The high potential of Pelargonium roseum plant for phytoremediation of heavy metals

The major objective of this investigation was to evaluate the potential of scented geraniums, Pelargonium roseum, to uptake and accumulate heavy metals nickel (Ni), cadmium (Cd), or lead (Pb). For this, plants were grown in an artificial soil system and exposed to a range of metal concentrations over a 14-day treatment period. Then, metals from the entire biomass were extracted. The results showed that scented geranium plants accumulated in excess of 20,055 mg of Ni kg^?1 dry weight (DW) of root and 10,889 mg of Ni kg^?1 DW of shoot, and in excess of 86,566 mg of Pb kg^?1 DW for roots and 4,416 mg of Pb kg^?1 DW for shoots within 14 days. Also, the uptake and accumulation of cadmium in roots of scented geranium plants increased with the exposure at low (250, 500 mg?L^?1) and medium level (750 mg?L^?1) followed by a decline at the highest level (1,000 mg?L^?1). The highest accumulation in roots (31,267 mg?kg^?1 DW) was observed in 750 mg?L^?1 cadmium treatment. In the shoots of scented geraniums, the highest amount of metal accumulation (1,957 mg?kg^?1 DW) was detected at 750 and 1,000 mg?L^?1 of cadmium in the culture solution. Finally, since the high concentrations of Ni or Pb accumulated in shoots of scented geranium has far exceeded 0.1 % DW and for Cd has far exceeded 0.01 % DW, P. roseum is a new hyperaccumulator species for these metals and can be used in phytoremediation industry.     

A robust multi-objective optimization model for project scheduling considering risk and sustainable development criteria

Environment, Development and Sustainability - There is limited research that considers the sustainability aspect of the projects’ schedule. The present study proposes a model to cover this...     

Sustainable application of cochineal-based anthraquinone dye for the coloration of bio-mordanted silk fabric

Natural colors particularly animal-based colorants are employed in the field of cosmetics, food, and flavors and also gaining popularity in textiles, due to their soothing nature. In this study, the microwave-assisted extraction of colorant from cochineal insects for dyeing of bio-mordanted silk has been carried out. Acidic, methanolic, and acidified methanol solubilized media were used to extract the natural colorant from cochineal under microwave irradiation for 1–6 min. Bio-mordants have been employed at optimized conditions to make the process greener and sustainable. It is found that acid solubilized extract of pH 4, employed at 55 °C for 55 min containing 5 g/100 mL of Glauber’s salt as exhausting agent has given high color strength onto microwave-treated silk fabric. Suggested ISO standards for colorfastness have revealed that bio-mordants have given excellent color depth and excellent rating of fastness properties, compared with chemical mordants used. It is found that microwave treatment has not only improved the dyeing behavior of colorant extracted from cochineal in acid solubilized medium but also enhanced the color characteristics onto bio-mordanted silk fabric.     

Synthesis, spectral assignment and application of a recently synthesized macrocyclic ionophore to simultaneous pre-concentration and determination of ultra traces of copper and lead by solid phase extraction-flame atomic absorption spectrometry

Ethyl(2-ethylamino)thiophenol-2,6-pyridinedicarboxylate (ETPD) was synthesized from the reaction of disodium pyridine-2,6-dicarboxylate with 1,2-dibromoethane in methanol, followed by treatment with 2-aminothiophenol. The spectral characterization of ETPD is described in detail. This electron-donating agent was successfully utilized for simultaneous enrichment of ultra trace levels of copper and lead in a wide variety of samples. By passing the aqueous solutions through octadecylsilyl bonded phase membrane disks impregnated with 12 mg of ETPD at flow rates of 45 mL min^?1, Cu and Pb were selectively trapped on the disk surface over the pH range 3.0 to 7.0, whereas most other ions were negligibly retained. Numerous chemical parameters affecting sorption and subsequent elution were also investigated. The target ions were stripped from the disk surfaces by reverse flow, at rates of 12 mL min^?1, and were immediately introduced to the nebulizer of an atomic absorption spectrometer. This inexpensive and off-line method offers enrichment factors of 400 and 300 and detection limits of 2.5 and 0.2 μg L^?1 for copper and lead, respectively. The potential applicability of the method was confirmed by its reliable use in quantification of these elements in some real water samples, industrial effluents, three tea samples and peppers, as well as by comparison with graphite furnace atomic absorption spectrometric determinations.     

Appraisal of methane production and anaerobic fermentation kinetics of livestock manures using artificial neural networks and sinusoidal growth functions

This study aimed to perform a comparative analysis of the performance of five models (Gompertz, logistic, Richards, the first-order, artificial neural networks) in predicting methane production rate from anaerobic digestion of livestock manures. The input variables were fermentation time, digestion temperature, biogas temperature, ambient temperature, pH, and specific biogas production rate. The physicochemical compositions of cow manure and sheep manure showed that volatile solid (VS) contents were close to each other in manure compositions (77.6% and 64.7%, respectively), while the potential of methane production from cow manure (673.44 mL CH₄/g VS) was greater than that from sheep manure (320.32 mL CH₄/g VS). The determination coefficients (R²) for logistic function, Gompertz, Richards, the first-order, and ANN models were obtained as 0.968, 0.967, 0.975, 0.825, and 0.995 for the cow manure, respectively. In case of the sheep manure, the R² values obtained from these models were 0.976, 0.979, 0.981, 0.968 and 0.991, respectively. Although the determination coefficients of all models were in satisfactory agreement with the experimental data, the ANN model showed competitive lower RMSE values of 0.111 and 0.164 for cow and sheep manure data sets, respectively, indicating its superior performance than other models.

     

Biosynthesis of iron nanoparticles and their application in removing phosphorus from aqueous solutions

This paper reports the biosynthesis of nanoscale zero-valent iron (nZVI) using the extracts of Shirazi thyme leaf (Th-nZVI) and pistachio green hulls (P-nZVI). Scanning electron microscopy verified the successful synthesis of the poorly crystalline nZVI with a spherical shape and diameter in the range of 40–70 nm. According to X-ray diffraction and Fourier transform infrared spectroscope analyses, the synthesised nZVI were composed of iron oxides nanoparticles and ployphenol obtained from Shirazi thyme leaf and pistachio green hulls extracts acting as both reducing and capping agents. The phosphorus removal efficiency of Th-nZVI and P-nZVI increased with time and reached equilibrium at about 4 and 2h, respectively. Sorption of phosphorus on both sorbents was observed to be pH-dependent with maximum phosphorus removal occurring in the pH range of 2–5. Langmuir, Freundlich, Redlich–Peterson, and Temkin models were used to describe phosphorus sorption at pH 5 and maximum sorption capacity for Th-nZVI and P-nZVI was about 40.52 and 29.33?mg?g^?1, respectively. Correlation coefficient (R²) and standard errors of estimate showed that the Elovich model was better than other models at describing the kinetic data. These results suggested that the synthesised nZVI with Shirazi thyme leaf and pistachio green hulls extracts could be employed as an efficient sorbent for the remediation of phosphorus from contaminated water sources.     

Hepatitis E Virus Genotype 4 Sequences Detected in Sewage from Treatment Plants of China

The aim of this study was to investigate the occurrence of hepatitis E virus (HEV) in sewage samples in Shen Zhen, China. Sewage samples were collected from 152 sewage plants including livestock sewage, domestic sewage and treated sewage from May to July of 2015. Two of 152 samples were HEV positive (1.32%) from the livestock sewage plants. Partial ORF2 fragments of HEV were sequenced and a phylogenetic tree was constructed using MEGA5.1. Blast and phylogenetic analyses showed that both of these two sequences belonged to HEV Genotype 4. To the best of our knowledge, this is the first study on the molecular characterization of HEV in wastewater in China and the first time to detect Genotype 4 in the sewage. Results from this study indicate that the possibilities of sporadic infections of HEV should be emphasized because virus still has the possibility to be circulating in the sewage in China.     

Adsorption and photocatalytic properties of porphyrin loaded MIL-101 (Cr) in methylene blue degradation

Environmental Science and Pollution Research - In this study for the very first time, zinc tetraphenylporphyrin (ZnTPP) was loaded into MIL-101 (Zn[TPP]@MIL-101) to perform an adsorptive and...     

Geochemical fractions and phytoavailability of Zinc in a contaminated calcareous soil affected by biotic and abiotic amendments

Many studies have conducted to determine the best management practice to reduce the mobility and phytoavailability of the trace metals in contaminated soils. In this study, geochemical speciation and phytoavailability of Zn for sunflower were studied after application of nanoparticles (SiO₂ and zeolite, with an application rate of 200 mg kg^?1) and bacteria [Bacillus safensis FO-036b(T) and Pseudomonas fluorescens p.f.169] to a calcareous heavily contaminated soil. Results showed that the biotic and abiotic treatments significantly reduced the Zn concentration in the aboveground to non-toxicity levels compared to the control treatment, and the nanoparticle treatments were more effective than the bacteria and control treatments. The concentration of CaCl₂-extractable Zn in the treated soils was significantly lower than those of the control treatment. The results of sequential extraction showed that the maximum portion of total Zn belonged to the fraction associated with iron and manganese oxides. On the contrary, the minimum percent belonged to the exchangeable and water-soluble Zn (F₁). From the environmental point of view, the fraction associated with iron and manganese oxides is less bioavailable than the F₁ and carbonated fractions. On the basis of plant growth promotion, simultaneous application of the biotic and abiotic treatments significantly increased the aboveground dry biomass yield and also significantly reduced the CaCl₂-extractable form, uptake by aboveground and translocation factor of Zn compared to the control treatment. Therefore, it might be suggested as an efficient strategy to promote the plant growth and reduce the mobile and available forms of toxic metals in calcareous heavily contaminated soils.     

The Effect of Fiber Pretreatment and Compatibilizer on Mechanical and Physical Properties of Flax Fiber-Polypropylene Composites

Recently, investigations have been conducted on the use of natural fibers as reinforcement in low-melting point thermoplastics to improve mechanical properties of composites. However, due to some limitations of natural fibers, composite formulation and processing parameters must be controlled to produce a product with improved properties. This study was conducted to investigate the influence of flax fiber loading, use of compatibilizer and pretreatment on physical and mechanical properties of compression-molded composite. In this study, untreated and treated (sodium hydroxide-treated and mild-bleached flax fibers) fibers at 15% and 30% of the total product mass were used in formulations. To investigate the effect of compatibilizer on product properties, maleic anhydride grafted polypropylene (MAPP) was added at 5% by mass in the formulations. After extrusion of composites formulations, they were formed using compression molding. Results indicated that using flax fiber in composites without pretreatment and compatibilizer could result into products with inferior physical and mechanical properties; this could be compensated by the use of a compatibilizer. However, the use of compatibilizer had some negative effects on some other physical properties like color and melt flow index (MFI).