粉末活性炭对三烯丙基异氰脲酸酯的吸附性能简

用静态吸附法考察粉末活性炭对水中三烯丙基异氰脲酸酯（CAIC）的吸附行为，采用单因素分析法对活性炭吸附化工废水中TAIC的工艺条件进行研究。实验结果表明，在TAIC模拟废水中，其TAIC初始浓度为800 mg/L，pH为7，在温度为298 K、转速为150 r/min的条件下，当活性炭的投加量达到4.4 g/L，吸附反应时间为50 min时，TAIC的去除效率最高为96.17%；对于实际废水，其TAIC初始浓度为1 500 mg/L，溶液pH为3，在温度为298 K、转速为150 r/min的条件下，当活性炭投加量达到10 g/L，吸附反应时间为2 h时，TAIC的去除效率最高为46.8%。这也是由于实际废水组分复杂，其他有机物存在一定的吸附竞争机制。     

臭氧氧化6-APA制药厂生化处理出水的特性及动力学简

通过现场实验研究了6-APA制药厂生化处理出水的臭氧氧化特性及其动力学规律。结果表明，当臭氧浓度为27.5 mg/L，气水接触时间为80 min时，COD、UV₂₅₄、NH₃-N和色度的去除率分别可达72.95%、73.28%、72%和96.25%，达到《发酵类制药废水工业水污染物排放标准》（GB 21903-2008）排放控制要求。拟合结果表明，在0~10、10~30和30~90 min时段内，臭氧氧化过程遵循拟一级反应，但反应速率逐渐降低。当气水接触时间为30 min时，废水可生化性可由0.1提高至0.35，采用臭氧/生物处理的联合工艺也有望使出水达到相同的排放控制要求。     

有机改性成都粘土预处理垃圾渗滤液

以成都粘土为原料,十六烷基三甲基溴化铵(HDTMA)为改性剂制备有机改性土,并将其应用于垃圾渗滤液的预处理。采用单因素静态吸附实验,以粘土对垃圾渗滤液COD和氨氮的去除率作为考查指标,初步探究有机改性土预处理垃圾渗滤液的适宜条件;并对有机改性粘土及原土进行性能表征,初步分析其吸附机理。研究结果表明,有机土的处理效果明显优于原土,处理效果上比原土提高了1.6~2.3倍;有机土预处理垃圾渗滤液适宜条件为:投加量120 g/L、搅拌速度200 r/min、搅拌时间50 min、pH=7、静置时间为6 h。     

介质阻挡放电协同Ag/Al_2O_3对NO_x脱除的影响

为有效去除发电厂烟气中产生的NOx,利用介质阻挡放电(DBD)产生低温等离子体并结合催化剂Ag/Al2O3进行烟气脱硝实验,研究了在加入乙烯的条件下,平均负载量、催化温度和装置的布置方式对NOx脱除的影响。结果表明,随着负载的增多,NO脱除率呈现先增大后减小的趋势,5种负载量中最佳为1.76%;随着催化温度的升高,NO脱除率同样呈现先增大后减小的趋势,最佳的催化温度为150℃左右;3种不同布置方式对NO和NOx脱除有明显差别,单独催化剂在NO和NOx的脱除率都比较低;单独介质阻挡放电NO脱除率很高,但是NOx很却很低;而两者结合在NO和NOx都达到了很好的效果。     

悬挂链生物接触氧化工艺处理河道污水

采用悬挂链曝气式接触氧化工艺在3个时段内处理城市河道污水,通过采用磷脂法、TTC-脱氢酶活性法和MPN法研究载体表面生物膜特性,来验证装置的水质净化效果。结果表明,进水水质变化幅度较大的时段1内,水质对缺氧区和好氧区内生物膜量及活性有很大冲击,对污染物的去除效果影响不大,COD、NH+4-N、TN和TP的平均去除率分别达到75.9%、80.8%、64.6%和78.3%;进水水质稳定的时段2内,缺氧区和好氧区内生物膜量和活性要高于其他时段,COD、NH+4-N、TN和TP的平均去除率分别达到77.0%、80.6%、69.4%和55.3%;低温运行的时段3内,缺氧区和好氧区内生物膜量和活性都低于其他时段,水质净化效果明显下降,COD、NH+4-N、TN和TP的平均去除率分别为71.1%、68.5%、48.9%和46.6%。     

Contamination assessment of arsenic and heavy metals in a typical abandoned estuary wetland—a case study of the Yellow River Delta Natural Reserve

Coastal and estuarine areas are often polluted by heavy metals that result from industrial production and agricultural activities. In this study, we investigated the concentration trait and vertical pattern of trace elements, such as As, Cd, Ni, Zn, Pb, Cu, and Cr, and the relationship between those trace elements and the soil properties in coastal wetlands using 28 profiles that were surveyed across the Diaokouhe Nature Reserve (DKHNR). The goal of this study is to investigate profile distribution characteristics of heavy metals in different wetland types and their variations with the soil depth to assess heavy metal pollution using pollution indices and to identify the pollution sources using multivariate analysis and sediment quality guidelines. Principal component analysis, cluster analysis, and pollution level indices were applied to evaluate the contamination conditions due to wetland degradation. The findings indicated that the concentration of trace elements decreased with the soil depth, while Cd increases with soil depth. The As concentrations in reed swamps and Suaeda heteroptera surface layers were slightly higher than those in other land use types. All six heavy metals, i.e., Ni, Cu, As, Zn, Cr, and Pb, were strongly associated with PC1 (positive loading) and could reflect the contribution of natural geological sources of metals into the coastal sediments. PC2 is highly associated with Cd and could represent anthropogenic sources of metal pollution. Most of the heavy metals exhibited significant positive correlations with total concentrations; however, no significant correlations were observed between them and the soil salt and soil organic carbon. Soil organic carbon exhibited a positive linear relationship with Cu, Pb, and Zn in the first soil layer (0–20 cm); As, Cr, Cu, Ni, Pb, and Zn in the second layer (20–40 cm); and As, Cr, Cu, Ni, Pb, and Zn in the third layer (40–60 cm). Soil organic carbon exhibited only a negative correlation with Cd (P?I _geo values), which averaged less than 0 in the three soil layers, this finding indicates that the soils have remained unpolluted by these heavy metals. The mean concentrations of these trace elements were lower than Class I criteria. The degradation wetland restoration suggestions have also been provided in such a way as to restore the reserved flow path of the Yellow River. The results that are associated with trace element contamination would be helpful in providing scientific directions to restore wetlands across the world.     

Multivariate characterization of elements accumulated in Wolfiporia extensa mushroom from Yunnan province of China

ABSTRACT

Dried sclerotia of Wolfiporia extensa have been used as medicine in Asia from Eastern Han Dynasty, and also used as traditional snack called “fulingjiabing” in Beijing, China. In this paper, 18 macro and trace elements (Ag, As, Ba, Cd, Co, Cr, Cs, Cu, Fe, Li, Mn, Ni, Pb, Rb, Se, Sr, V, and Zn) in both flesh and peel of Wolfiporia extensa from seven sites of Yunnan province in China were determined by inductively coupled plasma mass spectrometer. The average recovery rates of certified reference materials for GBW10015 (spinach leaves) ranged from 90.5 to 113%, for GBW10028 (citrus leaves) from 92.8 to 106%, and for GBW07603 (bush branch and leaves) from 83.3 to 114.6%. Generally speaking, the concentration of all elements determined was at common level. The results of this survey indicate that mineral compositions in peel were higher than in flesh. In peel, the contents of investigated trace metals in mushroom samples were found to be in the range of 1,660–13,400 µg·g^?1 dry matter (dm) for Fe and 29.6–710 µg·g^?1 dm for Mn. The mean contents of Cr, Cu, Rb, V, and Zn in peel were between 10 and 20 µg·g^?1 dm, followed by As, Co, Li, Ni, Pb, Se, and Sr with mean contents between 1 and 10 µg·g^?1 dm, while Ag, Cd, and Cs had mean contents of <1 µg·g^?1 dm. In flesh, the concentration of Fe was in the range of 54–900 µg·g^?1 dm, and it was 1.5–49 µg·g^?1 dm for Mn, followed by Ba, Cu, Rb, and Zn in the range of 1 to 10 µg·g^?1 dm, while for Ag, As, Cd, Co, Cr, Cs, Li, Ni, Pb, Se, Sr, and V it was <1 µg·g^?1 dm. The concentration of toxic elements, such as As, Cd, and Pb, in both flesh and peel was below the permissible limits of World Health Organization. However, As and Pb contents in peel were higher than the limits permitted in the Chinese Pharmacopoeia. The results of principal component analysis showed that the flesh of Wolfiporia extensa from all the seven sites of the Yunnan province tend to cluster together, most probably because the origin of mineral elements in both flesh and peel is wood substrate (old and dead pine trees).     

抗生素与LED209对大肠杆菌的联合毒性机制

抗生素是一把双刃剑,在提高医疗水平的同时会促进抗性基因的发展。群体感应抑制剂(quorum sensing inhibitors,QSIs)可有效地避免这一缺陷,有望成为抗生素的替代品而与抗生素有环境共存的可能,但目前尚缺乏它们的联合毒性机制及其相关的环境风险评价研究。本文以大肠杆菌为受试生物,测定了群体感应抑制剂N-苯基-4-(3-苯基硫代脲基)苯磺酰胺(LED209)与5种抗生素的单一和二元联合毒性。结果表明,LED209与5种抗生素的联合毒性作用均表现为拮抗,推测是LED209通过影响鞭毛合成,减弱了抗生素对大肠杆菌的生物有效性;同时通过拆分分子式,发现了拮抗作用可能源于LED209分子式中的含苯基和硫代脲基的L1分子,因此建议未来在LED209药物优化时,应尽可能的保留L1部分的基团,从而保证混合体系的最小环境风险。本研究不仅为联合用药提供依据,而且从环境风险评价角度为抗生素替代品LED209的结构优化提供理论指导。     

Evolutionary game analysis of WEEE recycling tripartite stakeholders under variable subsidies and processing fees

Environmental Science and Pollution Research - The standardization of formal recycling and rational subsidy plays an important role in waste electrical and electronic equipment recycling. In order...     

肠道微生物对土壤中铜、锌、锰生物可给性的影响

为了更全面、准确地评价土壤中金属元素对人体的健康风险,研究土壤中金属元素在结肠阶段的生物可给性具有重要意义。通过采集我国一些地区的6种土壤,利用in vitro方法(PBET和SHIME联用)研究土壤中Cu、Zn、Mn在胃、小肠、结肠阶段的生物可给性。研究显示,土壤中Cu、Zn、Mn在胃阶段的生物可给性分别为23.8%~63.0%、21.2%~64.4%、11.7%~35.6%;从胃阶段到小肠阶段,土壤中Cu的生物可给性提高了0.4%~14.4%,而土壤中Zn在小肠阶段的生物可给性降低了6.7%~38.7%。结肠阶段,土壤中Cu、Zn、Mn的生物可给性分别为2.4%~12.9%、5.7%~18.7%、6.2%~18.9%,与小肠阶段相比,分别降低了21.7%~56.9%、0.4%~36.8%、4.5%~19.1%。结果表明,在肠道微生物存在的情况下,土壤中Cu、Zn、Mn在结肠阶段有较低的人体健康风险。