Treatment of oily refinery wastes using a dissolved air flotation process

Refinery wastewater from Moustorod oil refinery, Cairo, Egypt, was treated by chemical coagulation. This step was followed by rapid solid-liquid separation using flotation under pressure of 4 atm. A flotation tank was designed for this purpose. Gas liquid chromatography was used for determination and identification of hydrocarbon compounds in refinery wastewater. The treatment technique proved to be very promising for reducing the hydrocarbon compounds, as well as other pollutants, to a very low concentration. The results obtained showed that some of the hydrocarbon compounds were completely removed.     

Hazardous wastes,adverse impacts,and management strategies: a way forward to environmental sustainability

Environment, Development and Sustainability - There has been great concern about producing, converting, or disposing of the waste obtained from different sources. Waste production is a continuous...     

Root uptake of 137Cs by natural and semi-natural grasses as a function of texture and moisture of soils

This work studies the dependence of 137Cs root uptake on the structure of landscape, especially on texture and moisture of soils, under natural conditions, on abandoned radiopolluted lands in Northern Ukraine. Researches were carried out on a wide range of landscape conditions, at various levels of 137Cs contamination (from 20 up to 5000 kBqm(-2)), with different types of soils (approx. 20 soil varieties), which differ in texture, granulometric composition, degrees of gleyization and water regime, and anthropogenic transformation. The results showed that transfer factor (TF) values of 137Cs differ 50 times for the natural grassy coenoses and 8 times for the semi-natural ones. The lowest 137Cs TF values were measured in the herbages of dry meadows at automorphous loamy soils, while the highest were observed in wetland meadows at organic soils. Finally, the correlation between 137Cs TF values and granulometric composition of soil was determined for both automorphic and hydromorphic mineral soils.     

Drying wastes from urban forestry as an option for their recovery and use in furniture and small wooden objects

The management of urban trees generates wood wastes that are commonly destined for use as firewood or compost. However, they can be used for more noble purposes such as making furniture or small wooden objects. This study aimed to investigate the drying and the shrinkage of the wood of seven typical urban afforestation species to determine the possibility of high-valued alternative use(s). Samples of these species (Cenostigma pluviosum (DC.) E. Gagnon & G.P. Lewis.; Delonix regia (Bojer ex Hook.) Raf.; Ficus benjamina L.; Licania tomentosa (Benth.) Fritsch; Nectandra megapotamica (Spreng.) Mez; Terminalia catappa L.; and Tipuana tipu (Benth.) Kuntze) underwent a drastic drying test in a laboratory oven at 103?±?2 °C, followed by weighing on an analytical balance to monitor the weight over a 24-h period, separated into four intervals of 4 h and one of 8 h. The drying rate, shrinkage and anisotropy coefficient of the species were evaluated. Wood wastes of the species C. pluviosum and L. tomentosa showed greater shrinkage during drying, with the lowest drying rates being found among the other species. F. benjamina, D. regia, N. megapotamica, T. catappa and T. tipu showed lower values of shrinkage and regular anisotropy coefficients close to ideal for application to make small wooden objects according to the characteristics of the species already present in the industrial market. The seven species thus have potential for application in the production of small wooden objects and furniture. This use is a potential alternative for environmental and social betterment.

     

Chemical contaminants in feedlot wastes: concentrations, effects and attenuation

Commercial feedlots for beef cattle finishing are potential sources of a range of trace chemicals which have human health or environmental significance. To ensure adequate protection of human and environmental health from exposure to these chemicals, the application of effective manure and effluent management practices is warranted. The Australian meat and livestock industry has adopted a proactive approach to the identification of best management practices. Accordingly, this review was undertaken to identify key chemical species that may require consideration in the development of guidelines for feedlot manure and effluent management practices in Australia. Important classes of trace chemicals identified include steroidal hormones, antibiotics, ectoparasiticides, mycotoxins, heavy metals and dioxins. These are described in terms of their likely sources, expected concentrations and public health or environmental significance based on international data and research. Androgenic hormones such as testosterone and trenbolone are significantly active in feedlot wastes, but they are poorly understood in terms of fate and environmental implications. The careful management of residues of antibiotics including virginiamycin, tylosin and oxytetracycline appears prudent in terms of minimising the risk of potential public health impacts from resistant strains of bacteria. Good management of ectoparasiticides including synthetic pyrethroids, macrocyclic lactones, fluazuron, and amitraz is important for the prevention of potential ecological implications, particularly towards dung beetles. Very few of these individual chemical contaminants have been thoroughly investigated in terms of concentrations, effects and attenuation in Australian feedlot wastes.     

Mixotrophic cyanobacteria and microalgae as distinctive biological agents for organic pollutant degradation

Millions of natural and synthetic organic chemical substances are present in both soil and aquatic environments. Toxicity and/or persistence determine the polluting principle of these substances. The biological responses to these pollutants include accumulation and degradation. The responses of environments with organic pollutants are perceptible from the dwindling degradative abilities of microorganisms. Among different biological members, cyanobacteria and microalgae are highly adaptive through many eons, and can grow autotrophically, heterotrophically or mixotrophically. Mixotrophy in cyanobacteria and microalgae can provide many competitive advantages over bacteria and fungi in degrading organic pollutants. Laboratory culturing of strict phototrophic algae has limited the realization of their potential as bioremediation agents. In the natural assemblages, mixotrophic algae can contribute to sequestration of carbon, which is otherwise emitted as carbon dioxide to the atmosphere under heterotrophic conditions by other organisms. Molecular methods and metabolic and genomic information will help not only in identification and selection of mixotrophic species of cyanobacteria and microalgae with capabilities to degrade organic pollutants but also in monitoring the efficiency of remediation efforts under the field conditions. These organisms are relatively easier for genetic engineering with desirable traits. This review presents a new premise from the literature that mixotrophic algae and cyanobacteria are distinctive bioremediation agents with capabilities to sequester carbon in the environment.     

Measurements of radiation level in petroleum products and wastes in Riyadh City Refinery

Recent concern has been devoted to the hazard arising from naturally occurring radioactive materials (NORM) in oil and gas facilities. Twenty-seven petroleum samples were collected from Riyadh Refinery. Fourteen samples were products and 13 were waste samples; three of them were scale samples and 10 were sludge samples. The specific radioactivities of (238)U, (232)Th, (226)Ra, (224)Ra, (40)K, and (235)U for all samples were determined using high-resolution gamma-ray spectrometry. The radium equivalent activity, radiation hazard indices and absorbed dose rate in air for all waste samples were estimated. The radon emanation coefficient of the waste samples was estimated. It ranged between 0.574 and 0.154. The age of two scale samples was determined and found to be 2.39 and 3.66 years. The chemical structure of the waste samples was investigated using X-ray florescence analysis (XRF) and Mg, Al, Si, S, Cl, Ca and Fe were found in all samples. From this study, it was noticed that the concentrations of the natural radionuclides in the petroleum wastes were higher than that of the petroleum products.     

Soil mutagenicity as a strategy to evaluate environmental and health risks in a contaminated area

Soil can be a storage place and source of pollutants for interfacial environments. This study looked at a site contaminated with wood preservatives as a source of mutagens, defined routes and extent of the dispersion of these contaminants by particle remobilization and atmospheric deposition, considering an evaluation of risk to human health by quantifying mutagenic risk. Soil sampling sites were chosen at gradually increasing distances (150, 500 and 1700 m) from SI (industrial area pool) and indoor dust (pool in an area at risk at 385 m and at 1700 m). Mutagenesis was evaluated in the Salmonella/microsome assay, TA98, TA97a and TA100 strains with and without S9 mix, YGs strains 1041, 1042 and 1024 for nitrocompounds. Acid extracts were analyzed to define the effects of metals and organics for polycyclic aromatic hydrocarbons (PAHs) and nitroderivates, besides concentrations of these compounds and pentachlorophenol (PCP). Risk to human health was obtained from the relation between the quantified potential of mutagenic risk and estimated soil ingestion for children according to USEPA. Metal concentrations showed a gradient of responses with As, Cr and Cu (total metal) or Cr and Cu (fraction available) higher for SI. However, mutagenic effects of the mixtures did not show this grading. Site SR1700, without a response, was characterized as a reference. In organic extracts, the mutagenesis responses showed the mobility of these compounds from the source. In the surrounding area, a smaller pattern similar to SI was observed at SR150, and at the other sites elevated values of direct mutagenesis at SR500 and diminished effects at SR1700. Tests with YG strains indicated that nitrated compounds have a significant effect on the direct mutagenesis found, except SR500. The investigation of indoor dust in the surrounding area enabled confirmation of the particle resuspension route and atmospheric deposition, showing responses in mutagenicity biomarkers, PAH concentrations and PCP dosage similar to SI. The range of values obtained, considering the soil masses needed to induce mutagenicity was 0.02 to 0.33 g, indicating a high risk associated with human populations exposed, since these values found surpass the standard estimate of 200 mg/day of rate of soil ingestion for children according to USEPA. The study showed that it is essential to evaluate the extent of contamination from the soil to delimit remedial measures and avoid damage to the ecological balance and to human health.     

Evaluating the effectiveness of fingerling stocking and ecological perspectives in enhancing fish harvest in a large tropical reservoir of Northern India

Environment, Development and Sustainability - The present study evaluated the effectiveness of stocking the Gangetic carps, viz. Labeo catla, Labeo rohita, and Cirrhinus mrigala, in a large...     

Morphological and biological features of plants related to their adaptation to coastal habitats

The results of studies on the biomorphological features of 22 plant species growing on the southern coast of the Russian Far East provide evidence for the diversity of pathways of their adaptation to stressful habitat conditions. An analysis of the anatomical and mesostructural characteristics of their leaves has revealed representatives of euhalophytes, crinohalophytes, and glycohalophytes among these plants. Adaptation is achieved by means of halomorphosis, haloxerophytism, and development of some heliophilic features accounted for by species-specific manifestations of succulence, the presence of salt excreting trichomes, and thick pubescence. The similarity of these adaptations to those of desert plants is discussed. Along with plants characterized by a high germination rate, species that counterbalance a low efficiency of seed reproduction by active vegetative propagation have also successfully established themselves on the coast. Adaptation to coastal habitats is also achieved due to the diversity of life forms characterized mainly by tap root systems with laterally extending branch roots, creeping shoots, and a high vegetative mobility.     

Carbon taxation as a means to incentivize forest and fire management

Environment, Development and Sustainability - Wildland fires are increasingly becoming a major concern for many European countries, affecting ecosystems and societies, and they are expected to...     

Poverty alleviation as a pathway to sustainable forest management

In a major deviation from conventional joint forest management approaches where the emphasis of management is on provision of forest products to the participating villagers, the Tamil Nadu Afforestation Project (TAP) focused on poverty alleviation as the principal means to achieve sustainable forest management. This study assesses the effectiveness of TAP’s strategy in improving the ecology and socio-economic conditions of forest fringe villages using a diverse set of research methods. Results indicate that in a span of four to seven years, there was significant increase in forest cover, biodiversity, and agricultural productivity. The project villages have also shown considerable progress in various indicators of socio-economic development. The authors, however, suggest continued poverty alleviation and promotion of alternative livelihood opportunities to place the programme on a stable ground. Meeting the development needs of local villagers through strong and durable institutional linkages is also suggested for the programme to sustain and succeed.     

Self-fertility in scots pine as a mechanism of resistance to chemical mutagens

Experiments on chemical mutagenesis have shown that the seed progeny of self-fertile Scots pine trees (generations M₁ and M₂) have increased resistance to supermutagens, since the frequency of mitotic pathologies in them has proved to be even lower than in the F₁ progeny of self-sterile trees chronically exposed to anthropogenic impact (automobile exhausts). This is evidence that the use of self-fertile forms in selective breeding for general and specific resistance holds much promise.     

Condensational enlargement as a supplement to particle control technologies

An experimental study has been undertaken at the Colorado School of Mines to evaluate the feasibility of using condensational enlargement to enhance the collection efficiency of existing dust control technologies for sub-micron particulates. Although the study was begun to consider the problem of respirable dust control in the underground coal mine environment, this enhancement technique shows promise for a more general class of applications. In the experiments to be reported on, particulates are injected into a continuous flow thermal diffusion chamber and subjected to varying environmental conditions; saturation ratio (rel. humidity), temperature, and residence time were the parameters. The results show that condensation on a dust nucleus (≈0.1 micron) can bring it to a size of several microns in a sufficiently short period of time as to indicate engineering applicability of the concept.     

Long-term flux of Chernobyl-derived 137Cs from soil to French rivers: a study on sediment and biological indicators

Sediment and aquatic plants were collected annually since the early 1990s in the main French rivers, upstream of nuclear power plants. These time series were used in order to assess the parameters of a compartmental model describing the Chernobyl-derived (137)Cs flux from soil to rivers. In order to reduce the dispersal of (137)Cs measured activities in sediment samples due to the granulometric heterogeneity, a correction method was set up using sediment test-fractions artificially enriched with specific diameter particles. The method was based on (137)Cs affinity for fine particles, especially clays, and thus clay and fine silt contents of each sample was analysed. Corrected sediment data showed (1) that the method efficiently reduced the variability; and (2) that (137)Cs activities in French rivers decreased with a half-life of 4 to 6 years since 1987 (after correction by radioactive decay). A similar half-life value was obtained for aquatic plants pointing out that this half-life is related to the gradual decay of the flux from soil to rivers, not to the indicator itself. Comparing our results with similar ones published by other authors, it appeared possible that this kinetic varies with the time period over which the study is conducted, the longer the period the lower is the kinetic.     

Nail polish as a source of exposure to triphenyl phosphate

Triphenyl phosphate (TPHP) is primarily used as either a flame retardant or plasticizer, and is listed as an ingredient in nail polishes. However, the concentration of TPHP in nail polish and the extent of human exposure following applications have not been previously studied. We measured TPHP in ten different nail polish samples purchased from department stores and pharmacies in 2013–2014. Concentrations up to 1.68% TPHP by weight were detected in eight samples, including two that did not list TPHP as an ingredient. Two cohorts (n = 26 participants) were recruited to assess fingernail painting as a pathway of TPHP exposure. Participants provided urine samples before and after applying one brand of polish containing 0.97% TPHP by weight. Diphenyl phosphate (DPHP), a TPHP metabolite, was then measured in urine samples (n = 411) and found to increase nearly seven-fold 10–14 h after fingernail painting (p < 0.001). To determine relative contributions of inhalation and dermal exposure, ten participants also painted their nails and painted synthetic nails adhered to gloves on two separate occasions, and collected urine for 24 h following applications. Urinary DPHP was significantly diminished when wearing gloves, suggesting that the primary exposure route is dermal. Our results indicate that nail polish may be a significant source of short-term TPHP exposure and a source of chronic exposure for frequent users or those occupationally exposed.