Concentrations and sources of Dechlorane Plus in sewage sludge

Sewage sludge from 31 urban Spanish wastewater treatment plants (WWTP) was analyzed for the emerging halogenated flame retardant Dechlorane Plus (DP). Concentrations of the two major isomers in the technical mixture, syn and anti, ranged between 0.903-19.2 and 1.55-75.1 ng g⁻¹ dry weight, respectively. Overall, concentrations of DP were lower than those of polybrominated diphenyl ethers (PBDEs) (9.10-995 ng g⁻¹ dry weight) and this is likely related to the higher usage of brominated flame retardants. The average ratio of the syn isomer to total DP (f_syn) was 0.28 ± 0.05, which is similar to that of the commercial mixture. Comparing different wastewater treatment methods, we found lower concentrations in those using biological nitrogen and phosphorous elimination, suggesting that DP is susceptible to microbial degradation and that anti-DP is more so, given the enrichment of syn-DP in the sewage sludge. Principal components analysis revealed significant positive correlation (r = 0.619, p < 0.05) between total DP concentrations with the contribution of industrial input to waste streams. This implies release of DP is related to industrial activity, likely stemming from the use of the technical product during manufacture of consumer goods. However, use and disposal of products containing DP could not be dismissed. According to our knowledge, this is the first report on DP in WWTP sludge.     

气候波动与土地利用变化对西班牙比利牛斯山脉中部径流影响的评价

在地中海国家扩大灌溉土地的面积,应当考虑气候与土地利用变化对水资源的影响.本文利用降水和温度资料,分析了20世纪中叶以来西班牙比利牛斯山脉中部流域径流的变化趋势.降水与径流之间关系的年变化表明,径流在所研究期间的后半时段相对较低,这一趋势与土地利用变化一致.在月水平上,降水量在10月、4月和7月明显增加,而在3月则有下降;温度在1月和2月有所增加,而在4月则趋于下降.但过去50年间径流在大部分月份中呈显著下降趋势,土地利用和植被覆盖的变化是解释年平均径流下降大约30%的惟一非气候因素.     

Degradation of propyl paraben by activated persulfate using iron-containing magnetic carbon xerogels: investigation of water matrix and process synergy effects

An advanced oxidation process comprising an iron-containing magnetic carbon xerogel (CX/Fe) and persulfate was tested for the degradation of propyl paraben (PP), a contaminant of emerging concern, in various water matrices. Moreover, the effect of 20 kHz ultrasound or light irradiation on process performance was evaluated. The pseudo-first order degradation rate of PP was found to increase with increasing SPS concentration (25–500 mg/L) and decreasing PP concentration (1690–420 μg/L) and solution pH (9–3). Furthermore, the effect of water matrix on kinetics was detrimental depending on the complexity (i.e., wastewater, river water, bottled water) and the concentration of matrix constituents (i.e., humic acid, chloride, bicarbonate). The simultaneous use of CX/Fe and ultrasound as persulfate activators resulted in a synergistic effect, with the level of synergy (between 35 and 50%) depending on the water matrix. Conversely, coupling CX/Fe with simulated solar or UVA irradiation resulted in a cumulative effect in experiments performed in ultrapure water.     

Geomorphological consequences of fraquent and infrequent rainfall and hydrological events in Pyrennez Mountains of Spain

Various aspects of pluviometric andhydrological events have been studiedworldwide, one of which is the geomorphichazards as the intensity of the eventsexceeds various geomorphic thresholds.During the last few years, rainstorms ofdifferent intensities have occurred in theCentral Spanish Pyrenees, including one ofexceptional character. Large, historicaldebris flows have been studied, as well asthe actual sediment transport in smallexperimental catchments. This study showsthat during the most frequent eventssuspended sediment transport is the commongeomorphic process. Bedload is mobilizedseveral times per year while small rockavalanches and channelized debris flowshave a return period of at least 5 years.Hillslope debris flows are triggered byrainfall events with a 25–30 year returnperiod. Reactivation of large, deep massmovements is linked to rainfalls of around100 year return period (between 130 and160 mm in 24 hours). Catastrophicgeomorphic processes occur whenprecipitation exceeds a 100 year returnperiod, as was the case of the Biescascampsite disaster. Geomorphic processestriggered by intense rainfall events havecaused major damage and human disastersbut the hazards have been reduced by theintroduction of several control measures,including reforestation, the constructionof check-dams, canalization of riversegments and improved flood forecasting.     

Design of graphene-based TiO2 photocatalysts—a review

There is a recent increase in the interest of designing high-performance photocatalysts using graphene-based materials. This review gathers some important aspects of graphene?CTiO₂, graphene oxide?CTiO₂, and reduced graphene oxide?CTiO₂ composites, which are of especial relevance as next generation photocatalysts. The methods used for the preparation of these materials, the associated mechanistic fundamentals, and the application of graphene-based composites on the photocatalytic degradation of pollutants are reviewed. Some structural, textural, and chemical properties of these materials and other photo-assisted applications, such as hydrogen production from water splitting and dye-sensitized solar cells, are also briefly included.     

Continuous flow photo-Fenton treatment of ciprofloxacin in aqueous solutions using homogeneous and magnetically recoverable catalysts

The degradation of ciprofloxacin was studied in aqueous solutions by using a continuous flow homogeneous photo-Fenton process under simulated solar light. The effect of different operating conditions on the degradation of ciprofloxacin was investigated by changing the hydrogen peroxide (0–2.50 mM) and iron(II) sulphate (0–10 mg Fe L^?1) concentrations, as well as the pH (2.8–10), irradiance (0–750 W m^?2) and residence time (0.13–3.4 min) of the process. As expected, the highest catalytic activity in steady state conditions was achieved at acidic pH (2.8), namely 85 % of ciprofloxacin conversion, when maintaining the other variables constant (i.e. 2.0 mg L^?1 of iron(II), 2.50 mM of hydrogen peroxide, 1.8 min of residence time and 500 W m^?2 of irradiance). Additionally, magnetite magnetic nanoparticles (ca. 20 nm of average particle size) were synthesized, characterized and tested as a possible catalyst for this reaction. In this case, the highest catalytic activity was achieved at natural pH, namely a 55 % average conversion of ciprofloxacin in 1.8 min of residence time and under 500 W m^?2. Some of the photocatalytic activity was attributed to Fe²⁺ leaching from the magnetic nanoparticles to the solution.     

Environmental occurrence,origin, physical and geochemical properties,and carcinogenic potential of erionite near San Miguel de Allende,Mexico

Detailed geologic surveys and different microscopic and analytical techniques were conducted near Tierra Blanca de Abajo where lung cancer and malignant mesothelioma (MM) are the primary causes of death. Results show that erionite-K occurs as a diagenetic product in altered Oligocene–Miocene rhyolitic tuffs. The microscopic structure of erionite minerals shows concentrations of individual fibers in the range of 0.14–0.547 μm in diameter and 2.81–50 μm in length, with a few “bundles” about 0.2–2.5 μm wide by 10–50 μm long. Chemical properties of erionite show Si/Al in the range of 3.23–3.58 (at.%) and T _Si in the range of 0.76–0.78 (at.%). Potassium is the dominant cation (K > Ca > Mg > Fe). Associated minerals are heulandite, clinoptilolite, quartz, sanidine, anorthite, smectite and opal. This mineral assemblage formed in the lower part of an open catchment, where bicarbonate-rich (T > 30 °C, pH > 8) groundwater discharge conditions prevailed in the past. The physical and chemical characteristics of erionite near San Miguel de Allende are similar to those of erionite from the Cappadocian region of Turkey where erionite is associated with MM. The presence of erionite and the type of respiratory diseases that occur in the village strongly suggest the need for detailed health-based studies in the region. Pliocene–Holocene fine-grain deposits, used in the past for the construction of adobe-houses and exposed in recreational areas, also contain erionite associated with erosion and alluvial transport from the rhyolitic tuffs, potentially affecting more than 13 villages located downstream toward the Allende Dam.     

Shifting frames: mobilizing policy attention for landscape values in a Dutch urban–rural fringe

Despite framing being a powerful mechanism in policy agenda setting, the planning and policy science literature does not yet devote much attention to the analysis of interactional framing processes in policy change processes. We analyse the framing processes that preceded tipping points in the mobilization of policy attention in a Dutch peri-urban region that over time managed to position the development of landscape values on the agendas of local and regional governments, despite various institutional barriers and blockages. After identifying tipping points in the agenda-setting process, and shifts in frames and coalitions, the paper discusses why these shifts occurred. Two framing mechanisms are identified: (1) framing issues, relationships, and interaction processes in conjunction with one another and (2) resemiotizing original frames to establish a fit to the self-referential frames of targeted supporters within and outside government. The conclusion is that a research focus on human interactions at the grassroots level and on the processes of meaning construction over time reveals detailed insights about why and how structural change and transitions come about. The paper concludes with some lessons for policy-makers and planners with regard to developing a more adaptive attitude to emerging initiatives in civil society.