Cement replacement by sugar cane bagasse ash: CO2 emissions reduction and potential for carbon credits

This paper presents a study of cement replacement by sugar cane bagasse ash (SCBA) in industrial scale aiming to reduce the CO₂ emissions into the atmosphere. SCBA is a by-product of the sugar/ethanol agro-industry abundantly available in some regions of the world and has cementitious properties indicating that it can be used together with cement. Recent comprehensive research developed at the Federal University of Rio de Janeiro/Brazil has demonstrated that SCBA maintains, or even improves, the mechanical and durability properties of cement-based materials such as mortars and concretes. Brazil is the world’s largest sugar cane producer and being a developing country can claim carbon credits. A simulation was carried out to estimate the potential of CO₂ emission reductions and the viability to issue certified emission reduction (CER) credits. The simulation was developed within the framework of the methodology established by the United Nations Framework Convention on Climate Change (UNFCCC) for the Clean Development Mechanism (CDM). The State of São Paulo (Brazil) was chosen for this case study because it concentrates about 60% of the national sugar cane and ash production together with an important concentration of cement factories. Since one of the key variables to estimate the CO₂ emissions is the average distance between sugar cane/ethanol factories and the cement plants, a genetic algorithm was developed to solve this optimization problem. The results indicated that SCBA blended cement reduces CO₂ emissions, which qualifies this product for CDM projects.     

The application of electrochemical technology to the remediation of oily wastewater

The successful application of electrochemical technology, employing a dimensionally stable anode (DSA((R))), for the remediation of wastewater from the oil extraction industry has been demonstrated. Samples from the oil-water separation box of an effluent treatment plant were submitted to voltammetry, chronoamperometry and electrolysis studies using a DSA anode of nominal composition Ti/Ru(0.34)Ti(0.66)O(2). Electrolysis of the oily wastewater lead to a time-dependent reduction in chemical oxygen demand (COD) in the sample that could be attributed to: (i) the direct oxidation of oil components at the electrode, by the metal oxide itself or by OH() radicals available at the electrode surface, (ii) the indirect oxidation of oil components by intermediate oxidising agents formed in parallel reactions (ex. ClO(-)), and (iii) the aggregation of suspended oil droplets by electroflotation. The largest reduction (57%) in COD was obtained following electrolysis of an oily sample for 70 h at 50 degrees C with a current density of 100 mA cm(-2). The stability of DSA electrodes for use in oily wastewater remediation has been assessed.     

Radionuclides, heavy metals and fluorine incidence at Tapira phosphate rocks, Brazil, and their industrial (by) products

Inorganic phosphate fertilizers may contain radionuclides, heavy metals and fluorine. This paper presents the possible environmental hazards from Tapira phosphate rocks and their (by) products (Brazil) utilized as phosphate fertilizers. The activity concentration of 238U, 234U, 226Ra and 40K in Tapira phosphate rocks is within the world range for these rock types. The 232Th activity concentration is higher than the mean reported in phosphate rocks. A value of 2184 nGy h(-1) was obtained for the exposure dose rate in Tapira phosphate deposit area, which is indicative of a high background radiation area. The flotation-separation process causes the incorporation of no more than 9%, 11% and 24% of radionuclides, heavy metals and fluorine, respectively, into the phosphate concentrate. The radionuclides and heavy metals existing in phosphate fertilizers applied in Brazilian crops according to the recommended rates, do not raise their concentration in soils to harmful levels.     

Effects of insecticides used in strawberries on stingless bees Melipona quadrifasciata and Tetragonisca fiebrigi (Hymenoptera: Apidae)

Environmental Science and Pollution Research - The use of pesticides is considered one of the most important threats to pollinators, especially since they are widely used in agriculture for pest...     

The effects of field-realistic doses of imidacloprid on Melipona quadrifasciata (Apidae: Meliponini) workers

Environmental Science and Pollution Research - The presence of Brazilian native bees can improve tomato production by increasing pollination effectiveness. However, the extensive use of pesticides...     

Solid wastes from the enzyme production as a potential biosorbent to treat colored effluents containing crystal violet dye

Environmental Science and Pollution Research - Sugarcane bagasse, a largely available waste worldwide, was submitted to solid-state fermentation (SSF) using the fungus Metarhizium anisopliae,...     

The Nexus Between CO2 Emissions and Genetically Modified Crops: a Perspective from Order Theory

Genetically modified crops (GMCs) and climate change have been two ecological issues intensely debated over the years. The search for global solutions to the effects of climate change on agriculture has led to the proposal of GMCs as a tool to reduce the environmental impact of agricultural practices and to improve their efficiency of production. At least 27 countries, all over the world, have cultivated GMCs. The purpose of the present paper is to provide insights about the possible linkages between the cultivated areas and the CO₂ emissions in these countries. In addition, the study intends to establish meaningful relationships between attributes related to the particular socio-economic situations and the environmental impacts of GMCs. Some examples are the connection between acreages of GMCs and the status of each country with respect to the Cartagena Protocol on Biosafety, as well as their classification according to the mean income per capita and their CO₂ emissions. In order to give the mathematical support to these links, the methodology known as Order Theory was employed. The results show that Paraguay, India, Burkina Faso, Brazil and Pakistan could be the best contributors to the mitigation of the climate change by the reduction of their CO₂ emission levels through GMCs.

     

Testing instrumental and downscaled reanalysis time series for temperature trends in NE of Spain in the last century

In the context of climatic temperature studies, more often than not a time series is affected by artificial inhomogeneities. To overcome such limitation, we propose a new simple methodology in which promising results point not only toward the detection of unknown inhomogeneous periods but also toward the possibility of reconstructing the uncertain portion of the series. It is based on a parsimonious statistical downscaling (Multiple Linear Regression) of the large-scale 20CR reanalysis data. This method is successfully applied upon two long-range temperature series from a couple of centennial observatories (Ebre and Fabra, NE of Spain) which do not have nearby suitable temperature series to compare with. Results of trend analysis point to a clear signal of warming, with a larger rate of increase for the maximum temperature (respect to the minimum one), for the more recent decades (respect to the whole available period), and for the original series (respect to the reconstructed ones).     

Chlorophyll and suspended sediment mapping to the Caribbean Sea from rivers in the capital city of the Dominican Republic using ALOS AVNIR-2 data

This study aims to study the distribution of contaminants in rivers that flow into the Caribbean Sea using chlorophyll-a (Chl-a) and suspended sediment (SS) as markers and ALOS AVNIR-2 satellite sensor data. The Haina River (HN) and Ozama and Isabela Rivers (OZ-IS) that flow through the city of Santo Domingo, the capital of the Dominican Republic, were chosen. First, in situ spectral reflectance/Chl-a and SS datasets obtained from these rivers were acquired in March 2011 (case A: with no rain influence) and June 2011 (case B: with rain influence), and the estimation algorithm of Chl-a and SS using AVNIR-2 data was developed from the datasets. Moreover, the developed algorithm was applied to AVNIR-2 data in November 2010 for case A and August 2010 for case B. Results revealed that for Chl-a and SS estimations under cases A and B conditions, the reflectance ratio of AVNIR-2 band 4 and band 3 (AV4/AV3) and the reflectance of AVNIR-2 band 4 (AV4) were effective. The Chl-a and SS mapping results obtained using AVNIR-2 data corresponded with the field survey results. Finally, an outline of the distribution of contaminants at the mouth of the river that flows into the Caribbean Sea was obtained for both rivers in cases A and B.