Megaprojects and social and environmental changes: The case of the Thai "water grid"

Large-scale development of irrigation has long been an attractive option of postwar development, and the Mekong region has been no exception. Thailand has developed approximately four million hectares of irrigated land, and its northeastern region (Isaan)--both the driest and poorest part of the country--has been the target of many water projects. However, "full development" of its potential has been constrained by the lack of storage sites and the difficulty of diverting water from the Mekong River. Several ambitious projects have been discussed during the last 50 y, all of which have been aimed at "greening Isaan." In 2003, the Thai administration launched the idea of a national "water grid" that would triple the area of irrigated land in the country. This paper analyzes the emergence of this megaproject, its governance, and its economic and environmental soundness.     

Aqueous solubility, effects of salts on aqueous solubility, and partitioning behavior of hexafluorobenzene: experimental results and COSMO-RS predictions

The aqueous solubility of hexafluorobenzene has been determined, at 298.15 K, using a shake-flask method with a spectrophotometric quantification technique. Furthermore, the solubility of hexafluorobenzene in saline aqueous solutions, at distinct salt concentrations, has been measured. Both salting-in and salting-out effects were observed and found to be dependent on the nature of the cationic/anionic composition of the salt. COSMO-RS, the Conductor-like Screening Model for Real Solvents, has been used to predict the corresponding aqueous solubilities at conditions similar to those used experimentally. The prediction results showed that the COSMO-RS approach is suitable for the prediction of salting-in/-out effects. The salting-in/-out phenomena have been rationalized with the support of COSMO-RS σ-profiles. The prediction potential of COSMO-RS regarding aqueous solubilities and octanol-water partition coefficients has been compared with typically used QSPR-based methods. Up to now, the absence of accurate solubility data for hexafluorobenzene hampered the calculation of the respective partition coefficients. Combining available accurate vapor pressure data with the experimentally determined water solubility, a novel air-water partition coefficient has been derived.     

Optimisation and use of tandem-in-time mass spectrometry in comparison with immunoassay and HRGC/HRMS for PCDD/F screening

Rapid screening of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans using quadrupole ion storage tandem-in-time mass spectrometry (QISTMS) conjointly with polyclonal antibody immunoassay has been considered. The optimisation of the fragmentation of the parent ion in the trap has been completed. The analysis of fly ashes from a municipal waste incinerator contaminated at different levels has then been realised. Results obtained using QISTMS, HRMS and immunoassay are compared.     

Coupled solar photo-Fenton and biological treatment for the degradation of diuron and linuron herbicides at pilot scale

A coupled solar photo-Fenton (chemical) and biological treatment has been used to remove biorecalcitrant diuron (42 mg l(-1)) and linuron (75 mg l(-1)) herbicides from water at pilot plant scale. The chemical process has been carried out in a 82 l solar pilot plant made up by four compound parabolic collector units, and it was followed by a biological treatment performed in a 40 l sequencing batch reactor. Two Fe(II) doses (2 and 5 mg l(-1)) and sequential additions of H2O2 (20 mg l(-1)) have been used to chemically degrade the initially polluted effluent. Next, biodegradability at different oxidation states has been assessed by means of BOD/COD ratio. A reagent dose of Fe=5 mg l(-1) and H2O2=100 mg l(-1) has been required to obtain a biodegradable effluent after 100 min of irradiation time. Finally, the organic content of the photo-treated solution has been completely assimilated by a biomass consortium in the sequencing batch reactor using a total suspended solids concentration of 0.2 g l(-1) and a hydraulic retention time of 24h. Comparison between the data obtained at pilot plant scale (specially the one corresponding to the chemical step) and previously published data from a similar system performing at laboratory scale, has been carried out.     

Assimilative capacity and pollutant dispersion studies for the industrial zone of Manali

In this study the micro-meteorological parameters have been analyzed and the assimilative capacity of Manali is estimated on the basis of ventilation coefficient for the four seasons of the year 1998. Among the various seasons, summer has the lowest pollution potential. The industrial source complex short-term model has been used to predict the spatial distribution of three pollutants namely sulfur dioxide, oxides of nitrogen and suspended particulate matter. The model has been validated using the data measured at site. Statistical evaluation of the model indicates satisfactory performance. Using the model predictions, isopleths have been drawn. The northeastern part of Manali has been identified as vulnerable to high levels of pollution necessitating mitigation measures to be initiated in the region.     

燃煤手烧炉烟尘生成特征及其控制

使用烟气净化测试系统,对燃煤手烧炉燃烧过程烟尘浓度变化进行了在线测定,对水浴净化前后烟气中的颗粒分散度进行了测定分析,并对SW型烟气净化装置的除尘效率进行了测定计算。实验表明,燃煤手烧炉的烟尘生成过程,与其加煤方式直接相关,且受燃烧温度的一定影响。在正常工作条件下,SW型燃煤炉窑烟气净化装置的平均除尘效率可达96 4%。     

Bioavailability of persistent organic pollutants in soils and sediments--a perspective on mechanisms, consequences and assessment

It has been observed that as soil-pollutant contact time increases, pollutant bioavailability and extractability decreases. This phenomenon has been termed 'ageing'. Decreased chemical extractability with increased soil-chemical contact time is evident where both 'harsh' techniques, e.g. dichloromethane Soxhlet extraction, and 'non-exhaustive' techniques, e.g. butanol shake extraction, have been used. It has also been observed that the amount of chemical extracted by these techniques varies considerably over time. Similarly, decreases in bioavailability with increased soil-pollutant contact time have been described in bacterial, earthworm and other organism studies. From these investigations, it has been shown that the fraction of pollutant determined to be bioavailable can vary between organisms. Thus, there is an immediate definition problem, what is bioavailability? Additionally, if bioavailability is to be assessed by a chemical means, which organisms should (or can) be mimicked by the extraction procedure? This review provides a background to the processes inherent to ageing, a discussion of its consequences on bioavailability and ends with some reflections on the appropriateness of chemical extraction techniques to mimic bioavailability     

固硫型煤的生产技术和使用效果

针对链式炉炉内脱硫，设计了固硫型煤生产线，通过测试、试验、生产和实际使用，使固硫型煤满足脱硫要求，同时，节能效果也较明显。另外，对固硫剂、粘结剂的选用和配比作了介绍。     

Development of a new model for batch sedimentation and application to secondary settling tanks design.

Assuming that settling takes place in two zones (a constant rate zone and a variable rate zone), a model using four parameters accounting for the nature of the water-suspension system has been proposed for describing batch sedimentation processes. The sludge volume index (SVI) has been expressed in terms of these parameters. Some disadvantages of the SVI application as a design parameter have been pointed out, and it has been shown that a relationship between zone settling velocity and sludge concentration is more consistent for describing the settling behavior and for design of settling tanks. The permissible overflow rate has been related to the technological parameters of secondary settling tank by simple working equations. The graphical representations of these equations could be used to optimize the design and operation of secondary settling tanks.     

National and sub-national drinking water fluoride concentrations and prevalence of fluorosis and of decayed,missed, and filled teeth in Iran from 1990 to 2015: a systematic review

Fluoride intake, fluorosis, and dental caries could affect quality of life and disease burden worldwide. As a part of the National and Sub-national Burden of Disease Study (NASBOD) in Iran, we conducted a systematic review to evaluate province-year-specific mean drinking water fluoride concentrations and prevalence of fluorosis and of decayed, missed, and filled teeth (DMFT) in Iran from 1990 to December 2015. We did electronic searches of all English and Persian publications on PubMed, ScienceDirect, Google Scholar, and Iranian databases. Results revealed that the weighted mean drinking water fluoride concentration in Iran from 1990 to 2015 has been about 0.65?±?0.38 mg/l. However, based on the WHO guideline value (1.50 mg/l) and the maximum permissible Iranian national fluoride standard (1.40 to 2.40 mg/l depending on the region's climate), there have been some regions in Iran with non-optimum fluoride concentrations in their drinking water (up to 7.0 mg/l). Overall, concentrations have been higher in southern parts of Iran and in some areas of Azerbaijan-e-Gharbi Province in the northwest and lower in the rest of the northwest and central parts of Iran. In addition, some hotspots have been found in Bushehr Province, southwest of Iran. The highest prevalence of dental flourosis has been reported in normal index while the lowest prevalence has been expressed in severe index. The lowest DMFT (about 0.1) was in Arsanjan City in Fars Province, and the highest (about 6.7) was for Najaf Abad City in Isfahan Province. Prevalence of fluorosis has been rather high in studied areas of Iran (e.g. 100 % in Maku City in Azarbaijan-e-Gharbi Province), and there was discrepancy for DMFT, but a lack of studies renders the results inconclusive. Further studies, health education and promotion plans, and evidence-based nutrition programs are recommended.     

Entry and Movement in Vegetation of Lead Derived From Air and Soil Sources

The body of information presented in this paper is directed to individuals concerned with the state of our knowledge on lead uptake and translocation by plants and its subsequent effects. Lead, a non-essential element, is taken up by many plant species primarily via their roots. Large amounts of lead are deposited on plant foliage and most remains as a topical deposit but foliar uptake has been demonstrated. To date it has been assumed that soil lead levels above 1000 ppm are required to cause observable plant effects. Environmental variables, plant age, and species are very important determinants of lead uptake. The few studies done with plant age and speciation, however, provide no clear generalization. Increasing soil lead availability increases plant uptake. Plant uptake decreases with increasing soil phosphorus, organic content, and pH. The lack of observable lead intoxication of native and agricultural plants is surprising in light of evidence that lead concentrations as low as 1 ppm have a profound effect on events associated with photosynthesis and respiration, this has been explained because even though large amounts of lead may be taken up by plant roots they are immobilized by dictyosome vesicles and deposited in the cell wall. It has been suggested that a similar process is operative throughout the plant. The extant data provide no basis for any fear that lead is an imminent dietary hazard to man.     

Concentration,sources and particle size distribution of the atmospheric aerosol of the oviedo urban nucleus (Spain)

The average hourly variation of particle concentration and its charged fraction has been determined in the city of Oviedo (Spain). The population density in the central zone of Oviedo, a city of 180,000 inhabitants, is one of the highest in Europe. The city is not very industrialized.The average particle size distribution in winter and summer has been studied resulting in unimodal spectra, which are fitted to a log-normal distribution.It has been demonstrated that the average distributions in the city of Oviedo are a direct consequence of two primary sources, traffic and heating systems.     

结晶工艺在废水处理领域的应用与发展

结晶水处理工艺具有占地面积小、不产生污泥、可回收资源等优势,近年在国内外备受关注,随着理论和工艺技术的不断完善,其应用范围逐渐扩大。到目前为止,国外已将结晶水处理工艺成功应用于众多实际工程,但国内对其的研究仍局限于实验室阶段。基于上述原因,本文较全面地综述了结晶工艺在废水处理领域的发展现状,并重点对结晶工艺在磷酸盐、重金属的去除与回收以及工业防垢领域的理论研究和工程应用进展进行讨论,同时探讨了目前结晶工艺存在的几个问题以及下一步的发展方向。     

An Evaluation of Catalytic and Direct Fired Afterburners for Coffee and Chicory Roasting Odors

Though the aroma of roasting coffee can be pleasant in small amounts, large scale plants tend to cause public complaints. As a means of control thermal afterburners operating at 1200°F and higher have been commonly employed. Australian coffee consumption in the past has been relatively small but in recent years it has been increasing markedly. As a result, odor complaints have been increasing and one plant, large by Australian standards, caused a public outcry of no small order. High cost of fuel rendered thermal afterburning unattractive and, consequently, the firm in question decided upon catalytic combustion as an alternative. Subsequently, the unit was installed and before and after tests were made for various components. At an operating temperature of about 700°F the results showed comparable fume reductions to thermal afterburning and the findings were confirmed by the cessation of complaints by the public.     

Reduction of dioxins and furanes by spray dryer absorption from incinerator flue gas

Reduction of gas phase polychlorinated dibenzodioxins and dibenzofuranes by spray dryer absorption from incinerator flue gas has been investigated. Results from pilot plant and industrial scale spray absorption systems are reported. The results show that conditions for very high removal efficiencies exist for all isomer groups. Total removal above 95% has been achieved.     

Lead concentrations and source strength in the atmosphere of an urban site

A series of atmospheric lead concentration measurements in the Oviedo urban area have been carried out. A linear correlation between lead and large positive ion concentrations has been obtained (r² = 0.88). From this correlation and by use of a box diffusion model, the lead source strength has been calculated. As an application, measurements of large positive ion concentrations can provide an easy method for lead monitoring in an urban site.     

电化学法生成Fenton试剂及其在工业染料废水降解脱色中的应用

以多孔石墨电极为阴极 ,电解时在阴极通以氧气或空气 ,电解生成的过氧化氢与阳极溶解的Fe2 +进行随后化学反应 ,现场生成羟基自由基 (Fenton试剂 ) ,进而对有机染整工业废水进行降解脱色反应。以可见光吸收谱图表征了工业染料废水经电解槽处理后吸光度的变化 ,以重铬酸钾法测试染料处理后的COD。实验结果表明 ,COD的去除率大于 80 % ,染料的脱色率达 1 0 0 % ,若将电解电流密度控制在 1 0mA/cm2 以下 ,槽电压可控制在 5V以内。实验结果表明 ,向阴极多孔石墨电极中通入空气与通入氧气的效果一致。     

Influence of transport and trends in atmospheric CO2 at Lampedusa

The study of the CO₂ 15-year records at Lampedusa (35° 31′N, 12° 37′E) is presented in this work. Short- and long-term CO₂ variability has been investigated. No significant diurnal variations are observable thus remarking the background character and representativeness of the observation site. The CO₂ long-term trend shows a mean linear growth rate (GR) of 1.9 ppm yr^?1. The periodic behaviour of the time series has been analysed and the mean seasonal cycle amplitude has been found to be 8.72 ppm. The seasonal cycle amplitude shows a marked interannual variability. The lowest value of the seasonal cycle amplitude has been detected in 2003, in concomitance with the strong anomalous heat wave recorded in Europe. CO₂ GR behaviour has been related to global processes such as El Niño Southern Oscillation (ENSO) and global temperature (T_g). The influence of ENSO event on GR is remarkable only during 1998. CO₂ GR curve shows peaks in the periods 1995, 2001 and 2005 (1.9, 3.7, 3.2 ppm yr^?1 respectively) that are characterized by high T_g values and by intense biomass burning events. The anomalous decrease in the GR during the warm 2003 has been attributed to changes in the atmospheric circulation regime. Evaluation of the influence of transport on CO₂ variability has been carried out using backward air-mass trajectory analysis and highlights the effect of the regional distribution of sources and sinks. The industrial activities and forests located in the Eastern European and Russian sector strongly affect the CO₂ mixing ratio. The CO₂ content of air-masses originating from this region is influenced in summertime by the high efficiency of the vegetation sink while in the winter period prevails the effect of industrial emissions.     

The ecology and toxicology of synthetic organic pigments

Current knowledge of the ecological and toxicological properties of synthetic organic pigments is reviewed. Presumably because of their generally low solubility pigments exhibit little biological activity, especially in terms of acute toxicity. Only a minority of products has been subjected to long-term feeding studies, but no evidence of carcinogenic activity has been found. Although pigments are not readily biodegradable there is no evidence that they create any significant ecological problems; in practice only small amounts reach open waters as a result of their manufacture or application.     

普通过磷酸钙清洁生产工艺的研究与应用

通过实现氟硅酸循环利用 ,用含氟硅胶生产白炭黑 ,基本消除普钙生产中含氟污染物的排放 ,且有较好的经济效益。