Emission characterization of unintentionally produced persistent organic pollutants from iron ore sintering process in China

Emission of unintentionally produced persistent organic pollutants (Unintentional POPs), including polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychorinated biphenyls (PCBs), hexachlorobenzene (HxCBz) and pentachlorobenzene (PeCBz), were investigated in four typical iron ore sintering plants in China. The emission factors and annual mass releases of the Unintentional POPs were calculated. The results indicated that PCDFs contributed more than 60% to the overall toxic equivalent quantity (TEQ) values, while the contribution of the dl-PCBs is relatively low, and only in the range of 8-9%. The dominant congeners of PCDD/Fs and dl-PCBs contributing most to the total TEQ were 1,2,3,7,8-PeCDD, 2,3,4,7,8-PeCDF and PCB-126. With regard to the TEQ contributions, the most abundant homologues were PeCDFs and HxCDD/Fs, followed by PeCDDs and non-ortho dl-PCB, whereas HpCDD/Fs, OCDD/Fs and mono-ortho dl-PCBs almost made no contributions. Due to the massive use of recycled waste in the feeding materials, the average emission factor of PCDD/Fs and dl-PCBs of the four plants was 3.95 μg WHO-TEQ ton⁻¹. Based on the results, the annual release of PCDD/Fs and dl-PCBs in 2007-2009 were estimated to be 2070 g, 2212 g, and 2307 g WHO-TEQ, respectively.     

Concentrations and distributions of 18 organochlorine pesticides listed in the Stockholm Convention in surface sediments from the Liaohe River basin,China

Organochlorine pesticides (OCPs) were analyzed in 26 surface sediment samples from the Liaohe River basin, and the distributions of and potential environmental risks posed by OCPs in the basin were evaluated. Eighteen OCPs listed in the Stockholm Convention were determined using isotope-dilution gas chromatography–high resolution mass spectrometry. This is the first study of hexachlorobenzene (HCB) in the Liaohe River basin sediments. The total OCP concentrations were 0.39–68.06 ng g^?1 dry weight. The total α-, β-, γ-, and δ-hexachlorocyclohexane (HCH), the total dichlorodiphenyltrichloroethane (DDT – p,p′-dichlorodiphenyldichloroethane (DDD), p,p′-dichlorodiphenyldichloroethylene (DDE), o,p^'-DDT, and p,p′-DDT), and the HCB concentrations in the sediment samples were 0.1–28.48 ng g^?1 (mean 4.01 ng g^?1), 0.08–6.52 ng g^?1 (mean 3.07 ng g^?1), and 0.18–24.8 ng g^?1 (mean 4.38 ng g^?1), respectively. The HCB concentrations were higher than the concentrations of the other OCPs, and the HCHs and HCB together were the dominant OCPs. β-HCH was the most abundant HCH isomer. The concentrations of DDTs and other OCPs were relatively low, and the (DDE+DDD)/DDT ratios (>0.5) and DDD/DDE ratios (<1) indicated that no recent DDT inputs had occurred in the Liaohe River system. The main sources of HCHs were probably the historical production and agricultural use of HCH in the study area. The DDT and HCH concentrations were generally below or similar to the concentrations that have been found in other parts of the world. An ecotoxicological evaluation indicated that HCHs in surface sediments pose slight risks to human and ecological health in the Liaohe River basin.     

苏州市工业用地地表径流污染特性研究

对苏州新区枫桥工业园湘江路段的10场有效降雨事件的地表径流污染特性进行了研究.研究表明.地表径流水质参数COD、SS、NH3-N、TN、TP均服从对数正态分布,在95%置信水平下,SS与COD、TP、TN之问存在线性相关性(R=0.45～0.72).统计了污染物事件平均浓度(EMC),COD、SS、NH3-N、TN、TP的EMC中值分别为213、491、2.65、5.19、1.07 mg/L,相对应的单位面积污染物负荷分别为1 898、4 375、24、46、10 kg/(hm2·a).与韩国Chongju工业区和上海市相比,SS负荷高是苏州新区枫桥工业园地表径流水质的主要特点,削减SS负荷对控制其非点源污染具有重要意义.     

制备方法对MgAl水滑石衍生氧化物负载钯催化剂丙烷完全氧化活性的影响

以沉积沉淀法(DP)、浸渍法(IM)和共沉淀法(CP)制备MgAl水滑石衍生氧化物负载钯催化剂,用ICP、XRD、SEM、TEM、EDS、TPR以及比表面测定等手段对催化剂进行了表征.ICP和XRD数据表明用上述3种方法均可成功制备水滑石为前体载钯催化剂.SEM、TEM、EDS数据表明不同方法制备的样品具有不同的形貌以及钯在其中的分散度.综合各类表征数据可知Pd在催化剂中暴露的活性位是影响其活性的主要因素.     

曝气条件对浸没式膜生物反应器内流场的影响

为深入研究流场动力学特性对浸没式膜生物反应器系统内膜面污染的控制,应用fluent软件对浸没式膜生物反应器内气液两相流动进行了三维数值模拟研究。采用标准k-ε湍流模型和欧拉多相流模型,考察了改变曝气条件对膜面气液速度场及气含率分布的影响。模拟结果表明,在相同曝气强度下,1 mm曝气孔径下膜面气液两相的速度增加较孔径2mm、3 mm的快;曝气孔径为1 mm时,膜面的液相速度随着曝气强度的增加逐渐增大;曝气孔径为1 mm时,曝气量为5.5m3/h所形成的漩涡区较大,膜面气含率值较高且分布较均匀,气液两相接触面积较大,膜面冲刷效果较好;模拟观察到反应器底部靠近壁面局部气含率较低,不利于活性污泥中微生物的生长,需要进一步优化曝气和反应器结构。     

双循环多级水幕脱硫塔的设计和性能测试

双循环多级水幕脱硫塔是在常规两段式湿法脱硫塔基础上加以改进而成的新型脱硫塔,其双循环浆液采用不同pH控制,低pH促进CaCO2溶解,高pH提高SO2吸收效果;同时,多级水幕强化气液流态,增加气液接触面积和传质动力,促进对SO2的吸收.实验利用SPSSV13.0软件进行正交实验设计,通过数据分析得出两个不同的优化运行方案,再利用多指标分析法中的综合平衡法进行单因素实验,得出最优运行方案.在最优运行方案条件下,即烟气流量为100 m3/h,上循环浆液pH为6.0,下循环浆液pH为4.8,上、下循环液气比均为20 L/m3,人口 SO2质量浓度为1 000mg/m3时,脱硫效率达97.8%,CaCO3利用率为95.2%,钙硫质量比约为1.03.双循环多级水幕脱硫塔具有良好的应用前景,实验结果对现场脱硫系统的调试和运行有很好的参考价值.     

好氧颗粒污泥自生动态膜生物反应器处理碱减量印染废水

自生动态膜生物反应器(SFDMBR)接种颗粒污泥启动,研究溶解氧浓度和水力停留时间对该反应器处理碱减量印染废水的影响。自生动态膜生物反应器形成稳定的动态膜后,出水浊度小于10 NTU,系统对浊度的去除率在90%以上,溶解氧和水力停留时间对反应器出水浊度基本无影响。系统对废水色度的去除率随着溶解氧浓度的提高和水力停留时间的延长而增加,但是系统对色度的去除效率一般不超过40%。溶解氧浓度由0.3 mg/L逐渐增大至2.4 mg/L,COD的去除率由40%提升至80%,而当溶解氧浓度大于1.0 mg/L后,UV254的去除率达到95%。水力停留时间在8~48 h时,COD去除效率由65%逐渐上升至85%左右;水力停留时间在8~32 h,UV254去除效率为68%~93%,超过32 h后水力停留时间对UV254去除效率的影响已不明显。     

厌氧氨氧化（ANAMMOX）生物滤池反应器的启动特性

采用平行对比实验,讨论不同实验条件下上向流厌氧氨氧化（ANAMMOX）滤池反应器的启动特性。对比条件为温度、接种污泥、联氨和羟胺。结果表明：温度是影响厌氧氨氧化细菌活性的主要因素;接种200mL具有活性的厌氧氨氧化污泥后,在避光、加热38℃、不控制联氨和羟氨的条件下,45d可成功启动厌氧氨氧化滤池反应器;反应过程NH4^＋N：NO2^-·N：NO3-N的化学计量摩尔比为1：1．17：0．30,其总氮去除率达到87．38％,总氮容积去除负荷可达到1．41kg／（m^3·d）。     

Bioaccumulation kinetics of sediment-associated DE-83 in benthic invertebrates (Nereis succinea, polychaete)

Polychaetes (Nereis succinea) were exposed to DE-83 contaminated sediments to investigate the bioaccumulation and bioavailability of nona- and deca-BDEs in sediment. All the major congeners in DE-83 were bioavailable to the lugworms. The uptake coefficients (K_s) of nona- and deca-BDE congeners in lugworms were in the range of 0.18-0.65 (d⁻¹), with the values of BDE-207 and -208 slightly higher than those of BDE-206 and -209. Elimination of nona- and deca-BDE congeners from lugworms was very fast. The estimated half-lives of nona- and deca-BDE congeners in the lugworms were at 0.7 d. The bioavailability of nona- and deca-BDE congeners was very low, with BSAF of 0.017 for BDE-206 and -209 and 0.054 for BDE-207 and -208. These may be due to the large molecular size and high affinity of PBDEs to sediment particles. The contribution of BDE-206 in the profile of nona-BDEs in lugworm tissue decreased with exposure time while those of BDE-207 and -208 increased, which could be the result of the biotransformation of BDE-209 to BDE-207 and -208.     

再入飞行力热环境预测与试验技术研究进展

总结了近5年来再入飞行力热环境预测与试验技术的研究进展.针对高速绕流流场引起的宽频声振环境和瞬态热环境,调研了国内外在上述环境的数值模拟预测、等效模拟试验和试验观测方面的最新研究情况和目前仍面临的难点问题.重点介绍了中物院总体所围绕再入飞行力热环境预测与试验方面开展的研究工作和已取得的部分研究成果.提出了后续研究方向和...