Fungal biodegradation and removal of cyanobacteria and microcystins: potential applications and research needs

Environmental Science and Pollution Research - Harmful cyanobacterial blooms (HCB) have severe impacts on marine and freshwater systems worldwide. They cause oxygen depletion and produce potent...     

Development of Cellulose Aerogel as a New Material for the Reduction of Harmful Substances in Cigarette Smoke

The current study proposes a novel and improved cigarette filtration design comprising cellulose nanofibers (CNFs) and powdered activated carbons (PACs) with different dry matter contents. The proposed filter samples were primarily analyzed to verify their applicability as cigarette filters via measurements and standard tests, such as SEM, BET, DSC, and airflow permeability analysis. The results were compared with the cellulose acetate (CA) sample used as a conventional cigarette filter. The preliminary results indicated noticeable improvement compared to the reference CA. Also, the cigarettes were tested using a smoking machine, and the filtered smoke was analyzed using GC–MS to evaluate the filters' performance in reducing the harmful substances present in the smoke. The results showed that the filters made of CNF and PAC significantly decreased the toxic substances compared with the reference but did not affect the nicotine substantially and therefore will not negatively impact the trance level of smokers.

     

Integrated process approach for degradation of p-cresol pollutant under photocatalytic reactor using activated carbon/TiO2 nanocomposite: application in wastewater treatment

Environmental Science and Pollution Research - Over the years, biodegradation has been an effective technique for waste water treatment; however, it has its own limitations. In order to achieve a...     

Ginkgo biloba mitigates silver nanoparticles-induced hepatotoxicity in Wistar rats via improvement of mitochondrial biogenesis and antioxidant status

Environmental Science and Pollution Research - Silver nanoparticles (AgNPs) are noble metal nanoparticles, due to their good physicochemical properties, which have been exploited in biological...     

Effects of soiling and cleaning on the reflectance and solar heat gain of a light-colored roofing membrane

A roof with high solar reflectance and high thermal emittance (e.g., a white roof) stays cool in the sun, reducing cooling power demand in a conditioned building and increasing summertime comfort in an unconditioned building. The high initial solar reflectance of a white membrane roof (circa 0.8) can be lowered by deposition of soot, dust, and/or biomass (e.g., fungi or algae) to about 0.6; degraded solar reflectances range from 0.3 to 0.8, depending on exposure. We investigate the effects of soiling and cleaning on the solar spectral reflectances and solar absorptances of 15 initially white or light-gray polyvinyl chloride membrane samples taken from roofs across the United States. Black carbon and organic carbon were the two identifiable strongly absorbing contaminants on the membranes. Wiping was effective at removing black carbon, and less so at removing organic carbon. Rinsing and/or washing removed nearly all of the remaining soil layer, with the exception of (a) thin layers of organic carbon and (b) isolated dark spots of biomass. Bleach was required to clear these last two features. At the most soiled location on each membrane, the ratio of solar reflectance to unsoiled solar reflectance (a measure of cleanliness) ranged from 0.41 to 0.89 for the soiled samples; 0.53 to 0.95 for the wiped samples; 0.74 to 0.98 for the rinsed samples; 0.79 to 1.00 for the washed samples; and 0.94 to 1.02 for the bleached samples. However, the influences of membrane soiling and cleaning on roof heat gain are better gauged by fractional variations in solar absorptance. Solar absorptance ratios (indicating solar heat gain relative to that of an unsoiled membrane) ranged from 1.4 to 3.5 for the soiled samples; 1.1 to 3.1 for the wiped samples; 1.0 to 2.0 for the rinsed samples; 1.0 to 1.9 for the washed samples; and 0.9 to 1.3 for the bleached samples.     

Urban growth containment policies for the guidance and control of peri-urbanization: a review and proposed framework

The purpose of this study is a review of urban growth containment policies for the guidance and control of peri-urbanization. The review of selected resources illustrates two policies: "urban growth containment policies based on planning interventions (UGCPI)" and "urban growth containment policies based on financial interventions (UGCFI)". The analysis of these policies reveals their distinct effects inside and outside the metropolitan boundaries, which, despite the positive results, create various practical consequences and challenges. This highlights the necessity of a special framework of growth guidance and control of peri-urbanization in response to the consequences and challenges of previous policies. The proposed framework is based on the four fundamental components, including regular growth, continuous activity interactions, optimal performance, and institutional capacity building that integration between them can make it possible to guide changes during the time. Certainly, the consequence of such an approach is the regular functional and structural landscape of peri-urban areas in the twenty-first century.

     

Simulating spatial pattern of urban growth using GIS-based SLEUTH model: a case study of eastern corridor of Tehran metropolitan region,Iran

Tehran metropolitan region (TMR) has experienced rapid urbanization in the last few decades. This accelerating urbanization trend mainly arising from high natural population growth and rural–urban migration along with rapid socioeconomic changes formed unplanned and uncontrolled urban expansion in peri-urban areas and resulted in degrading environmental quality and considerable changes in the urban landscapes of the TMR. Thus, the main objective of this research is to model spatial pattern of urban growth in eastern corridor of TMR using GIS-based SLEUTH model and the prediction of future developments of the region from 2014 to 2060. The SLEUTH is one of the most powerful models for urban growth modeling. This model analyzes the spatial pattern of urban growth based on historical data obtained from satellite images of 1987, 2003, 2011, and 2014. The results indicate that the most important factors affecting the urban growth are slope resistance and road gravity. The slope resistance is the highest coefficients value, which illustrates the limiting influence of the slopes on general trend of urban growth in eastern corridor of the TMR. The road gravity stands in second place where it displaces orientation of linear form of outlying pattern alongside the transportation network; it represents that the main pattern of urban growth in peri-urban areas of the region have a linear nature and edge expansion due to slope resistance and road-influenced growth, while spread, diffusion, and breed coefficients display low probability of new spreading center and spontaneous growth in the study area. In addition, the prediction of urban growth for 2020–2060 revealed that urban expansion which was 41,500 ha in 2014 will increase to 179,400 ha in 2060 with noticeable growth rate of 145.6 %. Comparing study area and other researches indicate that the urban growth happens in high rate in eastern corridor. One of the main reasons of this growth goes back to the formation of the second homes for residents of Tehran metropolitan city.     

Investigation of arsenic removal in batch wise water treatments by means of sequential hydride generation flow injection analysis

Arsenic water pollution is a big issue worldwide. Determination of inorganic arsenic in each oxidation state is important because As(III) is much more toxic than As(V). An automated arsenic measurement system was developed based on complete vaporization of As by a sequential procedure and collection/preconcentration of the vaporized AsH(3), which was subsequently measured by a flow analysis. The automated sensitive method was applied to monitoring As(III) and As(V) concentrations in contaminated water standing overnight. Behaviors of arsenics were investigated in different conditions, and unique time dependence profiles were obtained. For example, in the standing of anaerobic water samples, the As(III) concentration immediately began decreasing whereas dead time was observed in the removal of As(V). In normal groundwater conditions, most arsenic was removed from the water simply by standing overnight. To obtain more effective removal, the addition of oxidants and use of steel wools were investigated. Simple batch wise treatments of arsenic contaminated water were demonstrated, and detail of the transitional changes in As(III) and As(V) were investigated.     

Development of a Model for Simulation of Solute Transport in a Stream–Aquifer System

A model for simulation of solute transport in a dynamic stream–aquifer system is developed by integrating four existing sub-models. Interface packages are created to link the sub-models. The developed model is successfully used to simulate chloride transport in the stream–aquifer system of the Arkansas River and the Equus Beds Aquifer in Kansas and demonstrates that chloride concentration in the aquifer decreases in the vicinity of the simulated channel over time.