广州地区灰霾与清洁天气变化特征及影响因素分析

利用2006~2010年广州气象站逐时地面风场、湿度、能见度观测资料和2006~2009年珠江三角洲其他33个地面观测站风场观测资料,通过对灰霾与清洁天气过程的风速风向进行统计分析与矢量和分析,研究了广州地区灰霾与清洁天气过程的变化特征及影响因素.结果表明:灰霾天气过程在干季发生较频繁,主导风向为东南及东南偏南风,风速一般在1.5m/s以下,静风频率大于多年静风频率;灰霾天气过程风矢量和较小,扩散条件较差.清洁天气过程主要出现在湿季,风速普遍较大且主导风为东南及东南偏南风,干季也可以出现清洁天气过程,主要为较强的北风及偏北风;清洁天气过程风矢量和较大,有较强的平流输送.     

Comparative assessment of wet and dry garment cleaning Part 1. Environmental and human health assessment

Water-based cleaning of specialty garments is emerging as a potential alternative to dry cleaning. Perchloroethylene, the solvent used in dry cleaning, poses significant human and ecosystem health concerns. This paper is part 1 of a two part series that analyzes the key environmental, human health, performance, economic, and regulatory factors which influence the future of the garment cleaning industry. This paper inventories the environmental releases and wastes associated with the consumption of perchloroethylene in modern dry cleaning machines which ranges from 2.0 to 5.2 kg per 100 kg of clothing cleaned. In addition, water, electricity, and other inputs for both perchloroethylene-based and water-based garment cleaning are compared using data from previous demonstration projects. Toxicological and epidemiological studies provide evidence for the carcinogenicity of perchloroethylene although this classification is controversial. Cancer risks at low levels of exposure associated with modern dry cleaning equipment and good housekeeping practices are unknown and require further investigation. Regardless of these uncertainties, water-based cleaning is preferable to dry cleaning from a human and environmental health perspective.     

Helping small businesses implement toxics use reduction techniques: dry cleaners, auto shops, and floor finishers assisted in creating safer and healthier work places

The Toxics Use Reduction Institute (TURI), Boston Public Health Commission (BPHC), and Vietnamese American Initiative for Development (Viet-AID) have worked with small business sectors to reduce their use of toxic chemicals. Three cases, described here, in dry cleaning, auto shops and floor finishing share common approaches for creating successful models of effective dissemination of toxics use reduction in small businesses. These include direct business support, peer-to-peer training and promotion of alternatives, and collaborations with stakeholders to achieve greener businesses. These results were achieved despite predictable barriers of lack of resources, suspicion of safer alternatives, and language and cultural barriers.     

Fouling and cleaning of membrane--a literature review

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真空吸尘系统应用于散货码头的积尘清扫

描述了散货码头粉尘污染现状,分析比较了几种常用的积尘清扫方法。为了有效清扫散货码头的积尘,提出采用集中式真空吸尘系统。文章从系统形式、水力计算方法和工程实例等方面简单介绍了集中式真空吸尘系统。印尼Paiton燃煤电厂码头工程设计采用了集中式真空吸尘系统进行积尘清扫,工程建成投产一年多来,积尘清扫效果明显,有效地降低了粉尘污染。实例说明,真空吸尘是解决散货码头积尘清扫问题较为有效的方式。     

Pulse cleaning flow models and numerical computation of candle ceramic filters

ＩｎｔｒｏｄｕｃｔｉｏｎＣｌｅａｎｉｎｇｔｈｅｆｉｎｅｐａｒｔｉｃｌｅｓｉｎｈｉｇｈｔｅｍｐｅｒａｔｕｒｅ (450℃ -950℃ )ａｎｄｈｉｇｈｐｒｅｓｓｕｒｅｃｏｎｄｉｔｉｏｎｃａｎｅｎｈａｎｃｅｔｈｅｔｈｅｒｍａｌｅｆｆｉｃｉｅｎｃｙｏｆｃｌｅａｎｃｏａｌｔｅｃｈｎｏｌｏｇｉｅｓｓｕｃｈａｓＩＧＣＣｏｒＰＦＢＣ .Ｒｉｇｉｄｃｅｒａｍｉｃｆｉｌｔｅｒｓｏｆａｖａｒｉｅｔｙｏｆｓｔｒｕｃｔｕｒｅｓａｒｅｕｎｄｅｒｄｅｖｅｌｏｐｍｅｎｔｉｎｐｒｏｇｒａｍｓａｒｏｕｎｄｔｈｅｗｏｒｌｄ ,ｗｈｉｃｈｃａｎｆｉ…     

声波反吹清灰对除尘效率的影响

声波反吹清灰会使除尘效率略有降低，已被实验和统计资料所证实。为减小其对除尘效率的影响，又要达到降低除尘器运行阻力的目的，必须选择合适的鸣喇叭次数。对于较难脱落的粉尘应选较多的鸣喇叭次数，而对较易脱落的粉尘则不需每次清灰都鸣喇叭，仅需偶而启动一次。本文通过实验证明，对本实验所用的除尘系统，每四次反吹清灰后鸣喇叭一次是合适的。     

沈阳市服装干洗业氯代烃使用情况及污染状况调查

探讨了服装干洗业氯代烃使用情况及污染状况，并分析了目前广泛采用的服装干洗工艺．结果表明，目前服装干洗业全部采用四氯乙烯做干洗剂，沈阳市每年的消耗量在３００ｔ左右，干洗过程中约９８％的四氯乙烯通过挥发进入大气，２％通过蒸馏残渣排放进入土壤及水体．     

基于响应曲面法袋式除尘器清灰性能的数值研究

利用计算流体动力学（CFD）方法,采用二维、可压缩、非稳态流动数学模型,对袋式除尘器脉冲喷吹过程中滤袋内的清灰流场进行了数值模拟,比较了滤袋壁面压力峰值的模拟值和试验值.同时,利用该模型,基于响应曲面法并使用统计软件MinitabV15研究了喷嘴直径、喷吹高度、文丘里管喉管直径、文丘里管及布袋长度对袋式除尘器清灰性能的影响,并得出了这5个影响因子的二次多项式预测模型.结果表明,滤袋表面压力峰值的模拟值与试验值变化趋势基本上是一致的,误差在10%左右,从而验证了本文数值计算模型的可靠性.在上述5个影响因素中,喷嘴直径（d）、文丘里管喉管直径（de）及布袋长度（L）对清灰性能影响显著,其中,清灰性能随着喷嘴直径和文丘里管喉管直径的增大而提高,随着布袋长度的增大先提高后降低.在本文所研究的尺寸范围内,当d=20mm、de=60mm及L=3360mm时,清灰效果分别达到最优.所得结论有助于进一步改善袋式除尘器的清灰性能.     

Towards a better hydraulic cleaning strategy for ultrafiltration membrane fouling by humic acid: Effect of backwash water composition

As a routine measurement to alleviate membrane fouling, hydraulic cleaning is of great significance for the steady operation of ultrafiltration (UF) systems in water treatment processes. In this work, a comparative study was performed to investigate the effects of the composition of backwash water on the hydraulic cleaning performance of UF membranes fouled by humic acid (HA). Various types of backwash water, including UF permeate, Milli-Q water, NaCl solution, CaCl₂ solution and HA solution, were compared in terms of hydraulically irreversible fouling index, total surface tension and residual HA. The results indicated that Milli-Q water backwash was superior to UF permeate backwash in cleaning HA-fouled membranes, and the backwash water containing Na⁺ or HA outperformed Milli-Q water in alleviating HA fouling. On the contrary, the presence of Ca^2 + in backwash water significantly decreased the backwash efficiency. Moreover, Ca^2 + played an important role in foulant removal, and the residual HA content closely related to the residual Ca^2 + content. Mechanism analysis suggested that the backwash process may involve fouling layer swelling, ion exchange, electric double layer release and competitive complexation. Ion exchange and competitive complexation played significant roles in the efficient hydraulic cleaning associated with Na⁺ and HA, respectively.     

基于NaOCl扩散行为的膜清洗条件影响及优化

为了探究基于NaOCl扩散行为进行膜清洗的影响因素,建立完善的添加剂强化NaOCl扩散的新型膜清洗方法,本文以牛血清蛋白（BSA）、海藻酸钠（SA）作为模型污染物,通过批次膜清洗实验对膜面剩余污染物浓度、洗脱污染物粒径和膜面污染物形貌进行了测定分析和动态监控,探究不同活性氯（Cl_T）浓度,不同pH值及不同添加剂（十二烷基硫酸钠,SDS）浓度对强化扩散NaOCl清洗的影响,并对操作参数进行了优化,同时也验证了不同条件下的膜清洗机制.结果表明,在Cl_T浓度为200mg/L,pH值为11,SDS浓度为0.4mmol/L的条件下对膜面的清洗效率 > 95%.     

广州地区灰霾过程和清洁过程的边界层特征对比分析

利用2014~2016年广州国家基本气象站的微波辐射计、风廓线雷达和地面观测数据,研究广州地区灰霾过程和清洁过程的边界层结构特征.结果表明：（1）灰霾过程中,270m高度以下风速随高度递减,270m高度以上的风速随高度递增,2000m以下的风速增率小于2000m以上的风速增率,盛行风向随高度的增加呈顺时针旋转,510m高度以下风速基本小于3.0m/s,其中08：00至20：00,390m高度以下风速小于2.0m/s;清洁过程中510~1590m和2790~3000m存在风速大于5.0m/s的高值中心,1830m高度以下,清洁过程各层的平均风速明显高于灰霾过程;（2）贴地逆温与能见度总体上呈负相关,与PM_2.5浓度呈正相关,相关系数分别为-0.367和0.455,而当贴地逆温和低空逆温同时存在时,其相关性更高,其相关系数分别为-0.5和0.601,说明多层逆温的存在更容易出现灰霾天气.灰霾过程中,低空逆温与能见度和PM_2.5的相关不明显,而清洁过程中,低空逆温的出现主要与冷空气南下有关,其与能见度呈正相关（0.217）,和PM_2.5浓度呈负相关（-0.64）,低空逆温不利于灰霾天气形成;（3）灰霾过程中,贴地逆温出现频率为60.68%,平均逆温强度为1.38℃/100m,平均逆温厚度为153.20m,明显高于清洁过程;清洁过程中,低空逆温的逆温强度、厚度和出现频率分别为0.27℃/100m、691.07m和64.61%,明显高于灰霾过程.（4）清洁过程的混合层高度明显高于灰霾过程,清洁过程的日均混合层高度（958.92m）是灰霾过程（398.03m）的2.4倍.     

黄土丘陵区土地利用与土壤水分的时空关系

论文根据连续两年土壤水分的定点和观测数据,对黄土丘陵区不同土地利用类型及其结构与土壤水分的时空关系进行了分析。结果表明:①在欠水年,土地利用间土壤水分的差异显著,而在丰水年,土地利用间土壤水分的差异不显著;②在丰水年,土壤水分的年内变化只有灌木地为消耗型,间作地、果园、林地、草地、撂荒地和农地等6种土地利用类型为平衡型或增长型,欠水年所有土地利用均为消耗型;③从丰水年到欠水年,土壤水分的剖面结构类型降低型向波动型转化,波动型向增长型转化;④单一土地利用结构的土壤水分从坡顶到坡脚具有增长的趋势,而土地利用结构复杂的土壤水分沿坡面分布复杂。     

Chemical cleaning of fouled PVC membrane during ultrafiltration of algal-rich water

Cleaning of hollow-fibre polyvinyl chloride (PVC) membrane with di erent chemical reagents after ultrafiltration of algal-rich water was investigated. Among the tested cleaning reagents (NaOH, HCl, EDTA, and NaClO), 100 mg/L NaClO exhibited the best performance (88.4% 1.1%) in removing the irreversible fouling resistance. This might be attributed to the fact that NaClO could eliminate almost all the major foulants such as carbohydrate-like and protein-like materials on the membrane surface, as confirmed by Fourier transform infrared spectroscopy analysis. However, negligible irreversible resistance (1.5% 1.0%) was obtained when the membrane was cleaning by 500 mg/L NaOH for 1.0 hr, although the NaOH solution could also desorb a portion of the major foulants from the fouled PVC membrane. Scanning electronic microscopy and atomic force microscopy analyses demonstrated that 500 mg/L NaOH could change the structure of the residual foulants on the membrane, making them more tightly attached to the membrane surface. This phenomenon might be responsible for the negligible membrane permeability restoration after NaOH cleaning. On the other hand, the microscopic analyses reflected that NaClO could e ectively remove the foulants accumulated on the membrane surface.     

Safer alternatives assessment: the Massachusetts process as a model for state governments

In 2006 the Massachusetts Toxics Use Reduction Institute conducted a study to determine if states could identify safer alternatives to five chemicals of concern. The chemicals investigated included di (2-ethylhexyl) phthalate (DEHP), formaldehyde, hexavalent chromium, lead and perchloroethylene. First, the Institute developed a methodology for assessing alternatives to these five chemicals that allowed it to quickly determine priority uses and alternatives to assess and to research the pertinent decision criteria, which included performance, technical, financial environmental and human health parameters. The methodology included important feedback from stakeholders in the state, which helped to focus and enhance the value of the work. Second, the Institute implemented the methodology over a ten month period. Based on the activities conducted by the Institute, safer alternatives were identified for each of the priority uses associated with the five chemicals studied. This report summarizes the methodology employed and provides examples of the results for one of the five chemicals, namely DEHP. The experience of the Institute and the information contained in this report indicates that alternatives assessment was a useful approach to organizing and evaluating information about chemicals and alternatives.     

袋式除尘器声波反吹清灰方式的研究

在不同的声波作用下，测定了除尘器内的残余阻力和清灰周期，阐明了声波反吹清灰效果与声波频率和声压的关系。通过实验证明，延长反吹时间、增大反吹风速、多次反吹以及增加清灰次数都不是改善反吹袋式除尘器清灰效果的理想办法，声波反吹清灰能有效地降低残余阻力和残留粉尘负荷，并能明显地延长清灰周期，因而是一种理想的清灰方式。本文还对反吹与声波的作用次序进行了实验，结果表明，在反吹清灰的过程中间鸣喇叭，清灰效果最好     

中国2000年水环境污染直接经济损失与治理费用估算

本文以我国部分省、市、地区的有关数据为样本,对水体污染负荷量及水污染造成的直接经济损失进行了统计分析,提出了估算我国水环境污染造成直接经济损失的数学模型,并按目前发展趋势估算了我国到公元2000年时水环境污染对能造成的直接经济损失。初步估算结果表明,如不采取有力措施控制污染物排放,在1986年至2000年的15年中,全国水环境污染造成的直接经济损失将达到2735亿元。 本文还以我国数百套污水处理装置的调查结果为依据,给出了较为简单的污水处理费用函数,并估算了我国公元2000年前不同时期、不同目标的污水治理费用。      

生活废弃物焚烧处置烟气中二(口恶)英排放特性研究

研究了某市10座生活垃圾焚烧炉烟气中二噁英的排放特性,对比了焚烧炉炉型、焚烧处理量、烟气净化系统对二噁英排放特性的影响.结果表明:10座生活垃圾焚烧炉二噁英的排放浓度为0.016~0.104 ng·Nm~(-3)(以I-TEQ计),9座垃圾焚烧炉二噁英排放满足国家相应的排放标准(0.1 ng·Nm~(-3)(以I-TEQ计)).根据二噁英排放浓度排序对应的烟气净化系统分别为SNCR(Selective Non-Catalytic Reduction)+半干法+活性炭喷射+布袋湿法+活性炭喷射+布袋半干法+活性炭喷射+布袋,表明安装SNCR装置有利于二噁英的减排.另外,不同垃圾焚烧炉排放的二噁英指纹特性不仅与烟气净化系统和炉型有关,还与垃圾来源有一定关联.     

滤筒式除尘器清灰性能研究

对 4种不同规格滤筒分别进行了清灰性能试验研究 ,试验结果表明滤筒夹角对滤筒清灰性能影响很大。当滤筒夹角小到一定程度时 ,在线清灰基本不起作用 ,必须采用离线清灰。试验还发现同一滤筒不同部位清灰效果不同 ,上部清灰效果最差 ,在此分析了其原因并提出改进措施。     

三相流化床气体净化技术及其应用研究

介绍了丰相流化床气体净化技术的机理，研究了净化２种不同性质的工业气体所采取的措施。结果表明，该技术对大流量工业气体的净化，特别对纸浆厂备料车间的尾气处理和燃煤电厂的烟气除尘脱硫，具有非常明显的竞争优势。