生物砂滤池对有机物和氨氮的去除

当在常规工艺前加生物预处理并取消预加氯时,砂滤池就成为生物砂滤池。与普通砂滤池相比其对有机物、氨氮和浊度的去除率都有很大的提高。实验以珠江源水为水源研究了生物砂滤池对高锰酸盐指数、NH3-N、NO2--N和浊度的去除,在实验期间生物砂滤池出水高锰酸盐指数、NH3-N、浊度平均值分别为1.32mg/L、0.098mg/L、0.171NTU,其相对于沉淀池出水的高锰酸盐指数、NH3-N、浊度的平均去除率分别为18.52%、72.93%、64.45%,而砂滤池出水NO2--N几乎检测不出来。滤池进水与出水溶解氧的变化也证明了砂滤池中生物的存在,并且生长状况良好。     

离子强度、pH值和Ca2+/Al3+对马尾松幼苗的铝毒影响

测定了在不同溶液酸度、不同离子强度和Ca~(2+)/Al~(3+)比下,铝对马尾松幼苗生长状况的影响。结果表明,溶液酸度增加,离子强度减小时,铝的毒害作用增大。钙对铝毒有明显缓解作用,当Ca~(2+)/Al~(3+)增大时,铝的毒性减小,但其缓解作用与铝浓度有关,当铝浓度增加,钙的缓解能力下降。     

微絮凝双层滤料过滤处理含油废水试验研究

针对机电和机械加工行业排水中含油废水的特性 ,提出了微絮凝双层滤料过滤法处理工艺。通过实验 ,肯定了其良好的除油效果 ,并对影响除油率的因素进行了分析讨论 ,确定了处理工艺流程及合理的设计参数     

Effects of simulated acid rain on cation release in soils of South China

This paper deals with the release of base cations and Al3+ at the treatment with simulated acid rain (SAR) in main soil types collected from South China. Results showed that the amounts of base cations increased obviously when the pH value of simulated acid rain was lower than 3.0 or 3.5. Compared with the leaching of K+ and Na+, the leaching of Ca2+ and Mg2+ was affected by the pH value of SAR. Only when the amounts of base cations leached from soils exceeded the cation exchange capacity, the pH value of leaching solutions decreased sharply and the amounts of released Al3+ increased. The H+ buffering mechanisms, which were affected notonly by the pH values of SAR, but also by the types and solid components of soils, were proposed for the main soils studied.     

Efficient degradation of organic pollutants by S-NaTaO3/biochar under visible light and the photocatalytic performance of a permonosulfate-based dual-effect catalytic system

Removing large concentrations of organic pollutants from water efficiently and quickly under visible light is essential to developing photocatalytic technology and improving solar energy efficiency. This study used a simple hydrothermal method to prepare a non-metallic, S-doped NaTaO₃ (S-NTO) photocatalyst, which was then loaded onto biochar (BC) to form a S-NTO/BC composite photocatalyst. After uniform loading onto BC, the S-NTO particles transformed from cubic to spherical. The photogenerated electron-hole pair recombination probability of the composite photocatalyst was significantly lower than those of the NTO particles. The light absorption range of the catalyst was effectively widened from 310 nm UV region to visible region. In addition, a dual-effect catalytic system was constructed by introducing peroxymonosulfate (PMS) into the environment of the pollution to be degraded. The Rhodamine B, Methyl Orange, Acid Orange 7, tetracycline, and ciprofloxacin degradation efficiency at 40 mg/L reached 99.6%, 99.2%, 84.5%, 67.1%, and 70.7%, respectively, after irradiation by a 40 W lamps for 90 min. The high-efficiency visible-light catalytic activity of the dual-effect catalytic system was attributed to doping with non-metallic sulfur and loading of catalysts onto BC. The development of this dual-effect catalytic system provides new ideas for quickly and efficiently solving the problem of high-concentration organic pollution in aqueous environments, rationally and fully utilizing solar energy, and expanding the application of photocatalytic technology to practice.     

Prevalence and clinical significance of anticardiolipin antibodies in pregnancies complicated by parvovirus B19 infection

Anticardiolipin antibodies were measured in 60 pregnant women with acute parvovirus B19 infection. Test results for eight (13.3 per cent) women were positive for anticardiolipin antibody. Six of these eight women became negative later, yielding a prevalence of anticardiolipin antibodies of 3.3 per cent (2/60) 6 months after acute parvovirus B19 infection. Anticardiolipin antibody positivity was not associated with an increased risk of abortion, fetal death, or maternal complications. This study suggests that there is an elevated frequency of anticardiolipin antibodies in pregnant women with acute parvovirus B19, probably representing an epiphenomenon. However, this is not associated with an adverse maternal or perinatal outcome.     

A fetus with a parvovirus B19 infection and congenital anomalies

A fetus with multiple structural defects was seen at prenatal ultrasound examination. After termination of the pregnancy a bilateral cleft lip, alveolus, and palate; micrognathia; and webbed joints were seen. Fetal tissues showed indications of infection, intranuclear inclusion bodies, chronic stress, haemolysis, arterial wall damage, and profuse haemorrhage. Parvovirus B19 DNA was detected in fetal tissues by dot hybridization after polymerase chain reaction. The possibility of parvovirus B19 infection leading to congenital malformations is discussed.     

In-situ-reduced synthesis of cyano group modified g-C3N4/CaCO3 composite with highly enhanced photocatalytic activity for nicotine elimination

Graphite carbon nitride has many excellent properties as a two-dimensional semiconductor material so that it has a wide application prospect in the field of photocatalysis. However, the traditional problems such as high recombination rate of photogenerated carriers limit its application. In this work, we introduce nitrogen deficiency into g-C₃N₄ to solve this problem a simple and safe in-situ reduction method. g-C₃N₄/CaCO₃ was obtained by a simple and safe one-step calcination method with industrial-grade micron particles CaCO₃. Cyano group modification was in-situ reduced during the thermal polymerization process, which would change the internal electronic structure of g-C₃N₄. The successful combination of g-C₃N₄ and CaCO₃ and the introduction of cyanide have been proved by Fourier transform infrared spectroscopy and X-ray photoelectron spectrometer. The formation of the cyano group, an electron-absorbing group, promotes the effective separation of photogenic electron hole pairs and inhibits the recombination of photogenic carriers. These advantages result in the generation of more •O₂⁻ and ¹O₂ in the catalytic system, which increases the photocatalytic efficiency of nicotine degradation by ten times. Furthermore, the degradation process of nicotine has been studied in this work to provide a basis for the degradation of nicotine organic pollutants in the air.     

清洁的胡椒基T醚生产工艺的研究I,5-丙基-1,3-苯并二氧杂茂的氯甲基化废水的处理

报道了胡椒基丁醚生产中５－丙基－１，３－苯并二氧杂茂的氯甲基化的废水处理，该废水经蒸馏可回收９４％的盐酸，此酸吸收氯化氢后浓度在３６％以上，可再用于氯甲基化反应。蒸馏残液经分油、Ｆｅｎｔｏｎ试剂处理和五次生炭柱吸附后ＣＯＤＣｒ等项指标均可国家二类污染物的一级排放标准。     

Upgrading of organic waste: production of the copolymer poly-3-hydroxybutyrate-co-valerate by Ralstonia eutrophus with organic waste as sole carbon source

Two types of fermented organic waste (trade and industry waste and fruit and vegetable waste) were successfully used as a sole carbon source to produce poly-3-hydroxybutyrate-co-valerate (PHBV) by Ralstonia eutrophus (formerly Alcaligenes eutrophus) via oxygen limitation.The production of PHBV could be optimized by optimizing the oxygen transfer through the fermentor. Thereby, a peak concentration of 1.1 g PHBV per liter cell suspension, 40 w% of cell dry weight, was obtained at an aeration rate of 0.24 mol O₂/h·kg biomass. The yield of PHBV on the fatty acid concentration in the organic waste was 0.16 g polymer/g volatile organic matter. The process obtained, compares well with the commercial production process of PHBV based on glucose.