飞灰-氢氧化钙/聚苯硫醚(PPS)滤料对烟气中单质汞的脱除

在汞固定床实验台上进行了飞灰-氢氧化钙和PPS滤料负载飞灰-氢氧化钙吸附单质汞,以及不同温度、气体成分对滤料负载吸附剂脱除汞影响的实验研究。实验结果表明,质量配比为2∶1的飞灰-Ca(OH)2吸附剂对Hg0的脱除效果最好,最高可达到34.5%左右,比纯飞灰条件下的脱除效率提高了近10%。120℃条件下,PPS滤料负载飞灰-Ca(OH)2吸附剂对汞的脱除率最高达72%,远高于滤纸薄膜上吸附剂的脱除率。随着温度升高,PPS滤料负载吸附剂的脱除效率降低。HCl、SO2和NO对PPS负载吸附剂脱除汞表现出不同程度的促进作用,HCl具有很强的促进作用,少量HCl足以大幅度提高脱除效果,SO2有一定的促进作用,NO的促进效果并不明显。     

Characteristics of total gaseous mercury concentrations at a coastal area of the Yangtze Delta,China

In this study, we report on total gaseous mercury (TGM) field observations made in the rural area of Shanghai, Chongming Island, China, from September 2009 to April 2012. The average TGM was 2.65 ± 1.73 ng m^?3 in Chongming Island, which is higher than the TGM background value of the Northern Hemisphere (1.5–1.7 ng m^?3); this indicates that to some extent, the Chongming area has been affected by anthropogenic mercury emissions. The observed TGM follows a seasonal pattern; concentrations are highest in winter, followed by autumn, summer, and spring. There is also a clear diurnal variation in TGM. All peak values appear between 7:00 and 9:00 in all four seasons; this appears to be the result of the height change in the atmospheric boundary layer that occurs between day and night. TGM concentrations in Chongming remain high in the westerly wind direction, especially in the southwest direction because of its low frequency, so the greatest source contribution to TGM in Chongming lies to the northwest. Wind speed is also a significant factor affecting TGM, and was negatively correlated with TGM concentrations. TGM is also closely related to carbon monoxide (CO) concentrations, indicating that TGM is impacted by human activities. The slope of the linear fitting of TGM and CO demonstrates that the contribution of noncoal source emissions to TGM in summer is greater than in autumn, mainly because the high temperature and intensive sunlight in summer increase mercury emissions from natural sources.

Implications: Except for some studies in the coastal areas (e.g., Kang Hwa Island by Kim et al., 2006, An–Myun Island by Kim et al., 2002, and Okinawa by Chan et al., 2008), data specifically for coastal areas are lacking. Monitoring of total gaseous mercury (TGM) in the rural area of Shanghai, Chongming Island, can help us understand mercury distribution.     

加氢装置中羰基镍的生成及预防

羰基镍(以下简称Ni(CO)4)是挥发性和毒性极强的物质,在低浓度环境下就能造成人员严重危害或死亡.炼油厂加氢装置在正常操作或正常的开停工时形成的可能性很小,但是当装置所使用的催化剂中Ni组分或原料油中Ni杂质沉积在催化剂上时,进行装置的开停工操作就有可能生成Ni(CO)4,从而对人员造成危害.     

Enantioselective toxic effects and biodegradation of benalaxyl in Scenedesmus obliquus

Enantioselectivity in ecotoxicity and biodegradation of chiral pesticide benalaxyl to freshwater algae Scenedesmus obliquus was studied. The 96 h-EC₅₀ values of rac-, R-(−)-, S-(+)-benalaxyl were 2.893, 3.867, and 8.441 mg L⁻¹, respectively. Therefore, the acute toxicities of benalaxyl enantiomers were enantioselective. In addition, the pigments chlorophyll a and chlorophyll b, antioxidant enzyme activities catalase (CAT) and superoxide dismutase (SOD) as well as lipid peroxide malondialdehyde (MDA) were determined to evaluate the different toxic effects. Chlorophyll a was induced by S-(+)-benalaxyl but inhibited by R-(−)-benalaxyl at 1 mg L⁻¹. Chlorophyll b were both induced at 1 mg L⁻¹, but S-(+)-form was fourfold higher than R-(−)-form. S-(+)-benalaxyl inhibited more CAT activities at 3 mg L⁻¹ and 5 mg L⁻¹, induced less SOD activity and MDA content at 5 mg L⁻¹ than R-(−)-benalaxyl. Based on these data, enantioselectivity occurred in anti-oxidative stress when S. obliquus response to benalaxyl. In the biodegradation experiment, the half-lives of S-(+)-benalaxyl and R-(−)-benalaxyl were 4.07 d and 5.04 d, respectively, resulting in relative enrichment of the R-(−)-form. These results showed that toxic effects and biodegradation of benalaxyl in S. obliquus were enantioselective, and such enantiomeric differences must be taken into consideration in pesticide risk.     

滤料负载粉尘层对气态汞脱除性能的实验研究

通过不同性能纤维滤料负载燃煤飞灰粉尘层,来模拟袋式除尘器滤袋表面粉尘附着层,进而研究袋滤器用不同性能纤维滤料和粉尘附着层对燃煤烟气中Hg0的联合脱除性能。在固定床实验系统上分别进行了不同纤维滤料和燃煤飞灰粉尘层,以及经实验优选得到的华博特滤料负载燃煤飞灰粉尘层脱除燃煤烟气中Hg0的实验研究。结果表明,燃煤飞灰粉尘层和华博特滤料对Hg0分别有一定的脱除作用,脱除效率可达35%和42.5%,它们对Hg0的脱除是物理吸附和化学吸附共同作用的结果;同时,华博特滤料负载燃煤飞灰粉尘层对Hg0的联合脱除效率受到吸附反应温度、入口汞浓度和烟气停留时间等因素的影响,最佳脱汞率可达64.4%;吸附反应温度越高,脱除效率越低;烟气停留时间越大,脱除效率越高;入口汞浓度的提高并不一定提高华博特滤料负载飞灰粉尘层的脱汞效果。     

负载V2O5-WO3/TiO2掺炭纤维脱除烟气中Hg0

通过固定床实验系统研究烟气脱除零价汞的实验，首先研究了滤袋常用的聚苯硫醚（polyphenylene sulfide，PPS）以及活性炭纤维（activated carbon fiber，ACF）在不同温度、不同气体组分下负载V₂O₅-WO₃/TiO₂催化剂，对模拟燃煤烟气中零价汞（Hg⁰）的脱除效果。然后对比研究了活性炭纤维协同滤袋常用纤维负载催化剂后，对模拟燃煤烟气中Hg⁰的脱除性能。结果表明，在汞蒸气入口浓度为50 μg/m³，纯N₂气氛下，当温度为25℃时，两者脱除率均能达到99%，当温度为200℃，负载催化剂的活性炭纤维脱除率在30%左右，PPS纤维仅为10%左右。在200℃情况下，模拟烟气的组分为N₂+O₂时，2种纤维的Hg⁰脱除率提高了10%~20%，当在混合气体中添加0.01‰后，负载催化剂的PPS纤维Hg⁰脱除率能达到80%，活性炭纤维Hg⁰脱除率能达到98%。当温度为200℃，模拟烟气的组分为N₂+O₂+HCl时，不同性能掺炭纤维负载催化剂后Hg⁰脱除率在69%~95%范围之间变化，其中PPS掺炭纤维对Hg⁰脱除效率最高达到95%，因此，负载V₂O₅-WO₃/TiO₂催化剂的PPS掺炭纤维能在高温烟气中保持较高的Hg⁰脱除率。     

负载V2O5-WO3／TiO2掺炭纤维脱除烟气中Hg^0

通过固定床实验系统研究烟气脱除零价汞的实验，首先研究了滤袋常用的聚苯硫醚（polyphenylene sulfide，PPS）以及活性炭纤维（activated carbon fiber，ACF）在不同温度、不同气体组分下负载V2O5-WO3／TiO2催化剂，对模拟燃煤烟气中零价汞（Hg^0）的脱除效果。然后对比研究了活性炭纤维协同滤袋常用纤维负载催化剂后，对模拟燃煤烟气中Hg^0的脱除性能。结果表明，在汞蒸气人口浓度为50μg／m^3，纯N2气氛下，当温度为25℃时，两者脱除率均能达到99％，当温度为200℃，负载催化剂的活性炭纤维脱除率在30％左右，PPS纤维仅为10％左右。在200℃情况下，模拟烟气的组分为N2＋O2时，2种纤维的Hg^0脱除率提高了10％～20％，当在混合气体中添加0．01％。后，负载催化剂的PPS纤维Hg^0脱除率能达到80％，活性炭纤维Hg^0脱除率能达到98％。当温度为200℃，模拟烟气的组分为N2＋O2＋HCl时，不同性能掺炭纤维负载催化剂后Hg^0脱除率在69％～95％范围之间变化，其中PPS掺炭纤维对Hg^0脱除效率最高达到95％，因此，负载V2O5-WO3／TiO2催化剂的PPS掺炭纤维能在高温烟气中保持较高的Hg^0脱除率。     

原油在土壤中迁移及降解的研究

为了解原油在土壤中淋滤及降解的规律，剖析了大庆老油田开发区贮油池土壤含油状况，进行了自然植被不同类型土壤的浇油、室内原油淋滤模拟及栽培试验。结果表明：贮油池土壤原油淋滤深度绝大部分集中在0～30cm，以下原油明显减少（除沙化土壤外）；盐碱土集中在0～10cm；草甸黑钙土集中在0～50cm；柱内油水混合渗透试验，80％集中在0～20cm；原油覆盖土壤表面时清水淋渗较弱，在0～20cm内残留94％；加原油的土壤降解试验，平均降解59．92％，范围为53．94％～62．25％，盆栽试验平均降解61．99％，范围为55.12％～70．68％。     

基于物联网的智能环境污染检测与控制系统研究

为了实行对环境污染的远程智能检测,提出基于物联网技术的智能环境污染检测与控制系统设计方法,采用无线传感组网技术进行智能环境污染检测系统物联网设计,实现对环境污染信息采样,采集的环境污染数据主要有水污染数据、土壤污染数据和大气污染数据等。将数据输入的集成控制单元中,通过上位机进行远程传输控制,采用TMS320VC5409A智能处理DSP芯片作为集成控制芯片进行控制系统硬件设计,环境污染检测与控制系统硬件模块分为物联网传感模块、AD模块、上位机通信模块和数据输出接口模块等。在嵌入式Linux内核中实现环境污染检测程序加载,实现污染检测和优化控制。测试结果表明,采用该方法进行环境污染检测与控制的智能性较好,准确度较高,实时性较好,总体性能较优。     

芘污染对马氏珠母贝(Pinctada martensi)D型面盘幼虫发育的影响

多环芳烃(PAHs)是一类广泛存在于环境中的持久性有机污染物,大多具有潜在毒性、致癌性及致畸诱变作用。选取马氏珠母贝(Pinctada martensi)作为模式动物,研究芘对马氏珠母贝D型面盘幼虫发育的影响。将马氏珠母贝D型面盘幼虫暴露于不同浓度(2、4、8、16和32μg·L-1)芘(pyrene)中,在暴露后第12、24、36、48、60、72和84小时,分别测定其死亡率和畸形率,并观察形态学的变化。结果表明,芘对D型面盘幼虫的发育有显著影响,同一浓度组的死亡率与时间呈正相关。在2～32μg·L-1浓度范围内,不同暴露时间段,死亡率与浓度呈正相关。芘暴露对马氏珠母贝D型面盘幼虫的形态也有显著影响,随着芘浓度的增大幼虫畸形的比例增高,并呈现明显的剂量-效应关系,其中8和32μg·L-1浓度组的响应最敏感。同时,芘暴露对马氏珠母贝D型面盘幼虫的半数致死浓度(LC50)随着时间的推移逐渐降低,60h后趋于稳定,LC50值为43.50μg·L-1。研究结果表明,芘暴露能影响马氏珠母贝D型面盘幼虫的发育,并可能对其种群结构产生不利影响。