Radioactivity concentration in liquid and solid phases of scale and sludge generated in the petroleum industry

Scales and sludge generated during oil extraction and production can contain uranium, thorium, radium and other natural radionuclides, which can cause exposure of maintenance personnel. This work shows how the oil content can influence the results of measurements of radionuclide concentration in scale and sludge. Samples were taken from a PETROBRAS unit in Northeast Brazil. They were collected directly from the inner surface of water pipes or from barrels stored in the waste storage area of the E&P unit. The oil was separated from the solids with a Soxhlet extractor by using aguarras at 90+/-5 degrees C as solvent. Concentrations of 226Ra and 228Ra in the samples were determined before and after oil extraction by using an HPGe gamma spectrometric system. The results showed an increase in the radionuclide concentration in the solid (dry) phase, indicating that the above radionuclides concentrate mostly in the solid material.     

Adsorption studies and the removal of dissolved metals using pyrolusite as adsorbent

The adsorption of metals from aqueous solutions of Pb²⁺, Zn²⁺ and Mg²⁺ on naturally occurring pyrolusite have been studied. The chemical stability of the pyrolusite has been determined in NaOH, H₂SO₄, HNO₃, HCl, NaCl and NK₄Cl solutions of various concentrations. Adsorption of the metal ions followed the order Pb²⁺>Zn²⁺>Cd²⁺.The maximum adsorption of Pb²⁺ (100%) occurred at pH 7. the relation between the amount of Pb²⁺ adsorbed per unit weight of pyrolusite and the concentration of Pb²⁺ at equilibrium follows the Freundlich adsorption isotherm.The efficiency of pyrolusite has been demonstrated by removing lead from synthetic waste water. 100% and 96% removal of lead have been achieved from synthetic waste water containing 5 mg l^–1 and 120 mg l^–1 of Pb²⁺ respectively at pH 7. The results of these studies suggest that pyrolusite might provide an economical method for the removal of lead from industrial waste water.     

Health risk assessment of hexachlorocyclohexane in soil,water and plants in the agricultural area of Potohar region,Punjab, Pakistan

Environmental Geochemistry and Health - As the largest organ of the human body, the skin is the major exposure route of NO2. However, the evidence for a relationship between NO2 exposure and...     

Network analysis reveals contrasting effects of intraspecific competition on individual vs. population diets

Optimal foraging theory predicts that individuals should become more opportunistic when intraspecific competition is high and preferred resources are scarce. This density-dependent diet shift should result in increased diet breadth for individuals as they add previously unused prey to their repertoire. As a result, the niche breadth of the population as a whole should increase. In a recent study, R. Svanb?ck and D. I. Bolnick confirmed that intraspecific competition led to increased population diet breadth in threespine stickleback (Gasterosteus aculeatus). However, individual diet breadth did not expand as resource levels declined. Here, we present a new method based on complex network theory that moves beyond a simple measure of diet breadth, and we use the method to reexamine the stickleback experiment. This method reveals that the population as a whole added new types of prey as stickleback density was increased. However, whereas foraging theory predicts that niche expansion is achieved by individuals accepting new prey in addition to previously preferred prey, we found that a subset of individuals ceased to use their previously preferred prey, even though other members of their population continued to specialize on the original prey types. As a result, populations were subdivided into groups of ecologically similar individuals, with diet variation among groups reflecting phenotype-dependent changes in foraging behavior as prey density declined. These results are consistent with foraging theory if we assume that quantitative trait variation among consumers affects prey preferences, and if cognitive constraints prevent individuals from continuing to use their formerly preferred prey while adding new prey.     

How does the brown mussel Perna perna respond to environmental pollution? A review on pollution biomarkers

The brown mussel Perna perna (Linnaeus, 1758) is a valuable resource for aquaculture in tropical and subtropical coastal regions. It presents desirable characteristics for biomonitoring, including being sessile, widely distributed and abundant, and is a filter-feeder able to accumulate several classes of pollutants (e.g., metals, hydrocarbons, among others). Mussels’ biological responses to pollution exposure can be measured as biomarkers, which include alterations ranging from molecular to physiological levels, to estimate the degree of environmental contamination and its effects on biota. This full review compiles two decades (2000–2020) of literature concerning biological effects on P. perna mussel caused by environmental pollutants (i.e., metals, hydrocarbons, and emerging pollutants), considering environmental and farm-based biomonitoring. Biochemical markers related to mussels’ oxidative status were efficient for the biomonitoring of metals (i.e., antioxidant enzymes associated with oxidative damage in biomolecules). Genotoxicity and cytotoxicity indicators (i.e., comet, micronucleus, and neutral red assays) provided a depiction of hydrocarbon contamination. The neutral red assay gave a time-concentration cytotoxic response to a wide range of pollutants, including emerging pollutants (e.g., pharmaceuticals and biocides) and hydrocarbons. Perna perna hemocyte parameters provided a useful approach for biocide biomonitoring. This paper summarizes useful biomarkers from molecular to physiological levels in this mussel species used to identify and quantify the degree of coastal pollution. An integrated biomarker analysis may provide a way to overcome possible biomarker variations and assess multi-polluted sites. Nevertheless, it is necessary to investigate biomarker variations according to natural factors (e.g., season and gonad maturation stage) to standardize them for trustworthy biomonitoring.     

Microfinance institutions and a coastal community's disaster risk reduction,response, and recovery process: a case study of Hatiya,Bangladesh

Several researchers have examined the role of microfinance institutions (MFIs) in poverty alleviation, but the part that they play in disaster risk reduction remains unaddressed. Through an empirical study of Hatiya Island, one of the most vulnerable coastal communities of Bangladesh, this research evaluates perceptions of MFI support for the disaster risk reduction, response, and recovery process. The findings reveal no change in relation to risk reduction and income and occupation aspects for more than one‐half of the clients of MFIs. In addition, only 26 per cent of them have witnessed less damage as a result of being members of MFIs. One can argue, though, that the longer the membership time period the better the disaster preparedness, response, and recovery process. The outcomes of this study could help to guide the current efforts of MFIs to enhance the ability of coastal communities to prepare for and to recover from disasters efficiently and effectively.     

Elaeis guineensis-activated carbon for methylene blue removal: adsorption capacity and optimization using CCD-RSM

Environment, Development and Sustainability - The activated biochar is a carbonaceous material obtained from thermal degradation of biomass with high adsorption potential. On the other hand, the...     

Integrated spatiotemporal trends using TRMM 3B42 data for the Upper São Francisco River basin,Brazil

Trend analysis is an important issue for the decision-making processes. Thus, trends of rainfall, consecutive dry days (CDD), and consecutive wet days (CWD) in the Upper São Francisco River basin, Brazil, using daily rainfall data from the Tropical Rainfall Measuring Mission (TRMM) for recent 18 years, were analyzed. Instead of analyzing the trend of one average time series for one specific confidence level, a spatiotemporal analysis over the entire area with 169 continuous time series is done by applying the nonparametric Mann-Kendall and Sen tests for simultaneously 13 confidence levels and a new integrated confidence classification is proposed. The results show that the rainfall has increased during the less rainy periods (from June to October) and has decreased in the rainy periods (from November to May), with the highest and lowest confidence levels, respectively. An analysis of CDD and CWD shows that the number of CDD has decreased, while the number of CWD has increased, which revealed that the dry periods are more frequently interrupted for the period studied.     

Thermal Degradation and Kinetic Parameters of Polyester and Poly(Lactic Acid) Blends Used in Shopping Bags in Brazil

In this work, synthetic polyester and poly(lactic acid) blends used as biodegradable shopping plastic bags were studied, together with control samples of polyethylene containing pro-oxidant catalysts (called “oxidegradable bags” in the market). Samples of these materials were weighed and buried in simulated soil for 3 months, and then studied by Thermal Analysis including a non-isothermal kinetic analysis. It was observed that although there was no significant mass loss in the period of the ageing, the activation energies for the thermal decomposition processes were substantially reduced for the biodegradable samples, but not for the oxidegradable ones.     

Energy consumption and emission projection for the road transport sector in Malaysia: an application of the LEAP model

This study has attempted to estimate the energy consumption and emission of pollutants namely carbon dioxide (CO₂), carbon monoxide (CO), nitrogen oxides (NOx) and non-methane volatile organic compounds (NMVOC) from the road transport sector in Malaysia from the year 2012 till 2040. This was done using the long-range energy alternatives planning (LEAP) model. Estimates of energy consumption and emissions were evaluated and analysed under a business-as-usual scenario and three other alternative fuel policy scenarios of biodiesel vehicles (BIO), natural gas vehicles (NGV) and hybrid electric vehicles (HEV). The aim of this study has been to identify the potential alternative fuel policies that would be effective in reducing the future growth of road transport energy consumption and emission in Malaysia. Results indicate that the NGV scenario contributes towards the highest reduction in road transport energy consumption followed by BIO and HEV. The NGV scenario also achieves highest mitigation of emission of all the four pollutants. In the case of CO₂ emission, BIO scenario attains second highest mitigation, whereas in the event of CO, NOx and NMVOC emission, HEV scenario achieves second highest mitigation.