Implications of climate change for evaporation from bare soils in a Mediterranean environment

The purpose of this study was to predict quantitative changes in evaporation from bare soils in the Mediterranean climate region of Turkey in response to the projections of a regional climate model developed in Japan (hereafter RCM). Daily RCM data for the estimation of reference evapotranspiration (ET _r) and soil evaporation were obtained for the periods of 1994–2003 and 2070–2079. Potential evaporation (E _p) from bare soils was calculated using the Penman–Monteith equation with a surface resistance of zero. Simulation of actual soil evaporation (E _a) was carried out using Aydin model (Aydin et al., Ecological Modelling 182:91–105, 2005) combined with Aydin and Uygur (2006, A model for estimating soil water potential of bare fields. In Proceedings of the 18th International Soil Meeting (ISM) on Soils Sustaining Life on Earth, Managing Soil and Technology, Sanliurfa, 477–480pp.) model of predicting soil water potential at the top surface layer of a bare soil, after performances of Aydin model (R ² = 94.0%) and Aydin and Uygur model (R ² = 97.6) were tested. The latter model is based on the relations among potential soil evaporation, hydraulic diffusivity, and soil wetness, with some simplified assumptions. Input parameters of the model are simple and easily obtainable such as climatic parameters used to compute the potential soil evaporation, average diffusivity for the drying soil, and volumetric water content at field capacity. The combination of Aydin and Aydin and Uygur models appeared to be useful in estimating water potential of soils and E _a from bare soils, with only a few parameters. Unlike ET _r and E _p projected to increase by 92 and 69 mm (equivalent to 8.0 and 7.3% increases) due to the elevated evaporative demand of the atmosphere, respectively, E _a from bare soils is projected to reduce by 50 mm (equivalent to a 16.5% decrease) in response to a decrease in rainfall by 46% in the Mediterranean region of Turkey by the 2070s predicted by RCM, and consequently, to decreased soil wetness in the future.     

CaCl2高温热处理垃圾焚烧飞灰中重金属的挥发特性

以深圳市某垃圾焚烧厂飞灰为原料,采用高温管式电阻炉,研究了在0．6L／minN,气氛下,CaCl2在不同添加量、处理温度及处理时间下对飞灰中重金属Pb、Cd、Zn和Cu挥发特性的影响,并对收集到的二次飞灰进行成分及物相分析。结果显示,X射线衍射仪和EDS分析表明,二次飞灰主要是由NaCl、KCl和部分SiCl4组成,zn主要以K2ZnCl4形式挥发,而Pb则主要以氧化物PbO和Pb3SiO5的形式挥发。最终得到CaCl2热处理飞灰的最佳二次气化条件：以0．6L／minN,为载气,添加14wt％的CaCl2,在1100℃高温下处理2．5h。经CaCl2热处理后的剩余飞灰,其浸出毒性达到了《生活垃圾填埋场污染控制标准》要求。     

CaCl2高温热处理垃圾焚烧飞灰中重金属的挥发特性

以深圳市某垃圾焚烧厂飞灰为原料,采用高温管式电阻炉,研究了在0.6 L/min N₂气氛下,CaCl₂在不同添加量、处理温度及处理时间下对飞灰中重金属Pb、Cd、Zn和Cu挥发特性的影响,并对收集到的二次飞灰进行成分及物相分析。结果显示,X射线衍射仪和EDS分析表明,二次飞灰主要是由NaCl、KCl和部分SiCl₄组成,Zn主要以K₂ZnCl₄形式挥发,而Pb则主要以氧化物PbO和Pb₃SiO₅的形式挥发。最终得到CaCl₂热处理飞灰的最佳二次气化条件:以0.6 L/min N₂为载气,添加14 wt%的CaCl₂,在1 100℃高温下处理2.5 h。经CaCl₂热处理后的剩余飞灰,其浸出毒性达到了《生活垃圾填埋场污染控制标准》要求。     

丝光印染废碱液回用技术的研究

印染企业丝光机排出的废碱液,Na0H质量浓度为3%～5%,废水温度在50℃～70℃,色度>1000倍,SS>400mg/L,含较多棉纱线等,为探讨废碱液回收技术的合理性及可行性,本中试系统采用"滤网过滤+板框压滤+陶瓷膜过滤+蒸发浓缩"的耦合技术,对丝光机排放的废碱液进行预处理及浓缩,中试结果表明,该技术可达到废碱液100%回用,处理后的碱液浓度可达15%～25%,SS<30mg/L,色度<100倍,达到印染行业丝光工序回用的要求。     

海水淡化技术及其应用

海水淡化技术是指利用海水脱盐生产淡水的技术过程。目前,海水淡化技术已是解决全球淡水资源危机的重要途径之一。介绍了几种海水淡化方法,对多级闪蒸、低温多效和反渗透三种海水淡化技术的原理、工艺、优缺点及其应用实例行了详细的阐述和比较。     

长江流域养殖池塘氮磷污染负荷估算

长江流域平原区水网密布、渔业发达,养殖池塘造成的氮磷污染问题突出,是河湖富营养化的重要污染源之一;从大空间尺度,精细化估算养殖池塘的氮磷污染负荷,对水污染的精准防控具有重要意义.以长江流域为研究区,依托Google Earth Engine遥感大数据平台,构建了基于机器学习算法的养殖池塘识别模型,精细化识别了长江流域养殖池塘的分布与类型;梳理养殖坑塘的氮磷污染研究案例,针对长江流域养殖坑塘的特征,构建氮磷污染负荷的估算方法,评估氮磷污染负荷的时空分布.研究结果表明：2021年,长江流域养殖池塘总面积为14567km²,包括鱼塘5820 km²、虾蟹塘8747 km²、氮磷排放量分别为95059、16224 t;中部地区的氮磷污染负荷最大,东部地区次之,西部地区最小.本研究是遥感大数据在大尺度污染负荷定量分析的尝试应用,方法适用于其它类型污染负荷的估算.     

围岩散热计算及壁面水分蒸发的处理

笔者采用湿度系数法对壁面水分蒸发进行了处理,对计算壁面处饱和空气含湿量的方法进行了改进,将饱和空气含湿量与温度的关系拟合为二次曲线;建立了在考虑壁面水分蒸发情况下解算巷道围岩温度场分布及围岩向风流的散热量的数学方程,并采用异步长有限差分法对其进行了数值模拟求解;解算出巷道壁面水分蒸发情况下围岩温度分布、壁面温度和围岩散热量的变化规律;并与将饱和空气含湿量与温度的关系拟合为线型关系曲线时的解算结果进行了对比,将饱和空气含湿量和温度之间的关系拟合为线性的计算结果存在一定的误差,通风时间越长,湿度系数越大,风流相对湿度越小,拟合为线性时计算出来的壁面温度和围岩散热量的误差越大。     

FUTURE SOURCES OF COOLING WATER FOR POWER PLANTS IN ARID REGIONS1

ABSTRACT: Electric generation facility water requirement will increase substantially in the future in the Western United States because new power plants are to be constructed at inland sites rather than on the coast. At the inland locations, power plants will have to compete with agriculture and public users for fresh water supplies, and will be constrained by environmental legislation to dispose of cooling waste water in lined evaporation ponds. The various options for power plant cooling are analyzed in respect to cost, water consumption, and environmental hazard, and also in respect to their compatibility with existing state and federal regulations. Several proposals for balancing the water requirements of various users in water-scarce areas are reviewed and criticized.     

石油烃在水面上蒸发过程的研究

原油溢流到水体后对水体造成污染。研究油污的转化规律对于污染事故评价、污染治理方面有着非常重要的意义。通过对三种不同性质的原油进行的风化和蒸发实验 ,证明三种原油低组分具有很快的蒸发速度 ,4天时间就可蒸发掉90 %以上的原油 ,同时得出了不同原油的蒸发规律。     

Suitability of Golf Course Ponds for Amphibian Metamorphosis When Bullfrogs Are Removed

Abstract:  Managing areas designed for human recreation so that they are compatible with natural amphibian populations can reduce the negative impacts of habitat destruction. We examined the potential for amphibians to complete larval development in golf course ponds in the presence or absence of overwintered bullfrog tadpoles ( Rana catesbeiana ), which are frequently found in permanent, human-made ponds. We reared larval American toads ( Bufo americanus ), southern leopard frogs ( R. sphenocephala ), and spotted salamanders ( Ambystoma maculatum ) with 0 or 5 overwintered bullfrog tadpoles in field enclosures located in ponds on golf courses or in experimental wetlands at a reference site. Survival to metamorphosis of American toads, southern leopard frogs, and spotted salamanders was greater in ponds on golf courses than at reference sites. We attributed this increased survival to low abundance of insect predators in golf course ponds. The presence of overwintered bullfrogs, however, reduced the survival of American toads, southern leopard frogs, and spotted salamanders reared in golf course ponds, indicating that the suitability of the aquatic habitats for these species partly depended on the biotic community present. Our results suggest that ponds in human recreational areas should be managed by maintaining intermediate hydroperiods, which will reduce the presence of bullfrog tadpoles and predators, such as fish, and which may allow native amphibian assemblages to flourish.