湛江市夏季大气挥发性有机物污染特征及来源解析

臭氧污染在全国呈加剧态势,在非重点区域和非重点城市其相关研究薄弱.在湛江市选取3个采样点,使用苏玛罐和2,4-二硝基苯肼(DNPH)吸附管采样,并利用气相色谱-质谱/氢离子火焰检测器(GC-MS/FID)和高效液相色谱(HPLC)分析了101种挥发性有机物(VOCs),分析其主要组分和变化特点,计算VOCs的臭氧生成潜势(OFP),并利用正定矩阵因子分解模型(PMF)进行源解析.结果表明,采样期间湛江市φ(TVOCs)平均值为1.28×10^-7,其中OVOCs占比最高,为52%,其次为烷烃(36%)、烯烃(7%)、卤代烃(2.42%)、芳香烃(1.61%)和炔烃(0.78%).VOCs组分日变化特征表明,芳香烃和烷烃早晚体积分数高而中午低,受光化学反应影响大;而OVOCs在光化学反应强烈的中午体积分数低而傍晚高,表明傍晚采样点附近OVOCs直接排放增多或受到上风向污染源输送的影响.湛江市TVOCs的OFP为3.28×10^-7,优势物种为甲醛、1-丁烯、正丁烷、2-丁酮和乙醛.表征气团老化程度的X/E值和气团后向轨迹分析表明,采样期间,当受来自...     

Solubility and sorption of petroleum hydrocarbons in water and cosolvent systems

The solubility and sorption of oil by uncontaminated clay loam and silt loam soils were studied from water and cosolvent/water solutions using batch techniques. The data obtained from the dissolution and sorption experiments were used to evaluate the applicability of the cosolvent theory to oil as a complex mixture. Aqueous solubility and soil-water distribution coeffcients (Kd,w, L/kg) were estimated by extrapolating from cosolvent data, with a log-linear cosolvency model, to the volume fraction of cosolve...     

Performance of landfill leachate treatment system with disc-tube reverse osmosis units

Reverse osmosis system with the disc-tube module (DT-RO) was applied to treat landfill leachate on full scale at the Changshengqiao Sanitary Landfill, Chongqing City, China. In the first six-mouth operation phase, the treatment performance of DT-RO system had been excellent and stable. The removal rate of chemical oxygen demand (COD), total organic carbon (TOC), electrical conductivity (EC), and ammonia nitrogen (NH₃-N) reached 99.2–99.7%, 99.2%, 99.6%, and over 98%, respectively. The rejection of Ca²⁺, Ba²⁺, and Mg²⁺ was over 99.9%, respectively. Suspended solid (SS) was not detected in product water. Effective methods had been adopted to control membrane fouling, of which chemical cleaning is of utmost importance to guarantee the long smooth operation of the DT-RO system. The DT-RO system is cleaned in turns with Cleaner A and Cleaner C. At present, the 1st stage cleaning cycle by Cleaner A and Cleaner C is conducted every 100 and 500 h, respectively, depending on raw the water quality.     

滑移装置抑制甲烷爆炸影响分析*

为减少瓦斯二次爆炸带来的危害,研发新型抑爆弹性滑移装置,并将滑移装置与固定装置对比,分析其对9.5%甲烷/空气预混气体爆炸抑制效果。结果表明:滑移装置抑爆效果优于固定装置;滑移装置能缩短火焰燃烧时间,固定装置超压峰值高于滑移装置;由于轻碳板反向速度提高,弹性系数为0.85 N/mm的滑移装置对火焰和超压抑制效果优于弹性系数为1.63 N/mm的滑移装置。     

大型商圈安全评价体系及案例研究*

为整体评价大型商圈的安全性,结合公共安全科技三角形理论,从突发事件的危险性、承灾载体的脆弱性、应急能力3方面构建大型商圈安全评价指标体系,通过网络分析法和模糊综合评价法确定指标间权重系数,对大型商圈进行安全风险评价。结果表明:体系全面考虑了大型商圈安全风险影响因素及其内在关系,可为大型商圈安全评价体系构建和定量评估提供参考。     

Spatiotemporal heterogeneity of PM2.5 and its driving difference comparison associated with urbanization in China’s multiple urban agglomerations

Environmental Science and Pollution Research - The development of urban agglomeration further deteriorates the air pollution status arising from urbanization. However, disparities in the...     

Removal of F− and organic matter from coking wastewater by coupling dosing FeCl3 and AlCl3

Coagulation and precipitation is a widely applied method to remove F^? from wastewater. In this work, the effect of coagulation on the removal of F^? and organic matter from coking wastewater was studied using AlCl₃ and FeCl₃ as compound coagulants. The removal rates of F^? and organic matter under different coagulant doses and pH conditions were investigated. The results show that the highest removal rates of F^? by AlCl₃ and FeCl₃ are 94.4% and 25.4%, respectively; when the dosage is 10 mmol/L, the TOC removal rates of FeCl₃ and AlCl₃ reach 20.4% and 34.7%, respectively. Therefore, the removal rate of F^? by AlCl₃ is higher than that of FeCl₃, but the removal rate of organic matter by FeCl₃ is relatively higher. The addition of Ca²⁺ can promote the removal of F^?, but the removal rate of organic matter decreases. In addition, by investigating the effects of different pH and Fe–Al ratio on the removal rate, the removal effect of adding FeCl₃ and AlCl₃ at the same time was discussed. The results show that the most suitable working condition for the removal of organic matter and F^? is that the pH is 6.5 and the molar ratio of Al/Fe is 8:2. Overall, the removal mechanism of F^? and organic matter in coking wastewater by FeCl₃ and AlCl₃ was explored in this study. The experimental results can provide reference for the advanced treatment of coking wastewater.     

黑碳仪测量气溶胶吸收系数的校正算法和影响因素研究进展

黑碳仪作为常用的吸收系数测量方法之一,广泛应用于气溶胶光吸收特性的实验室和外场观测研究.然而,受测量方法的限制,吸收系数测量的准确性受到颗粒物负载效应,以及滤膜和颗粒物的多重散射效应的影响.本文综述了黑碳仪的测量原理及现有校正算法,探究了其吸收系数测量的影响因素,分析了黑碳气溶胶的混合状态对其吸收系数测量偏差（C_ref’）的影响,探讨了C_ref’与气溶胶单次散射反照率（SSA）的关系以及C_ref’的波长依赖关系,并提出了今后相关研究的建议.     

居民住宅室内甲醛现状及温湿度影响分析

本文通过对乌鲁木齐市234户住宅1 076个居室,根据不同功能区居室,装修完成后时间段、温度、湿度三个要素分析室内空气中甲醛数据得出,居室样本总体超标率为50.0%。甲醛超标样本(浓度大于0.150 mg/m³)占样本总量的20.5%。随时间变化总体呈下降趋势,室内甲醛污染最严重的时段在装修后6个月内以及每年5—9月。当温度、湿度变化幅度在1℃、5%rH时,甲醛浓度分别增加24.5%、21.6%。不同功能区居室的甲醛平均含量高低顺序为：儿童房>厨房>书房>主卧>次卧>卫生间>客厅。     

“双十一”与日常网络购物关注度耦合协调的空间格局及驱动研究

挖掘"双十一"与日常网络购物之间的耦合关注特征对制定营销策略和调配运输资源具有重大意义。基于百度指数获取网络用户对"双十一"与日常网络购物的关注度,计算它们之间的耦合协调度并分析其空间格局与驱动机制。结果表明:①关注度两极分化显著,大部分城市的耦合协调等级较低。②耦合协调度空间正相关显著,呈现出东—中—西空间分异格局。③住户存款余额影响作用最大,消费能力决定消费倾向。④华北和东北地区属于消费主导区,西北和西南地区属于次消费主导区,华南地区属于生产主导区。