ASBBR处理超高盐榨菜腌制废水

研究以超高盐榨菜腌制废水为对象,考察填料种类、负荷和温度对ASBBR启动及处理效能的影响。研究结果表明,在温度为30℃,盐度为7%（NaCl计）,负荷为1 kg COD/（m³·d）的条件下,采用聚氨酯泡沫填料的反应器经67 d可成功构建超高盐榨菜腌制废水厌氧生物处理系统,较未设置填料、投加半软性组合填料、球形组合填料和聚苯乙烯泡沫填料的反应器分别缩短了26、6、24和18 d,且运行至第79天,可使出水COD降至375 mg/L,COD去除率为92.86%;通过对负荷的阶段逐步提高,可提升反应器有机负荷至15 kg COD/（m³·d）,使进水COD为（27 000±2 000）mg/L的超高盐废水,出水COD均值降至2 200 mg/L ,平均去除率达到92.03%;温度对反应器处理效能影响显著,温度分别为30、25、20、15和10℃时,反应器COD去除率分别为92.63%、84.07%、67.13%、54.61%和44.19%。     

响应面优化CCl4增强超声降解左旋氧氟沙星模拟废水

利用响应面优化实验设计方法对CCl₄增强超声降解左旋氧氟沙星模拟废水的影响因素进行探讨和分析,考察了溶液初始pH值、超声功率、左旋氧氟沙星初始浓度的影响。应用Box-Behnken中心组合设计得到一个二次多项式数学模型,确定了US/CCl₄降解左旋氧氟沙星的优化条件:初始pH值6.8,超声功率189 W,左旋氧氟沙星初始浓度为5 mg/L时,左旋氧氟沙星的去除率达到最大(82.99%)。经实验验证, 实际值与模型预测值吻合性良好,偏差仅为0.036%。     

Evaluation of a classification method for biodegradable solid wastes using anaerobic degradation parameters

We studied the biochemical and anaerobic degradation characteristics of 29 types of materials to evaluate the effects of a physical composition classification method for degradable solid waste on the computation of anaerobic degradation parameters, including the methane yield potential (L₀), anaerobic decay rate (k), and carbon sequestration factor (CSF). Biochemical methane potential tests were conducted to determine the anaerobic degradation parameters of each material. The results indicated that the anaerobic degradation parameters of nut waste were quite different from those of other food waste and nut waste was classified separately. Paper was subdivided into two categories according to its lignin content: degradable paper with lignin content of <0.05 g g VS^?1, and refractory paper with lignin content >0.15 g g VS^?1. The L₀, k, and CSF parameters of leaves, a type of garden waste, were similar to those of grass. This classification method for degradable solid waste may provide a theoretical basis that facilitates the more accurate calculation of anaerobic degradation parameters.     

天然膨润土还原吸附Cr（Ⅵ）

以天然膨润土为吸附剂,还原吸附处理含Cr（Ⅵ）模拟废水。实验结果表明：以（NH₄）₂FeSO₄为还原剂吸附效果最佳;在还原剂加入量为理论值的0.8倍、膨润土加入量为6 g/L、吸附时间为30 min、吸附温度为30 ℃、初始Cr（Ⅵ）质量浓度为1 mg/L的条件下,Cr（Ⅵ）去除率可达99.6%,处理后模拟废水中总铬质量浓度低至0.003 mg/L。天然膨润土对Cr（Ⅵ）的还原吸附符合准二级动力学模型及Freundlich等温吸附模型。     

粉煤灰的改性及对刚果红的吸附

分别采用沸水浸泡、酸浸、碱浸和加热的方法对粉煤灰进行改性处理,利用FTIR仪和XRD仪对改性粉煤灰的成分和官能团进行了分析,并利用改性粉煤灰对模拟刚果红废水进行脱色。实验结果表明：碱改性粉煤灰中含有大量官能团,以及NaPl型沸石类物质,能够明显提高粉煤灰对刚果红的吸附性能;与活性炭相比,碱改性粉煤灰具有更高的性价比;在初始刚果红质量浓度为20mg/L、碱改性粉煤灰加入量为50g/L的条件下,废水的脱色率可达87.52%;碱改性粉煤灰对刚果红的吸附过程遵循二级反应动力学,较好地符合Langmuir等温式和Freundlich等温式。     

零价铁类Fenton试剂氧化降解废水中有机污染物的研究进展

综述了近年来国内外Fe0类Fenton试剂氧化反应降解废水中有机污染物的研究现状,介绍了Fe0-H2O2体系、紫外光-Fe0-H2O2体系和可见光-Fe0-H2O2体系处理有机污染物的机理、特点和效果,并对未来Fe0类Fenton试剂氧化反应体系处理有机污染物的发展前景进行了展望。     

改性SiO2气凝胶对废水中Fe3+的吸附性能

制备了改性SiO₂气凝胶,考察了经不同类型、不同配比的改性剂改性的SiO₂气凝胶对模拟含Fe³⁺废水的吸附处理效果。实验结果表明：改性SiO₂气凝胶的最佳制备条件为三甲基氯硅烷（TMCS）作改性剂,V（TMCS）#x02236;V（正己烷）=1#x02236;5;当改性SiO₂气凝胶加入量为75g/L、吸附时间为4h、Fe³⁺质量浓度为10mg/L时,模拟含Fe³⁺废水的Fe³⁺去除率为98.32%,剩余Fe³⁺质量浓度为0.168mg/L;采用改性SiO₂气凝胶动态吸附处理流量为420mL/h、Fe³⁺质量浓度为100mg/L的模拟含Fe³⁺废水,吸附后废水中剩余Fe³⁺质量浓度仅为0.196mg/L。     

Occurrence, distribution, and sources of six phenolic endocrine disrupting chemicals in the 22 river estuaries around Dianchi Lake in China

The objectives of this study are to track the occurrence, distribution, and sources of phenolic endocrine disrupting compounds (EDCs) in the 22 rivers around Dianchi Lake in China, to estimate the input and output amounts of phenolic EDCs in the water system, and to provide more comprehensive fundamental data for risk assessment and contamination control of phenolic EDCs in aquatic environment. Six phenolic EDCs were systematically evaluated in water and surface sediment in the estuaries of those rivers. The water and sediment samples were preconcentrated by solid-phase extraction system and microwave-assisted extraction system, respectively. Phenolic EDCs were analyzed by GC-MS (Thermo Fisher Scientific, USA) after derivatization. Phenolic EDCs were found ubiquitously in the aquatic environment. The total concentrations ranged from 248 to 4,650 ng/L in water, and 113 to 3,576 ng/g dry weight in surface sediment. The residue amount of phenolic EDCs in Dianchi Lake was 258 kg/a. Concentrations of the phenolic EDCs in the Lake decreased with increase in distance to the estuaries of those rivers which run through urban and industrial areas. The rivers seriously contaminated by phenolic EDCs were Xin River, Yunliang River, Chuanfang River, Cailian River, Jinjia River, Zhengda River, and Daqing River which run through the old area of Kunming City. Satisfying correlations were observed between the concentrations of the target compounds in water and in surface sediment. NP1EO, NP2EO, and BPA were identified as the three predominant phenolic EDCs. There were significant correlations between phenolic EDCs and many basic water quality parameters. Urban and industrial areas are the major contributors for phenolic EDCs, especially in Kunming City. Compositional profiles of phenolic EDCs in surface sediment were similar to those in river water. The concentrations of phenolic EDCs in the rivers located in the northwest part of the valley were very high, and posed a potential risk to aquatic organisms and even human. The concentrations of NP2EO, NP1EO, and BPA were at moderate levels of other areas. The basic water quality parameters (TOC, TN, DO, and pH) play important roles on the distribution, fate, and behavior of phenolic EDCs in the valley.     

Joint action and lethal levels of toluene, ethylbenzene, and xylene on midge (Chironomus plumosus) larvae

Aquatic ecosystems are vulnerable to the exposure with petrochemicals such as toluene, ethylbenzene, and xylene (o-, m-, and p-xylene) (TEX) and their adverse effects. Considering the widespread use, occurrence, and high toxicity of TEX, the aim of this work was to investigate the differential toxicity of TEX against midge (Chironomus plumosus) larvae and reveal the joint action of binary and ternary mixtures of TEX using the predictive concentration addition model. More importantly, this research can afford the basic toxicity data and scientific reference for the establishment of water quality criteria or benchmark, water pollution control, and aquatic risk assessment. Single and joint toxic effects of TEX on C. plumosus larvae were investigated using a semi-static bioassay, and the type of joint effects of TEX was ascertained. In the single toxicant experiments, the toxicity of the three pollutants could be sequenced as ethylbenzene > xylene > toluene. Specifically, LC_50s of T, E, and X after a 48-h exposure were 64.9, 37.8, and 42.0 mg/L, respectively. In the binary mixture experiments, the interaction between toluene and ethylbenzene, ethylbenzene and xylene, and toluene and xylene was largely in conformity with partial additive or additive effect as determined by isobologram representation and toxic unit models. In the ternary mixture experiments, the interaction was basically dependent on the use of additive index and mixture toxicity index methods. However, the antagonistic and synergistic actions were not significant. Thus, the tertiary mixture interaction could be regarded as additive action. The concentration addition model could successfully predict the joint action of TEX mixtures on C. plumosus larvae. Particularly, the additive action of TEX on C. plumosus larvae can be further recommended to evaluate water quality criteria of TEX.     

Cadmium tolerance in six poplar species

Selection of poplar species with greater Cd tolerance and exploiting the physiological mechanisms involved in Cd tolerance are crucial for application of these species to phyto-remediation. The aim of this study is to investigate variation in Cd tolerance among the six poplar species and its underlying physiological mechanisms. Cuttings of six Populus species were cultivated for 10 weeks before exposure to either 0 or 200 μM CdSO₄ for 20 days. Gas exchange in mature leaves was determined by a portable photosynthesis system. Cd concentrations in tissues were analyzed by a flame atomic absorbance spectrometry. Subsequently, Cd amount per plant, bio-concentration factor (BCF) and translocation factor (T _f) were calculated. Nonenzymatic compounds and activities of antioxidative enzymes in tissues were analyzed spectrophotometrically. Cd exposure caused decline in photosynthesis in four poplar species including Populus cathayana (zhonghua 1). Among the six species, P. cathayana (zhonghua 1) displayed the highest Cd concentrations in tissues, the largest Cd amount in aerial parts, the highest BCF in aerial parts and T _f under Cd exposure. Under Cd stress, increases in total soluble sugars in roots but decreases in starch in roots, wood, and leaves of P. cathayana (zhonghua 1) were found. Induced O ₂ ^?? and H₂O₂ production in roots and leaves, and increases in free proline, soluble phenolics, and activities of antioxidative enzymes were observed in P. cathayana (zhonghua 1). Based on results of this pot experiment, it is concluded that P. cathayana (zhonghua 1) is superior to other five species for Cd phyto-remediation, and its well-coordinated physiological changes under Cd exposure confer the great Cd tolerance of this species.