陶粒复合垂直流人工湿地对污水季节性处理效果的试验研究

研究了四种陶粒组合、一种石灰石碎石5套复合垂直流人工湿地在不同季节处理生活污水的运行效果。结果表明:陶粒组合人工湿地系统对COD、TP、NH3-N的去除效果均优于石灰石碎石湿地;复合垂直流人工湿地对COD的去除效果在冬季有所下降,但仍保持在50%以上;湿地系统对TP去除率受季节性变化影响不显著,但随着复合垂直流人工湿地系统的运行,基质层对TP的吸附逐渐饱和,去除效率缓慢下降;1号~5号人工湿地对氨氮的去除率分别从秋季42.0%、55.1%、61.1%、49.9%、50.2%下降至冬季21.9%、31.0%、36.5%、28.5%、29.2%,春、夏季处理效率开始回升,并保持稳定的状态。     

寒冷地区化粪池的效果评价和探讨

寒冷地区化粪池具有水温低,处理效果差的特点,针对哈尔滨市幸福家园化粪池的水质情况进行了研究,为化粪池的改造和优化提供依据,并对化粪池问题和技术进行探讨。在化粪池前后的检查井处进行取样,每隔1个小时取一个样,总共取24小时,然后对CODtot、CODss、CODcol、CODdis、NH3-N、总氮、总磷、SS、VSS、pH、水温进行测定。水温在14～17度下,平均去除率分别是16.9%、47.2%、26.4%、-49.1%、-39.3%、7.5%、12.4%、59.3%和59.5%,可见,污水的可生化性有明显提高,但是对污染物的去除作用不大。研究结果对于全面评价寒冷地区化粪池的功能特征,进而为化粪池的取舍和改造提供技术的参考依据。     

Adsorption and leaching of novel fungicide pyraoxystrobin on soils by <Superscript>14</Superscript>C tracing method

Pyraoxystrobin, (E)-2-(2-((3-(4-chlorophenyl)-1-methyl-1H-pyrazole-5-yloxy)methyl)phenyl)-3-methoxyacrylate, is a newly developed strobilurin fungicide with high antifungal efficiency. It has high potential to enter soil environments that might subsequently impact surface and groundwater. Therefore, ¹⁴C-labeled pyraoxystrobin was used as a tracer to study the adsorption/desorption and migration behavior of this compound under laboratory conditions in three typical agricultural soils. The adsorption isotherms conformed with the Freundlich equation. Single factor analysis showed that organic matter content was the most important factor influencing the adsorption. The highest adsorption level was measured in soil with low pH and high organic carbon content. Once adsorbed, only 2.54 to 6.41% of the adsorbed compound could be desorbed. In addition, the mobility results from thin-layer chromatography and column leaching studies showed that it might be safe to use pyraoxystrobin as a fungicide without causing groundwater pollution from both runoff and leaching, which might be attributed to its strong hydrophobicity. High organic matter content enhanced pyraoxystrobin adsorption and desorption because of the rule of similarity (lipid solubility). In the column leaching study, 95.02% (minimum value) of the applied ¹⁴C remained within the upper 4.0-cm layer after 60 days.     

Polyoxometalates for photocatalytic degradation of aqueous dyestuff solutions and quantitative structure–property relationship study on photolysis rate constants

Polyoxometalate, K₆TiW₁₁O₃₉Sn·7H₂O (TiW₁₁Sn), was synthesized and characterized. TiW₁₁Sn and K₆ZrW₁₁O₃₉Sn·12H₂O (ZrW₁₁Sn) were evaluated for their photocatalytic degradation of triarylmethane (brilliant green and acid blue 9), bisazo (C.I. reactive black 5), and monoazo dyestuffs (C.I. reactive red 24, C.I. reactive red 194, and C.I. reactive orange 5) with natural sunlight in homogeneous aqueous solutions. TiW₁₁Sn and ZrW₁₁Sn effectively and photocatalytically decolorized the dyestuffs. The TiW₁₁Sn- and ZrW₁₁Sn-mediated photocatalytic degradation of the dyestuffs involved a pseudo-first-order reaction and was modeled by Langmuir–Hinshelwood-type kinetics. The observed pseudo-first-order rate constants (K^/) of triarylmethane dyestuffs were generally bigger than that of the azo dyestuffs. Quantitative structure–property relationship models of the K^/ of the dyestuffs were developed using partial least-square regression. The cumulative variance of the dependent variable explained by the partial least-square components was > 0.753 for each optimal model. This value indicated that the model had good predictive ability and robustness. The K^/ values of the dyestuffs were related to the energy of the lowest unoccupied molecular orbital, and the most positive net atomic charges on a sulfur atom of dyestuffs. The linear correlation coefficients between the predicted and experimental values were all > 0.9950.     

UV_(185 nm)-H_2O_2组合工艺处理高浓度棘白菌素类抗生素发酵废水

采用UV_(185 nm)-H_2O_2组合工艺处理高浓度棘白菌素类抗生素发酵废水。结果表明:UV_(185 nm)-H_2O_2组合工艺较好地实现了高浓度棘白菌素类抗生素发酵废水的强化处理,其处理效果明显优于单独UV_(185 nm)光氧化工艺;在废水pH为2.50、光照时间为60 min、H_2O_2投加量为5 g/L、反应温度为室温的条件下,UV_(185 nm)-H_2O_2组合工艺对废水色度和COD的去除率分别高达96.4%和46.9%;该联合氧化过程需在酸性体系中进行;联合氧化过程中产生了大量蜂王浆提取物类黑褐色物质,处理出水中显色物质的种类明显减少,实现了废水的高效脱色。     

铁氧体工艺处理含重金属污水的沉渣特性研究

本文研究了铁氧体工艺处理含重金属废水的沉渣结构特性,对铁氧体沉渣的综合利用提供理论依据。      

BP及RBF人工神经元网络对臭氧生物活性炭水处理系统建模的比较

运用BP和RBF人工神经元网络建立臭氧生物活性炭系统模型,考察了两个网络对水处理系统建模的适应性。研究表明,BP和RBF人工神经元网络的臭氧生物活性炭系统模型准确地描述了系统影响因素的关系,可以求出系统中臭氧的经济投量;用BP人工神经元网络建立水处理系统模型,泛化能力好,但逼近速度较慢;运用RBF人工神经元网络建模,泛化能力较差,但逼近速度快。该项研究克服了运用传统方法建模的不足,为实现水处理系统的优化设计提供了可行的途径。     

Outdoor air pollution exposure and the risk of asthma and wheezing in the offspring

Environmental Science and Pollution Research - According to the “fetal origin of disease” hypothesis, air pollution exposure in pregnancy may play an important role in stimulating the...     

Blind identification of active landslides in urban areas: a new set of comprehensive criteria

Environmental Science and Pollution Research - More than 70% of catastrophic landslides were previously unknown and brought tremendous losses to human life and property in urban regions; therefore,...     

SBR法处理工业废水中pH值对污泥膨胀的影响

主要研究了在SBR法处理啤酒废水和化工废水中pH值对污泥膨胀的影响。试验研究的结果表明,进水的pH值在 5 0～ 6 0,啤酒废水长期保持进水pH值为 5 0时,活性污泥的污泥指数SVI<10 0mL g,当pH值 5 0～ 2 5时,会引起活性污泥活性抑制和污泥上浮 (尤其是化工废水 )。进水pH值在 9 0～ 12 0时,2种废水的污泥指数略有上升,但SVI<110mL g,活性污泥皆表现出活性的抑制和污泥的解体。若进水的pH值在 3 5～ 7 0,且控制反应周期内pH值不变,则 2种废水的活性污泥上浮加剧,化工废水污泥较啤酒废水的污泥上浮程度更严重。在整个试验过程中,镜检未见过量真菌和其它丝状菌,可见用SBR法处理工业废水时,过低或过高的pH值不一定引起污泥膨胀