粉煤灰活性炭处理六价铬废水的试验研究

本研究用火电厂废渣—粉煤灰的浮选炭制得的颗粒活性炭,对六价铬废水进行净化处理。结果表明,粉煤灰活性炭对六价铬废水处理效果良好。实验探讨了粉煤灰活性炭处理六价铬废水的一般规律及影响因素。     

堆放参数对瑞安矿煤堆自燃风速的影响

为确定瑞安矿煤堆自燃的环境风速,提高煤堆自燃的预判能力,使用COMSOL Multiphysics 5.0数值仿真软件,开展了5个不同尺寸分别在孔隙率0.2~0.6和环境风速0.05 m/s~13 m/s条件下堆放180 d的自热-自燃过程数值模拟。结果表明,煤堆自燃风速范围因孔隙率和堆放参数不同而异,孔隙率越小煤堆的自燃风速范围越宽,且最小、最易、最大自燃风速与孔隙率之间具有幂函数关系;影响煤堆最小、最易、最大自燃风速显著的参数分别为顶宽、底宽、高度、角度和孔隙率、孔隙率、高度和孔隙率,并构建了三个自燃风速的合理解算方程。     

硫化纳米零价铁对PCB153的降解研究

硫化纳米零价铁(S-nZVI)是近年来兴起的一种纳米零价铁改性材料,已有研究发现其在重金属污染物去除方面具有较好的效果,而有关其对多氯联苯(PCBs)的反应活性目前尚未见报道.因此,本研究对比了采用前置硫化合成法制备的S-nZVI(S/Fe=0.103)、纳米零价铁(nZVI)和羧甲基纤维素稳定纳米零价铁(CMC-nZVI)3种纳米零价铁材料降解六氯联苯PCB153的反应动力学,研究了pH值、阴离子、腐殖酸(HA)等因素对该反应的影响,分析了反应前后材料表面性质的变化,探讨了脱氯路径和反应机理.结果表明,3种纳米零价铁材料对PCB153的降解反应符合准一级动力学,降解机理相似,降解效果依次为CMC-nZVInZVIS-nZVI.硫化改性降低了nZVI去除PCB153的反应活性,S-nZVI表面的硫铁化物并未直接参与PCB153降解反应,S-nZVI反应活性低的原因可能是硫铁化物的形成损耗了一部分Fe~0的还原能力.此外,与CMC-nZVI、nZVI不同,高pH更有利于S-nZVI对PCB153的降解,阴离子和HA对3种纳米零价铁活性的影响规律相似.研究结果可为S-nZVI在持久性有机污染物降解中的应用提供理论依据和技术支持.     

风障联合压实防治煤堆自燃技术工艺参数优化

为提高煤堆自燃的防治效果,降低经济成本和提高施工的灵活性,基于煤堆自燃理论,使用COMSOLMultiphysics 5.0数值仿真软件,建立煤堆自燃模型,研究了煤堆最高温度和自然发火期变化及相关措施实施后最高温度降低规律,对比了单独压实、独立风障和风障联合压实的温度降低量,优化了联合措施的工艺。结果表明,煤堆孔隙率越小,自燃风速范围越宽,最小、最易、最大自燃风速越大;单独进行煤堆压实存在因孔隙率增加而降低的最低不宜风速;针对6 m高煤堆单独使用风障时,只有风障高12 m、距离煤堆25 m才能避免煤堆自燃;风障联合压实措施中,风障高7.5~9 m,设置距离煤堆10~30 m即能保证煤堆不自燃。说明联合的煤堆最高温度降低量更大,且能扩大压实的适用范围,降低风障高度,节约经济成本,增加风障现场施工的灵活性。     

有机负荷对厌氧流化床反应器处理模拟味精废水的影响

在中温(35±1℃)条件下,以新型橡胶颗粒为载体的厌氧流化床(AFB)反应器处理模拟味精废水为研究体系,考察有机负荷(OLR)由2.08 kg/(m3.d)提高到19.20 kg/(m3.d)期间,污染物去除率、胞外聚合物(EPS)含量及其在生物膜和混合液中的分布、生物膜中MLVSS含量及脱氢酶活性等的变化情况。结果表明,随有机负荷增加,污染物去除稳定,COD去除率维持在80%左右;EPS在生物膜中的量大于在混合液中的量,并以蛋白质为主要成分,但其总量呈递减趋势;当有机负荷为19.20 kg/(m3.d)时,生物膜中MLVSS含量约为23.1 mg/g载体,脱氢酶活性则为22.6 mg/(L.h);载体生物膜的生物相以独缩虫属、聚缩虫属、累枝虫属和钟虫等为主。     

Release of pentachlorophenol from black carbon-inclusive sediments under different environmental conditions

To investigate the feasibility of using black carbon (BC) in the control of hydrophobic organic contaminants (HOCs) in sediment, we added BCs from various sources (rice straw charcoal (RC), fly ash (FC) and soot (SC)) to sediment to create different BC-inclusive sediments and studied the release of pentachlorophenol (PCP) in the sediments under different condition. Different pH values had no obvious effect on the release of PCP in BC-inclusive sediment, but solid/liquid ratio, temperature, salinity and dissolved organic matter (DOM) content had significant influences on the release of PCP in all sediments except the RC-inclusive sediment. Adding 2% RC to sediment resulted in a 90% decrease in PCP release, which was a greater decrease than observed with FC- and SC-inclusive sediments. Therefore, from the standpoint of HOC release, the application of RC is feasible for organic pollution control in the water environment.     

Examination of Resource Curse Hypothesis: Mineral Resources Exploitation and Economic Growth in Xinjiang Autonomous Region

The mineral resources exploitation stage and the economic growth rate are various in different regions of Xinjiang Autonomous region. Using the method of location quotient, this paper identifies and classifies the intensive regions of three types of mineral resources, known as coal, oil and natural gas, respectively. The intensive regions of economic growth were also identified, according to the rate of per capita GDP growth at prefecture, autonomous prefecture and city. The relationships between different mineral resources and economic growth are different, for example, the relationship between economic growth and coal resource is positive, while the relationship between economic growth and oil resource, or natural gas resource is negative. This study empirically examines the effects of natural resources on economic growth of Xinjiang. The results show that whilst natural resources have a positive impact on growth, and can make a negative impact on growth through the transmission channels, such as investment, manufacture, human capital, and scientific and technologic innovation. Moreover, it studies the transmission channels, that is, the effect of natural resources on the other explanatory variables, and calculates the indirect effect of natural resources on growth for each transmission channel, and comprehensive effects of natural resources on growth. The calculated result of comprehensive effects indicates that the positive direct effects of natural resources on growth are shown to outweigh the negative indirect effect of Xinjiang autonomous region.     

Organic composition of fogwater in the Texas–Louisiana gulf coast corridor

Fogwater and air samples were collected in Baton Rouge between November 2004–February 2005 and during February 2006 at Houston. Organic compounds present in the fog samples were detected, quantified and then grouped into different compound classes based on molecular size, solubility and polarity using gas chromatography/mass spectrometry, high performance liquid chromatography with diode array detection and ion chromatography. Organic compounds were grouped as n-alkanes, aromatics and polycyclic aromatics, carbonyls, alcohols, amides and esters. Organic compounds in fog and air samples in Houston indicated clear urban/industrial anthropogenic origin, while compounds detected in Baton Rouge fog and air samples showed a mix of both agricultural and urban/industrial anthropogenic inputs. Among the various polycyclic aromatic compounds detected, the total concentration of naphthalene and its derivatives was 2.8 μg m^?3 in Houston and 0.08 μg m^?3 in Baton Rouge air. Analysis of concentrations of organic compounds pre- and post- fog revealed that compounds with low vapor pressure had higher scavenging efficiency in fog sampled at the two locations. Concentrations of organic compounds in fog samples were higher than those predicted by conventional air-water Henry's law equilibrium. Observed higher concentrations in the aqueous phase were modeled accounting for surface adsorption and accumulation of gas phase species and the presence of humic-like substances in fogwater.     

杭州市区大气能见度变化趋势及其与主要污染物相关性分析

利用2004-2006年地面气象观测资料和同期环境空气质量自动监测数据,分析了杭州市区大气能见度变化趋势及其与主要污染物的相关性.结果表明,杭州市区能见度的日分布特征为14时最好,8时最差;季节变化特征为夏季>春季>秋季>冬季,全年仅7月能见度超过10 km;SO2、NO2、PM10浓度均随能见度增高而逐渐降低;影响能见度的首要因子为相对湿度和PM2.5,能见度与PM2.5浓度具有较好的相关性.     

二氧化钛对活性艳红X-3B的光催化降解研究

以TiO2作为光催化剂,研究了TiO2对活性艳红X-3B的光催化氧化降解行为。结果表明,以锐钛矿为主的混晶型Ti02的催化活性最好;X-3B的光催化降解动力学符合Langmuir-Hinshelwood动力学模式,并求出其动力学参数女(表观反应速率常数)为0．5921,KA(吸附平衡常数)为0．1725;温度对X-3B的降解影响很小,其活化能仅为6．04kJ／mol;溶液中盐度的增加会不断降低TiO2对X-3B的光催化降解速率。