Biofilm thickness measurement using an ultrasound method in a liquid phase

In this report, the development of an online, noninvasive, measurement method of the biofilm thickness in a liquid phase is presented. The method is based in the analysis of the ultrasound wave pulse-echo behavior in a liquid phase reproducing the real reactor conditions. It does not imply the removal of the biomass from the support or any kind of intervention in the support (pipes) to detect and perform the measurements (non-invasiveness). The developed method allows for its sensor to be easily and quickly mounted and unmounted in any location along a pipe or reactor wall. Finally, this method is an important innovation because it allows the thickness measurement of a biofilm, in liquid phase conditions that can be used in monitoring programs, to help in scheduling cleaning actions to remove the unwanted biofilm, in several application areas, namely in potable water supply pipes.     

Cumulative influences of a small city and former mining activities on the sediment quality of a subtropical estuarine protected area

This study aimed to evaluate the sediment quality in the estuarine protected area known as Cananéia-Iguape-Peruíbe (CIP-PA), located on the southeastern coast of Brazil. The study was designed considering possible negative effects induced by the city of Cananéia on the sediment quality of surrounding areas. This evaluation was performed using chemical and ecotoxicological analyses. Sediments were predominantly sandy, with low CaCO₃ contents. Amounts of organic matter varied, but higher contents occurred closer to the city, as well as did Fe and Total Recoverable Oils and Greases (TROGs) concentrations. Contamination by Cd and Cu was revealed in some samples, while concentrations of Zn were considered low. Chronic toxicity was detected in all tested sediments and acute toxicity occurred only in sediments collected near the city. The principal component analysis (PCA) revealed an association among Cd, Cu, Fe, TROG, fines, organic matter, CaCO₃, and chronic toxicity, whereas acute toxicity was found to be associated with Zn and mud. However, because Zn levels were low, acute toxicity was likely due to a contaminant that was not measured. Results show that there is a broad area within the CIP-PA that is under the influence of mining activities (chronic toxicity, moderate contamination by metals), whereas poorer conditions occur closer to Cananéia (acute toxicity); thus, the urban area seems to constitute a relevant source of contaminants for the estuarine complex. These results show that contamination is already capable of producing risks for the local aquatic biota, which suggests that the CIP-PA effectiveness in protecting estuarine biota may be threatened.     

Variability in environmental impacts of Brazilian soybean according to crop production and transport scenarios

Soybean production and its supply chain are highly dependent on inputs such as land, fertilizer, fuel, machines, pesticides and electricity. The expansion of this crop in Brazil in recent decades has generated concerns about its environmental impacts. To assess these impacts, two representative chains supplying soybeans to Europe were identified: Center West (CW) and Southern (SO) Brazil. Each supply chain was analyzed using Life Cycle Assessment methodology. We considered different levels of use of chemical and organic fertilizers, pesticides and machinery, different distances for transportation of inputs and different yield levels. Because transportation contributed strongly to environmental impacts, a detailed study was performed to identify the routes used to transport soybeans to seaports. Additionally, we considered different levels of land occupation and land transformation to represent the impact of deforestation in the CW region. Environmental impacts were calculated for 1000 kg of soybean up to and including the delivery to Europe at the seaport in Rotterdam, at 13% humidity. Overall results showed that the impacts are greater for CW than for SO for all impact categories studied, including acidification (7.7 and 5.3 kg SO₂ eq., respectively), climate change (959 and 510 kg CO₂ eq.), cumulative energy demand (12,634 and 6,999 MJ) and terrestrial ecotoxicity (4.9 and 3.1 kg 1,4-DCB eq.), except eutrophication and land occupation. The same trend was observed for the crop-production stage. Efforts to reduce chemical fertilizers and diesel consumption can reduce CO₂ emissions. Although deforestation for crop production has decreased in recent years, the contribution of deforestation to climate change and cumulative energy demand remains significant. In the CW scenario deforestation contributed 29% to climate change and 20% to cumulative energy demand. Results also showed that although there are different transportation options in Brazil, the current predominance of road transport causes severe environmental impacts. In CW, road transport contributed 19% to climate change and 24% to cumulative energy demand, while in SO it contributed 12% and 15% to these impacts, respectively. Improvements in the logistics of transportation, giving priority to rail and river transports over road transport, can contribute significantly to reducing greenhouse gas emissions and decreasing energy use. Future studies involving Brazilian soybeans should take into account the region of origin as different levels of environmental impact are predicted.     

Garnering support for Pigouvian taxation with tax return: a lab experiment

Environmental Economics and Policy Studies - To test if tax return can effectively and efficiently increase the acceptance of externality taxation, a laboratory experiment with a negative...     

Development of a real-time immuno-PCR assay for the quantification of 17β-estradiol in water

A competitive real-time (RT) immuno-polymerase chain reaction (iPCR) (RT-iPCR) assay was developed for the sensitive quantification of 17β-estradiol in water. Using a universal iPCR method and polyclonal antibodies, 17β-estradiol was accurately quantified at concentrations ranging from 1 pg mL^?1 to 10 µg mL^?1. The RT-iPCR assay's limit of detection was 0.7 pg mL^?1. The RT-iPCR assay provided an 800-fold increase in sensitivity as well as an expanded working range compared with the corresponding enzyme-linked immunosorbent assay. Assay cross-reactivity to estrone and estriol, two structurally related estrogens, was below 8%. Water samples spiked with 17β-estradiol were analyzed by RT-iPCR to determine the assay's potential as a rapid screen for the monitoring of manure-borne estrogens in the environment. The assay showed recoveries of 82, 102 and 103% for Milli-Q, tap, and irrigation water, respectively, without requiring sample extraction or concentration prior to analysis.     

Treatment of digestate from a co-digestion biogas plant by means of vacuum evaporation: Tests for process optimization and environmental sustainability

Vacuum evaporation consists in the boiling of a liquid substrate at negative pressure, at a temperature lower than typical boiling temperature at atmospheric conditions. Condensed vapor represents the so called condensate, while the remaining substrate represents the concentrate.This technology is derived from other sectors and is mainly dedicated to the recovery of chemicals from industrial by-products, while it has not been widely implemented yet in the field of agricultural digestate treatment. The present paper relates on experimental tests performed in pilot-scale vacuum evaporation plants (0.100 and 0.025 m³), treating filtered digestate (liquid fraction of digestate filtered by a screw-press separator). Digestate was produced by a 1 MW_e anaerobic digestion plant fed with swine manure, corn silage and other biomasses. Different system and process configurations were tested (single-stage and two-stage, with and without acidification) with the main objectives of assessing the technical feasibility and of optimizing process parameters for an eventual technology transfer to full scale systems.The inputs and outputs of the process were subject to characterization and mass and nutrients balances were determined.The vacuum evaporation process determined a relevant mass reduction of digestate.The single stage configuration determined the production of a concentrate, still in liquid phase, with a total solid (TS) mean concentration of 15.0%, representing, in terms of mass, 20.2% of the input; the remaining 79.8% was represented by condensate. The introduction of the second stage allowed to obtain a solid concentrate, characterized by a content of TS of 59.0% and representing 5.6% of initial mass.Nitrogen balance was influenced by digestate pH: in order to limit the stripping of ammonia and its transfer to condensate it was necessary to reduce the pH. At pH 5, 97.5% of total nitrogen remained in the concentrate. This product was characterized by very high concentrations of total Kjeldhal nitrogen (TKN), 55,000 mg/kg as average.Condensate, instead, represented 94.4% of input mass, containing 2.5% of TKN. This fraction could be discharged into surface water, after purification to meet the criteria imposed by Italian regulation. Most likely, condensate could be used as dilution water for digestion input, for cleaning floor and surfaces of animal housings or for crop irrigation.The research showed the great effectiveness of the vacuum evaporation process, especially in the two stage configuration with acidification. In fact, the concentration of nutrients in a small volume determines easier transportation and reduction of related management costs. In full scale plants energy consumption is estimated to be 5–8 kWh_e/m³ of digestate and 350 kWh_t/m³ of evaporated water.     

Environmental policy for sustainable development of natural resources

This paper describes new environmental policies and expanded administrative agencies which in recent years have been adopted by many governments faced with a continuing decline in the quality of their environments. In a number of developed and developing countries, devising a far reaching environmental policy for sustainable development of the natural resources sector is a national priority. Specific environmental policies may be classified according to objectives, timeframe, mechanisms for implementation, whether or not they are binding, and the nature of sanction. This paper provides some generalizations about certain features common to most environmental policies. In the first section an examination is made of some of the most pressing problems which environmental policies relating to natural resources seek to address. The second section discusses environmental policies themselves. The third section, which makes up the main body of the paper, assesses the strengths and weaknesses of a variety of mechanisms available for implementing environmental policies to promote sustainable development in the natural resources sector.     

Evaluation of the Impacts of Dock Structures and Land Use on Tidal Creek Ecosystems in South Carolina Estuarine Environments

Tidal creeks and their associated salt marshes are the primary link between uplands and estuaries in the southeastern region. They are also critical nursery and feeding grounds. In addition, the uplands surrounding creeks are preferred sites for homebuilding because of their natural beauty and the ability to access the estuary from a personal dock structure. The objective of this study was to evaluate the cumulative impacts of docks on tidal creek nursery habitats for both small and large tidal creeks. The number of docks was associated with the amount of impervious cover in both small and large creeks. The presence of docks had little measurable effect on sediment metal concentrations at the scale of small and large creeks. In small and large creeks, sediment polycyclic aromatic hydrocarbon (PAH) concentrations were related to the human activity in the upland that includes the presence of docks at the scale of small and large creeks. Some impacts on the benthic community were associated with docks and human activity in small creeks but not in large creeks. Suburban development may reduce fish and crustacean abundances, but the dock may potentially mediate the development effect. Individually, the harm to the marine environment resulting from dock shading, chrominated copper arsenate leachates, and PAH contamination was small at the scale of tidal creeks. However, impacts from dock structures could not be separated from anthropogenic watershed-scale effects. These results demonstrate that suburban development with its accompanying dock construction does represent a major source of environmental degradation to tidal creeks and associated salt marsh habitats.     

Exposure of workers in mineral processing industries in Brazil

The mining, milling and processing of uranium and thorium bearing minerals may result in radiation doses to workers. A preliminary survey pilot program, that included six mines in Brazil (two coal mines, one niobium mine, one nickel mine, one gold mine and one phosphate mine), was launched in order to determine the need to control the radioactive exposure of the mine-workers. Our survey consisted of the collection and analysis of urine samples, complemented by feces and air samples. The concentrations of uranium, thorium and polonium were measured in these samples and compared to background data from family members of the workers living in the same dwelling and from residents from the general population of Rio de Janeiro. The results from the coal mines indicated that the inhalation of radon progeny may be a source of occupational exposure. The workers from the nickel, gold and phosphate mines that were visited do not require a program to control internal radiological doses. The niobium mine results showed that in some areas of the industry exposure to thorium and uranium might occur.