Effect of temperature and organic nutrients on the biodegradation of linear alkylbenzene sulfonate (LAS) during the composting of anaerobically digested sludge from a wastewater treatment plant

Limits on the application of biosolids (anaerobically processed sludges from wastewater treatment plants) as fertilizers for the amendment of soil are becoming greater because of the accumulation of recalcitrant substances, making necessary the use of techniques that bring the concentration of xenobiotics to lower concentrations than those permitted. In general, the biosolids composting process is sufficient to reduce the usual concentration of linear alkylbenzene sulfonates (LAS) to low levels. In this work, an assessment is made on the effect of temperature in the capacity of enriched bacterial populations to biodegrade LAS, together with the influence that the available nutrients may have in the biodegradation of these compounds. The results show that the microbial metabolism of LAS was not observed in the thermophilic range. The optimum temperature for the biodegradation of LAS appears to be around 40 degrees C, this is, the lowest assayed here, and at this temperature the differences in the biodegradation of LAS among the nutritionally supplemented cultures are small.     

BR-319: Brazil’s Manaus-Porto Velho Highway and the Potential Impact of Linking the Arc of Deforestation to Central Amazonia

Brazil’s BR-319 Highway linked Manaus, in the state of Amazonas, to Porto Velho, Rondônia, until it became impassable in 1988. Now it is proposed for reconstruction and paving, which would facilitate migration from the “Arc of Deforestation” in the southern part of the Amazon region to new frontiers farther north. The purpose of the highway, which is to facilitate transport to São Paulo of products from factories in the Manaus Free Trade Zone, would be better served by sending the containers by ship to the port of Santos. The lack of a land connection to Manaus currently represents a significant barrier to migration to central and northern Amazonia. Discourse regarding the highway systematically overestimates the highway’s benefits and underestimates its impacts. A variety of changes would be needed prior to paving the highway if these potential impacts are to be attenuated. These include zoning, reserve creation, and increased governance in various forms, including deforestation licensing and control programs. More fundamental changes are also needed, especially the abandonment of the long-standing tradition in Brazil of granting squatters’ rights to those who invade public land. Organizing Amazonian occupation in such a way that road construction and improvement cease to lead to explosive and uncontrolled deforestation should be a prerequisite for approval of the BR-319 and other road projects for which major impacts are expected. These projects could provide the impetus that is needed to achieve the transition away from appropriation of public land by both small squatters and by grileiros (large-scale illegal claimants). A delay in reconstructing the highway is advisable until appropriate changes can be effected.     

Effect of Cadmium on Microbial Activity and a Ryegrass Crop in Two Semiarid Soils

Soil pollution with Cd is an environmental problem common in the world, and it is necessary to establish what Cd concentrations in soil could be dangerous to its fertility from toxicity effects and the risk of transference of this element to plants and other organisms of the food chain. In this study, we assessed Cd toxicity on soil microorganisms and plants in two semiarid soils (uncultivated and cultivated). Soil ATP content, dehydrogenase activity, and plant growth were measured in the two soils spiked with concentrations ranging from 3 to 8000 mg Cd/kg soil and incubated for 3 h, 20 days, and 60 days. The Cd concentrations that produced 5%; 10%;, and 50%; inhibition of each of the two soil microbiological parameter studied (ecological dose, ED, values) were calculated using two different mathematical models. Also, the effect of Cd concentration on plant growth of ryegrass (Lolium perenne, L.) was studied in the two soils. The Cd ED values calculated for soil dehydrogenase activity and ATP content were higher in the agricultural soils than in the bare soil. For ATP inhibition, higher ED values were calculated than for dehydrogenase activity inhibition. The average yields of ryegrass were reduced from 5.03 to 3.56 g in abandoned soil and from 4.21 to 1.15 g in agricultural soil with increasing concentrations of Cd in the soil. Plant growth was totally inhibited in abandoned and agricultural soils at Cd concentrations above 2000 and 5000 mg/kg soil, respectively. There was a positive correlation between the concentration of Cd in the plants and the total or DTPA-extractable concentrations of Cd in the soil.     

Study of the evolution of aerosol emissions from coal-fired power plants due to coagulation, condensation, and gravtitational settling and health impact

This paper studies the scavenging efficiencies of aerosol emissions from coal-fired power plants under different removal mechanisms (coagulation, heterogeneous nucleation and gravitational settling) as a function of time. It also analyses the ‘health impact’ of the aerosol before and after the above dynamic mechanisms by comparing the respirable dust fractions. The well-known equations of evolution are applied to an average PSD that represents the exhaust particulate emissions from coal-fired power plants (i.e. Aboño power plant in Asturias that belongs to Hidrocantábrico Group, S.A.). From this study it is inferred that respirable dust is scavenged with the greatest difficulty and when compared with the initial volume of respirable dust, roughly 20% remains after 18 h of gravitational settling. Therefore, gravitational settling is the main removal mechanism of respirable dust compared to condensation and coagulation.     

Biochar as low-cost sorbent of volatile fuel organic compounds: potential application to water remediation

Pyrolysis of waste materials to produce biochar is an excellent and suitable alternative supporting a circular bio-based economy. One of the properties attributed to biochar is the capacity for sorbing organic contaminants, which is determined by its composition and physicochemical characteristics. In this study, the capacity of waste-derived biochar to retain volatile fuel organic compounds (benzene, toluene, ethylbenzene and xylene (BTEX) and fuel oxygenates (FO)) from artificially contaminated water was assessed using batch-based sorption experiments. Additionally, the sorption isotherms were established. The results showed significant differences between BTEX and FO sorption on biochar, being the most hydrophobic and non-polar contaminants those showing the highest retention. Furthermore, the sorption process reflected a multilayer behaviour and a relatively high sorption capacity of the biochar materials. Langmuir and Freundlich models were adequate to describe the experimental results and to detect general differences in the sorption behaviour of volatile fuel organic compounds. It was also observed that the feedstock material and biochar pyrolysis conditions had a significant influence in the sorption process. The highest sorption capacity was found in biochars produced at high temperature (>?400 °C) and thus rich in aromatic C, such as eucalyptus and corn cob biochars. Overall, waste-derived biochar offers a viable alternative to be used in the remediation of volatile fuel organic compounds from water due to its high sorption capacity.

     

Larvicidal and pupicidal activities of eco-friendly phenolic lipid products from Anacardium occidentale nutshell against arbovirus vectors

Environmental Science and Pollution Research - Aedes aegypti and Culex quinquefasciatus are vectors of diseases that constitute public health problems. The discovery of products capable of...     

Simultaneous removal of metronidazole and Pb(II) from aqueous solution onto bifunctional activated carbons

Environmental Science and Pollution Research - In this work, it was analyzed the behavior of three commercial activated carbons with different textural and chemical properties to adsorb...     

Microplastic distribution in surface sediments along the Spanish Mediterranean continental shelf

Environmental Science and Pollution Research - Microplastics (MPs) are widely recognised as a contaminant of emerging concern in the marine environment. This work provides original data of the...     

Ovariectomy predisposes female rats to fine particulate matter exposure’s effects by altering metabolic,oxidative, pro-inflammatory,and heat-shock protein levels

Environmental Science and Pollution Research - The reduction of estrogen levels, as a result of menopause, is associated with the development of metabolic diseases caused by alterations in...     

Hierarchical priority setting for restoration in a watershed in NE Spain, based on assessments of soil erosion and ecosystem services

Maintaining and enhancing ecosystem services through the restoration of degraded ecosystems have become an important biodiversity conservation strategy. Deciding where to restore ecosystems for the attainment of multiple services is a key issue for future planning, management, and human well-being. Most restoration projects usually entail a small number of actions in a local area and do not consider the potential benefits of planning restoration at broad regional scales. We developed a hierarchical priority setting approach to evaluate the performance of restoration measures in a semiarid basin in NE Spain (the Martín River Basin, 2,112 km²). Our analysis utilized a combination of erosion (a key driver of degradation in this Mediterranean region) and six spatially explicit ecosystem services data layers (five of these maps plotted surrogates for soil retention and accumulation, water supply and regulation, and carbon storage, and one plotted a cultural service, ecotourism). Hierarchical maps were generated using a geographic information system that combined areas important for providing a bundle of ecosystem services, as state variables, with erosion maps, as the disturbance or regulatory variable. This was performed for multiple scales, thereby identifying the most adequate scale of analysis and establishing a spatial hierarchy of restoration actions based on the combination of the evaluation of erosion rates and the provision of ecosystem services. Our approach provides managers with a straightforward method for determining the spatial distribution of values for a set of ecosystem services in relation to ecological degradation thresholds and for allocating efforts and resources for restoration projects in complex landscapes.