Recycling of waste glass as a partial replacement for fine aggregate in concrete

Waste glass creates serious environmental problems, mainly due to the inconsistency of waste glass streams. With increasing environmental pressure to reduce solid waste and to recycle as much as possible, the concrete industry has adopted a number of methods to achieve this goal. The properties of concretes containing waste glass as fine aggregate were investigated in this study. The strength properties and ASR expansion were analyzed in terms of waste glass content. An overall quantity of 80 kg of crushed waste glass was used as a partial replacement for sand at 10%, 15%, and 20% with 900 kg of concrete mixes. The results proved 80% pozzolanic strength activity given by waste glass after 28 days. The flexural strength and compressive strength of specimens with 20% waste glass content were 10.99% and 4.23%, respectively, higher than those of the control specimen at 28 days. The mortar bar tests demonstrated that the finely crushed waste glass helped reduce expansion by 66% as compared with the control mix.     

Pollution levels of thiobencarb, propanil, and pretilachlor in rice fields of the muda irrigation scheme, Kedah, Malaysia

The purpose of this study was to investigate the potential risk of pretilachlor, thiobencarb, and propanil pollutants in the water system of the rice fields of the Muda area. The study included two areas that used different irrigation systems namely non-recycled (N-RCL) and recycled (RCL) water. Regular water sampling was carried out at the drainage canals during the weeding period from September to October 2006 in the main season of 2006/2007 and April-May 2007 in off season of 2007. The herbicides were extracted by the solid-phase extraction method and identified using a GC-ECD. Results showed that the procedure for identification of the three herbicides was acceptable based on the recovery test values, which ranged from 84.1% to 96.9%. A wide distribution pattern where more than 79% of the water samples contained the herbicide pollutants was observed at both the areas where N-RCL and RCL water was supplied for the two seasons. During September to October 2006, high weedicide residue concentration was observed at the N-RCL area and it ranged from 0.05 to 1.00 μg/L for pretilachlor and propanil and 10-25 μg/L for thiobencarb. In the case of the area with RCL water, the weedicide residue ranged from 1 to 5 μg/L for pretilachlor and propanil and 10-25 μg/L for thiobencarb. The highest residue level reached was 25-50, 50-100, and 100-200 μg/L for pretilachlor, propanil, and thiobencarb, respectively. During April to May 2007, high residue concentration frequently occurred at the area supplied with N-RCL irrigation water and it ranged from 0.05 to 1.00, 10 to 25, and 25 to 50 μg/L for pretilachlor, propanil, and thiobencarb, respectively. The highest residue level reached was 25-50 μg/L for pretilachlor and 100-200 μg/L for propanil and thiobencarb. There was an accelerated increase in the concentration of the herbicide residues, with the maximum levels reached at the early period of weedicide application, followed by a sharp decrease after the rice fields were completely covered with the rice crop. During the main season of 2006/2007, the concentration of propanil residue gradually rose, although that of the other herbicides declined.     

Determination of the effects of temporal change in urban and agricultural land uses as seen in the example of the town of Akhisar, using remote sensing techniques

Today, as a result of erratic and unplanned urbanization, towns are rapidly becoming a mass of concrete and town-dwellers are suffocated by their busy and stressful professional lives. They feel a need for places where they can find breathing-space in their free time. Green areas within towns are important spaces where townspeople are able to carry out recreational activities. These places form a link between townspeople and nature. The importance of urban green areas is increasing with every passing day due to their social, psychological, ecological, physical and economic functions and their impact on the quality of towns. In this study it has been attempted to demonstrate the pressures of urban development on agricultural land by determining the changing land use situation over the years in the district of Akhisar. In this research, an aerial photograph from year 1939 and satellite images of the town from the years 2000 and 2007 were used. Land use changes in the region were determined spatially. As a result of this study, which aims to determine in which direction urbanization is progressing in the district, the importance of town planning emerges. This study will be informative for the local authorities in their future town planning projects. With its flat and almost flat fertile arable land, the district of Akhisar occupies an important position within the province of Manisa. From the point of view of olive production the region is one of Turkey's important centres. Fifty-five percent of the olive production in the province of Manisa is realized in Akhisar. However, the results of the present study show that while agricultural areas comprised 2.5805 km(2) in 1939, these had diminished to 1.5146 km(2) in the year 2000 and had diminished to 1.0762 km(2) in the year 2007 and residential area (dense) 0.449 km(2) occupied in 1939, in the year 2000 this had risen to 1.9472 and 2.3238 km(2) in the year 2007. This planless urbanization in the study area has led to great losses of farmland.     

Dynamic behaviour of Cd2+ adsorption in equilibrium batch studies by CaCO3 −-rich Corbicula fluminea shell

This work presents the structural and adsorption properties of the CaCO₃ ^?-rich Corbicula fluminea shell as a natural and economic adsorbent to remove Cd ions from aqueous solutions under batch studies. Experiments were conducted with different contact times, various initial concentrations, initial solution pH and serial biosorbent dosage to examine the dynamic characterization of the adsorption and its influence on Cd uptake capacity. The characterization of the C. fluminea shell using SEM/EDX revealed that the adsorbent surface is mostly impregnated by small particles of potentially calcium salts. The dominant Cd adsorption mechanism is strongly pH and concentration dependent. A maximum Cd removal efficiency of 96.20 % was obtained at pH 7 while the optimum adsorbent dosage was observed as 5 g/L. The Langmuir isotherm was discovered to be more suitable to represent the experimental equilibrium isotherm results with higher correlation coefficients (R ²?>?0.98) than Freundlich (R ²?<?0.97).The correlation coefficient values (p?<?0.01) indicated the superiority of the Langmuir isotherm over the Freundlich isotherm.     

Local community acceptance of the rare earth industry: the case of the Lynas Advanced Materials Plant (LAMP) in Malaysia

This paper provides a detailed analysis of the local community response to a newly installed rare earth (RE) refinery facility and the factors underlying its acceptance. House-to-house interviews, using structured questionnaire, were conducted in 2013 (N = 370). Results show that the community was divided into deciding whether they agreed with the presence of the facility, 41.36 % (for) and 41.62 % (against). The remaining fraction of the community was undecided, which made up 17.03 % of the total respondents. This paper identifies six significant predictors of risk acceptance: gender, education status, place of residence, Factor 1 (variables—perception of safety, concern on effects, and trust in the operators), Factor 2 (variables—social and individual benefits), and Factor 3 (variables—no confidence in government). This study gives insights on how the public respond to potential hazardous facilities and highlights the need for policy makers to consider public sentiment which can interfere with further expansion of the RE industry.     

Synthesis of linear low-density polyethylene-g-poly (acrylic acid)-co-starch/organo-montmorillonite hydrogel composite as an adsorbent for removal of Pb(Ⅱ) from aqueous solutions

The purpose of this work is to remove Pb(II) from the aqueous solution using a type of hydrogel composite. A hydrogel composite consisting of waste linear low density polyethylene, acrylic acid, starch, and organo-montmorillonite was prepared through emulsion polymerization method. Fourier transform infrared spectroscopy (FTIR), Solid carbon nuclear magnetic resonance spectroscopy (CNMR)), silicon^-29 nuclear magnetic resonance spectroscopy (Si NMR)), and X-ray diffraction spectroscope ((XRD) were applied to characterize the hydrogel composite. The hydrogel composite was then employed as an adsorbent for the removal of Pb(II) from the aqueous solution. The Pb(II)-loaded hydrogel composite was characterized using Fourier transform infrared spectroscopy (FTIR)), scanning electron microscopy (SEM)), and X-ray photoelectron spectroscopy ((XPS)). From XPS results, it was found that the carboxyl and hydroxyl groups of the hydrogel composite participated in the removal of Pb(II). Kinetic studies indicated that the adsorption of Pb(II) followed the pseudo-second-order equation. It was also found that the Langmuir model described the adsorption isotherm better than the Freundlich isotherm. The maximum removal capacity of the hydrogel composite for Pb(II) ions was 430 mg/g. Thus, the waste linear low-density polyethylene-g-poly (acrylic acid)-co-starch/organo-montmorillonite hydrogel composite could be a promising Pb(II) adsorbent.     

High-performance biological treatment of tuna wash processing wastewater using Yarrowia lipolytica

Environmental Science and Pollution Research - It is well known that the lack of an effective treatment of tuna wash processing wastewater may pose substantial environmental and public health...     

Assessment of trophic status of the northeastern Mediterranean coastal waters: eutrophication classification tools revisited

Environmental Science and Pollution Research - The Eastern Mediterranean and its Cilician Basin offshore waters have oligotrophic features with low nutrient concentrations, low primary production,...     

Performance of recycled ceramic waste as aggregates in hot mix asphalt (HMA)

Ceramic waste materials from the production of titles has increased over the years. Preliminary studies on the properties of ceramics showed that this material can be incorporated into asphalt mixtures as aggregates. Laboratory tests were conducted to evaluate the feasibility of utilizing ceramic materials from tile manufacturing firms. A study was undertaken to look into the performance of crushed ceramics that were incorporated in asphalt mixtures to replace the conventional granite aggregates from sizes 5.0 mm down including the 75 micron filler. The replacement was done proportionally with a 0, 20, 40, 60, 80, and 100% percent by weight of granite aggregates. The outcome of the study showed that the performance of recycled ceramic aggregates in hot mix asphalt (HMA) reached an optimum at about 20% which means there is a great potential for the use of it in asphalt mixtures. The Marshall stability showed an increment of about 25% while the resilient modulus strength improved by 13.5% as compared with the control specimen. All samples were analyzed at various proportions of ceramic–granite aggregate combination and were observed that a 20% use of 5 mm down ceramic aggregates blended with granite aggregates produce higher strength HMA.     

Graphene and its derivatives: synthesis,modifications, and applications in wastewater treatment

Graphene was discovered in 2004 and has attracted intensive interests because of its unique mechanical, electric, thermal, optical, and structural properties, which makes graphene a potential candidate for various applications. Graphene is being used as a composite or filler material with metals, metal oxides, and polymers for potential advanced applications in solar cells, lithium-ion batteries, photocatalysis and sensing. These applications depend upon the distinctive properties of graphene, which in turn depend on the adopted synthetic approach. This article reviews the recent developments in synthesis of graphene and related composite materials. The synthesis of graphene through exfoliation, epitaxial growth and direct growth via carbon source, and modification approaches by covalent and noncovalent methodologies are discussed. Graphene-based metal and metal oxide composites for the purification of wastewater using photolytic process are also presented.