Carbon dioxide emissions from cities in China based on high resolution emission gridded data

Based on the China high resolution emission gridded data (1 km spatial resolution), this article is aimed to create a Chinese city carbon dioxide (CO₂) emission data set using consolidated data sources as well as normalized and standardized data processing methods. Standard methods were used to calculate city CO₂ emissions, including scope 1 and scope 2. Cities with higher CO₂ emissions are mostly in north, northeast, and eastern coastal areas. Cities with lower CO₂ emissions are in the western region. Cites with higher CO₂ emissions are clustered in the Jing-Jin-Ji Region (such as Beijing, Tianjin, and Tangshan), and the Yangtze River Delta region (such as Shanghai and Suzhou). The city per capita CO₂ emission is larger in the north than the south. There are obvious aggregations of cities with high per capita CO₂ emission in the north. Four cities among the top 10 per capita emissions (Erdos, Wuhai, Shizuishan, and Yinchuan) cluster in the main coal production areas of northern China. This indicates the significant impact of coal resources endowment on city industry and CO₂ emissions. The majority (77%) of cities have annual CO₂ emissions below 50 million tons. The mean annual emission, among all cities, is 37 million tons. Emissions from service-based cities, which include the smallest number of cities, are the highest. Industrial cities are the largest category and the emission distribution from these cities is close to the normal distribution. Emissions and degree of dispersion, in the other cities (excluding industrial cities and service-based cities), are in the lowest level. Per capita CO₂ emissions in these cities are generally below 20 t/person (89%) with a mean value of 11 t/person. The distribution interval of per capita CO₂ emission within industrial cities is the largest among the three city categories. This indicates greater differences among per capita CO₂ emissions of industrial cities. The distribution interval of per capita CO₂ emission of other cities is the lowest, indicating smaller differences of per capita CO₂ emissions among this city category. Three policy suggestions are proposed: first, city CO₂ emission inventory data in China should be increased, especially for prefecture level cities. Second, city responsibility for emission reduction, and partitioning the national goal should be established, using a bottom-up approach based on specific CO₂ emission levels and potential for emission reductions in each city. Third, comparative and benchmarking research on city CO₂ emissions should be conducted, and a Top Runner system of city CO₂ emission reduction should be established.     

纳米TiO2-石墨烯光催化剂的水热合成及其光催化性能

以钛酸四正丁酯和石墨为原料,通过水热法制备了锐钛矿型为主的纳米TiO2复合光催化剂（纳米TiO2-石墨烯）,并采用XRD,FTIR,FESEM,TEM技术对其进行了表征。通过紫外光照射降解溶液中的罗丹明B（RhB）研究了TiO2-石墨烯的光催化活性,分析了初始罗丹明B质量浓度、催化剂加入量、溶液pH和催化剂使用次数等影响降解效果的因素。实验结果表明：在初始RhB质量浓度为20 mg/L、溶液pH为7.10、催化剂加入量为1.000 g/L的条件下,紫外光照射30 min时,纳米TiO2-石墨烯对RhB的降解率高达98.69%,明显高于纳米TiO2的44.69%;纳米TiO2-石墨烯稳定性较强,可多次重复使用。     

Mn/γ-Al2O3催化剂的制备及头孢合成废水的催化臭氧氧化法深度处理

对Mn/γ-Al₂O₃催化剂的制备条件及头孢合成废水的催化臭氧氧化法深度处理工艺条件进行了优化。实验结果表明：以Mn（NO₃）₂溶液为浸渍液,Mn/γ-Al₂O₃催化剂的最优制备条件为浸渍液浓度0.10 mol/L、浸渍时间9 h、焙烧温度400 ℃、焙烧时间2 h;在反应时间为30 min、废水pH为9.0、臭氧通量为4.6 mg/min、催化剂加入量为5 g/L的条件下,当进水COD、BOD₅、ρ（氨氮）和色度分别为220~250 mg/L,8~10 mg/L,10~12 mg/L和60~70倍时,出水COD、BOD₅、ρ（氨氮）和色度的平均去除率分别为53%,30%,33%和93%,出水水质满足GB 21904—2008《化学合成类制药工业水污染物排放标准》的要求。     

活性炭纤维负载TiO2催化剂的制备及其电催化性能

采用溶胶-凝胶法制备了活性炭纤维负载TiO₂催化剂（TiO₂/ACF）,并通过SEM和XRD等手段对TiO₂/ACF进行了表征。以邻苯二甲酸二甲酯（DMP）为目标降解物,考察了催化材料的电催化活性。实验结果表明：在反应温度为25 ℃、初始DMP质量浓度为100.0 mg/L、电解质Na₂SO₄质量浓度为100 mg/L、电流密度为62.5 mA/cm²、电极板间距为4 cm的条件下,经过40 min的降解,DMP质量浓度为1.8 mg/L,DMP去除率为98.2%;TiO₂/ACF在反应过程中可以原位再生,经6次重复使用后仍保持很高的催化活性,对DMP的去除率仍达90%以上。     

TiO2-Cu2O/蒙脱土复合光催化剂的制备与性能

以钠基蒙脱土（MMT）为载体,先采用溶胶-凝胶法将纳米TiO₂引入到MMT层间,再采用化学沉积法将纳米Cu₂O负载在TiO₂/MMT上,制备出TiO₂-Cu₂O/MMT纳米复合光催化剂。采用XRD、SEM、紫外-可见漫反射技术对催化剂进行了表征。以甲基橙为目标污染物,考察了催化剂的光催化性能。表征结果显示：TiO₂与Cu₂O均匀分布在MMT的表面与片层孔隙中;TiO₂-Cu₂O/MMT结合了TiO₂和Cu₂O的特性,拓宽了催化剂的光吸收范围。实验结果表明,在光源为可见光、初始甲基橙质量浓度为20 mg/L、光催化剂加入量为2 g/L的条件下,TiO₂-Cu₂O/MMT纳米复合光催化剂对甲基橙的光催化降解效果明显优于单一负载的Cu₂O/MMT和TiO₂/MMT,大幅提高了催化剂的光催化效率,反应300 min时TiO₂-Cu₂O/MMT对甲基橙溶液的脱色率达到93%。     

降解SO2功能菌的16S rRAN基因测序及降解特性

用低浓度SO2诱导驯化方法获得高效脱硫菌群,并用分离培养与16S rRNA基因测序技术相结合的方法鉴定菌群种属,分析驯化过程中种群结构的动态变化,同时研究分离纯菌种的脱硫性能。结果表明,从诱导驯化7 d和14 d菌液中分别分离出23株菌和22株菌,16S rRNA序列分析发现这些菌归属于13个种,其中有6个种(Rhodococcus erythropolis、Pseudomonas putida、Microbacterium oxydans、Sphingomonas koreensis、Acinetobacter junii、Acinetobacter johnsonii)对SO2-3有较强的降解能力,并在持续驯化过程中稳定的生长传代,降解产物以硫酸根为主,还有极少量的单质硫。与含混合菌的驯化菌液降解SO2-3的能力相比,单一脱硫菌的脱硫性能较弱。脱硫功能菌株及其基本特性的研究为微生物处理SO2烟气提供了丰富的菌源信息和理论基础。     

聚环氧琥珀酸对锰渣中砷的萃取

以锰渣为材料,用聚环氧琥珀酸(PESA)作为萃取剂,研究PESA在不同pH、萃取剂浓度、土液比下对砷(As)的萃取效果。实验结果表明,与丙烯酸/马来酸酐共聚物(MA/AA)相比较,PESA对锰渣中As有优良的萃取效果。在萃取体系条件为pH=1、萃取剂浓度50 mg/mL、土液比1∶200、搅拌60 min并浸泡过夜时,PESA对砷的萃取率可达78.3%。实验还发现,PESA对三价砷和五价砷均有螯合萃取作用,对砷的萃取无价态的选择性。     

新型二氧化铅电极处理染料废水

利用高压塑片法制备掺杂镧和活性炭以及聚四氟乙烯(PTFE)的新型二氧化铅电极,采用X衍射(XRD),循环伏安曲线(CV),扫描电镜(SEM)等手段对电极性能进行表征,研究了其电催化处理有机染料废水(亚甲基蓝)的降解效果,并对反应机理进行了相关研究。研究表明,该电极具有良好的抗腐蚀能力,对亚甲基蓝具有较好的降解效果。通过与普通二氧化铅电极比较,该电极在染料脱色和去除COD方面都有较明显优势,显示出较好的工业应用前景。     

纳米二氧化钛复合石墨烯催化剂的制备及处理染料废水

以硫酸钛为原料,采用共沉淀法,制备了一系列纳米二氧化钛复合石墨烯催化剂,采用XRD和FTIR对样品进行表征。通过紫外光照射亚甲基蓝溶液光催化降解实验,研究石墨烯的加入量对TiO2光催化性能的影响,结果表明,TiO2-GO-5具有最佳的光催化性能。在pH=6.00、TiO2-GO-5的投加量为0.070 g/50 mL、光照3 h条件下,100 mg/L亚甲基蓝溶液的脱色率达到最大值为90.52%。     

二氧化钛脱除高温烟气中的氯化氢

HCl是城市垃圾焚烧产生的主要气体污染物之一。将一种新型脱氯剂TiO2引入到垃圾焚烧系统中,并与其他脱氯剂的性能进行比较。研究了不同脱氯剂使用量、不同反应温度和不同HCl气体浓度对TiO2、CaO和CaTiO3脱氯效果的影响。结果显示,TiO2能在高温(800~1 000℃)、高HCl浓度(1 303.6~1 629.5 mg/m3)下获得较好的脱氯效果。与传统的脱氯剂CaO相比,TiO2更适合于高温烟气脱氯,其在1 000℃时的氯容(36.3 mg HCl/g TiO2)几乎是相同情况下的CaO氯容(9.3 mg HCl/g CaO)的4倍。而CaTiO3的脱氯效果不但受到自身分解效率的影响,还受到TiO2和CaO脱氯效果的影响,其脱氯效果较差。