Evaluating the effects of local floodplain management policies on property owner behavior

Floodplain management programs have been adopted by more than 85% of local governments in the nation with designated flood hazard areas. Yet, there has been little evaluation of the influence of floodplain policies on private sector decisions. This article examines the degree to which riverine floodplain management affects purchase and mitigation decisions made by owners of developed floodplain property in ten selected cities in the United States. We find that the stringency of such policies does not lessen floodplain property buying because of the overriding importance of site amenity factors. Indeed, flood protection measures incorporated into development projects appear to add to the attractiveness of floodplain location by increasing the perceived safety from the hazard. Property owner responses to the flood hazard after occupancy involve political action more often than individual on-site mitigation. Floodplain programs only minimally encourage on-site mitigation by the owner because most owners have not experienced a flood and many are unaware of the flood threat. It is suggested that floodplain programs will be more effective in meeting their objectives if they are directed at intervention points earlier in the land conversion process.     

Enhanced photoelectrocatalytic degradation of ammonia by in situ photoelectrogenerated active chlorine on TiO2 nanotube electrodes

TiO_2 nanotube(Ti NT) electrodes anodized in fluorinated organic solutions were successfully prepared on Ti sheets. Field-emission scanning electron microscopy(FE-SEM) and X-ray diffraction(XRD) were performed to characterize the TiNT electrodes. The linear voltammetry results under irradiation showed that the TiNT electrode annealed at 450°C presented the highest photoelectrochemical activity. By combining photocatalytic with electrochemical process, a significantly synergetic effect on ammonia degradation was observed with Na_2SO_4 as supporting electrolyte at pH 10.7. Furthermore, the photoelectrocatalytic efficiency on the ammonia degradation was greatly enhanced in presence of chloride ions without the limitation of pH. The degradation rate was improved by 14.8 times reaching 4.98 × 10~(-2) min~(-1) at pH 10.7 and a faster degradation rate of 6.34 × 10~(-2) min~(-1)was obtained at pH 3.01. The in situ photoelectrocatalytic generated active chlorine was proposed to be responsible for the improved efficiency. On the other hand, an enhanced degradation of ammonia using TiNT electrode fabricated in fluorinated organic solution was also confirmed compared to TiNT electrode anodized in fluorinated water solution and TiO_2 film electrode fabricated by sol–gel method. Finally, the effect of chloride concentration was also discussed.     

水污染源在线设备比对监测问题与解决方案——以长沙市在线监测系统为例

总结了长沙市7年来水污染源在线监测系统开展比对监测工作的情况,对氨氮、p H、重金属比对监测存在的问题进行了剖析,分析了在线监测仪器比对不合格的原因以及目前在线监测仪器部分项目缺乏误差标准等亟待解决的问题,研究出各因子误差的合理区间,提出了切实可行的解决方案:氨氮应该按照检测浓度高低确定误差范围;p H质控样不应使用相对误差,建议采用±0.3 p H的绝对误差;重金属实际水样浓度小于一定量时,用接近水样浓度的低浓度质控样替代。     

岷江大桥控制单元水体氨氮和总磷源解析

采用单因素法对岷江流域国控断面的岷江大桥水体进行评价,从污染源分担率、污染物时空变化等方面解析污染物的主要来源与变化。结果表明,水体不达标的主要因子为氨氮和总磷;污染物的主要来自城镇生活污水和规模化畜禽养殖废水的不达标排放,按各个污染源占比统计,2个主要污染源对于氨氮和总磷的污染分担率分别是42.54%、35.31%;受上游来水、其他补给水源的影响,氨氮浓度集中在1~5月超标严重,在2013年4月份出现峰值,总磷在2011~2014年普遍超标严重,在2014年5月出现峰值,由于"十二五"期间治污力度的加强,2015年氨氮污染趋势得到控制,总磷浓度明显有所降低,MIKE 21二维水动力水质模型模拟显示只要汇入支流断面均达到要求、污染负荷得到有效控制,控制单元能满足达标要求;最后从源头减排、区域综合整治、全程监管3个方面构建了使控制单元水体达标的策略。     

Steam cavity and explosion intensity of molten copper column interaction with water

The steam explosion is one of the most serious accidents in the metallurgical industry. In this paper, an experimental study on the interaction of molten copper column with cooling water was carried out using high-speed camera and transient pressure measurement system. The effects of temperature, falling height, diameter and mass of molten copper column on the interaction were investigated. The steam cavity phenomenon was observed in the interaction and the percentage of steam cavity volume affects the probability of fragmentation of molten copper column. The maximum percentage of steam cavity volume increases firstly and then decreases with the increase of temperature and falling height. It increases with the increase of diameter of molten copper column, but the mass has a weak effect. The pressure wave generated by the interaction of molten copper column with cooling water gradually increases with an increase in the temperature of molten copper column. The energy conversion rate in the interaction of molten copper column with cooling water was calculated. The rate of energy conversion from the thermal energy of molten copper column to the energy of pressure wave is low because most of the thermal energy is dissipated into the cooling water by heat transfer.     

氨法烟气联合脱硫脱氮技术工艺

SOx和NOx是燃煤锅炉排放的主要污染物,传统分步脱硫脱氮设备昂贵且效率不高,而氨法烟气脱硫脱氮具有显著的技术优势:脱硫效率高,脱硫脱氮一举两得;不产生废渣、废水;脱硫剂利用充分、耗量小、具有节能功效。因此它具有广阔的应用前景。     

Spatial variability of ammonium and nitrate in soils near a poultry farm

This paper assesses the distribution of ammonium (NH4+) and nitrate (NO3-) nitrogen deposition in native bushland soil adjacent to an open ventilated poultry farm. The farm is located in Thirlmere 150 km south west of Sydney, Australia. A total of 104 geographically referenced soil cores were obtained from the study area. Soil pH, electrical conductivity (EC), NH4(+) - and NO3(-)-nitrogen concentrations were analysed for variable trends at three depths, i.e. 0-30, 30-60, and 60-90 cm. Significantly higher concentrations of the two nitrogen forms and EC were observed nearer to the farm in the surface soil samples (0-30 cm). The distribution of NH4+, NO3- and EC were all correlated in surface samples throughout the study area. There was no indication of NH4+ and NO3- leaching within soil profile sampled and it appears that weeds and native vegetation had utilised the accumulated nitrogen. The level of N deposition adjacent to the poultry farm decreased downwind due to dispersion of plume and to the buffering effects from the bushland.     

皖西大别山区资源转化模式探讨

皖西大别山区处于亚热带湿润季风气候区和半湿润季风气候区的过渡地带,生物资源种类较多;但是,作为主体的林业资源已严重萎缩。当地人们在生存与生产活动中正在寻求资源转化的延伸与替代。其资源转化的基本模式是:资源—产品—商品—货币—资源。前段注重于开发利用,后段注重于保护增值。每个环节,在不同的时间与空间都会有一定的替代内容。今后应采取有效措施,促成资源转化模式的适度组配,以保证山区农民在开发利用与保护增值资源的辩证统一中,尽快脱贫致富。     

赖溪河的氨污染对发展渔业的影响

本文根据近几年来对赖溪河水质的调查研究,讨论了环境因素与水中氨浓度的关系及氨污染对发展淡水渔业的影响,并提出了对策。     

An estimate of the conversion rates of SO_2 to SO_4~(2-)- and NO_2 to HNO_(3+) NO_3~- for the evaluation air pollution in Beijing

The conversion rates of SO2 to SO42- and NO2 to HNO3+NO3- are estimated from the field-data obtained in Beijing in summer, 1988. The results show that the conversion rate of NO2 is about four times as much as that of SO2; The conversion rates have a diurnal variation in a day. On the average, the rate of SO2 is estimated to be 4.7% h-1 during the daytime and 3.4% h-1 during the nighttime. Similarly, the rate of NO2 is estimated to be 17.2% h-1 and 12% h-1 respectively.