Phenol degradation using combined effects of hydrodynamic cavitation and oxidant: Doehlert matrix

Hydrodynamic cavitation (HC)-based treatments have been proposed for the degradation of phenol as a toxic pollutant. The present work aimed to optimize the degradation of phenol using HC by means of Doehlert experimental design, which has not been previously addressed. Initially, operational parameters of hydraulic characteristics of the pump, inlet pressure, solution pH, and initial concentration were optimized; later, the effects of pH solution and H₂O₂ loading or initial pollutant concentration on phenol degradation were explored using the Doehlert experimental design. It was observed that phenol degradation is strongly dependent on the pH of the solution. Also, the acidic condition favors the formation of hydroxyl radicals and thus, the degradation of phenol. Based on the Doehlert matrix, the 94.1% phenol degradation and 68.60% total organic carbon (TOC) were obtained in 180 min at 304.5 mg/L of hydrogen peroxide at an initial concentration of 20 mg/L, 2.0 pH, and 90 psi inlet pressure, providing a cavitational yield of 6.33 × 10⁻⁶ mg/J and minimum treatment cost of US$/L 0.13. Overall, it has been observed that HC can be a promising route for the removal of pollutants (phenol) effectively using hydrogen peroxide as an additive.     

企业安全生产管理责任矩阵应用

在全面分析安全生产责任矩阵的基础上,进一步提出针对落实企业安全生产主体责任的企业安全生产管理责任矩阵新方法。围绕企业安全生产责任管理,彻底分解企业安全生产管理任务,明确划分企业安全生产管理个人和部门的角色,并按照每一项安全生产任务有且只有一个角色、每一个角色至少参与一项安全管理任务的准则,建立一般类型的中小企业安全生产管理责任矩阵,将企业安全生产责任管理有序清晰地体现在一个责任矩阵中,使企业安全生产主体责任管理权有所属、事有所任、责有所归。这对指导和落实企业安全生产主体责任具有一定的参考作用和借鉴意义。     

模糊聚类分析法在分析数据评估上的应用

模糊数学是应用数学重要分支之一,其应用范围日益扩大.本文运用模糊聚类法对用六种分析设备所测定的某污染水源Cr、Fe和Al数据进行了分类对比,从而为分析设备筛选提供参考.结果表明:模糊聚类及相关方法是一种有效的评估手段.可简化计算、提高评估准确度.     

Characterization of Volatile Organic Compounds (VOCs) and Their Sources in the Air of Izmir, Turkey

Air samples were collected in Izmir, Turkey at two (suburban and urban) sites during three sampling programs in 2002 and 2004 to determine the ambient concentrations of several monoaromatic, chlorinated and oxygenated volatile organic compounds (VOCs). Samples were analyzed for 60 VOCs using gas chromatography/mass spectrometry and 28 compounds were detected in most samples. On the average, urban air VOC concentrations were about four times higher than those measured at the suburban site. Toluene (40.6%) was the most abundant compound in suburban site and was followed by benzene (7.4%), o,m-xylene (6.5%), and 1,2-dichloroethane (5.1%). In urban site, toluene (30.5%), p-xylene (14.9%), o,m-xylene (11.4%), and ethyl benzene (7.2%) were the dominating compounds in summer. In winter, toluene (31.1%), benzene (23.9%), 1,2-dichloroethane (9.5%), and o,m-xylene (8.2%) were the most abundant compounds. Receptor modeling (positive matrix factorization) has been performed to estimate the contribution of specific source types to ambient concentrations. Six source factors (gasoline vehicle exhaust, diesel vehicle exhaust+residential heating, paint production/application, degreasing, dry cleaning, and an undefined source) were extracted from the samples collected in the urban site. Three source factors (gasoline vehicle exhaust, diesel vehicle exhaust, and paint production/application) were identified for the suburban site.     

Effects of landscape transformation on bird colonization and extinction patterns in a large‐scale,long‐term natural experiment

Conversion of agricultural land to forest plantations is a major driver of global change. Studies on the impact of forest plantations on biodiversity in plantations and in the surrounding native vegetation have been inconclusive. Consequently, it is not known how to best manage the extensive areas of the planet currently covered by plantations. We used a novel, long‐term (16 years) and large‐scale (30,000 ha) landscape transformation natural experiment (the Nanangroe experiment, Australia) to test the effects of land conversion on population dynamics of 64 bird species associated with woodland and forest. A unique aspect of our study is that we focused on the effects of plantations on birds in habitat patches within plantations. Our study design included 56 treatment sites (Eucalyptus patches where the surrounding matrix was converted from grazed land to pine plantations), 55 control sites (Eucalyptus patches surrounded by grazed land), and 20 matrix sites (sites within the pine plantations and grazed land). Bird populations were studied through point counts, and colonization and extinction patterns were inferred through multiple season occupancy models. Large‐scale pine plantation establishment affected the colonization or extinction patterns of 89% of studied species and thus led to a comprehensive turnover in bird communities inhabiting Eucalyptus patches embedded within the maturing plantations. Smaller bodied species appeared to respond positively to plantations (i.e., colonization increased and extirpation of these species decreased in patches surrounded by plantations) because they were able to use the newly created surrounding matrix. We found that the effects of forest plantations affected the majority of the bird community, and we believe these effects could lead to the artificial selection of one group of species at the expense of another.     

Anaerobic co-digestion of food waste and landfill leachate in single-phase batch reactors

In order to investigate the effect of raw leachate on anaerobic digestion of food waste, co-digestions of food waste with raw leachate were carried out. A series of single-phase batch mesophilic (35 ± 1 °C) anaerobic digestions were performed at a food waste concentration of 41.8 g VS/L. The results showed that inhibition of biogas production by volatile fatty acids (VFA) occurred without raw leachate addition. A certain amount of raw leachate in the reactors effectively relieved acidic inhibition caused by VFA accumulation, and the system maintained stable with methane yield of 369–466 mL/g VS. Total ammonia nitrogen introduced into the digestion systems with initial 2000–3000 mgNH₄–N/L not only replenished nitrogen for bacterial growth, but also formed a buffer system with VFA to maintain a delicate biochemical balance between the acidogenic and methanogenic microorganisms. UV spectroscopy and fluorescence excitation–emission matrix spectroscopy data showed that food waste was completely degraded.We concluded that using raw leachate for supplement water addition and pH modifier on anaerobic digestion of food waste was effective. An appropriate fraction of leachate could stimulate methanogenic activity and enhance biogas production.     

基于生态安全约束的再生利用项目规划设计方案决策

为确保我国旧工业建筑(区)再生利用项目方案设计阶段免受生态破坏与环境污染等因素的影响,提出了"生态安全约束"这一概念。考虑到决策者面对收益和损失的不同态度引入了前景理论,建立了生态安全约束下基于前景理论再生利用项目规划设计方案决策模型。首先,构建了包含总体规划、建筑设计、传承保护等因素的决策指标体系,并采用AHP与熵权相结合的方法计算权重,使得权重计算结果不仅体现了决策者的主管意愿,也反映了再生利用项目的客观规律;其次,以决策者预期值作为参考点给出期望矢量,将不同属性的决策数据信息规范化处理得初始决策矩阵,再根据指标间相对参考点的差值建立前景决策矩阵,通过计算各方案的综合前景值以确定最优方案。最后,通过北京首钢、云南871、陕西老钢厂、太原锅炉厂等5个实例的再生利用项目规划设计方案决策过程加以验证。结果表明,模型计算过程清晰,结果可信度高,验证了模型的合理性和科学性,可为规划设计阶段有效控制生态环境破坏与厂区环境污染提供新的思路。     

滇中城市群发展的SWOT矩阵分析

新时期的经济竞争,转向了以中心城市为核心的城市群综合实力的竞争.在运用SWOT分析法定性分析的基础上,引用QSPM矩阵,对影响滇中城市群一体化进程的内外条件做量化评价.结果表明,滇中城市群尚处于城市群发育的初期阶段.在其影响因素中,优势与劣势都很明显,机遇胜过威胁.从总体作用效能来看,滇中城市群发育的内部动力需要得到进一步强化,外部动力是难得的发展机遇,正在或将会成为滇中城市群成长的助推剂.     

管制员人为差错影响因素及指标权重分析

根据SHELL模型,将影响管制员人为差错的因素从内部因素和外部因素进行分析,内部因素包括管制员生理因素、心理因素、管制员业务技能三个部分;外部因素包括管制员与管制员班组之间、管制员与管制设备之间、管制员与管制程序等软件之间。通过分析和专家咨询,建立了影响管制员人为差错的影响因素指标体系,在模糊层次分析法的基础之上引入0.1-0.9标度法的三角模糊数,通过对各影响因素进行对比分析,得出了影响管制员人为差错的三级指标的重要度排序,排在前八位的因素依次为酒精及药物影响、形势意识、班组人员性格搭配、班组人员能力搭配、疲劳、人机界面、外界压力、情绪状态。为管制员培训和管理层进行安全检查提供了基础理论依据。     

基于PMF的武汉市大气细颗粒物消光来源解析

利用武汉2020年7月(夏季)和10月(秋季)的在线观测数据,同时将颗粒物的光学参数和化学组分数据输入正定矩阵因子分解(PMF)源解析模型,对PM_2.5消光系数的源贡献进行定量解析.研究发现,对吸收系数贡献较大的源为机动车(66.3%)和工业源(14.2%),对散射系数贡献较大的源为以硝酸盐为主的二次无机盐Ⅰ(38.4%)和机动车(27.0%),光散射的源贡献率呈现出明显的季节变化,二次无机盐Ⅰ在夏季(14.6%)的贡献较秋季(47.4%)显著降低.消光系数源贡献方面,夏季机动车(37.2%)和以硫酸盐为主的二次无机盐Ⅱ(21.2%)对消光的贡献较大,而秋季主要的消光源为二次无机盐Ⅰ(44.7%)和机动车(26.7%).最后,还获取了几个重要源的波长吸收指数(AAE)值:机动车(0.96)、工业源(1.04)、扬尘(1.39)、生物质燃烧(2.24).