The false alarm/surprise trade-off in weather warnings systems: an expected utility theory perspective

Environment Systems and Decisions - Early warning systems for weather events are becoming widespread as technological capacities develop. For warnings to be effective, they must allow enough lead...     

Polyaniline films for efficient removal of aromatic acids from water

Adsorbents in the form of powders are commonly used to filtrate organic compounds in waters. However, this technique requires the separation of the solid phase from the solution after adsorption experiments. Here we propose the use of films as adsorbents. We synthesized polyaniline films by chemical oxidative polymerization of aniline on red ceramic brick. This film was tested to remove trimellitic, hemimellitic and pyromellitic acids as model molecules of the biodegradation of aquatic humic substances. We evaluated the effect of pH, contact time and initial concentration. Our results show that optimal adsorption conditions required 45 min of solid/liquid contact at pH 7 and an initial concentration of 20 mg/l. The maximum adsorption capacities for hemimellitic, trimellitic and pyromellitic acids are 154.83 for hemimellitic acid, 161.88 for trimellitic acid and 175.26 mg/g for pyromellitic acid. The adsorption efficiency of the polyaniline film decreased only by 13 % after four cycles. Overall, we conclude that polyaniline films are promising separable adsorbents compared to conventional adsorbents for removal of aromatic polycarboxylic acids from water.     

Maximising the net social benefit of the construction of post‐disaster alternative housing projects

The widespread destruction that follows large‐scale natural disasters, such as Hurricane Katrina in August 2005, challenges the efficacy of traditional temporary housing methods in providing adequate solutions to housing needs. Recognising these housing challenges, the Congress of the United States allocated, in 2006, USD 400 million to the Department of Homeland Security to support Alternative Housing Pilot Programs, which are intended to explore the possibilities of providing permanent and affordable housing to displaced families instead of traditional temporary housing. This paper presents a new methodology and optimisation model to identify the optimal configurations of post‐shelter housing arrangements to maximise the overall net socioeconomic benefit. The model is capable of quantifying and optimising the impacts of substituting temporary housing with alternative housing on the social and economic welfare of displaced families as well as the required additional costs of doing so. An application example is presented to illustrate the use of the model and its capabilities.     

Field dissipation and health hazard assessment of Fenhexamid on Egyptian grapes

Dissipation behavior and hazard assessment of the fungicide fenhexamid applied to grapes were investigated under climatic conditions in Egypt. Fenhexamid residues were extracted from grape samples with ethyl acetate. The extract was cleaned up by QuEChERS (quick, easy, cheap, effective, rugged, and safe) method, and determined by gas chromatographic method (GC-μECD). The average recoveries ranged between 94.2% and 99.4% with associated relative standard deviation not exceeding 12%. The estimated limit of quantification for fenhexamid was 0.1 mg/kg. The field results showed that fenhexamid dissipated rapidly from grapes and had a half-life of approximately 4.21 days. Hazard assessment was evaluated by using the hazard quotient (HQ). Data showed that the HQ value was significantly less than HQ = 1. Results indicate that hazard of fenhexamid use in grape even at 1.5-fold higher than recommended dosage was negligible to humans. This study could provide guidance for safe and reasonable use of fenhexamid in grapes and prevent health problems to consumers. However, further hazard assessment studies are needed to ascertain the hazard of fenhexamid residues on grape to vulnerable groups, including children, pregnant women, and elderly consumers.     

Mitigation of glyphosate-based herbicide toxicity in maize (Zea mays L.) seedlings by ascorbic acid

Abstract

The toxicity of glyphosate at 3.6?mg L^?1 to maize seedlings raised from un-treated seeds and the effectiveness of seed pretreatment by soaking in 0.25?mmol L^?1 ascorbic acid (AsA) solution for mitigation of toxicity were evaluated in hydroponic culture. Glyphosate dramatically reduced the growth of roots and photosynthetic pigments in the leaves but increased protein content in the leaves. Superoxide dismutase activity and AsA concentration in the roots were increased, and guaiacol peroxidase (GPOX) activity was unaffected. Pretreatment with AsA improved the dry mass of the roots and shoots, increased the protein content in roots and leaves, and significantly decreased the activity of GPOX in roots. The positive effect of AsA treatment was not associated with more efficient functioning of the antioxidative system.     

Environmental risk assessment of cobalt and manganese from industrial sources in an estuarine system

A total of 74 samples of soil, sediment, industrial sludge, and surface water were collected in a Mediterranean estuarine system in order to assess the potential ecological impact of elevated concentrations of Co and Mn associated with a Terephthalic (PTA) and Isophthalic (PIPA) acids production plant. Samples were analyzed for elemental composition (37 elements), pH, redox potential, organic carbon, and CaCO₃ content, and a group of 16 selected samples were additionally subjected to a Tessier sequential extraction. Co and Mn soil concentrations were significantly higher inside the industrial facility and around its perimeter than in background samples, and maximum dissolved Co and Mn concentrations were found in a creek near the plant’s discharge point, reaching values 17,700 and 156 times higher than their respective background concentrations. The ecological risk was evaluated as a function of Co and Mn fractionation and bioavailability which were controlled by the environmental conditions generated by the advance of seawater into the estuarine system during high tide. Co appeared to precipitate near the river mouth due to the pH increase produced by the influence of seawater intrusion, reaching hazardous concentrations in sediments. In terms of their bioavailability and the corresponding risk assessment code, both Co and Mn present sediment concentrations that result in medium to high ecological risk whereas water concentrations of both elements reach values that more than double their corresponding Secondary Acute Values.     

Feasibility of incorporating treated lignins in fiberboards made from agricultural waste

This paper studies the feasibility of incorporating treated lignins in fiberboards made from Vitis vinifera as an agricultural waste. The treated lignins are the purified Kraft lignin and the alkaline hydrolyzed Kraft lignin. V. vinifera raw material and its fibers were characterized in terms of chemical composition and the results were compared to other biomass species. The chemical composition of treated lignins shows that they have high purity compared to the lignin raw material. The lignin-V. vinifera fibreboards were produced on laboratory scale by adding powdered treated lignins to the material that had previously been steam exploded. Some of the important properties of fibreboards prepared using the treated lignins as natural adhesives were evaluated. These properties were density, thickness swelling, water absorption, modulus of elasticity, modulus of rupture, internal bond strength. The explored levels of treated lignins vary from 5% to 20%. The results showed that binderless fibreboards, fibreboards made from V. vinifera fibers and alkaline hydrolyzed Kraft lignin have weaker mechanical properties. However, the fibreboards obtained using purified Kraft lignin have good mechanical and water resistance properties which satisfy the requirements of the relevant standards specifications.     

Decision making under uncertainty using PEES–fuzzy AHP–fuzzy TOPSIS methodology for landfill location selection

The location selection for landfill municipal solid waste is an important issue in waste management. Selection of the optimal location requires consideration of multiple alternative solutions and evaluation factors because of system complexity. Further, ranking of the alternative locations and selection of the most optimal and efficient locations for landfill waste are an important multi-criteria decision-making problem. In this study, the candidate locations for landfill are determined based on Political, Economical, Environmental and Social factors are assessed through decision-makers’ opinion and by the methodology that incorporates fuzzy analytic hierarchy process (fuzzy AHP) and fuzzy technique for order preference by similarity to ideal solution (fuzzy TOPSIS). Specifically, the fuzzy AHP technique is applied to determine the weights of selected criteria impacting the location selection process, and the fuzzy AHP is adapted to model the linguistic vagueness and ambiguity, which can also be expressed as triangular fuzzy numbers. Furthermore, fuzzy TOPSIS technique is employed to rank the alternative locations. The applicability of this methodology is demonstrated by a case study of landfill waste location selection in the region of Casablanca, Morocco, and the results are compared with other techniques. Finally, to complete the treatment, a sensitivity analysis is performed to examine the impact of the preferences given by decision-makers to choose the best location.     

Synthesis,Characterization and Application of Biodegradable Crosslinked Carboxymethyl Chitosan/Poly(Ethylene Glycol) Clay Nanocomposites

Crosslinked carboxymethyl chitosan (CMCh)/poly(ethylene glycol) (PEG) nanocomposites were synthesized using terephthaloyl diisothiocyanate as a crosslinking agent, in presence of montmorillonite (MMT), in different weight ratios of the two matrices. Characterization of nanocomposites was performed using different analyses. Swelling behavior was studied in different buffered solutions. It was found that formation of crosslinked CMCh/PEG nanocomposites increased the swell ability. Metal ions adsorption had also been investigated. The results indicated that crosslinked CMCh adsorbs various metal ions much more than non-crosslinked CMCh. Antimicrobial activity was examined against Gram-positive bacteria (S. aureus (RCMB 010027) and S. Pyogens (RCMB 010015), Gram-negative bacteria (E. coli (RCMB 010056), and also against fungi (A. fumigates (RCMBA 02564, G. candidum (RCMB 05096) and C. albicans (RCMB 05035). Data indicated that most of these nanocomposites exhibited good antimicrobial potency. Degradation studies were carried out in simulated body fluid for different time periods in order to find out the degradation index. Results showed that weight loss (%) of most of the nanocomposites increased as a function of incubation time.     

Androgens,oestrogens, and progesterone concentrations in wastewater purification processes measured with capillary electrophoresis

A novel analytical-scale concept to improve reliability of detection and analysis of natural and processed wastewater samples from a purification plant was developed. A sequential sample clean-up system of polymer-based octadecyl and silane-based quaternary amine sorbents were used for concentrating human based steroid hormones and their metabolites and detecting them by UV absorption with capillary electrophoresis (CE). The water samples were collected from influent and effluent processes of the water purification plant in Helsinki, Finland.The CE methods were partial-filling micellar electrokinetic chromatography and capillary zone electrophoresis. The analysis times and method concentration levels were optimized with eight steroids at the range of 0.5–10 mg/L. Since in CE the detectable quantities were higher than the existing amounts in the process waters, the real samples needed matrix removal combined with steroid enrichment. After 20,000-fold concentration testosterone-glucoside, androstenedione, progesterone, and estradiol-glucoside could be determined in the process water samples. The amounts of individual steroids in influent and effluent waters were 0–429 and 0–207 ng/L, respectively. Correspondently, their total amounts were 735 and 212 ng/L with excellent in day and inter-day repeatability. The RSD values were less than 1, 9.7, and 19% in repeated analyses, calculated from 60 analyses during 24 h, and from 130 analyses during 15 months, respectively. The steroid removal in purification process was 65% on average. The solid particles separated in three steps during the water clean-up concept contained 9.8–45 ng/g steroids in combined dry precipitates.