高铁酸钾同时降解微污染水中苯酚和Cr(Ⅵ)的研究

研究了高铁酸钾同时去除微污染水中苯酚和Cr(Ⅵ). 利用静态试验,分析了去除效果的影响因素,并初步探讨了其降解机理.结果表明,高铁酸钾氧化-絮凝协同去除Cr(Ⅵ)、苯酚和CODMn在氧化pH值为4.0,氧化时间20min,絮凝pH值为7.0,絮凝时间30min,高铁酸钾与苯酚的质量比为10:1的最佳条件下,Cr(Ⅵ)、苯酚、CODMn的去除率分别达到84.41%、28.33%、23.34%.说明高铁酸钾是一种可高效去除微污染水中Cr(Ⅵ)的水处理剂.     

Removal of pentachlorophenol from contaminated soil by catalytic oxidation with iron(III)-porphyrin complexes and potassium monopersulfate

Pentachlorophenol (PCP) in contaminated soil was removed by treatment with aqueous solutions of iron(III)-porphyrin complexes as catalysts and potassium monopersulfate (KHSO₅) as the oxygen donor. The contaminated soils were artificially prepared by spiking PCP to the kaolin and ando soils. Three types of iron(III)-porphyrin complexes, tetra(?p-sulfophenyl) porphineiron(III) (Fe(III)-TPPS), tetra(N-methyl-4-pyridil)porphineiron(III) (Fe(III)-TMPyP) and heme, were examined, and Fe(III)-TPPS was found to be the most effective for removing PCP. Although the sequential addition of KHSO₅ was examined, in an attempt to improve the efficiency of PCP removal, it was not effective. In a preliminary test of various aqueous solutions, the addition of humic acid (HA), with a lower degree of humification, led to a significant enhancement in PCP removal. When HA was added to the soil system, the percentages of PCP removal were increased by up to 10% compared to the absence of HA. Therefore, the addition of HA to the catalytic system was useful in enhancing PCP removal from contaminated soil.     

Gamma radiation measurements and dose rates in commercially-used natural tiling rocks (granites)

The gamma radiation in samples of a variety of natural tiling rocks (granites) imported in Cyprus for use in the building industry was measured, employing high-resolution gamma-ray spectroscopy. The rock samples were pulverised, sealed in 1-l plastic Marinelli beakers, and measured in the laboratory with an accumulating time between 10 and 14 h each. From the measured gamma-ray spectra, activity concentrations were determined for (232)Th (range from 1 to 906 Bq kg(-1)), (238)U (from 1 to 588 Bq kg(-1)) and (40)K (from 50 to 1606 Bq kg(-1)). The total absorbed dose rates in air calculated from the concentrations of the three radionuclides ranged from 7 to 1209 nGy h(-1) for full utilization of the materials, from 4 to 605 nGy h(-1) for half utilization and from 2 to 302 nGy h(-1) for one quarter utilization. The total effective dose rates per person indoors were determined to be between 0.02 and 2.97 mSv y(-1) for half utilization of the materials. Applying dose criteria recently recommended by the EU for superficial materials, 25 of the samples meet the exemption dose limit of 0.3 mSv y(-1), two of them meet the upper dose limit of 1 mSv y(-1) and only one clearly exceeds this limit.     

紫外分光光度法测定总氮空白值过高原因分析

碱性过硫酸钾消解紫外分光光度法测定总氮过程中,常常发生空白值过高而影响测定的情况,可能造成空白值过高的原因很多．主要包括纯水质量、试剂纯度、实验条件等几个方面,通过对可能造成总氮测定空白值过高的各项原因进行逐一系统分析和试验．发现造成空白值过高的原因主要为试剂过硫酸钾纯度不够,含有的总氮杂质过高所致,采用二次重结晶的方法时过硫酸钾试剂提纯后使用。同时严格地按照标准方法要求控制实验条件,即可大大降低总氮测定的空白值。     

联合多种荧光光谱和GC-MS研究高铁酸钾对菲的降解机理

研究了高铁酸钾对PAHs中的菲的降解反应过程,对该反应过程联合了时间扫描、偏振、偏振三维(PEEM)、三维(EEM)等多种荧光光谱模式进行了表征和分析,并结合GC-MS进一步检测分析了该反应过程的中间产物,最后系统探讨了高铁酸钾对菲降解的动力学反应规律及降解机理.实验结果表明,在设定的高铁酸钾-菲降解体系的物质的量之比为1∶1、1∶2、1∶3、2∶1、3∶1的各个降解反应过程均符合一级反应动力学特征,其拟合系数在0.905—0.995之间.通过不同摩尔比的高铁酸钾-菲降解过程的时间扫描荧光参数直接求得了各反应的动力学方程及曲线;菲降解过程的荧光偏振度值与PEEM共同揭示出高铁酸钾对菲的有效降解,且产物均为无偏振效应、无产生新的特征荧光的小分子结构,各特征光谱峰强与时间变化关系也与时间扫描荧光曲线相符合;最后结合GC-MS深入分析了菲的降解产物,并由此推测了高铁酸钾对菲的降解机理.降解产物中9,10-菲醌的大量存在表明菲结构中9,10位发生氧化而开始降解.     

Soil microbial response to waste potassium silicate drilling fluid

Potassium silicate drilling fluids (PSDF) are a waste product of the oil and gas industry with potential for use in land reclamation. Few studies have examined the influence of PSDF on abundance and composition of soil bacteria and fungi. Soils from three representative locations for PSDF application in Alberta, Canada, with clay loam, loam and sand textures were studied with applications of unused, used once and used twice PSDF. For all three soils, applying ≥40 m³/ha of used PSDF significantly affected the existing soil microbial flora. No microbiota was detected in unused PSDF without soil. Adding used PSDF to soil significantly increased total fungal and aerobic bacterial colony forming units in dilution plate counts, and anaerobic denitrifying bacteria numbers in serial growth experiments. Used PSDF altered bacterial and fungal colony forming unit ratios of all three soils.     

Soil microbial response to waste potassium silicate drilling fluid

Potassium silicate drilling fluids(PSDF) are a waste product of the oil and gas industry with potential for use in land reclamation. Few studies have examined the influence of PSDF on abundance and composition of soil bacteria and fungi. Soils from three representative locations for PSDF application in Alberta, Canada, with clay loam, loam and sand textures were studied with applications of unused, used once and used twice PSDF. For all three soils, applying ≥ 40 m3/ha of used PSDF significantly affected the existing soil microbial flora. No microbiota was detected in unused PSDF without soil. Adding used PSDF to soil significantly increased total fungal and aerobic bacterial colony forming units in dilution plate counts, and anaerobic denitrifying bacteria numbers in serial growth experiments.Used PSDF altered bacterial and fungal colony forming unit ratios of all three soils.     

高铁酸钾氧化降解氯酚的研究

研究了pH,投加摩尔比等反应条件对高铁酸钾氧化降解氯酚的影响,并应用HPLC手段对其降解产物进行了分析,推测了其可能的反应历程。     

高铁酸钾-微波耦合对印染污泥脱水性能的影响研究

分别采用微波、微波耦合高铁酸钾对印染污泥进行脱水预处理.结果表明,适宜的微波辐射可改善污泥脱水性能.2320、3240、4000 W·L-1对应的最适时间分别是140 s、100 s和80 s.在3240 W·L-1的微波下辐射100 s后,污泥的沉降速率(SV30)、污泥比阻(SRF)和粘度较原污泥分别减少4.00%、18.89%、35.05%.同时,高铁酸钾的加入能更好地提高污泥脱水性能,其最佳投加量为0.1767 g·g-1(以SS计,下同),对应的污泥SV30、毛细吸水时间(CST)、粘度相比原污泥分别降低了13.50%、51.18%、40.79%.泥饼含固率相比原污泥则增加14.58%.微波耦合高铁酸钾能有效破坏污泥絮体结构.随着高铁酸钾投量增加,上清液的蛋白质含量持续增加,多糖含量则先增加后减少.     

高铁酸钠电化学合成条件的研究

利用含铁材料为阳极,铜为阴极,NaOH溶液为电解液,于隔膜电解槽中电解制备高铁酸钠.探索了该工艺所必需的各种参数和反应条件,确定了隔膜材料,并对Na2FeO4浓度和电流效率的非一致性变化作出了解释.研究结果表明:在阳极距离为1.3 cm(极距2.3 cm)、阳极电解液浓度为14 mol/L,阴极电解液浓度为4 mol/L、温度为35℃、电压为8～9 V时,电解2 h后得到的Na2FeO4浓度为18.7g/L,电流效率为20%.