Optimization of alkaline extraction of natural dye from Henna leaves and its dyeing on cotton by exhaust method

The alkaline conditions for extraction of natural dye from Henna leaves were optimized and the resulting extract was used to further optimize its dyeing conditions on cotton by exhaust method. Dyeings without any mordant were compared with those obtained with premordanting and postmordanting with alum and iron. It was found that dyeings produced with alkaline extracts of Henna leaves have better colour strength than the dye extracts obtained in distilled water. Furthermore, dyeings with alkaline extracts have moderate to good fastness properties and that mordanting did not result in any significant improvement in fastness properties. Finally, in comparative studies between synthetic and this natural dye, it was inferred that natural dye has good potential to act as co-partner with synthetic dye.     

Investigation of thermal treatment on selective separation of post consumer plastics prior to froth flotation

Plastics have become the widely used materials because of their advantages, such as cheapness, endurance, lightness, and hygiene. However, they cause waste and soil pollution and they do not easily decompose. Many promising technologies are being investigated for separating mixed thermoplastics, but they are still uneconomical and unreliable. Depending on their surface characteristics, these plastics can be separated from each other by flotation method which is useful mineral processing technique with its low cost and simplicity.The main objective of this study is to investigate the flotation characteristics of PET and PVC and determine the effect of plasticizer reagents on efficient plastic separation. For that purpose, various parameters such as pH, plasticizer concentration, plasticizer type, conditioning temperature and thermal conditioning were investigated. As a result, PET particles were floated with 95.1% purity and 65.3% efficiency while PVC particles were obtained with 98.1% purity and 65.3% efficiency.     

Reliable method for prediction of the flash point of various classes of amines on the basis of some molecular moieties for safety measures in industrial processes

This work presents a novel, reliable and simple method of estimating the flash point of various types of flammable amines, which are important for safety measures in industrial processes. Different amines include aliphatic amines such as primary, secondary, tertiary and cyclic amines as well as aromatic amines and hetero arenes containing nitrogen heteroatom. The proposed correlation is based on the contribution of some specific molecular moieties and functional groups, which can easily be used for any types of amines. Intermolecular forces are important in the new method, which are counted by two increasing and decreasing parameters. The root mean square (rms) deviation is 18 K for different classes of amines including 133 diverse compounds. The estimated flash points have been compared with one of the best available predictive methods, which gives much lower value of the rms deviation.     

Impacts of urban growth on forest cover in Istanbul (1987–2007)

This article reports findings of a study that examined the impacts of urban growth on forest cover in Istanbul between 1987 and 2007. Four Landsat images from 1987, 1990, 2000, and 2007 were classified with maximum likelihood supervised classification method by using ERDAS IMAGINE 9.1. Forest and urban areas were given highest importance in the classification, while other land-use characteristics, like agriculture and bare soil, were grouped into a third class as others. The study revealed that rapid increase in population and accompanying unplanned urban growth in Istanbul resulted in significant changes in land use after 1987. Urban areas have expanded 87.9% from 1987 to 2007, while forest areas declined 5.4% in the same period. One of the most significant results of the study was that total forest areas in Istanbul have increased 0.3% between 2000 and 2007. This suggests that progress has been made in Istanbul not only in having sustainable urban growth, but also in preserving, restoring, and even expanding forest areas, especially after the year 2000.     

Environmental and climatic signals from stable isotopes in Anatolian tree rings, Turkey

Dendrochronological and oxygen–carbon isotopic analysis was conducted on tree rings collected at two different elevations from three different regions in western Anatolia, Turkey. Tree rings were sampled from Anatolian black pines (Pinus nigra Arn. subsp. pallasiana (Lamb.) Holmboe) of at least 200?years old through an N–S transect covering Bolu-Mengen (north), Kütahya–Simav, and Antalya–Alanya (south) forests. Cellulose was extracted from 5-year blocks of tree rings from lower to upper altitudes in each region. Dendrochronological site chronologies were built for each of the 6 sites, and response to climate was evaluated. The long-term δ¹³C chronologies comprising the period 1800–2008 strongly decline by an average of 2.5‰ from the mid-twentieth century, which corresponds with the commencement of industrialization in Turkey. Oxygen isotope (δ¹⁸O) time series show dominantly low undulations, although some high-frequency variations of up to 6‰ are also observed. As a result of latitude and continent effects, oxygen isotope values of tree rings show an average of 3‰ increase from south (Antalya) to the north (Bolu). Correlations between carbon isotope ratios yield high positive values indicating that industrial pollution exerts a major control on the δ¹³C systematics of the studied trees. Corrected δ¹³C ratios are mostly represented by strong positive responses to variations in temperature and precipitation, whereas δ¹⁸O and summer temperature/precipitation are negatively correlated. Tree-ring widths and δ¹⁸O display similar responses to the temperature and sensitivity to the climatic impact of historic volcanic eruptions, and changes in the solar irradiance record are also detected in other high-resolution paleoclimate archives for the region.     

Thermal Degradation Mechanism of Low-Density Polyethylene Plastic Wastes in Cyclohexane

The thermal LDPE degradation mechanism harnessing a high-pressure autoclave surrounded by a furnace was investigated in this work. Rates of formation of gas, liquid, and solid during degradation of PE plastic wastes in cyclohexane as solvent at 400 and 425°C have been experimentally determined. Four reaction mechanisms have been proposed and tested to estimates of gas, liquid, and solid. Proposed mechanisms are based on the assumption that the reactions are pseudo-first-order with respect to the reacting species. Pseudo-first-order rate constants for each of the indicated mechanistic steps have been calculated by nonlinear regression analysis. The best fit was obtained by model 2 (pure parallel reaction mechanism), and its activation energy was determined.     

Biofuel production,hydrogen production and water remediation by photocatalysis,biocatalysis and electrocatalysis

The energy crisis and environmental pollution have recently fostered research on efficient methods such as environmental catalysis to produce biofuel and to clean water. Environmental catalysis refers to green catalysts used to breakdown pollutants or produce chemicals without generating undesirable by-products. For example, catalysts derived from waste or inexpensive materials are promising for the circular economy. Here we review environmental photocatalysis, biocatalysis, and electrocatalysis, with focus on catalyst synthesis, structure, and applications. Common catalysts include biomass-derived materials, metal–organic frameworks, non-noble metals nanoparticles, nanocomposites and enzymes. Structure characterization is done by Brunauer–Emmett–Teller isotherm, thermogravimetry, X-ray diffraction and photoelectron spectroscopy. We found that water pollutants can be degraded with an efficiency ranging from 71.7 to 100%, notably by heterogeneous Fenton catalysis. Photocatalysis produced dihydrogen (H₂) with generation rate higher than 100 μmol h⁻¹. Dihydrogen yields ranged from 27 to 88% by methane cracking. Biodiesel production reached 48.6 to 99%.

     

Phytoremediation of a petroleum-polluted soil by native plant species in Lorestan Province,Iran

Petroleum hydrocarbons are potentially toxic for organisms due to the inherent properties, such as solubility, volatility, and biodegradability. The petroleum materials released from corroded old pipelines would pollute soils, shallow groundwater and air as a consequence, and threat the health of human and environment. Therefore, the removal of these compounds from environment is vital. The stability of these pollutants at the soil and their gradual accumulation over time would disrupt the normal function of the soil, such as reduced agricultural capability. In this research, the influence of two plant species (Bromus tectorum L. and Festuca arundinacea) with different amendments including arbuscular mycorrhizal fungi, alfalfa residues, and nutrient solution on the degradation rate of petroleum hydrocarbons in soil was studied. The results showed that the most effective treatment for petroleum remediation was related to B. tectorum L. plant when treated with mycorrhizal fungi and nutrient solution. The degradation rate during 40 days was about 83.27% when compared to the control. Arbuscular mycorrhizal associations are important in the restoration of degraded ecosystems because of the benefits to their symbiotic partners. This fungal phytotechnological mechanism is still in its infancy and there has been little research on aged-contaminated soils.

     

Seasonal variation in ambient PM mass and number concentrations (case study: Tehran, Iran)

Tehran, the capital city of Iran, is an important industrial and commercial center. This city is one of the worst cities in the world in terms of air pollution, which is mostly due to mobile sources rather than stationary sources. Particulate matter (PM), which is a complex mixture of extremely small particles and liquid droplets, is considered as an important source of air pollution in Tehran. In this study, our objective was to study PM₁₀, PM_2.5, and PM_1.0 mass and number concentrations and find the correlations of these two parameters in the west-central parts of Tehran during two consecutive warm and cold seasons. The particles collected from five stations were analyzed for their mass and number simultaneously by a laser-based Grimm dust monitor. In general, it was found that the accumulation of the PM in this region is more in the cold season. PM₁₀ mass concentration increases almost twofold and PM_2.5 and PM_1.0 almost three times in this season. The mean number concentration of the particles (0.3–20 μm) was found to be almost 4.8 times in the cold season. It was also noticed that the average dimensions of the particles decrease in that season.