空气中粉尘粒子的侧向散射效应研究

目的从米散射的基本理论出发。对有关的粉尘粒径的米散射效应进行研究。方法所用的方法主要通过对米散射理论的深入学习、研究,运用Matlab编程软件对0~5μm之间的微粒进行散射光强和散射相函数的计算,得到不同粒径的散射光强、散射相函数,然后利用COMS相机对激光拍摄得到其散射图像,利用散射图像的灰度值与0~5μm之间加权平均的粒子散射相函数值作对比,比较程序实现的可行性。结果得到了0~5μm之间微粒的散射光强以及相应的散射相函数以及激光灰度图像在72°到108°的灰度值。结论通过图像灰度值与散射向函数的曲线对比,证明了程序的可行性。     

高效液相色谱-串联质谱法同时测定地表水中33种药物

采用固相萃取-高效液相色谱-串联质谱法(SPE-HPLC-MS/MS)建立了地表水中25种抗生素类药物和8种非抗生素类药物的分析方法。通过重点优化质谱参数、色谱条件、样品pH、洗脱溶剂组成及用量等确定了最佳分析条件。水样经过滤、固相萃取柱富集净化后,选择Shim-pack XR-ODS为色谱柱,以乙腈和0.2%甲酸-2 mmol/L乙酸铵-水溶液为流动相进行梯度洗脱,采用电喷雾电离源,在多反应监测模式下(MRM)分析测定,内标法定量。33种药物的仪器定量限为0.012～4.68 ng/L,方法检出限为0.011～7.60 ng/L,地表水加标回收率为53.7%～122%,相对标准偏差为1.22%～32.1%(n=6)。方法成功应用于北京市凉水河12个地表水样分析,共检出32种药物,检出质量浓度为未检出～239 ng/L。利托那韦(RTV)作为新型冠状病毒诊疗方案中推荐的药物在凉水河检出率为100%。     

包装废弃物添加脱氯半焦制备SRF的热解及动力学特性

利用热重红外分析仪(TG-FTIR)对包装废弃物添加了4种不同比例脱氯半焦制备而成的固体衍生燃料(SRF)的热解特性及热反应动力学进行了研究分析.研究发现,4种燃料热解过程主要包括4个阶段,其中300~400℃和400~500℃为两个主要失重阶段.前一阶段,SRF-1失重显著高于SRF-2、SRF-3和SRF-4,而后一阶段失重分别呈2、3、4倍增加.4种燃料热解残余量的顺序为SRF-4SRF-3SRF-2SRF-1,即添加了脱氯半焦的燃料热解程度越高.FTIR分析表明,添加了脱氯半焦的SRF燃料第三失重峰处不产生氯代烃.随脱氯半焦添加量的增加,第二失重峰CO2产生的浓度减少;第三失重峰CH4析出浓度增加;第四失重峰CO2析出的浓度增加.采用DEAM分布活化能法得到,转化率α0.3时,SRF-2和SRF-3的活化能均高于SRF-1的活化能,0.3α0.9时(α为0.6时除外),SRF-2、SRF-3和SRF-4 3种燃料的活化能低于SRF-1,且SRF-1的活化能呈升高的趋势,而其他3种燃料呈相反趋势.脱氯半焦的添加有利于SRF燃料的热解.     

气相色谱-高分辨双聚焦磁质谱测定水中超痕量多氯萘

采用固相萃取法处理水样,气相色谱-高分辨双聚焦磁质谱法测定水中超痕量多氯萘,同位素内标法定量,并对样品前处理条件和仪器条件进行优化。试验表明：方法在0．500 ng/L～500 ng/L范围内线性良好;当取样体积为1 L时,方法检出限为0．005 ng/L～0．01 ng/L;对实际水样进行2个质量浓度水平的加标回收试验,平行测定6次的 RSD为2．7％～8．7％,回收率为70．2％～110％。方法适用性试验表明,水样中复杂的基质对测定无影响。     

城市生活垃圾填埋场的物质存量特征及其环境影响:以粤港澳大湾区为例

填埋场中的生活垃圾成分复杂,即使在封场后其存量垃圾仍将持续产生温室气体、恶臭、地下水污染等环境问题,是城市生态环境修复的重点领域之一.生活垃圾填埋场物质存量、组成成分和理化特征是掌握其潜在环境影响的关键.但是目前关于填埋场物质存量及其环境影响的研究还不多见.本研究以我国城市化程度最高、人口最为密集的粤港澳大湾区城市群为例,基于国内外报道的科技信息和统计数据,对11个城市的生活垃圾产生量、处理量、组成成分、填埋场存量及关键元素碳存量进行分析.结果表明:①粤港澳大湾区2017年生活垃圾产生量为26. 4 Tg,平均每年增长0. 8 Tg,其中卫生填埋处置占58. 9%;②总生活垃圾填埋处置量为230. 1 Tg,其中食物、塑料和纸类垃圾的累计填埋处置量最多,分别为109. 6、38. 9和29. 6 Tg;③2001～2017年,大湾区城市生活垃圾填埋场总碳输入量为50. 0 Tg,通过填埋气排放的碳为7. 1 Tg,通过渗滤液排放的碳为1. 5 Tg,累积碳存量为41. 4 Tg.本研究可为研究城市生活垃圾填埋场的环境影响提供基础数据,为大湾区城市生态环境修复提供科学依据.     

Highly active mixed-phase TiO2 photocatalysts fabricated at low temperature and the correlation between phase composition and photocatalytic activity

The idea of varying volume ratio of water to ethanol in solvent was firstly employed to yield phase composition controllable mixedphase titanium dioxide (TiO2) photocatalysts via a low temperature solvothermal route at 353 K. It was found that anatase contents increase from 0 to 100% with increase of ethanol contents in solvent. The mixed-phase TiO2 with 60% anatase content exhibited the best photocatalytic activity in photodecomposing formaldehyde (FAD) under UV light irradiation, which increases by about ...     

北京公园水体中邻苯二甲酸酯类物质的测定及其分布特征

为了正确评估北京市公园水体受PAEs污染的程度,采集了北京11个公园湖水的水样,采用固相萃取-气相色谱联用技术检测了其中六种邻苯二甲酸酯类物质(PAEs)的含量,该方法加标回收率在73%～89.3%,RSD为5.9%～18.1%,检出限在0.40～4.58mg/L。实验结果为北京公园水体中总PAEs浓度在6.4～138.1μg/L,平均值为27.9μg/L,证明北京公园水体受到不同程度的PAEs污染,主要的污染物为邻苯二甲酸二丁酯(DBP)和邻苯二甲酸双(2-乙基己基)酯(DEHP),其中东南部以及西北部的公园污染较严重。分析了PAEs在公园湖水底泥中和水体中的分布特征,结果显示,PAEs在湖水底泥中的含量明显大于在水体中的含量。     

Variation in some chemical parameters and organic matter in soils regenerated by the addition of municipal solid waste

The organic fraction of a municipal solid waste was added in different doses to an eroded soil formed of loam and with no vegetal cover. After three years, the changes in macronutrient content and the chemical-structural composition of its organic matter were studied. The addition of the organic fraction from a municipal solid waste had a positive effect on soil regeneration, the treated soils being covered with spontaneous vegetation from 1 yr onwards. An increase in electrical conductivity and a fall in pH were noted in the treated soils as were increases in macronutrients, particularly N and available P and the different carbon fractions. Optical density measurements of the organic matter extracted with sodium pyrophosphate showed that the treated soils contained an organic matter with less condensed compounds and with a greater tendency to evolve than the control. A pyrolysis-gas chromatography study of the organic matter extracted with pyrophosphate showed large quantities of benzene both in the treated soils and control; pyrrole was also relatively abundant, although this fragment decreased as the dose rose. Xylenes and pyridine were present in greater quantities in the control and furfural in the treated soils. Three years after addition to the soil, the organic matter had a higher proportion of fragments derived from aromatic compounds and a smaller proportion derived from hydrocarbons. Similarity indices showed that, although the added and newly formed organic matter 3 yr after addition continued to differ from that of the original soil and to be more mineralizable, the transformations it has undergone made it more similar to the original organic matter of the soil than it was at the moment of being added.     

垃圾填埋场垃圾堆体压实机理研究

通过填埋场现场运行实验，对生活垃圾在填埋场中的压实机理进行了研究，实验结果表明，压力是决定压实效果的最重要的外在因素，垃圾在外力下的形变大体可分为三个阶段：垃圾组分之间的大空隙被填没，垃圾体不可逆蠕变，垃圾体的范性变形；决定压实效果的内在因素有垃圾组分、垃圾含水率等。另外，作业过程中垃圾堆体的摊铺厚度、机械行程次数、行驶速度和坡向及坡度等也是影响垃圾堆体压实效果的重要因素。     

Numerical simulation of stratified turbulent two phase flow in aquatic environment

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