.(2)The high emission areas of BVOCs were mainly concentrated in the central parts of Yibin City and Luzhou City in the South Sichuan urban agglomeration,the northeastern part of Leshan City in the Chengdu Plain urban agglomeration,and the northern parts of Bazhong City and Dazhou City in the Northeastern Sichuan urban agglomeration.The spatial distribution characteristics of isoprene and monoterpene emissions were basically consistent with those of BVOCs emissions,while the spatial distribution characteristics of methanol showed significant differences.(3)BVOCs emissions had an obvious diurnal characteristic and the highest emission occurred at 14:00.(4)The CMAQ simulation results showed that the cities with large contributions of BVOCs emissions to O3 generation were Leshan,Meishan,Ya'an,and Neijiang,with contribution rate of over 30%.In terms of spatial distribution,BVOCs emissions in the northern part of Leshan and the central-western parts of Meishan in Chengdu Plain urban agglomeration had the most significant contribution to O3 generation.From July to August 2022,the contribution of BVOCs emissions to O3 generation in high temperature weather was 4.99%higher than that of last year.Based on the above research results,BVOCs emissions in Sichuan Basin has an significant impact on O3 pollution,and the contribution rate to O3 generation further increases in high temperature weather,which is the focus for O3 pollution prevention and control.
