添加剂对垃圾焚烧飞灰熔融过程二不断噁英分解的影响

为了研究添加剂对垃圾飞灰熔融处理过程中二噁英分解特性的影响，选择碱性氧化物CaO和液体陶瓷(LC)2种添加剂，改变温度、气氛和熔融时间研究2种添加剂对二噁英分解率的影响．研究表明CaO对二噁英分解影响随气氛不同而改变，氧化气氛下，加入CaO使二噁英的分解率略微降低，而在还原气氛下则会使二噁英分解率升高．液体陶瓷添加剂对熔融过程二噁英分解有显著影响．1400℃时，随着LC添加比例由0增加到10％，二噁英分解率则从99．997％升高到100％．同时加入10％的LC可以使二噁英的完全分解温度由无添加剂时的1460℃降低至1100℃．     

臭氧氧化去除吐氏酸溶液COD的动力学研究

研究了臭氧氧化条件下，吐氏酸水溶液在鼓光反应器内的COD去除动力学，考察了pH值、温度、自由基抑制剂及进气口臭氧浓度等因素对反应的影响。结果表明：在pH=8左右时，COD去除效果较好；在17－30℃范围内，温度对反应影响不大；自由基抑制剂明显影响氧化效果，说明氧化过程是分子臭氧和其分解产生的自由基共同参与的结果；氧化降解效果与进气中臭氧浓度与正相关；臭氧氧化明显改善吐氏酸的生物降解性能，BOD5／COD可达0．18。研究表明：吐氏酸臭氧化的COD去除过程符合一级反应动力学。     

The effects of benzoate, cyclohex-1-ene carboxylate, and cyclohexane carboxylate on biotransformation of o-phthalate in sediment slurries under sulfate-reducing conditions

It was found in this study that while addition of the predicted intermediate product benzoate did not, addition of cyclohex-1-ene or cyclohexane carboxylate did inhibit the biotransformation of o-phthalate in sulfate-reducing o-phthalate-adapted sediment slurries under a CO2/H2 atmosphere. Biotransformation rates of benzoate were slightly higher than those of o-phthalate in sediment slurries amended with o-phthalate plus benzoate. By using the most probable number (MPN) method to determine the number of o-phthalate transformers, similar growth dynamics of o-phthalate transformers were observed in sediment slurries amended with or without benzoate. The number of benzoate transformers (1x10(9)cellsg-1 of sediment) remained the same in sediment slurries repeatedly amended with a mixture of o-phthalate and benzoate after their transformation. o-Phthalate transformers decreased about three orders (1x10(9) to 1x10(6)cellsg-1 of sediment) of magnitude after biotransformation of o-phthalate, and remained at the low number thereafter until re-amendment with o-phthalate. o-Phthalate transformers increased to 1x10(8)cellsg-1 of sediment just prior to the onset of biotransformation of the o-phthalate.     

基于大面积网格法的商场疏散时间预测

为了准确预测商场人员疏散时间,文中结合群集流动规律及离散法建立新的大面积网格算法,将时间离散为微小单元Δt,空间离散为大面积网格,利用人员流动速度—密度公式,计算每一Δt时间内网格中人员流动速度,迭代累计各单元时间得到疏散时间。以某商场人员疏散演练为例进行分析,结果表明,大面积网格算法预测的人员疏散时间与实际疏散演习时间基本吻合,其相对误差为3.4%,预测精确度较高。     

Influence of the structure and composition of Fe–Mn binary oxides on rGO on As(III) removal from aquifers

Fe–Mn binary oxide (FMBO) possesses high efficiency for As(III) abatement based on the good adsorption affinity of iron oxide and the oxidizing capacity of Mn(IV), and the composition and structure of FMBO play important roles in this process. To compare the removal performance and determine the optimum formula for FMBO, magnetic graphene oxide (MRGO)–FMBO and MRGO–MnO₂ were synthesized with MRGO as a carrier to improve the dispersity of the adsorbents in aquifers and achieve magnetic recycling. Results indicated that MRGO–FMBO had higher As(III) removal than that of MRGO–MnO₂, although the ratios of Fe and Mn were similar, because the binary oxide of Fe and Mn facilitated electron transfer from Mn(IV) to As(III), while the separation of Mn and Fe on MRGO–MnO₂ restricted the process. The optimal stoichiometry x for MRGO–FMBO (Mn_xFe_3-xO₄) was 0.46, and an extraordinary adsorption capacity of 24.38 mg/g for As(III) was achieved. MRGO–FMBO showed stable dispersive properties in aquifers, and exhibited excellent practicability and reusability, with a saturation magnetization of 7.6 emu/g and high conservation of magnetic properties after 5 cycles of regeneration and reuse. In addition, the presence of coexisting ions would not restrict the practical application of MRGO–FMBO in groundwater remediation. The redox reactions of As(III) and Mn(IV) on MRGO–FMBO were also described. The deprotonated aqueous As(III) on the surface of MRGO–FMBO transferred electrons to Mn(IV), and the formed As(V) oxyanions were bound to ferric oxide as inner-sphere complexes by coordinating their “–OH” groups with Mn(IV) oxides at the surface of MRGO–FMBO. This work could provide new insights into high-performance removal of As(III) in aquifers.     

Adsorption-oxidation of hydrogen sulfide on Fe/walnut-shell activated carbon surface modified by NH3-plasma

Walnut-shell activated carbon(WSAC) supported ferric oxide was modified by non-thermal plasma(NTP), and the removal efficiency for hydrogen sulfide over Fe/WSAC modified by dielectric barrier discharge(DBD) was significantly promoted. The sample modified for10 min and 6.8 k V output(30 V input voltage) maintained 100% H2 S conversion over a long reaction time of 390 min. The surface properties of adsorbents modified by NTP under different conditions were evaluated by the methods of X-ray photoelectron spectroscopy(XPS), Brunauer–Emmett–Teller(BET) analysis and in-situ Fourier transform infrared spectroscopy(FTIR), to help understand the effect of the NTP treatment. NTP treatment enhanced the adsorption capacity of Fe/WSAC, which could due to the formation of micro-pores with sizes of0.4, 0.5 and 0.75 nm. XPS revealed that chemisorbed oxygen changed into lattice oxygen after NTP treatment, and lattice oxygen is beneficial for H2 S oxidation. From the in-situ FTIR result,transformation of the reaction path on Fe/WSAC was observed after NTP modification. The research results indicate that NTP is an effective method to improve the surface properties of the Fe/WSAC catalyst for H2 S adsorption-oxidation.     

Evaluation of PCDD/F congener distributions in MWI flue gas treated with SCR catalysts

Partitioning of PCDD/F congeners between gaseous and particulate phases and removal efficiencies of the air pollution control devices (APCDs) for PCDD/Fs at an existing municipal waste incinerator (MWI) in Taiwan are evaluated via stack sampling and analysis. The MWI investigated is equipped with electrostatic precipitators (EP), wet scrubbers (WS) and selective catalytic reduction system (SCR) as APCDs. The average PCDD/F concentration of stack gas is 1.49 ng/N m³, and the International Toxic Equivalent Quantity (I-TEQ) is 0.043 ng-I-TEQ/N m³. The EP increases PCDD/F concentration by 174.0% while the average removal efficiency of WS + SCR system for PCDD/Fs reaches 99.1%. In addition, the PCDF removal efficiency achieved with WS + SCR system (97.1–99.8%) is higher than that for PCDDs (96.5–99.3%). The results obtained on gas/particulate partitioning in flue gas indicate that the particulate-phase PCDD/Fs accounted for 65% at the inlet of EP, 20% at the outlet of EP and 50% at the stack, respectively, of the total PCDD/F concentrations. This study also indicates that as the chlorination level of PCDD/F congeners increases, the percentage of PCDD/Fs existing in gas phase decreases in all flue gas samples.     

有机染料废水处理研究进展

对有机染料废水的物化处理法（混萃取、吸附、电解、膜分离、蒸馏浓缩及焚烧法）和生化法的特点及进展，特别对湿式氧化、光氧化，Ｆｅｎｔｏｎ试剂氧化，臭氧氧化法的研究进展作了重点阐述。     

甲醛法在测定固定污染源排放SO2浓度中的应用

对用注射器采样甲醛法测定高浓度ＳＯ２样气精密度、准确度，采样效率，样品的稳定性进行了研究，并应用于燃煤，燃油锅炉排气中ＳＯ２浓度的测定，同时与碘量法结果进行比较和评价，表明注射器采样甲醛法测定了ＳＯ２基本可行。