基于GIS的耕地土壤重金属污染与农业功能定位研究——以山东省聊城市为例

按8km×8km的网格将聊城市耕地分为137个采样点,调查砷、镉、铬、铜、汞、镍、铅、锌等重金属的污染状况。采用国家土壤环境质量标准、农产品安全质量标准和绿色食品产地环境条件作为评价标准,采用单因子指数和综合指数为评价方法进行污染评价。研究表明,聊城市土壤污染强度依次为铜〉镍〉锌〉砷〉铬〉镉〉铅〉汞,但均未超标。以GIS为操作平台显示聊城市重金属空间分布状况,并对区域耕地进行了功能的定位。聊城市西南部土壤质量最优,适宜种植绿色食品;无公害蔬菜和安全粮食种植区在各县市均有不同程度的分布。     

Biofiltration treatment of odors from municipal solid waste treatment plants

An in situ compost biofilter was established for the treatment of odors from biostabilization processing of municipal solid waste. The concentrations of total volatile organic compounds (VOCs) in odors and their components were measured. Biofilter media was characterized in terms of total carbon (TC), total nitrogen (TN), total phosphorus (TP), organic matter (OM), pH value and determination of bacterial colony structure. Gas chromatography–mass spectrometry (GC–MS) analysis showed that the main components of the produced gas were benzene, toluene, ethylbenzene and xylene (BTEX) along with other alkanes, alkenes, terpenes, and sulphur compounds. The compost biofilter had remarkable removal ability for alkylated benzenes (>80%), but poor removal for terpenes (～30%). Total VOC concentrations in odors during the biostabilization process period ranged from 0.7 to 87 ppmv, and the VOC removal efficiency of the biofilter varied from 20% to 95%. After about 140 days operation, TN, TC, TP and OM in compost were kept almost stable, but the dissolved N, NH₄–N and NO₃–N experienced an increase of 44.5%, 56.2% and 76.3%, respectively. Dissolved P decreased by 27.3%. The pH value experienced an increase in the early period and finally varied from 7.38 to 8.08. Results of bacterial colony in packing material indicated that bacteria and mold colony counts increased, but yeasts and actinomyces decreased along with biofilter operation, which were respectively, 3.7, 3.4, 0.04 and 0.07 times of their initial values.     

Characteristics of atmospheric carbonyls and VOCs in Forest Park in South China

The diurnal variation of atmospheric carbonyls and VOCs in a forest in south China were studied in summer 2004. Twenty kinds of carbonyls and eight kinds of VOCs were identified and quantified. Formaldehyde and acetaldehyde were the two most abundant carbonyls, while the most abundant VOCs were isoprene, followed by o-xylene. Most C₃-C₁₀ carbonyls had higher concentrations from 09:00 to 15:00, and their levels were lower during night-time and often reached the lowest in early morning. Formaldehyde and acetaldehyde, however, showed two high levels in their diurnal patterns partly due to their different sources and sinks. The VOCs had different diurnal patterns compared to most carbonyls. The highest concentrations were observed from 03:00 to 06:00 for 1-butene, from 06:00 to 12:00 for isoprene, and from 12:00 to 15:00 for α-pinene. The highest levels for aromatic hydrocarbons occurred during midnight and the lowest in late afternoon. According to the study, emissions from vegetation and photo-oxidation of gas-phase hydrocarbons were the main sources for some carbonyls and VOCs in this region. Other compounds, such as formaldehyde, acetaldehyde and BTEX, showed anthropogenic sources.     

Occurrence and distribution of polycyclic aromatic carbons in sludges from wastewater treatment plants in Guangdong, China

In this study, the occurrence and distribution of polycyclic aromatic hydrocarbons (PAHs) were investigated in six sludge samples collected from Guangdong Province, China. Concentrations of PAHs varying from 2,534.1 to 6,926.6 μg kg^???1 (dry sludge) were observed in three municipal wastewater treatment plants with phenanthrene (Phe), fluoranthene, and pyrene being the main compounds. In addition, 682.6 μg kg^???1 PAHs were detected in one sludge sample from a food processing plant, with fluorene, Phe, and chrysene being the main components. No PAHs were detected in sludge samples obtained from two cosmetic plants. The levels and distributional characteristics of PAHs, polychlorinated biphenyls (PCBs), and polycyclic musks (PMs) from the samples were also compared. The results of this comparison indicated that petrochemical refineries and road traffic played important roles in the PAH loads in sludge, while PMs primarily originated from domestic wastewater and industrial wastewater from cosmetic plants. Finally, the presence of 98.8 μg kg^???1 PCBs in sludge suggested diffusional emission sources from electrical components containing PCBs.     

Effective removal of coordinated copper from wastewater using a new dithiocarbamate-type supramolecular heavy metal precipitant

A new dithiocarbamate-type heavy metal precipitant, sodium 1,3,5-hexahydrotriazinedithiocarbamate (HTDC), was prepared and used to remove coordinated copper from wastewater. In the reported dithiocarbamate-type precipitants, HTDC possesses the highest percentage of the effective functional groups. It could effectively precipitate copper to less than 0.5 mg l⁻¹ from both synthetic and actual industrial wastewater containing CuEDTA in the range of pH 3–9. UV–vis spectral investigation and elemental analysis suggested that the precipitate was a kind of coordination supramolecular compound, [Cu₃(HTDC)₂]_n. The toxicity characteristic leaching procedure (TCLP) and semi-dynamic leaching test (SDLT) indicated that the supramolecular precipitate was non-hazardous and stable in weak acid and alkaline conditions. Tests of an anion exchange resin D231 provided a clue to simultaneously remove excess HTDC and residual CuEDTA in practical process of wastewater treatment.     

The concentrations and distribution of polycyclic musks in a typical cosmetic plant

Polycyclic musks [cashmeran (DPMI), celestolide (ADBI), phantolide (AHMI), traseolide (ATII), tonalide (AHTN) and galaxolide (HHCB)] in the air, wastewater, sludge samples of a typical cosmetic plant were analyzed. DPMI, ADBI, HHCB and AHTN were found in all samples, and ATII was not found in any sample. HHCB and AHTN were the major components in all samples. The polycyclic musk concentrations were very high in the air of the cosmetic plant, and polycyclic musks were mostly contained in the gas phase at the percentage of 86.35-97.70%. Average polycyclic musk concentrations in effluent were high, and ranged from 0.62 to 32.06 microgl-1. The removal efficiency during the active sludge wastewater treatment was also high, resulting from the adsorption of those compounds into the sludge. So the polycyclic musk concentrations were very high in the primary sludge and second sludge, and ranged from 1.78 to 92.45 mgkg-1 (dry), and from 2.87 to 65.67 mgkg-1 (dry), respectively. Results suggested that the sludge needed to be further treated to make polycyclic musks less influence to the environment.     

Source apportionment of fine particles in Tennessee using a source-oriented model

Source apportionment of fine particles (PM2.5, particulate matter < 2 microm in aerodynamic diameter) is important to identify the source categories that are responsible for the concentrations observed at a particular receptor. Although receptor models have been used to do source apportionment, they do not fully take into account the chemical reactions (including photochemical reactions) involved in the formation of secondary fine particles. Secondary fine particles are formed from photochemical and other reactions involving precursor gases, such as sulfur dioxide, oxides of nitrogen, ammonia, and volatile organic compounds. This paper presents the results of modeling work aimed at developing a source apportionment of primary and secondary PM2.5. On-road mobile source and point source inventories for the state of Tennessee were estimated and compiled. The national emissions inventory for the year 1999 was used for the other states. U.S. Environmental Protection Agency Models3/Community Multi-Scale Air Quality modeling system was used for the photochemical/secondary particulate matter modeling. The modeling domain consisted of a nested 36-12-4-km domain. The 4-km domain covered the entire state of Tennessee. The episode chosen for the modeling runs was August 29 to September 9, 1999. This paper presents the approach used and the results from the modeling and attempts to quantify the contribution of major source categories, such as the on-road mobile sources (including the fugitive dust component) and coal-fired power plants, to observed PM2.5 concentrations in Tennessee. The results of this work will be helpful in policy issues targeted at designing control strategies to meet the PM2.5 National Ambient Air Quality Standards in Tennessee.     

Fenton试剂氧化苯酚过程中Fe（Ⅱ）浓度的变化

考察了Fenton试剂氧化降解苯酚过程中Fe(Ⅱ)浓度的变化,并通过实验探讨了其变化的原因.实验结果表明,在Fenton反应发生的第1 rain内,Fe(Ⅱ)浓度可降低到初始浓度的60%左右,随着反应的继续Fe(Ⅱ)浓度在大约20min降低到最小值,然后开始增大,说明了Fe(Ⅲ)还原作用的存在;Fenton试剂氧化降解苯酚的中间产物包括对苯二酚、邻苯二酚、间苯二酚和苯醌等,其中前三者能对Fe(Ⅲ)有效还原,是Fenton试剂氧化降解苯酚过程中Fe(Ⅲ)还原的主要途径之一.     

The accounting method and application of CO2 emissions responsibility by the electricity sector at the provincial level in China

When accounting the CO₂ emissions responsibility of the electricity sector at the provincial level in China,it is of great significance to consider the scope of both producers’ and the consumers’ responsibility,since this will promote fairness in defining emission responsibility and enhance cooperation in emission reduction among provinces.This paper proposes a new method for calculating carbon emissions from the power sector at the provincial level based on the shared responsibility principle and taking into account interregional power exchange.This method can not only be used to account the emission responsibility shared by both the electricity production side and the consumption side,but it is also applicable for calculating the corresponding emission responsibility undertaken by those provinces with net electricity outflow and inflow.This method has been used to account for the carbon emissions responsibilities of the power sector at the provincial level in China since 2011.The empirical results indicate that compared with the production-based accounting method,the carbon emissions of major power-generation provinces in China calculated by the shared responsibility accounting method are reduced by at least 10%,but those of other power-consumption provinces are increased by 20% or more.Secondly,based on the principle of shared responsibility accounting,Inner Mongolia has the highest carbon emissions from the power sector while Hainan has the lowest.Thirdly,four provinces,including Inner Mongolia,Shanxi,Hubei and Anhui,have the highest carbon emissions from net electricity outflow- 14 million t in 2011,accounting for 74.42% of total carbon emissions from net electricity outflow in China.Six provinces,including Hebei,Beijing,Guangdong,Liaoning,Shandong,and Jiangsu,have the highest carbon emissions from net electricity inflow- 11 million t in 2011,accounting for 71.44% of total carbon emissions from net electricity inflow in China.Lastly,this paper has estimated the emission factors of electricity consumption at the provincial level,which can avoid repeated calculations when accounting the emission responsibility of power consumption terminals（e.g.construction,automobile manufacturing and other industries）.In addition,these emission factors can also be used to account the emission responsibilities of provincial power grids.