脱硫脱硫弧菌转化二氧化硫气体的研究

运用连续处理工艺研究了SO_2进气摩尔流速和去除率的关系,并对主要转化产物硫化氢和硫化物进行了测定,研究了亚硫酸盐的积累情况及其对脱硫脱硫弧菌生长的影响,同时还对碳源的消耗及转化产物进行了定量研究.实验结果表明,随着SO_2流速的提高(4·975~20·149mmol·h~(-1))菌体对二氧化硫的去除率没有发生明显的变化,始终保持在93%以上,在SO2摩尔流速低于5·034mmol·h~(-1)时产物以硫化氢为主,而随着SO_2摩尔流速的提高,液相中硫化物和亚硫酸盐开始累积;当SO_2摩尔流速增大至20·149mmol·h~(-1)时,亚硫酸盐累积浓度达到74·23mg·L~(-1),该浓度对菌体生长不会产生抑制作用;系统在SO_2摩尔流速为14·063mmol·h~(-1)下运行时较为稳定,乳酸盐全部转化为乙酸盐,每还原1mmol SO_2消耗0·4mmol CH_3CHOHCOO~-.     

Sulfur-containing amino acid methionine as the precursor of volatile organic sulfur compounds in algea-induced black bloom

After the application of methionine, a progressive and significant increase occurred in five volatile organic sulfur compounds (VOSCs): methanethiol (MeSH), dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS) and dimethyl tetrasulfide (DMTeS). Even in the untreated control without a methionine addition, methionine and its catabolites (VOSCs, mainly DMDS) were found in considerable amounts that were high enough to account for the water’s offensive odor. However, blackening only occurred in two methionine-amended treatments. The VOSCs production was observed to precede black color development, and the reaching of a peak value for total VOSCs was often followed by water blackening. The presence of glucose stimulated the degradation of methionine while postponing the occurrence of the black color and inhibiting the production of VOSCs. In addition, DMDS was found to be the most abundant species produced after the addition of methionine alone, and DMTeS appeared to be the most important compound produced after the addition of methionine+glucose. These results suggest that methionine acted as an important precursor of the VOSCs in lakes suffering from algea-induced black bloom. The existence of glucose may change the transformation pathway of methionine into VOSCs to form larger molecular weight compounds, such as DMTS and DMTeS.     

2006~2010年珠三角地区SO2特征分析

对广州番禺大气成分站2006~2010年期间的SO2资料进行了分析,讨论了珠江三角洲(珠三角)地区地面SO2体积分数的年、季节、月、日变化特征和概率的分布特征.珠三角地区地面SO2变化特征的分析结果表明,2010年地面SO2体积分数的总体水平相对近年来有一定下降,高浓度事件发生频率降低;冬、春季SO2各项统计值要高于夏、秋季,干季明显高于湿季,可能与大气边界层高度和太阳辐射等因素的季节性变化相关;SO2干湿季的日变化趋势相仿,日最高峰时间相同,只是湿季达次高峰和最低点的时间比干季要提前1 h,这可能与季节性的大气边界层高度和辐射强度变化,以及日照时间长度有关;SO2体积分数的概率分布特征比较复杂,各月谱型分布各有不同,可能与季节性因素的变化规律相关.     

人工片状钙基脱硫剂的试制及其性能研究

介绍了用于沸騰炉燃煤锅炉脱硫的人工片状钙基脱硫剂的生产工艺,并用固定床反应器、压汞仪,扫描电子显微镜、强度仪等研究了该脱硫剂的物理化学特性。实验表明,采用该工艺生产的脱硫剂具有良好的抗压抗磨强度和耐水性,由于具有合理的孔分布,其固硫能力是石灰石的2—3倍,钙利用率可达40％,适用于850℃—1000℃的较宽温度范围。在3台沸腾炉共7个工况下的工业实验证明了该脱硫剂的上述特性。     

对厌氧消化中硫化氢毒性控制的探讨

在厌氧消化处理高浓度硫酸盐废水时，不但存在硫酸盐还原菌与产甲烷菌之间发生基质竞争的问题，而且硫酸盐还原菌将硫酸盐还原产生的硫化氢对产甲烷菌产生毒性作用。本文介绍硫化氢对产甲烷菌产生毒性作用的动力学方程，详细分析在厌氧消化条件下硫化氢对产甲烷菌产生毒性作用的机理，重点阐述三种控制硫化氢毒性的方法：气体吹脱法、化学沉淀法和生物除硫法。     

微氧条件下自养-异养联合反硝化工艺的电子平衡分析

自养-异养联合反硝化(integrated autotrophic and heterotrophic denitrification,IAHD)工艺可以同时进行硫化物,硝酸盐和有机物的降解,作为工业废水处理的关键单元近年来受到广泛关注.引入微量氧气作为电子受体的微氧技术已被证明是强化IAHD运行效能的有效策略.本研究关注于IAHD工艺的电子平衡计算并发现了IAHD生物反应器在微氧条件下运行时利用有限的硝酸盐可将硫化物和乙酸盐完全转化去除.在IAHD序批实验中,当电子缺失率达到峰值55. 1%时,硫化物、硝酸盐和乙酸盐去除效率和去除速率均最高.进一步的硫化物氧化间歇实验表明,电子得失不平衡现象发生在生物硫化物氧化过程中,当氧气含量为5 m L和10 m L时,电子缺失率分别为18. 7%和38. 2%. Illumina微生物群落测序结果表明,Thiobacillus、Thauera、Mangroviflexus和Erysipelothrix为硫氧化过程的主要占优属,其中Thiobacillus的相对丰度随着电子缺失率的增加而增加.本研究揭示了微氧条件下电子受体缺失现象与强化的IAHD运行效能之间的潜在联系,并为深入探讨硫、氮和有机碳的代谢机制提供了新的研究视角.     

制备条件对低温NH_3-SCR脱硝催化剂Mn-Ce/TiO_2结构与性能的影响

采用溶胶凝胶法制备了Mn-Ce/TiO2催化剂,以NH3为还原剂,通过程序升温反应考察其选择性催化还原NO的催化性能.同时,着重探讨了焙烧温度、焙烧时间、活性物质负载量及Mn、Ce负载比例对催化剂结构和性能的影响,并用BET、XRD等对催化剂进行了表征.结果表明,活性组分负载量由0增至20%时,NO转化率随着负载量的增加而提高,当(Mn+Ce)质量分数为20%,催化剂活性最高,此后随着活性组分负载量的增加,NO转化率明显下降;Mn与Ce的负载比例为0.85∶0.15时,催化剂比表面积最大,为112.31m2·g-1;焙烧温度500℃时催化剂晶相均为TiO2锐钛矿型结构,焙烧温度升高至600℃,催化剂晶相为TiO2锐钛矿型和金红石型混合结构,且催化剂比表面积急剧减小;焙烧时间对催化剂晶相结构影响不大,焙烧时间为5h时,Mn-Ce/TiO2的脱硝性能最好.     

硫磺/石灰石自养反硝化系统脱氮除磷性能研究

为了考察硫磺/石灰石系统对于低C/N的城市污水进行同步脱氮除磷的性能,设计了体积比为1∶1的硫磺/石灰石柱式反应器,以人工配水为处理对象,采用厌氧生物滤池运行方式,研究了HRT、初始磷浓度、pH、温度等因素对其脱氮除磷性能的影响.结果表明,在进水NO 3^--N为30 mg/L左右,PO4^3--P为15 mg/L条件...     

衡阳大气硫同位素组成环境意义的研究

1996-1997年度衡阳大气硫同位素监测结果是:大气降水δ(34S)均值为6.12‰,大气二氧化硫δ(34S)均值为-3.48‰,大气气溶胶δ(34S)均值为10.73‰.数值体系较好地符合硫同位素分馏规律,研究认为,该地大气环境受西南气流影响甚微,北方南下气流进一步推断为作用该地大气硫的主因;生物硫源对降水硫影响不容忽视;衡阳与珠江三角洲及粤北城市硫同位素监测结果均不支持降水硫同位素区域分异学说.      

Sulfur speciation and bioaccumulation in camphor tree leaves as atmospheric sulfur indicator analyzed by synchrotron radiation XRF and XANES

Analyzing and understanding the effects of ambient pollution on plants is getting more and more attention as a topic of environmental biology.A method based on synchrotron radiation X-ray fluorescence and X-ray absorption near edge structure spectroscopy was established to analyze the sulfur concentration and speciation in mature camphor tree leaves (CTLs),which were sampled from 5 local fields in Shanghai,China.Annual SO2 concentration,SO42-concentration in atmospheric particulate,SO42-and sulfur concentration in soil were also analyzed to explore the relationship between ambient sulfur sources and the sulfur nutrient cycling in CTLs.Total sulfur concentration in mature camphor tree leaves was 766-1704 mg/kg.The mainly detected sulfur states and their corresponding compounds were +6 (sulfate,include inorganic sulfate and organic sulfate),+5.2 (sulfonate),+2.2 (suloxides),+0.6 (thiols and thiothers),+0.2 (organic sulfides).Total sulfur concentration was strongly correlated with sulfate proportion with a linear correlation coefficient up to 0.977,which suggested that sulfur accumulated in CTLs as sulfate form.Reduced sulfur compounds (organic sulfides,thiols,thioethers,sulfoxide and sulfonate) assimilation was sufficed to meet the nutrient requirement for growth at a balanced level around 526 mg/kg.The sulfate accumulation mainly caused by atmospheric sulfur pollution such as SO2 and airborne sulfate particulate instead of soil contamination.From urban to suburb place,sulfate in mature CTLs decreased as the atmospheric sulfur pollution reduced,but a dramatic increase presented near the seashore,where the marine sulfate emission and maritime activity pollution were significant.The sulfur concentration and speciation in mature CTLs effectively represented the long-term biological accumulation of atmospheric sulfur pollution in local environment.