Application of strategies for sanitation management in wastewater treatment plants in order to control/reduce greenhouse gas emissions

Greenhouse gases (GHG), basically methane (CH(4)), carbon dioxide (CO(2)) and nitrous oxide (N(2)O), occur at atmospheric concentrations of ppbv to ppmv under natural conditions. GHG have long mean lifetimes and are an important factor for the mean temperature of the Earth. However, increasing anthropogenic emissions could produce a scenario of progressive and cumulative effects over time, causing a potential "global climate change". Biological degradation of the organic matter present in wastewater is considered one of the anthropogenic sources of GHG. In this study, GHG emissions for the period 1990-2027 were estimated considering the sanitation process and the official domestic wastewater treatment startup schedule approved for the Metropolitan Region (MR) of Santiago, Chile. The methodology considers selected models proposed by the Intergovernmental Panel on Climate Change (IPCC) and some others published by different authors; these were modified according to national conditions and different sanitation and temporal scenarios. For the end of the modeled period (2027), results show emissions of about 65Tg CO(2) equiv./year (as global warming potential), which represent around 50% of national emissions. These values could be reduced if certain sanitation management strategies were introduced in the environmental management by the sanitation company in charge of wastewater treatment.     

Mapping fire behaviour under changing climate in a Mediterranean landscape in Greece

Understanding how future climate periods influence fire behaviour is important for organizing fire suppression strategy and management. The meteorological factors are the most critical parameters affecting fire behaviour in natural landscapes; hence, predicting climate change effects on fire behaviour could be an option for optimizing firefighting resource management. In this study, we assessed climate change impacts on fire behaviour parameters (rate of fire growth, rate of spread and fireline intensity) for a typical Mediterranean landscape of Greece. We applied the minimum travel time fire simulation algorithm by using the FlamMap software to characterize potential response of fire behaviour for three summer periods. The results consisted of simulated spatially explicit fire behaviour parameters of the present climate (2000) and three future summer periods of 2050, 2070 and 2100, under the A1B emissions scenario. Statistical significant differences in simulation outputs among the four examined periods were obtained by using the Tukey’s significance test. Statistical significant differences were mainly obtained for 2100 compared to the present climate due to the significant projected increase in the wind speed by the end of the century. The analysis and the conclusions of the study can be important inputs for fire suppression strategy and fire management (deployment of fire suppression resources, firefighter safety and exposure, transportation logistics) quantifying the effect that the expected future climate periods can have on fire suppression difficulty in Mediterranean landscapes.     

Gill and liver transcriptomic responses of Achirus lineatus (Neopterygii: Achiridae) exposed to water-accommodated fraction (WAF) of light crude oil reveal an onset of hypoxia-like condition

Environmental Science and Pollution Research - Crude oil is one of the most widespread pollutants released into the marine environment, and native species have provided useful information about the...     

Bacterial community patterns and thermal analyses of composts of various origins.

During composting, the degradation of organic waste is accompanied and driven by a succession of microbial populations exhibiting a broad range of functional capabilities. Detailed inventories of the microbial communities in mature compost, however, are not available. Mature composts, originating from biowaste as well as sewage sludge and anaerobic sludge, were studied by denaturing gradient gel electrophoresis-fingerprints after polymerase chain reaction (PCR) amplification of the 16S rRNA genes using three different universal primer pairs, as well as by differential scanning calorimetry and thermogravimetry. The composts of different origin had different bacterial communities. The influence of different 16S rDNA primer sets on the same batches of compost DNA was evaluated. The clearest separation of different compost types was obtained by using the PCR primer pair 338f + 518r which is suggested for future applications. Communities from the different biowaste compost samples clustered together and could be separated from sewage sludge communities indicating the establishment of different microbial consortia. A similar differentiation of composts was found with the thermogavimetric analyses. It may thus be concluded that the resulting humus quality is closely linked to the microbial communities involved.     

Characterization of a limestone in a batch fluidized bed reactor for sulfur retention under oxy-fuel operating conditions

CO₂ and SO₂ are some of the main polluting gases emitted into atmosphere in combustion processes using fossil fuel for energy production. The former is one of the major contributors to build-up the greenhouse effect implicated in global climate change and the latter produces acid rain. Oxy-fuel combustion is a technology, which consists in burning the fuel with a mix of pure O₂ and recirculated CO₂. With this technology the CO₂ concentration in the flue gas may be enriched up to 95%, becoming possible an easy CO₂ recovery. In addition, oxy-fuel combustion in fluidized beds allows in situ desulfurization of combustion gases by supplying calcium based sorbent.In this work, the effect of the principal operation variables affecting the sulfation reaction rate in fluidized bed reactors (temperature, CO₂ partial pressure, SO₂ concentration and particle size) under typical oxy-fuel combustion conditions have been analyzed in a batch fluidized bed reactor using a limestone as sorbent. It has been observed that sulfur retention can be carried out by direct sulfation of the CaCO₃ or by sulfation of the CaO (indirect sulfation) formed by CaCO₃ calcination. Direct sulfation and indirect sulfation operating conditions depended on the temperature and CO₂ partial pressure. The rate of direct sulfation rose with temperature and the rate of indirect sulfation for long reaction times decreased with temperature. An increase in the CO₂ partial pressure had a negative influence on the sulfation conversion reached by the limestone due to a higher temperature was needed to work in conditions of indirect sulfation. Thus, it is expected that the optimum temperature for sulfur retention in oxy-fuel combustion in fluidized bed reactors be about 925–950 °C. Sulfation reaction rate rose with decreasing sorbent particle size and increasing SO₂ concentration.     

High mercury bioaccumulation in Pacific salmons from the Sea of Okhotsk and the Bering Sea

Mercury (Hg) accumulation in fishes is a serious threat for food security because mercury induces dieseases. Here we studied the total mercury content in four species of Pacific salmon (pink, chum, sockeye and chinook), caught in the Sea of Okhotsk, the Bering Sea, and the Kuril oceanic waters. Results show that the lowest concentration of mercury was found in the pink salmon, and the highest was 5–6 times higher in sockeye. Hg concentrations exceed several times those in other species of Pacific salmon from the North Pacific     

Food Security in Protracted Crises: Building More Effective Policy Frameworks

This paper considers the principal elements that underpin policy frameworks for supporting food security in protracted crisis contexts. It argues that maintaining the food entitlements of crisis-affected populations must extend beyond interventions to ensure immediate human survival. A 'policy gap' exists in that capacities for formulating policy responses to tackle the different dimensions of food insecurity in complex, fluid crisis situations tend to be weak. As a result, standardised, short-term intervention designs are created that fall short of meeting the priority needs of affected populations in the short and long term and only partially exploit the range of policy options available. The paper discusses key attributes of agency frameworks that could support more effective policy processes to address longer term as well as immediate food security needs. Additionally, it points to some main challenges likely to be encountered in developing such frameworks and, with the participation of beneficiaries, translating them into effective action.     

Evolution of lead concentration in the particulate matter of Santiago,Chile, since 1978

Santiago is a city of over 4.5 million inhabitants and about 415000 motor vehicles using leaded gasoline. Twenty-four-hour samples were taken of total and fractionated particulate matter using a low-volume system and two Andersen cascade impactors, between 1978 and 1989 at different sites of the city of Santiago. Lead concentrations were determined by atomic absorption spectrophotometry. The results show that Pb concentrations vary greatly depending on the site selected. Higher values are always detected near the city center. An annual variation with the highest value during the autumn-winter period (May–July) is clearly observed. Lead concentrations versus size are clearly biased to particles smaller than 2 µm. A correlation is observed between Pb concentrations and the suspended particulate matter under 3 µm at different sites of the city. The curves of Pb concentration versus size of the aerosols emitted by the gas exhaust of motor vehicles using leaded gasoline are similar to those of the atmospheric aerosols.     

Improvement of the Bag-Mediated Filtration System for Sampling Wastewater and Wastewater-Impacted Waters

Environmental surveillance of poliovirus (PV) plays an important role in the global program for eradication of wild PV. The bag-mediated filtration system (BMFS) was first developed in 2014 and enhances PV surveillance when compared to the two-phase grab method currently recommended by the World Health Organization (WHO). In this study, the BMFS design was improved and tested for its usability in wastewater and wastewater-impacted surface waters in Nairobi, Kenya. Modifications made to the BMFS included the size, color, and shape of the collection bags, the filter housing used, and the device used to elute the samples from the filters. The modified BMFS concentrated 3–10 L down to 10 mL, which resulted in an effective volume assayed (900–3000 mL) that was 6–20 times greater than the effective volume assayed for samples processed by the WHO algorithm (150 mL). The system developed allows for sampling and in-field virus concentration, followed by transportation of the filter for further analysis with simpler logistics than the current methods. This may ultimately reduce the likelihood of false-negative samples by increasing the effective volume assayed compared to samples processed by the WHO algorithm, making the BMFS a valuable sampling system for wastewater and wastewater-impacted surface waters.     

The impact of economic activity in Asturias on greenhouse gas emissions: consequences for environmental policy within the Kyoto Protocol framework

Climate change is one of the major worldwide environmental concerns. It is especially the case in many developed countries, where the greenhouse gas emissions responsible for this change are mainly concentrated. For the first time, the Kyoto Protocol includes an international agreement for the reduction of the net emissions of these gases. To fulfil this agreement measures designed to reduce or limit current emissions have to be brought into force. Consequently, fears have arisen about possible consequences on competitiveness and future development of manufacturing activities and the need for support mechanisms for the affected sectors is obvious. In this paper, we carry out a study of the emissions of gases responsible for climate change in Asturias (Spain), a region with an important economic presence of sectors with intensive emissions of CO(2), the chief greenhouse gas. To be precise, in the first place, the volumes of direct emissions of the said gases in 1995 were calculated, showing that the sectors most affected by the Kyoto Protocol in Asturias are iron and steel and electricity production. Secondly, input-output analysis was applied to determine the direct and indirect emissions and the direct, indirect and induced emissions of the different production sectors, respectively. The results derived from the direct and indirect emissions analysis and their comparison with the results of the former allow us to reach some conclusions and environmental policy implications.