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The Use of Natural Sorbents for Spilled Crude Oil and Diesel Cleanup from the Water Surface
2014
Paulauskienė, T. | Jucikė, I. | Juščenko, N. | Baziukė, D.
Oil spills impose serious damage to the environment. A spilled crude oil or its products affect aquatic flora and fauna and influence the atmosphere as well. Such pollutants are especially dangerous for the water ecosystems, where biological self-purification processes are slower (for example the Baltic Sea), than in warmer regions. In this paper, we evaluate a sorption capacity of ecologically friendly natural sorbents, when the crude oil and diesel are spilled on the surface of water. The experiments are carried out in the laboratory, and the water from the Lithuanian Baltic Sea coastline and Curonian Lagoon is used. Moss, straw, wool, sawdust, and peat are the natural sorbents evaluated during the experiments. Chromatographic analysis of crude oil and diesel during the process of sorption was conducted as well. An experiment with some synthetic sorbents was carried out to compare the results with natural ones. The experiments showed that the most suitable material for crude oil or diesel fuel spilled on the water surface is peat. As well, Lagergren’s model was adopted to the case of the sorption processes we have investigated. It can be exploited as a decision support tool while deciding the required time interval to achieve maximum sorption capacity of the sorbent in use.
Show more [+] Less [-]Biosorption of Textile Dye by Aspergillus lentulus Pellets: Process Optimization and Cyclic Removal in Aerated Bioreactor
2014
Kaushik, Prachi | Mishra, Abhishek | Malik, Anushree | Pant, Kamal Kishore
The present study was conducted to maximize the biosorption of dye by utilizing the native (untreated) pellets of Aspergillus lentulus. The native (55.0 mg/g) and heat-treated (56.7 mg/g) pellets showed excellent dye biosorption capacity which declined upon alginate immobilization (27.2 mg/g). Fourier transform infrared and EDX spectra revealed that phosphate and –CH₃groups are important in determining the biosorption capacity of the pretreated fungal biomass. The operating conditions of the aerated fed batch reactor were optimized and 90 % removal of Acid Blue 120 in 12 h was achieved after five biosorption–desorption cycles. At the end of the fifth cycle, 508.57 mg/L dye could be removed in 60 h with the removal rate of 8.48 mg/L/h. Further, the potential utilization of fungal biomass for the treatment of complex effluent was validated by studying the dye removal from unprocessed textile effluent wherein 58.0 % dye was removed within 4 h of contact.
Show more [+] Less [-]Demonstrating a New BiOCl₀.₈₇₅Br ₀.₁₂₅ Photocatalyst to Degrade Pharmaceuticals Under Solar Irradiation
2014
Lester, Yaal | Avisar, Dror | Gnayem, Hani | Sasson, Y. (Yoel) | Shavit, Michal | Mamane, Hadas
This study demonstrates the potential of a new BiOCl₀.₈₇₅Br₀.₁₂₅ photocatalyst to degrade pharmaceuticals in water (i.e., carbamazepine (CBZ), ibuprofen (IBF), bezafibrate (BZF), and propranolol (PPL)), under simulated solar irradiation. Different parameters were examined through their influence on CBZ degradation. Increasing the catalyst concentration up to 500 mg/L increased CBZ degradation rate; however, above 500 mg/L, CBZ degradation rate was slightly reduced, most likely due to the catalyst’s light-screening effect at high concentrations. Increasing the pH of the tested solution from 4 to 9 decreased the degree of CBZ adsorption to the catalyst and consequently its degradation rate. Quantum yield for CBZ degradation was found to be 0.75 ± 0.05 % using an integrating sphere for absorbance measurements to correctly account for scattering of light by the suspended catalyst. Degradation rates of all examined compounds (at pH 7) followed the order PPL > BZF > IBF > CBZ (highest rate for PPL). Interestingly, PPL was least adsorbed to the catalyst, implying that adsorption is not always mandatory for efficient degradation with BiOCl₀.₈₇₅Br₀.₁₂₅. Different adsorption mechanisms were hypothesized for the different pharmaceuticals, including hydrophobic attraction for the neutrally charged CBZ and ion exchange for the negatively charged IBF and BZF.
Show more [+] Less [-]Trace Metal Mobilization from Surficial Sediments of the Seine River Estuary
2014
Hamzeh, Mariam | Ouddane, Baghdad | Daye, Mirna | Halwani, Jalal
Poses dam in the Seine River estuary acts as receptacle of water drain-offs from highly urbanized and industrialized catchment area; therefore, this water is highly contaminated by trace metals. Most trace elements are mainly bound to particulate matter and are incorporated rapidly into the sediments. Scavenging of these metals in the sediments can be reversible due to several perturbations so as sediments also act as a source of pollutants for the overlying water. For instance, natural events (tide, flood, storm) and anthropogenic processes (water management actions) can cause disturbance of sediments and subsequent remobilization of pollutants to the water column, thereby posing a potential threat for aquatic organisms. The purpose of this study was to evaluate the mobility of trace metals by different methods in the Seine estuary sediments. The surface sediment sampled at Poses dam was characterized by high pollution level of Cd, Cu, Zn, and Pb. The estimation of metal bioavailability through ratio ΣSEM/AVS (simultaneously extracted metals/acid volatile sulfides) indicates a potential bioavailability of trace metals. The chemical partitioning using the European Community of Bureau of Reference sequential extraction method revealed that over 85, 82, and 80 % of the total Cd, Zn, and Pb, respectively, were found to be associated with the exchangeable and reducible fractions of the sediment. Another approach used consists in the quantification of dissolved metals released by sediment resuspension experiments in laboratory under controlled conditions. The results indicated that metals are released rapidly from sediment with a sharp peak at the beginning of the experiment, followed by a fast coprecipitation and/or adsorption processes on the suspended particles. Also, the Cd, Pb, and Ni mobility is higher compared to that of the other metals.
Show more [+] Less [-]Evaluation of Water Quality from the Perspective of Eutrophication in Lake Eğirdir, Turkey
2014
Beyhan, Mehmet | Kaçıkoç, Meltem
Lake Eğirdir is one of the most important freshwater resources in Turkey. The lake is located at the border of Isparta province in South West Turkey, an area known as the “Lakes District”. Lake Eğirdir is very important to the regional economy, but knowledge of its water quality is somewhat limited. Our objective was to assess the current water quality in Lake Eğirdir and its major tributaries, in order to provide information for future management decisions. The temperature, pH, electrical conductivity (EC), dissolved oxygen (DO) concentration, chemical oxygen demand (COD), nitrogen species concentrations, phosphorus species concentrations, and Chl-a concentrations were monitored monthly at seven sampling points in the lake between December 2010 and November 2011. The total nitrogen (TN) and total phosphorus (TP) loads were determined in the three main tributaries of Lake Eğirdir over the same period. At the end of the water quality assessment period, we determined that the lake water has the characteristics of class 1 waters for nitrogen species and class 2 waters for TP, according to the Turkish surface water quality management regulations. The Chl-a values measured in the lake were lower than expected from the trophic state index (TSI) values because of macrophyte growth in the lake. Interestingly, the total nitrogen/total phosphorus (TN/TP) ratios in the lake were low, possibly indicating that the sediment is a significant internal phosphorus resource in Lake Eğirdir.
Show more [+] Less [-]Simultaneous Removal of Endocrine Disruptors from a Wastewater Using White Rot Fungi and Various Adsorbents
2014
Castellana, Giancarlo | Loffredo, Elisabetta
Endocrine disruptor compounds (EDCs) are dangerous pollutants largely present in urban, industrial, and agricultural wastes, and through leaching and degradation from/of these matrices, they can reach and contaminate the environment. Bioremediation of polluted systems from EDCs using white rot fungi can be a valuable alternative approach with respect to conventional physical and chemical methods. These fungi have the capacity to biodegrade numerous phenolic contaminants with their unspecific extracellular ligninolytic enzymes. This study investigated the simultaneous removal of the xenoestrogens bisphenol A (BPA), ethynilestadiol (EE2), and 4-n-nonylphenol (NP), the herbicide linuron, and the insecticide dimethoate from a waste landfill leachate (LEACH) adopting a combination of adsorption and biodegradation. Trametes versicolor and Stereum hirsutum were inoculated, separately, on potato dextrose agar alone or added with different adsorbent materials of low cost and wide availability. The substrates with the fungus were superimposed on the contaminated LEACH. The control used was the LEACH overlaid by not inoculated potato dextrose agar. Both fungi showed an adequate tolerance to LEACH. In a period of 20 days, T. versicolor growing on the various substrates removed almost 100 % of BPA, EE2, NP, and linuron, and from 59 to 97 % of dimethoate. S. hirsutum showed a marked degrading activity only towards NP, which was totally removed after 20 days or less with any substrate and, to a lesser extent, linuron. Even in the absence of fungus, the methodology adopted achieved a relevant contaminant removal, with the only exception of the very hydrophilic dimethoate.
Show more [+] Less [-]Column Tests to Characterise the Hydrogeochemical Response of Pre-oxidised Acid-Generating Tailings with a Monolayer Cover
2014
Pabst, Thomas | Aubertin, Michel | Bussière, Bruno | Molson, John
The study presented here focuses on the use of monolayer covers for reclaiming two acid-generating tailings sites located in Quebec, Canada. One of these covers is made of non-acid-generating tailings, and the other is made of a silty sand (till). The covers are part of the closure plans that aim at controlling acid mine (rock) drainage at these two sites. Reactive tailings and cover material samples were collected in situ and characterised in the laboratory. Large-size columns (230 cm in height) were set up to evaluate the hydrogeological and geochemical response of the tailings and cover systems. Monthly wetting and drying cycles were repeated over nearly 2 years to simulate climatic conditions. Water content, suction, and oxygen concentrations were monitored, and chemical analyses were performed on the leachate collected at the base during each cycle to follow the evolution of water quality, in terms of pH and concentrations of sulfates and metals. In addition, small columns (45 cm in height) were also set up, with a similar testing program, to assess the hydrogeochemical behaviour of exposed tailings. The specific objective of this experimental program was to evaluate the hydrogeological and geochemical behaviour of the tailings-cover systems under controlled conditions. The results indicate that, for the imposed conditions, the monolayer covers became significantly desaturated, thus insufficiently limiting the oxygen diffusion flux. Consequently, these covers do not efficiently prevent sulfide oxidation within the tailings. The implications of these results are also discussed.
Show more [+] Less [-]Comparison of Indicator Bacteria Concentrations Obtained by Automated and Manual Sampling of Urban Storm-Water Runoff
2014
Galfi, Helen | Nordqvist, Kerstin | Sundelin, Monica | Blecken, Godecke-Tobias | Maršálek, Jiři | Viklander, M.
A comparative study of indicator bacteria concentrations obtained by laboratory analysis of grab samples of storm water, which were collected manually or by automatic samplers, was carried out in two urban catchments. Samples were analyzed for four types of indicator bacteria, total coliforms, Escherichia coli (E. coli), enterococci, and Clostridium perfringens and further documented by measurements of total suspended solids (TSS) and turbidity. Analysis of complete data sets (N = 198) indicated no statistically significant differences in the geometric means of all the constituent samples collected automatically or manually, but there were some small differences between the results produced by the two sampling methods applied. Total coliform concentrations were positively biased in samples collected by automatic samplers, but for the three remaining indicator bacteria (E. coli, enterococci, and C. perfringens), the opposite was true. Risk of sample cross-contamination in automatic samplers was assessed in the laboratory by sampling consecutively synthetic storm water with high and low concentrations of E. coli and enterococci. The first low-concentration samples preceded by high-concentration samples were cross-contaminated and the measured concentrations were positively biased. This cross-contamination was explained by storm-water residue in the sampling line. Such a residue remained in place even after line purging by compressed air, and its mass depended on the sampling line length (tested up to 5 m), as verified by measurements in the laboratory. The study findings should be helpful for improving field protocols for indicator bacteria sampling.
Show more [+] Less [-]Sewage Sludge Usage in Agriculture: a Case Study of Its Destination in the Curitiba Metropolitan Region, Paraná, Brazil
2014
Bittencourt, Simone | Serrat, Beatriz Monte | Aisse, Miguel Mansur | Gomes, Debora
The agricultural destination of sewage sludge promotes the return of organic matter and nutrients to the soil, prevents contamination and degradation of hydric resources, and contributes to food and fiber production. In Brazil, the Resolution of the National Environment Council (Conama 375/06) and in the State of Paraná the Resolution of the State Environment Cabinet (Sema 021/09) established criteria and procedures for agricultural use of sewage sludge seeking to avoid risk to public health and the environment. This case study attempts to present the results of the destination of the sludge generated in the Sludge Management Units (SMU) in Curitiba Metropolitan Region (CMR), State of Paraná, Brazil from 2007 to 2010. Data analysis of agronomic parameters and inorganic substances (metals) of 99 batches of sewage sludge destined for agricultural use, based on 239 agronomic projects, was performed. The comparison of the characteristics of the batches generated in anaerobic and aerobic SMUs of CMR was also conducted. During the study, 88,166 t of sludge (33,404 dry tons) were destined for 2,288 ha of agricultural areas. The sludge provided 88 % of the lime, 74 % of N, 73 % of P₂O₅, and 35 % of K₂O for fertilizing the corn, soybean, bean, oat, wheat, green manure, and in the implementation and postharvest of stone fruit trees. The 80 benefited farmers reduced expenses with fertilizers and limestone, saving an average of US$813.45 per ha.
Show more [+] Less [-]The Effects of Radiation Pollution on the Population Diversities and Metabolic Characteristics of Soil Microorganisms
2014
Gu, Meiying | Zhang, Zhidong | Wang, Wei | Tang, Qiyong | Song, Suqing | Zhu, Jing | Xie, Yuqing | Zhang, Lijuan
The effects of radiation pollution on the population diversities and metabolic characteristics in soil microorganisms from radiation pollution areas were investigated. Microbial diversities were determined by using methods of cultured isolates and carbon source utilization on Biolog EcoPlate™. The results showed that radiation changed soil microbial community structure and function. With the increasing of radiation pollution, the number of bacteria and actinomycetes declined gradually. Carbon utilizations of microbial community were significant ly different from each other (ρ < 0.05). Microbial activity decreased gradually; Simpson index and McIntosh index increased, but Shannon-Wiener index was not significant different; the major utilized substrates indicated that microbes more tend to use carboxylic acids and polymers as carbon sources, instead of carbohydrates. In conclusion, the community composition of microorganisms as well as population diversity in soils was impacted obviously by radiation pollution.
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