Addressing the operational problems in a composting and recycling plant

The Istanbul composting and recycling plant, constructed in 2001, is one of the few composting plants in Turkey. During test operations of the plant, it was reported that the weight of the oversize materials (OM) above a 80-mm sieve was about 40% of the total incoming waste. They mainly consist of plastic bags that were full of garbage, which resulted in operational problems in the plant. In this paper, the composition of OM was determined and evaluated, particularly to find the economic losses in the plant. It was determined that approximately 58% of the OM transferred to the landfill area due to operational failures and interruptions could be used at the plant with improved operational conditions. Otherwise, the plant would realize an annual economic loss of about 640,800 US$. Compost quality in the plant has been satisfactory, but source separated collection, at least the separation of the wet from the dry fraction, is needed to increase the amount of compost and recovered materials.     

Estimation of transport parameters of phenolic compounds and inorganic contaminants through composite landfill liners using one-dimensional mass transport model

One-dimensional (1D) advection–dispersion transport modeling was conducted as a conceptual approach for the estimation of the transport parameters of fourteen different phenolic compounds (phenol, 2-CP, 2-MP, 3-MP, 4-MP, 2-NP, 4-NP, 2,4-DNP, 2,4-DCP, 2,6-DCP, 2,4,5-TCP, 2,4,6-TCP, 2,3,4,6-TeCP, PCP) and three different inorganic contaminants (Cu, Zn, Fe) migrating downward through the several liner systems. Four identical pilot-scale landfill reactors (0.25 m³) with different composite liners (R1: 0.10 + 0.10 m of compacted clay liner (CCL), L_e = 0.20 m, k_e = 1 × 10⁻⁸ m/s, R2: 0.002-m-thick damaged high-density polyethylene (HDPE) geomembrane overlying 0.10 + 0.10 m of CCL, L_e = 0.20 m, k_e = 1 × 10⁻⁸ m/s, R3: 0.002-m-thick damaged HDPE geomembrane overlying a 0.02-m-thick bentonite layer encapsulated between 0.10 + 0.10 m CCL, L_e = 0.22 m, k_e = 1 × 10⁻⁸ m/s, R4: 0.002-m-thick damaged HDPE geomembrane overlying a 0.02-m-thick zeolite layer encapsulated between 0.10 + 0.10 m CCL, L_e = 0.22 m, k_e = 4.24 × 10⁻⁷ m/s) were simultaneously run for a period of about 540 days to investigate the nature of diffusive and advective transport of the selected organic and inorganic contaminants. The results of 1D transport model showed that the highest molecular diffusion coefficients, ranging from 4.77 × 10⁻¹⁰ to 10.67 × 10⁻¹⁰ m²/s, were estimated for phenol (R4), 2-MP (R1), 2,4-DNP (R2), 2,4-DCP (R1), 2,6-DCP (R2), 2,4,5-TCP (R2) and 2,3,4,6-TeCP (R1). For all reactors, dispersion coefficients of Cu, ranging from 3.47 × 10⁻⁶ m²/s to 5.37 × 10⁻² m²/s, was determined to be higher than others obtained for Zn and Fe. Average molecular diffusion coefficients of phenolic compounds were estimated to be about 5.64 × 10⁻¹⁰ m²/s, 5.37 × 10⁻¹⁰ m²/s, 2.69 × 10⁻¹⁰ m²/s and 3.29 × 10⁻¹⁰ m²/s for R1, R2, R3 and R4 systems, respectively. The findings of this study clearly indicated that about 35–50% of transport of phenolic compounds to the groundwater is believed to be prevented with the use of zeolite and bentonite materials in landfill liner systems.     

Influence of marble wastes on soil improvement and concrete production

Waste marble dusts are obtained by different methods of cutting marble in marble manufacturing companies. However, environmental damage can occur from the uncontrolled spill of these waste materials in natural habitats. In this study, we investigated the utilization of waste marble in the soil improvement of clayey soils, and as a fine aggregate in concrete production. Specifically, we determined the physical, mechanical and physicochemical characteristics of clayey soils with marble dust (MD) additive. The test results showed that some improvement occurred in the behavior of clay soil. Also, the cutting waste of marble sludge can be used as a filler material instead of fine aggregate in concrete production. This will reduce the porosity of the concrete due to the filling of the pores by MD.     

Indoor and outdoor airborne bacteria in child day-care centers in Edirne City (Turkey), seasonal distribution and influence of meteorological factors

This paper presents information about airborne mesophilic bacteria in the indoor and outdoor air of child day-care centers (CDCCs) in the city of Edirne, Turkey. Air samples were collected using the Petri plate gravitational settling method from the indoor and outdoor air of CDCCs. Counts of airborne bacteria were measured as colony forming units (CFU) collected by gravity onto Brain Heart Infusion Agar plates (with 5% sheep blood). Samples were taken monthly over a period of 12 months between January and December 2004. A total of 3,120 bacteria colonies were counted on 192 Petri plates. Four groups of culturable bacteria were identified: Gram-positive cocci, Gram-positive bacilli, endospore-forming Gram-positive bacilli, and Gram-negative bacteria. Airborne Gram-positive bacteria were the most abundant at more than 95% of the measured population. While Gram-positive cocci were more common in indoor environments, Gram-positive bacilli were more dominant in outdoor air. Bacteria commonly isolated from CDCCs were identified at a genus level. Staphylococcus (39.16%), Bacillus (18.46%), Corynebacterium (16.25%), and Micrococcus (7.21%) were dominant among the genera identified in the present study. The dominant genera identified in the day-care centers were Staphylococcus, Micrococcus, and Corynebacterium for indoor air and Bacillus, Corynebacterium, and Staphylococcus for outdoor air. Staphylococcus, Streptococcus, Bacillus, and Corynebacterium genera were found in samples from every month. Bacterial colony counts were compared by sampling location (indoors and outdoors), seasons, and meteorological factors. We found negative correlations between the monthly total outdoor bacterial counts and the sampling day’s average relative humidity and average rainfall, and the monthly average rainfall. Fluctuations in bacterial counts in different seasons were observed.     

A study of background radioactivity level for Canakkale, Turkey

This study assesses the level of background radiation for Canakkale province of northwestern Turkey. Radon concentrations in indoor air were determined using CR-39 nuclear track detectors and ²²²Rn activity was found to be 167 Bq m^???3 (equivalent to an annual effective dose of 4.2 mSv). Measurements of outdoor gamma radiation (of terrestrial and cosmic origin) in air were performed using plastic scintillators, and the average absorbed gamma dose rate was found to be 66.4 nGy h^???1 (corresponding to an annual effective dose of 81.4 μSv). The radionuclide activity concentrations in soil samples collected from the study area were measured through gamma-ray spectrometry, and the average activities were determined as 94.55, 110.4, and 1,273 Bq kg^???1 for the natural radionuclides ²³⁸U, ²³²Th, and ⁴⁰K, respectively, and 19.39 Bq kg^???1 for the fission product ¹³⁷Cs. The natural radioactivity sources resulted in an annual effective dose of 184 μSv. The radioactivity levels of drinking water samples were measured as 0.0599 Bq l^???1 for gross-alpha activity and 0.0841 Bq l^???1 for gross-beta activity using a low-background counting technique (equivalent to an annual effective dose of 12.25 μSv). The results of this study show that the activity levels of radon in air, radionuclides in soil, and alpha activities in drinking water are higher compared to the data available for other Turkish cities and the world averages. On the other hand, the outdoor gamma dose rates in air and beta activities in drinking water are within natural limits.     

Effect of vegetation change from native broadleaf forest to coniferous plantation on selected soil properties

The objective of this study was to examine the effects of vegetation change from a native broadleaf forest to a coniferous plantation on selected soil properties, including soil texture, pH, organic matter, total nitrogen (N), total phosphorus (P), exchangeable cations (Ca²⁺, K⁺, Na⁺), and cation exchange capacity (CEC). Results showed that the amount of clay particles, Ca²⁺, and K⁺ values significantly increased, whereas Na⁺, total N, and organic matter and soil pH values decreased on the treatment plot after vegetation change. Soil acidity also increased and soil textural group changed from moderately fine-textured soils (clay loam) to medium-textured soils (loam) under both control and treatment plots. Organic matter, total N, and Na⁺ values increased, whereas Ca²⁺ concentration decreased through time on the control plot. Soil pH, total P, K⁺, and CEC did not show significant changes through time on the control plot.     

An acoustical landscaping study: the impact of distance between the sound source and the landscape plants on traffic noise reduction

Environment, Development and Sustainability - Due to the ongoing increase in the urbanization rate, people are exposed to various environmental pollutions. One of the most threatening types of...     

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.     

Wood Flour-Reinforced Green Composites: Parameter Optimization via Multi-criteria Decision-Making Methods

Journal of Polymers and the Environment - The aim of this study was to investigate the physical, mechanical, morphological, structural, and thermal properties of polylactic acid (PLA) and...     

Morphometric and electrophoretic analysis of 13 populations of Anatolian black pine in Turkey

The genetic variation in populations of Anatolian black pine (Pinus nigra Arn. subsp. pallasiana (L.) Holmboe.), one of the species covering large areas in Turkey, was investigated. Open pollinated seeds were collected from 13 populations in a natural distribution range. Six characters of seeds (length, width, ratio of length to width, weight/1000 seeds) and seedling characters (cotyledon number and hypocotyls height) and two enzyme systems viz. leucine aminopeptidase (LAP) and glutamate oxaloacetate transaminase, (GOT) were investigated. Significant differences were detected among the populations for the morphological characters. In addition, isozyme patterns of two enzyme systems revealed that LAP has two loci (one with 2 alleles and the other with 3), while GOT has three loci (two with 3 alleles and the third one with 2 alleles). Polymorphic loci were 74% on the average. The mean number of alleles per loci was 1.94 and expected heterozygosity was 19%. The mean total genetic diversity was calculated as 0.203; the mean gene diversity within populations was determined as 0.188, and the average between subpopulations diversity was 0.016. The relative magnitude of genetic differentiation among subpopulations was measured as 0.074 indicating that only 7.4% of the total genetic diversity was there between populations. Average genetic distance was 0.093 according to Gregorius. Nei's genetic distance was 0.022.