流化床O2/CO2气氛下添加SiO2对燃煤PM2.5的控制

采用小型流化床研究了在O2/CO2气氛下添加SiO2对PM2.5(空气动力学直径小于2.5 μm的颗粒物)的控制,试验在1123 K、O2/CO2气氛下进行,并采用荷电低压撞击器(ELPI)采集和分析燃烧后的PM2.5.结果表明,添加SiO2是燃烧过程中影响PM2.5生成的重要因素.添加SiO2后,生成PM1的质量浓度均降低,而PM1-2.5的质量浓度均略有增加;PM2.5质量粒径分布均呈双峰分布,峰值分别出现在0.2 μm和2.0μm左右.随着SiO2添加量的增加,PM2.5中的S、K、Na、Cu和Pb元素的含量呈减少的趋势;随着颗粒粒径减小,S、K、Na、Cu和Pb元素的含量有增高的趋势.     

分流比对土壤渗滤系统脱氮效果的影响研究

针对污染物浓度较高的养猪废水,开展了不同分流比条件下土壤渗滤系统处理效果的对比研究,并分析了分流比对系统中脱氮微生物数量及氧化还原电位(ORP)变化的影响.试验结果表明,分流比对土壤渗滤系统的脱氮效果影响较大,而对COD、TSS和TP的去除效果无明显影响,当水力负荷(HLR)为0.01m3·m-2·d-1且分流比为1∶2时,系统对TN的去除效果最好,平均去除率达80.20%,而对其他污染物的平均去除率均可达90%以上;分流比可影响土壤渗滤系统中脱氮微生物的数量,分流比的增大可促进系统中反硝化细菌数量的增加,强化系统的脱氮效果;另外,分流比还可影响系统填料层中ORP的变化.因此,根据系统进水水质选择合适的分流比,是强化土壤渗滤系统脱氮效果的关键因素.     

活性滤料滤池气提系统影响因素研究

为了研究气量、水深和提砂管规格对活性滤料滤池提砂系统性能的影响,本实验以石英砂作为活性滤料滤池的提升介质,在恒定水头状态下,测量了不同管径下被提升的水和砂的体积和质量随压缩空气流量的变化.结果表明:随着气量的增大,提升系统的提砂量和提砂效率均呈先增大后减小的趋势;提砂管管径是最大提砂量的限制因素,但提升的砂水体积比与管径无关;相同气量条件下,单位空气提砂量与水深呈线性关系.因此,在活性滤料滤池提砂系统的设计应用过程中应选择合适的提砂管径,尽量增加浸水率,并注意控制气量以提升系统能效.     

氟虫双酰胺在水稻和稻田中的残留动态研究

采用超高效液相色谱法(UPLC)测定了氟虫双酰胺19.8%悬浮剂(SC)在水稻及稻田环境中的残留动态.结果表明,当氟虫双酰胺及其代谢产物NNI-des-iodo的添加量为0.05～1.0 mg·kg-1时,其在水稻田土壤、田水、稻秆、稻米和稻壳中的平均回收率为78.2%～104.8%,变异系数为1.1%～4.4%.氟虫双酰胺在2011年三地(福建福州、天津、江苏南京)的稻田水中的降解半衰期为9.8～17.3 d,土壤中10.8～22.4 d,植株中7.6～17.3 d,其在稻田水样品中检出了代谢产物NNI-des-iodo,而在土壤和植株样品中未检出.在推荐使用剂量下,于末次施药10 d后,氟虫双酰胺在水稻稻米中的残留量均低于美国规定的在稻谷上的最大残留允许量(0.5 mg·kg-1).     

硫酸钙垢层清洗方法研究

从化学热力学角度和沉淀转化角度,理论上分析了碳酸钠、氢氧化钠分别与硫酸钙发生化学反应的可能性和反应进行的限度。并结合动力学规律,提出影响化学反应的条件,通过实验进行检验。最后提出,在实际工作中,达到良好清洗目的可采取的措施。     

Simultaneous preconcentration of cadmium and lead in water samples with silica gel and determination by flame atomic absorption spectrometry

A new method that utilizes pretreated silica gel as an adsorbent has been developed for simultaneous preconcentration of trace Cd(II) and Pb(II) prior to the measurement by flame atomic absorption spectrometry. The effects of pH, the shaking time, the elution condition and the coexisting ions on the separation/preconcentration conditions of analytes were investigated. Under optimized conditions, the static adsorption capacity of Cd(II) and Pb(II) were 45.5 and 27.1mg/g, the relative standard deviations were 3.2% and 1.7% (for n = 11), and the limits of detection obtained were 4.25 and 0.60 ng/mL, respectively. The method was validated by analyzing the certified reference materials GBW 07304a (stream sediment) and successfully applied to the analysis of various treated wastewater samples with satisfactory results.     

Waste oyster shell as a kind of active filler to treat the combined wastewater at an estuary

Estuaries have been described as one of the most difficult environments on Earth. It is difficult to know how to treat the combined wastewater in tidal rivers at the estuary, where the situation is very different from ordinary fresh water rivers. Waste oyster shell was used as the active filler in this study in a bio-contact oxidation tank to treat the combined wastewater at the Fengtang Tidal River. With a middle-experimental scale of 360 ma/day, the average removal efficiency of COD, BOD, NH3-N, TP and TSS was 80.05%, 85.02%, 86.59%, 50.58% and 85.32%, respectively, in this bio-contact oxidation process. The living microbes in the biofilms on the waste oyster shell in this bio-contact oxidation tank, which were mainly composed of zoogloea, protozoa and micro-metazoa species, revealed that waste oyster shell as the filler was suitable material for combined wastewater degradation. This treatment method using waste oyster shell as active filler was then applied in a mangrove demonstration area for water quality improvement near the experiment area, with a treatment volume of 5 × 10^3 m^3/day. Another project was also successfully applied in a constructed wetland, with a wastewater treatment volume of 1 ×10^3 m^3/day. This technology is therefore feasible and can easily be applied on a larger scale,     

曝气生物滤池去除邻苯二甲酸丁基苄酯的效果

采用陶粒滤料曝气生物滤池(BAF)处理邻苯二甲酸丁基苄酯(BBP)模拟废水,考察了空床接触时间(EBCT)、温度对BBP的去除效果的影响;运用气质联用仪(GC-MS)分析了BBP在曝气生物滤池内降解的中间产物并推测其可能的降解途径。结果表明,当温度为25℃,空床接触时间(EBCT)为8 h时,BAF对BBP的降解效果良好,去除率达到95.7%;BAF对BBP的去除率随着温度的升高和EBCT的增加而增大,EBCT为去除效果的主要影响因素。BAF出水中检测到邻苯二甲酸二丁酯(DBP)、邻苯二甲酸二甲酯(DMP)以及邻苯二甲酸(PA)等降解产物,据此推测邻苯二甲酸丁基苄酯的生物降解途径可能为BBP的苯环先断裂生成邻苯二甲酸二丁酯,而后断裂一个酯键形成单酯,接着再断裂另一酯键形成邻苯二甲酸,最终分解成二氧化碳和水。     

生化尾水垂直流-水平潜流组合湿地净化研究

采用垂直上升流-水平潜流组合人工湿地装置,对处理污水处理厂生化尾水进行深度处理,选用陶粒、沸石和砾石3种填料,美人蕉、再力花和菖蒲3种植物配置成6种不同的组合.8个月的试验结果表明,水力负荷为0.5 m3/(m2·d),试验装置对NH3-N和TP的去除效果较好,NH3-N平均去除率在69.3％以上,6组试验装置中4组的TP平均去除率在50％以上;COD,N03--N和TN去除效果较差,平均去除率分别在12.5％～ 15.1％,-1.8％ ～ 9.6％和6.3％～ 17.9％之间.以陶粒为填料种植美人蕉的组合湿地装置脱氮除磷效果最好,NH3-N,TN,N03--N,TP的平均去除率分别达到80.9％,17.9％,9.6％,77.5％.     

双水相浮选-HPLC法测定水中氯硝柳胺

文章建立了双水相浮选-高效液相色谱法来测定环境水中氯硝柳胺的含量。选择丙酮为亲水有机溶剂,40%(NH4)2SO4溶液为分相剂。当pH为3.0,氮气流速为20 min/mL,浮选时间为30 min时,萃取率达93.4%。该方法具有高效、绿色环保以及低成本等优点,是一种测定水样中氯硝柳胺含量的新方法。