过氧化钙去除水中糖皮质激素的响应面分析

结合响应面方法Box-Behnken实验设计,对过氧化钙降解代表性糖皮质激素曲安奈德过程中的影响因素（过氧化钙投加量、溶液初始pH值、反应时间、糖皮质激素初始浓度）进行了探讨与分析,并对反应条件进行了优化.得出最优反应条件为：过氧化钙投加量4g/L;溶液初始pH值5.7,反应时间15.7min,初始TA浓度为0.06mmol/L.最优条件下模型预测的目标物降解率（88.6%）和实验得出的降解率（82.8%）数值接近,说明此响应面模型能够较准确预测过氧化钙对糖皮质激素的去除效果,并用电子顺磁共振仪对过氧化钙降解有机物过程中的作用自由基进行了检测.研究结果对过氧化钙技术去除有机污染物的发展有一定的参考价值.     

响应面方法优化光催化降解抗生素类污染物过程研究

近年来抗生素类污染物对环境的影响及其生态毒性日益引起广大研究者的关注。对TiO2光催化降解典型抗生素类污染物磺胺二甲嘧啶（SMT）进行了研究。采用中心组合设计方法（CCD）进行试验设计,使用响应面方法（RSM）对光催化过程中的影响因素（TiO2浓度、初始磺胺二甲嘧啶浓度、双氧水浓度）进行了探讨和分析,并对反应过程进行了优化。优化结果表明,最佳反应条件为：TiO2浓度1.74 g/L、初始磺胺二甲嘧啶浓度20.0 mg/L、双氧水浓度106.28 mg/L,在优化条件下的磺胺二甲嘧啶光催化实际去除率为83.6%。响应面方法能够优化光催化条件,预测光催化结果,有利于优化光反应器的设计,对于工程化光催化水处理技术的发展具有一定的参考价值。     

Application of response surface methodology for the optimization of biodiesel production from yellow mustard (Sinapis alba L.) seed oil

In the present study, response surface methodology (RSM) involving central composite design (CCD) was applied to optimize the reaction parameters of biodiesel production from yellow mustard (Sinapis alba L.) seed oil during the single-step transesterification process. A total of 30 experiments were designed and performed to determine under the effects of variables on the biodiesel yield such as methanol to oil molar ratio (2:1–10:1), catalyst concentration (0.2–1.0 wt.% NaOH), reaction temperature (50–70°C), and reaction time (30–90 min). The second order polynomial model was used to predict the biodiesel yield and coefficient of determination (R²) was found to be at 0.9818. The optimum biodiesel yield was calculated as 96.695% from the model with the following reaction conditions: 7.41:1 of methanol to oil molar ratio, 0.63 wt. % NaOH of catalyst concentration, 61.84°C of reaction temperature, and 62.12 min of reaction time. It is seen that the regression model results were in agreement with the experimental data. The results showed that RSM is a suitable statistical technique for optimizing the reaction parameters in the transesterification process in order to maximize the biodiesel yield.     

2014年北京市PM2.5质量浓度分析及比对研究

本研究选择污染严重的北京作为研究区域,自2013年12月起至2014年12月,通过设在北五环中国环境科学研究院(CRAES)内的定点监测,获得375天有效平行样品(T和Q)。统计结果表明,2014年北京市PM_(2.5)质量浓度从优良水平的6.9μg/m~3到极重污染的422.1μg/m~3,年均浓度值在100μg/m~3左右。T组和Q组线性相关,但T/Q并非定值,冬季最高,R~2=0.974,对应T/Q=1.014,可能由于冬季污染程度较重,滤膜性能差异可忽略。除春季外,其它三季的PM_(2.5)都是T组>Q组,与石英膜的纤维结构不够致密有关。以T组质量浓度数据为准,与国控监测点奥体中心点公报的日均PM_(2.5)进行比对,结果显示二者基本同步,在春冬季呈现较高的污染浓度,在夏季最低。在严重污染时(PM_(2.5)>250.0μg/m~3),在线监测可能低估PM_(2.5)而T组能更客观地记录实际污染状况。统计2014年全年污染等级分布,4~8月份基本未出现重度污染,而在冬季采暖期10~12月份,优良天数不足50%。综合分析风速、相对湿度对PM_(2.5)质量浓度的影响,证实冬季取暖燃煤和无风、高湿、逆温的静稳天气是霾频发的主要原因。     

厌氧发酵产沼气过程中脱氢酶活性检测工艺及其优化

为了优化脱氢酶活性这一指标在厌氧发酵产沼气系统中的检测方法,分别以小麦秸秆、羊粪及其混合原料(质量比1∶1)为发酵底物,通过Box-Behnken试验及响应面分析法确定并优化了沼气发酵系统中碘硝基四唑紫法脱氢酶活性的检测工艺,并对脱氢酶活性与甲烷产量进行了相关性分析.结果表明,3种底物均以乙醇作为萃取剂,以甲醛作为终止剂时显色效果最好.分别以秸秆、粪便及其混合为发酵底物时,脱氢酶检测在pH值分别为6.5、7.2、7.7,反应温度均在37℃下,碘硝基四唑紫质量分数均为0.15%,反应时间均为50 min时比色效果最好.相关性分析显示,厌氧发酵产沼气系统中脱氢酶活性与甲烷产量相关性显著.     

中国省级环境决策支持系统的系统分析

中国省级环境决策支持系统(DSS)是基于GIS和各种模型的空间决策支持系统?该文介绍了DSS系统的系统分析方法和内容,包括软件需求说明?数据需求说明和总体设计      

Providing the Spark: Impact of financial incentives on battery electric vehicle adoption

To overcome adoption barriers and promote battery electric vehicles (BEVs) as an energy efficient consumer transportation option, a number of states offer subsidies to consumers for BEVs. We use a national data set of vehicle registrations and state-level financial incentives to assess the impact of vehicle purchase subsidies on adoption using both difference-in-differences and synthetic controls methods. We find that incentives offered as direct purchase rebates generate increased levels of new BEV registrations at a rate of approximately 8 percent per thousand dollars of incentive offered. Between 2011 and 2015, vehicle rebate incentives are associated with an increase in overall BEV registrations of approximately 11 percent. Our findings indicate incentives offered as state income tax credits do not have a statistically significant effect on BEV adoptions, though we caution this may be a result of limited temporal variation in BEV incentives across our sample. Responses to rebate incentives do not differ significantly by the make of the vehicle purchased (i.e., Tesla and non-Tesla vehicles). We combine our results with recent assessments of marginal environmental costs of electric vehicle charging and measure net welfare effects of BEV subsidy programs. Our analysis indicates these programs are not welfare-improving if only considering benefits associated with avoided emissions. Additional benefits associated with long-term market growth, production cost savings, network externalities, or accelerated innovation could substantially impact the net welfare outcomes.     

睾丸酮丛毛单胞菌对喹啉类化合物的降解

对喹啉、异喹啉、2-甲基喹啉、3-甲基喹啉、4-甲基喹啉和6-甲基喹啉在睾丸酮丝毛单胞菌(Comamonas testosteroni Q10)作用下的降解及底物之间的相互作用进行研究．结果表明,喹啉和3-甲基喹啉不仅能有效地被降解,而且细菌也有明显的生长,而其它化合物虽有部分降解但没有观察到细胞生长．底物初始浓度的增加对菌Q10有一定抑制作用．喹啉的存在对其它化合物的降解具有不同的促进效应,其中尤以6-甲基喹啉和4-甲基喹啉最为明显．能在较短时间内得到完全去除,而在各二元体系中喹啉的降解受到这些化合物的抑制作用．     

国产Q345钢在不同热-力路径下的材料性能对比和材料模型应用

为评估和分析钢结构的耐火性能,以我国10个钢厂生产的Q345钢的424次恒载升温试验和152次恒温加载试验结果为依据,对钢材强度和应变以及不同的热-力作用路径下的力学性能进行对比研究。结果表明,在所有热-力作用路径下,恒载升温试验的强度最小,应变最大,临界温度最低;恒温加载试验的强度最大,应变最小,临界温度最高。随温度升高,热-力作用路径对钢材的力学性能影响增大:在450℃以下影响较小,在500℃以上时影响显著。如果规范采用恒温加载试验强度,是不可靠的。恒载升温条件下的ε-T-k材料模型和恒温加载条件下的ε-k-T材料模型均不能单独用于超静定钢结构的性能分析。超静定钢结构的性能分析可把火灾过程离散为若干时段,把每个时段分解为两个独立的应变-温度过程和应变-应力过程,分别应用恒载升温条件下的ε-T-k和恒温加载条件下的ε-k-T材料模型进行分析,然后迭加计算以得出最后的应变。     

Optimization of the O3/H2O2 process with response surface methodology for pretreatment of mother liquor of gas field wastewater

• Real ML-GFW with high salinity and high organics was degraded by O₃/H₂O₂ process. • Successful optimization of operation conditions was attained using RSM based on CCD. • Single-factor experiments in advance ensured optimal experimental conditions. • The satisfactory removal efficiency of TOC was achieved in spite of high salinity. • The initial pH plays the most significant role in the degradation of ML-GFW. The present study reports the use of the O₃/H₂O₂ process in the pretreatment of the mother liquor of gas field wastewater (ML-GFW), obtained from the multi-effect distillation treatment of the gas field wastewater. The range of optimal operation conditions was obtained by single-factor experiments. Response surface methodology (RSM) based on the central composite design (CCD) was used for the optimization procedure. A regression model with Total organic carbon (TOC) removal efficiency as the response value was established (R² = 0.9865). The three key factors were arranged according to their significance as: pH>H₂O₂ dosage>ozone flow rate. The model predicted that the best operation conditions could be obtained at a pH of 10.9, an ozone flow rate of 0.8 L/min, and H₂O₂ dosage of 6.2 mL. The dosing ratio of ozone was calculated to be 9.84 mg O₃/mg TOC. The maximum removal efficiency predicted was 75.9%, while the measured value was 72.3%. The relative deviation was found to be in an acceptable range. The ozone utilization and free radical quenching experiments showed that the addition of H₂O₂ promoted the decomposition of ozone to produce hydroxyl radicals (·OH). This also improved the ozone utilization efficiency. Gas chromatography-mass spectrometry (GC-MS) analysis showed that most of the organic matters in ML-GFW were degraded, while some residuals needed further treatment. This study provided the data and the necessary technical supports for further research on the treatment of ML-GFW.