不同粒度飞灰中16种微量元素的含量分布

研究了不同粒级的燃煤飞灰中的Ｂａ、Ｂｅ、Ｃｄ、Ｃｒ、Ｃｕ、Ｈｇ、Ｌｉ、Ｍｎ、Ｎｉ、Ｐｂ、Ｓｒ、Ｔｉ、Ｖ、Ｚｎ、Ｚｒ元素的含量分布,煤中元素的含量比及富集因子。     

高速微涡活性污泥法提高氧利用效率的研究

概述了高速微涡活性污泥法的工艺特点，并对该法提高氧的转移及利用效率进行了研究和机理分析。     

Phytotoxicity and groundwater impacts of leaching from thermal treatment residues in roadways

The use of coal fly ash (CFA), municipal solid waste incinerator bottom ash (MSWIBA) and flue gas desulfurization residue (FGDR) in road construction has become very common owing to its economical advantages. However, these residues may contain toxic constituents that pose an environmental risk if they leach out and flow through the soil, surface water and groundwater. Therefore, it is necessary to assess the ecotoxicity and groundwater impact of these residues before decisions can be made regarding their utilization for road construction. In this study, the physico-chemical characteristics, leaching and phytotoxicity of these residues were investigated. Specifically, multivariate analyses were used to evaluate the contributions of the leaching constituents of the CFA, MSWIBA and FGDR leachates to the germination index of wheat seeds. B, Ba, Cr, Cu, Fe and Pb were found to be more toxic to the wheat seeds than the other heavy metals. Furthermore, the leached concentrations of the constituents from the CFA, MSWIBA and FGDR were below the regulatory threshold limits of the Chinese identification standard for hazardous wastes. Analyses conducted using a numerical groundwater model (WiscLEACH) indicated that the predicted field concentrations of metals from the CFA, MSWIBA and FGDR increased with time up to about 30 years at the point of compliance, then decreased with time and distance. Overall, this study demonstrated that the risks resulting from MSWIBA, CFA and FGDR leaching could be assessed before its utilization for road construction, providing crucial information for the adoption of these alternative materials.     

Insights into sludge granulation during anaerobic treatment of high-strength leachate via a full-scale IC reactor with external circulation system

In this study, a full-scale internal circulation(IC) reactor coupled with an external circulation system was developed to treat high-strength leachate from a municipal solid waste(MSW)incineration plant, in which anaerobic sludge granulation was intensively investigated. Results showed that the IC reactor achieved excellent treatment performance under high organic loading rates(OLR) of 21.06–25.16 kg chemical oxygen demand(COD)/(m3? day). The COD removal efficiency and biogas yield respectively reached 89.4%–93.4% and 0.42–0.50 m3/kg COD.The formation of extracellular polymeric substances(EPS) was closely associated with sludge granulation. Protein was the dominant component in sludge EPS, and its content was remarkably increased from 21.6 to 99.7 mg/g Volatile Suspended Solid(VSS) during the reactor operation. The sludge Zeta potential and hydrophobicity positively correlated with the protein/polysaccharide ratio in EPS, and they were respectively increased from-26.2 m V and 30.35% to-10.6 m V and 78.67%, which was beneficial to microbial aggregation. Three-dimensional fluorescence spectroscopy(3 D-EEM) and Fourier transform infrared spectroscopy(FT-IR)analysis further indicated the importance of protein-like EPS substances in the sludge granulation. Moreover, it was also found that the secondary structures of EPS proteins varied during the reactor operation.     

A comparison of chemical MSW compositional data between China and Denmark

Chemical waste compositions are important for municipal solid waste management, as they determine the pollution potentials from different waste strategies. A representative dataset for chemical characteristics of individual waste fractions is frequently required to assess chemical waste composition, but it is usually reported in developed countries and not in developing countries. In this study, a dataset for Chinese waste was established through careful data screening and assessment, named as CN dataset. Meanwhile, a dataset for Danish waste (DK dataset) was also summarized based on previous studies. In order to quantitatively evaluate the reliabilities of CN and DK datasets, the chemical waste compositions in four Chinese cities were estimated by utilizing both of them, respectively. It is indicated that the usage of CN datasets led to significantly lower discrepancies from the actual values based on laboratory analysis in most cases. Within the datasets, the moisture contents of food waste, paper, textiles, and plastics, the carbon content of food waste, as well as the oxygen content of plastics would induce significant divergences, which should be paid special attention when gathering the information. In addition, the fractional waste compositions in China showed similar features with other developing countries but differ significantly with developed countries. Thus the above-mentioned conclusions could also be true in other developing countries.     

A comprehensive classification method for VOC emission sources to tackle air pollution based on VOC species reactivity and emission amounts

In China, volatile organic compound(VOC) control directives have been continuously released and implemented for important sources and regions to tackle air pollution. The corresponding control requirements were based on VOC emission amounts(EA), but never considered the significant differentiation of VOC species in terms of atmospheric chemical reactivity. This will adversely influence the effect of VOC reduction on air quality improvement. Therefore,this study attempted to develop a comprehensive classification method for typical VOC sources in the Beijing–Tianjin–Hebei region(BTH), by combining the VOC emission amounts with the chemical reactivities of VOC species. Firstly, we obtained the VOC chemical profiles by measuring 5 key sources in the BTH region and referencing another 10 key sources, and estimated the ozone formation potential(OFP) per ton VOC emission for these sources by using the maximum incremental reactivity(MIR) index as the characteristic of source reactivity(SR). Then, we applied the data normalization method to respectively convert EA and SR to normalized EA(NEA) and normalized SR(NSR) for various sources in the BTH region.Finally, the control index(CI) was calculated, and these sources were further classified into four grades based on the normalized CI(NCI). The study results showed that in the BTH region,furniture coating, automobile coating, and road vehicles are characterized by high NCI and need to be given more attention; however, the petro-chemical industry, which was designated as an important control source by air quality managers, has a lower NCI.     

双酚A和邻苯二甲酸二正丁酯在纸类上的吸附特性研究

采用序批式实验,考察了报纸对双酚A(BPA)和邻苯二甲酸二正丁酯(DnBP)的吸附能力,用Freundlich、Langmuir、Dubinin-Radushkevich(D-R)、Flory-Huggins(F-H)、BET、Temkin 6种吸附等温线模型对实验数据进行了拟合.并选择了回归系数(R2)、均方根差(RMSE)和卡方检验(X2检验)3种非线性回归方法评价了模型拟合度.结果表明,Freundlich和Temkin吸附等温线模型能很好地描述BPA和DnBP在纸类表面的吸附,BPA和DnBP的R2均大于0.95(P<0.01),RMSE和X2分别小于0.05和0.02;吸附能力与吸附质的疏水性呈正相关.由D-R和F-H吸附等温线模型拟合结果可知,BPA和DnBP的吸附平均自由能分别为1.484和1.609 kJ/mol;Gibbs自由能分别为-6.559和-7.021 kJ/mol.说明BPA和DnBP在纸类上的吸附为自发的物理吸附.BPA和DnBP在纸类上的Freundlich吸附常数k分别为0.147和0.502 mg(1-n)·L"·g-1,均高于文献报道的底泥等的吸附常数,说明生活垃圾填埋场中纸类会阻碍BPA和DnBP的迁移和生物可利用性.     

Anaerobic treatment of fresh leachate from a municipal solid waste incinerator by upflow blanket filter reactor

This paper describes the feasibility of fresh leachate treatment by an upflow blanket filter (UBF). Through dilution and partial effluent recycling, the organic loading rates increased from 0.51 to 14.56 kg COD/(m³·d), meanwhile the corresponding hydraulic retention time decreased from 9.0 to 3.6 d. The reactor was able to achieve steady-state within 80 d. Based on the distribution of COD fluxes in the process, it was concluded that anabolism was the main pathway of COD removal in the initial phase (1–33 d), accounting for 57%–85% of total COD removed. As the anaerobic consortium of bacteria reached steady-state (after 70–86 d), the majority of COD removed was transformed into methane, because the specific methane yield was close to the theoretical value (0.36 L CH₄/(g COD_deg)).     

阴霾天气PM_(10)的微观特征及生物活性研究

利用高分辨率场发射扫描电镜(FESEM)、图像分析技术(IA),对北京市2004年12月一次严重的阴霾天气条件下采集的PM10(指空气动力学直径小于10μm的颗粒物)的微观形貌、粒度分布、主要颗粒物类型进行了分析,并运用质粒DNA评价法对阴霾和非阴霾天气条件下的PM10样品的生物活性进行了对比研究。结果表明,阴霾天气时PM10样品中以粒度较小的烟尘及其集合体为主,且多呈湿状,含有较多的二次颗粒物,并发现了残余的有机液滴颗粒。质粒DNA实验的结果显示,阴霾天气PM10样品的水溶和全样样品的TD20值(造成20%DNA破坏时所需要的样品剂量)分别为93μg.ml-1和50μg.ml-1,而同一月份非阴霾天气条件下PM10样品的水溶和全样样品的TD20值分别为200μg.ml-1和160μg.ml-1,表明阴霾天气PM10样品比非阴霾天气样品具较强的生物活性,即对人体健康存在着潜在的危害。且无论是阴霾还是非阴霾天气条件下的PM10的全样样品均较水溶样品具更大的生物活性。