Effects of SO2 and SO3 on the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans by de novo synthesis

The effects of SO2, SO3 on de novo synthesis of polychlorinated dibenzo-p-dioxins （PCDDs） and dibenzofurans （PCDFs） were studied using model fly ashes incorporating copper oxide and activated carbon. It was found that the inhibitive effect of SO2 on PCDD/Fs formation is similar to that of SO3. To investigate the inhibition mechanism, CuSO4 formations from both CuO and CuCl2 were examined. The ability of SO3 to convert CuCl2 and CuO on a silica support into sulfate is much stronger than that of SO2. However, replacing silica by activated carbon leads to a much high conversion of CuCl2 to CuSO4 in the presence of SO2. The promotion by activated carbon is explained by the reduction of CuCl2 to Cu2Cl2 and the eventual conversion of Cu2Cl2 into CuSO4 is the main inhibition mechanism of SO2 on de novo synthesis of PCDD/Fs.     

PCDD/FS EMISSION IN A 150T/D MSW AND COAL CO-FIRING FLUIDIZED BED INCINERATOR

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PCDD/FS emission in a 150T/D MSW and coal co-firing fluidized bed incinerator

Incineration as a method of reducing Municipal Solid Waste (MSW) volume and recovery of energy has been developed gradually in China. More attention is paid on polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans, (PCDD/Fs) formed in MSW incineration process. This paper presents results of the analysis of PCDD/Fs in the residues of a fluidized bed incinerator co-firing MSW and coal in the Yuhang Thermal Power Plant. The effects of operation conditions and the wet scrubber system on PCDD/Fs formation were also analyzed. PCDD/Fs emitting from the smoke stack was 0.92 I-TEQ ng/Nm³. After the wet scrubber emission of dioxins increased and the shifting of homologue profiles in flue gas was also observed, PCDFs were not detected in the incinerator residues. From this, we can see that in the MSW incineration process, the formation mechanism of PCDFs was different from that of PCDDs. The results will benefit further research on the optimal operation of incinerator and control of PCDD/Fs emission from the MSW incinerator. Project supported by the Special Funds for Major State Basic Research Projects 973. (G1999022211), and Natural Science Foundation of China (No. 59836210, No. N1986 2598780472).     

二噁英类有机污染物的TEF简易计算与QSAR研究

二噁英类有机污染物的TEF与QSAQ研究,通过定量结构活性相关模型,用简易量化方法,计算了83种典型二噁英的TEF毒性参数,并运用定量结构-性质相关技术研究了PCDDs-PCDFs的TEF,同logP、SHEIO氯原子数目、分子结构的定量关系。结果表明,二噁英化合物的毒性当量TEF同氯原子数目、logP有显著相关;同SEHIO和氯原子取代位置存在紧密相关。同时揭示二噁英的毒性是卤苯、苯酚、硝基苯、苯胺类衍生物毒性强度的50-70倍。     

氨水浓度对果壳活性炭结构及性能的影响

采用氨水浸渍法对果壳活性炭进行改性处理,讨论不同氨水浓度（5%、10%、15%、20%）对果壳活性炭结构及性能的影响。采用场发射扫描电镜、比表面及孔径分析仪及紫外分光光度计对改性后的果壳活性炭结构及吸附性能进行研究。结果表明:氨水浓度对果壳活性炭的结构及吸附性能有显著影响,当氨水浓度为10%时,活性炭表面形态清晰,凹槽分布均匀,比表面积提高至775.1382m2/g,较改性前提高了6.5%;改性前后活性炭微孔孔径集中分布在3.5 nm;果壳活性炭的吸附率随氨水浓度的变化而变化,当氨水浓度为10%和15%时,吸附率分别达到86.51%和86.54%,吸附率相比改性前有所提高。而当氨水浓度进一步增加时,活性炭对苯酚的吸附率略微下降。     

化学改性活性炭对Cu(Ⅱ)离子吸附性能的研究

将市售粉状活性炭用16%硝酸进行氧化,再用0.1mol.L-1的氢氧化钠进行处理,制得化学改性活性炭,并对其吸附性能进行了研究.实验结果表明,改性后的活性炭较改性前对Cu2 离子的吸附能力提高60%以上.     

废弃茶梗基活性炭对孔雀石绿的吸附研究

为拓宽茶产业剩余物的开发应用途径,以氯化锌为活化剂制备了废弃茶梗基活性炭,考察了各吸附条件对其吸附孔雀石绿效果的影响,并分析了其吸附动力学行为和等温吸附方程。结果表明：溶液pH等各因素对吸附效果都有一定影响;在染料初始浓度为100mg／L、吸附pH=7、吸附温度25℃、吸附剂投量为2g／L,吸附时间为150min的条件下,活性炭对孔雀石绿吸附量为57.8mg／g,对染料的去除率达到97.5％。活性炭对孔雀石绿的吸附过程是一个物理吸附控制的准二级动力学过程,等温吸附规律更符合Langmuir等温式。     

机械力化学技术制备磷酸法活性炭及其碘吸附性能的研究

研究采用机械力化学技术制备了吸附性能良好的活性炭。试验采用Plackett—Burman（PB）实验设计和Box—BehnkenDesign（BBD）设计法对影响活性炭碘吸附值的6个条件进行筛选优化。PB实验设计与统计学分析表明酸屑比、研磨时间、活化温度、磷酸浓度是影响活性炭碘吸附值的四个关键因素。以碘吸附值为响应目标,对四因素进行BBD设计,并经响应面法优化分析得到影响活性炭碘吸附值的二阶模型,确定了机械力化学技术制备磷酸活性炭的较优操作条件为：酸屑比2．00,研磨时间22min,活化温度406℃,磷酸浓度20％,活性炭的碘吸附值达1195．23mg／g。     

枣椰仁颗粒活性碳及其在多介质过滤器中余氯穿透曲线动态建模(英文)

采用物化活化工艺,以枣椰仁为原材料制作颗粒活性碳( GAC) ,制作过程主要有 6 个步骤: 清洗,烘干,粉碎,筛分,炭化和活化. 通过小试对新型 GAC 去除余氯的特性进行了研究,并将实验结果与 Langmuir和 Freundlich 等温方程进行了拟合. 通过理论和实验分析,考察了主要运行参数对吸附动力的影响. 结果表明: Langmuir 等温方程与实验数据最为吻合,说明其对余氯吸附为单层吸附. 新型 GAC 在余氯吸附方面具有巨大潜力,比传统的吸附剂更具竞争力. 采用托马斯扩展模型结合物质转移阻力对实验结果进行了验证,模拟结果与实验非常符合.     

活性炭/二氧化锰复合材料的制备及性能研究

采用水热法,以果壳活性炭为载体,制备活性炭（AC）/二氧化锰（MnO2）纳米线复合材料。采用X射线衍射仪（XRD）、场发射扫描电子显微镜（SEM）、比表面及孔径分析仪、同步热分析仪（TG）以及紫外可见吸收光谱（UV/Vis）对所得材料的组成、形貌和结构进行表征,并对其光催化性能进行研究。结果表明:采用水热法可实现活性炭与MnO2的有效复合。在复合材料中,MnO2纳米线多以无定形态的形式存在且尺寸均一,将活性炭有效胶结在一起,从而使得活性炭比表面积和孔隙率降低,但其孔径大小保持不变。光催化实验结果表明,AC/MnO2复合材料对于有机染料具有明显、高效的降解效果,对亚甲基蓝的降解主要是吸附和光催化两者协同效应的结果。该结果拓展了活性炭在光催化领域的应用。     

酸碱再生颗粒活性炭对麸酸脱色的影响

味精在生产过程中产生的色素和类黑色素会带入麸酸中,因而需要使用活性炭对其进行脱色精制。文章研究了磷酸法颗粒活性炭对麸酸脱色及酸碱再生效果的影响,分析不同孔径分布的磷酸法颗粒炭对麸酸中和脱色及酸碱再生的影响规律,并通过常规吸附检测项目探索麸酸脱色及酸碱再生的适宜性。结果表明:活性炭的BET比表面积、亚基蓝吸附值、高碘与麸酸中和液脱色及酸碱再生效果未呈正相关关系。YL-600-2大孔径型磷酸法颗粒活性炭比YL-600-1高比表面积型的活性炭更适合用于麸酸中和液的脱色和酸碱再生;通过颗粒活性炭的脱色、再生模拟实验获得适宜的颗粒活性炭的孔径范围。以上结果对味精生产厂家进行颗粒活性炭替代粉状活性炭的再生利用选择具有重要意义。     

Novel FGBAC reactor for controlling the leakage of microfauna in drinking water treatment

In order to reduce the microfauna leakage risk from a granular biological activated carbon （GBAC） reactor which employs granular activated carbon （GAC） as adsorption media in drinking water advanced treatment, a novel fiber and granular biological activated carbon （FGBAC） reactor which employs both GAC and activated carbon fiber （ACF） as adsorption media, was developed. The results showed that the species composition of microfauna leaking from FGBAC reactor is almost similar to that leaking from GBAC reactor, however the densities of microfauna leaking from FGBAC reactor is reduced by 26%-81% compared to those leaking from GBAC reactor. In addition, compared to GBAC reactor, FGBAC reactor can increase the removal efflciencies of chemical oxygen demand （COD） and turbidity by 7% and 10%, respectively, during the stable operation period of reactor.     

ZnCl2活化笋壳活性炭的制备及其对亚甲基蓝的吸附动力学研究

以笋壳为原料,采用氯化锌为活化剂制备活性炭,通过正交实验研究各影响因素对活性炭性能的影响。通过静态吸附实验研究ZnCl₂活化笋壳活性炭对亚甲基蓝的吸附特性,并从动力学角度探讨其吸附机理。结果表明,制备活性炭主要影响因素为活化温度,其次是ZnCl₂浓度,活化时间影响最小。制备活性炭的最佳条件是:ZnCl₂浓度为3 mol/L,活化温度控制在400 ℃,活化时间2 h。活性炭对亚甲基蓝的吸附符合准二级动力学方程和Elovich方程,吸附速率控制步骤主要为膜扩散控制。等温吸附曲线与Langmuir型和Freundlich型均拟合较好,吸附过程是优惠吸附。     

粉末活性炭对β-萘磺酸的吸附性能

通过静态吸附实验,研究了粉末活性炭对β-萘磺酸的吸附性能.结果表明,在298K时,粉末活性炭对β-萘磺酸具有较好的吸附性能,其静态饱和附容量可达到115.48 mg/g.粉末活性炭对β-萘磺酸的吸附等温线符合Langmuir模型,且属优惠型吸附.吸附过程的ΔG<0,ΔH<0,表明此反应过程是放热自发进行的,温度低于298 K时降低温度有利于吸附反应的发生.吸附动力学研究表明,粉末活性炭对β-萘磺酸的吸附过程遵循二级动力学方程.     

SDS改性活性炭对铜离子的吸附研究

商品化活性炭(AC)经柠檬酸预处理,再用十二烷基硫酸钠(SDS)进行改性,将得到的改性活性炭(SDS-AC)用于铜离子的吸附,考察改性剂用量、吸附时间、p H、SDS-AC投加量对吸附效果的影响,同时研究SDS-AC吸附铜离子的吸附等温线。结果表明:0.3%的SDS改性剂量效果最佳,最大吸附量为38.7621 mg/g,约为AC吸附量的2.5倍;200 m L铜离子初始浓度为50 mg/L的溶液吸附性能最佳条件为SDS-AC投加量为0.200 0 g,p H值为5,吸附时间为60 min;Langmuir等温线更符合铜离子在SDS-AC中的吸附行为的描述。     

Study on Regeneration of Powdered Activated Carbon by Electron Beam

1 IntroductionActivated carbon is very useful for removal ofpollutants in wastewater and raw drinking water for itslarge adsorbing power. After a cedain time of use, theabsorbing power of activated carbon decreased so that theused activated carbon must be regenerated for economicalreuse.There are many methods for activated carbonregeneration, such as medicamellt method['], oxidizingm.thodl'] and heating method .iC[3]. For reversibleadsorption of organic pollutants with high concenthaonand low…     

电子束再生粉状活性炭的研究

The powdered activated carbon which had adsorbed phenylglycine solution from pharmaceutics factory can be regenerated by mean of irradiation of high-energy electron beams in oxygen, nitrogen and water vapor respectively. The effects of radiation dose and beam current on regeneration of activated carbon in different atmosphere were studied. Differential scanning calorimetry (DSC) and the iodine number of activated carbon were used to monitor the change of carbon adsorption. The results show that the powder activated carbon polluted with phenlglycine could be regenerated effectively by irradiation of high energy electron beams in nitrogen stream. The generation did not need high temperature, and the weight loss of carbon and energy consumption were minimum.     

超声协助活性炭去除水中铅的正交试验研究

研究了超声温度、超声时间、吸附时间、pH值及活性炭负荷比等对含铅废水处理效果的影响及对活性炭再生效果的影响.分别以去除率、得率和再生后去除率为考察指标,依据L16 (44)正交表和L9(34)进行实验,石墨炉原子吸收法测定处理前后溶液中的铅含量,并对测定结果进行直观分析和方差分析.正交试验得出的优选条件:去除废水中铅时的超声温度为20℃、超声时间20 min,吸附时间20min、pH=5、活性炭负荷比为667∶1;活性炭再生处理时的超声温度40℃、pH值为1、超声时间40min.对优选的实验条件进行方法学考察,各项考察结果均符合要求.结果表明,该方法切实可行,具有简单、高效、快速等优点.     

Effect of a biological activated carbon filter on particle counts

Due to the importance of biological safety in drinking water quality and the disadvantages which exist in traditional methods of detecting typical microorganisms such as Cryptosporidium and Giardia, it is necessary to develop an alternative. Particle counts is a qualitative measurement of the amount of dissolved solids in water. The removal rate of particle counts was previously used as an indicator of the effectiveness of a biological activated carbon （BAC） filter in removing Cryptosporidium and Giardia. The particle counts in a BAC filter effluent over one operational period and the effects of BAC filter construction and operational parameters were investigated with a 10 m^3/h pilot plant. The results indicated that the maximum particle count in backwash remnant water was as high as 1296 count/ml and it needed about 1.5 h to reduce from the maximum to less than 50 count/ml. During the standard filtration period, particle counts stay constant at less than 50 count/ml for 5 d except when influenced by sand filter backwash remnant water. The removal rates of particle counts in the BAC filter are related to characteristics of the carbon. For example, a columned carbon and a sand bed removed 33.3% and 8.5% of particles, respectively, while the particle counts in effluent from a cracked BAC filter was higher than that of the influent. There is no significant difference among particle removal rates with different filtration rates. High post-ozone dosage （〉2 mg/L） plays an important role in particle count removal; when the dosage was 3 mg/L, the removal rates by carbon layers and sand beds decreased by 17.5% and increased by 9.5%, respectively, compared with a 2 mg/L dosage.     

活性炭吸附酸性铬蓝 K 的研究简

以小麦秸秆为原料。通过复合物理活化法制备高比表面积活性炭．用所得活性炭为吸附剂,研究了其对酸性铬蓝K的吸附行为,考察了吸附剂用量、pH值、初始浓度、温度与吸附时间对酸性铬蓝K的吸附容量与脱除效果的影响．结果表明。酸性铬蓝K在浓度50g／m^3、pH为2．02、温度320K、吸附剂用量0．1g与吸附时间40min时去除率达到99．9％．