中孔硅胶负载过氧乙酸深度脱除柴油硫化物

采用滴定吸附法将过氧乙酸组装于中孔硅胶中,通过红外光谱分析和N2吸附法对组装体进行了表征,研究了常温常压下,该组装体氧化、吸附、脱除柴油硫化物的活性.结果表明,该组装体具有优良的脱硫性能.柴油中硫化物与过氧乙酸在硅胶孔中发生氧化反应,氧化产物被吸附在硅胶上,使柴油的含硫量从1697μg/g降到14μg/g,符合美国环境保护署标准.     

基于NPP/VIIRS夜光遥感数据的淮安市夜间PM2.5浓度估算研究

PM_2.5是大气的重要污染物,掌握其空间分布对于大气污染防控具有重要意义．目前,PM_2.5遥感监测主要围绕卫星反演的日间AOD数据开展,无法反映夜间大气污染的空间格局．以2019年9—12月NPP/VIIRS夜间灯光影像和空气质量站点PM_2.5观测数据对江苏省淮安市夜间PM_2.5浓度进行估算研究．基于辐射传输方程分析夜间灯光辐射与PM_2.5浓度之间的关系,在此基础上综合考虑灯光辐射直接衰减和散射补偿确定了计算夜间PM_2.5浓度的空间自变量,运用多元线性回归模型（MLR）、随机森林（RF）、Cubist、极端梯度提升树（XGBoost）、神经网络（NNet）、支持向量机（SVM）及最近邻法（KNN）算法构建夜间PM_2.5浓度遥感估算模型．结果表明,多元线性归回模型精度明显低于各个机器学习模型,所有模型中SVM模型精度最高,决定系数R²为0.77,平均绝对误差MAE为20.83μg·m^-3,均方...     

Continuous pollution monitoring using Photobacterium phosphoreum

Photobacterium phosphoreum is a marine bacterium which is used extensively as a bioluminescent indicator of pollutants, where the presence of toxicants diminishes light output. To evaluate the utility of cell immobilisation in continuous toxicity testing, the sensitivity of P. phosphoreum to five gelling agents was evaluated relative to the retention of bioluminescence in 3% NaCl-glycerol suspensions. Following storage at 4°C, the control cultures retained light output for up to 2 weeks before significant decline; alginate-glycerol suspensions were stable for up to 4 weeks and bioluminescence was detectable for up to 6 weeks. Cells stored in agar were no more stable than the control, whereas cells gelled in agarose and low-melting point agarose showed a significant decline in bioluminescence within 2 weeks of storage. Bioluminescence was totally retained in alginate-glycerol suspensions stored at −80°C for up to 12 weeks. P. phosphoreum was successfully immobilised in strontium alginate and showed a dose-related response to four of the five heavy metal ions, SDS and pentachlorophenol tested when responses were followed over a time-course. A flow-through system for Sr-alginate immobilised cells was developed and conditions for operation were optimised. When cells were exposed to a pulse of 4-nitrophenol or salicylate then the nutrient feed continued, bioluminescence declined in response (pulse of 4–6 min) to these pollutants then recovered to a new stable rate of decline which was faster than the pre-exposure rate. These results demonstrate the potential of using immobilised P. phosphoreum in a continuous flow-through system for real-time environmental monitoring of water quality.     

有机配位剂对重金属絮凝剂DTSPAM去除水中Cd2+性能的影响

以聚丙烯酰胺、甲醛、亚硫酸氢钠、二硫化碳、氢氧化钠为原料,制备出新型重金属絮凝剂二硫代羧基化磺甲基聚丙烯酰胺（DTSPAM）,考察了3种常见有机配位剂EDTA、焦磷酸钠、柠檬酸钠对DTSPAM除Cd²⁺性能的影响.实验结果表明,在单一含Cd²⁺水样中,pH值为3.0~6.0时DTSPAM对Cd²⁺均有较好的去除性能;在不同EDTA浓度、不同pH值下的混合水样中,EDTA对DTSPAM除Cd²⁺均呈抑制作用;水样pH值为5.0、6.0时,焦磷酸钠、柠檬酸钠对DTSPAM除Cd²⁺均表现出促进作用,而pH值为2.0~4.0时,焦磷酸钠、柠檬酸钠对DTSPAM除Cd²⁺均呈抑制作用.     

石家庄市臭氧污染的时空演变格局和潜在源区

基于石家庄市46个国控、省控环境自动监测站在2019年4—10月的大气O₃-8 h和O₃-1 h浓度数据,在对其进行反距离加权插值（IDW）的基础上,分析了石家庄市域5—9月O₃浓度月度和时域空间演变格局,并结合全球资料同化系统（GDAS）气象资料和大气污染物数据（PM_2.5、NO₂、PM₁₀、SO₂及CO）,进行了空间自相关和后向轨迹分析,探讨了石家庄市O₃污染的空间积聚特征和潜在源区分布.结果表明：①石家庄市域大气O₃稳定程度较低,5—9月变动呈以6月为峰值的单峰型态势,时域变化呈以15：00—16：00为峰值的单峰型趋势;②5—9月O₃浓度为207~260 μg·m^-3,呈中西部高、外围区域低的空间格局;O₃质量浓度在0：00—6：00呈西北至东南向降幅逐渐增加的趋势,在6：00—12：00和12：00—15：00的变动过程中O₃浓度呈东南至西北向梯度交替递增的态势,即前一过程O₃浓度增长强度高的区域在后一过程变弱,其中长安区、井陉县和新华区O₃污染较严重;③O₃污染浓度全域有较强的空间积聚特征（p<0.05）,局部积聚特征出现在市域中部、东部和东南部（p<0.05）,与O₃后向轨迹聚类结果的东-东南向污染轨迹占比一致;④O₃污染潜在源区主要集中于600 km的空间内,权重浓度贡献较大的区域处于200 km的范围,河北中南部、河南中北部、山东西部和山西中部是潜在污染源区的集中范围,对石家庄市O₃污染贡献较大.     

许昌市典型区域土壤磁化率与有机质含量的相关性研究

为探讨土壤磁化率对有机质含量的指示作用,对许昌市典型区域土壤磁化率与有机质含量的相关性进行研究,结果显示:研究区域土壤样品Xlf变化范围在15×10~(-8)~125×10~(-8)m~3/kg,平均值为64×10~(-8)m~3/kg,说明研究区土壤样品中磁性矿物含量较低。Xfd值在4.67%~26.67%之间,平均值为10.02%,反映了样品中超顺磁颗粒含量很高,说明研究区域土壤磁性矿物主要由自然成土作用形成,现代工业生产活动和人类的生活活动贡献较小。土壤有机质含量范围为3.74~31.93 g/kg,均值为17.09 g/kg。研究区域土壤磁化率与有机质含量呈不显著正相关性,反映了在长期人工施肥活动和城市化进程中人类活动导致土壤各理化因子之间发生学联系的弱化。     

光助Ce-Fe/Al2O3催化H2O2降解阳离子红GTL模拟废水

利用Ce-Fe/Al2O3为催化剂的非均相光Fenton体系降解阳离子红GTL模拟废水,考察了H2O2浓度、催化剂用量、初始pH值及不同工艺过程对降解效果的影响,通过紫外-可见漫反射光谱、红外光谱、XPS手段研究铁在反应中的价态变化.结果表明,在11 W低压汞灯照射下,非均相光Fenton体系能够有效地降解结构稳定的阳离子红GTL,在pH 6,反应温度20℃,时间90 min,Ce-Fe/Al2O3 2 g/L,H2O2浓度340 mg/L,含50 mg/L阳离子红GTL模拟废水TOC去除率为92.40%;光Fenton反应中Fe(Ⅲ)转化为Fe(Ⅱ).     

Critical Impact Assessment of Organic Agriculture

Based on its productionguideline, organic agriculture has set foritself the goals of minimizing all forms ofpollution and maintaining sustainability of thefarming system. By striving for these goals,organic farming meets the demands of anincreasing number of consumers who are criticalof conventional production methods. This papergives an overview of the present state of theart in the different issues. Possibilities ofand limitations in performing the self-aimedgoals under the basic standards of organicagriculture are discussed. Concerningenvironmental protection, in general, the riskof adverse environmental effects is lower withorganic than with conventional farming methods,though not necessarily so; with reference tosoil fertility and nutrient management, organicfarming is suited to improve soil fertility andnutrient management markedly on the farm level;regarding biodiversity, comparison studies showthat organic farming has more positive effectson biodiversity conservation; in relation toproduct quality, under the basic standards oforganic farming, there is no sufficientevidence for a system-related effect on productquality due to the production method.     

某学院楼间走廊缺陷诊治

对楼间外走廊梁的缺陷进行了分析，并提出了加固处理方案。