An integrated methodology for the used product selection problem faced by third-party reverse logistics providers

The rise of electronic commerce and the stricter government regulations on the recovery of end-of-life products increased the number of products returned by customers. A company may deal with increasing product returns by developing its own reverse logistic system. However, high fixed costs associated with dedicated reverse logistics equipment and infrastructure force many companies to outsource their reverse logistics operations to third-party reverse logistics providers. One of the important problems faced by third-party reverse logistics providers is the selection of the types of used products to be collected. In this study, a four-phase used product selection methodology is proposed. First, the quantitative and qualitative selection criteria are determined. Then the weights of the criteria are calculated using fuzzy analytic hierarchy process. Next, simulation models are employed to determine the values of quantitative criteria. Finally, technique for order preference by similarity to ideal solution ranks alternative used product types. A numerical example is also provided in order to present the applicability of the proposed methodology.     

BMP estimation of landfilled municipal solid waste by multivariate statistical methods using specific waste parameters: case study of a sanitary landfill in Turkey

The main objective of this study was to determine whether methane potential of waste could be estimated more easily by a limited number of waste characterization variables. 36 samples were collected from 12 locations and 3 waste depths in order to represent almost all waste ages at the landfill. Actual remaining methane potential of all samples was determined by the biochemical methane potential (BMP) tests. The cumulative methane production of closed landfill (cLF) samples reached 75–125 mL at the end of experiment duration, while the samples from active landfill (aLF) produced in average 216–266 mL methane. The average experimental k and L ₀ values of cLF and aLF were determined by non-linear regression using BMP data with first-order kinetic equation as 0.0269 day^?1–30.38 mL/g dry MSW and 0.0125 day^?1–102.1 mL/g dry MSW, respectively. The principal component analysis (PCA) was applied to analyze the results for cLF and aLF along with BMP results. Three PCs for the data set were extracted explaining 72.34 % variability. The best MLR model for BMP prediction was determined for seven variables (pH–Cl–TKN–NH4–TOC–LOI–Ca). R ² and Adj. R ² values of this best model were determined as 80.4 and 75.3 %, respectively.     

Removal of 2, 4‐D from aqueous solution by the adsorbents from spent bleaching earth

Abstract

The removal of 2, 4‐D (2, 4‐ dichlorophenoxyacetic acid) from aqueous solutions by activated spent bleaching earths (SBE) was studied at 20 °C. Experiments were performed as a function of time, initial concentration, dose and particle size of the adsorbent. The Langmuir and Freundlich adsorption equations were fitted by the adsorption data obtained. The values of Langmuir and Freundlich constants were determined. The adsorption kinetic was found to follow Lagergren equation. Both the boundary layer and intraparticle diffusion played important roles in the adsorption rate of 2, 4‐D. As the size of the adsorbent increased, the time to reach equilibrium increased but adsorption capacity decreased.     

The occurrence and environmental effect of persistent organic pollutants (POPs) in Taurus Mountains soils

Purpose  

Persistent organic pollutants (POPs) are of global concern due to their ubiquitous presence and toxicity. The occurence of polychlorinated dibenzo-p-dioxins (PCDDs), -dibenzofurans (PCDFs), co-planar biphenyls (PCBs), hexachlorocyclohexanes (HCH), dichlorodiphenyltrichloroethanes (DDT), and organochlorine pesticides (OCPs) in forest soil collected from Taurus mountains may have adverse effects on the environment and health. The aim of the study was to investigate the outcome and distribution of POPs in the environment and the possible grasshopper effect along an altitude transect from sea level up to nearly 2,000 m a.s.l at a spatial distance of about 60 km in the southeastern Turkish Mediterranean Sea.     

Assessment of imidacloprid toxicity on reproductive organ system of adult male rats

In the current study it was aimed to investigate the toxicity of low doses of imidacloprid (IMI) on the reproductive organ systems of adult male rats. The treatment groups received 0.5 (IMI-0.5), 2 (IMI-2) or 8 mg IMI/kg body weight by oral gavage (IMI-8) for three months. The deterioration in sperm motility in IMI-8 group and epidydimal sperm concentration in IMI-2 and IMI-8 groups and abnormality in sperm morphology in IMI-8 were significant. The levels of testosterone (T) and GSH decreased significantly in group IMI-8 compared to the control group. Upon treatment with IMI, apoptotic index increased significantly only in germ cells of the seminiferous tubules of IMI-8 group when compared to control. Fragmentation was striking in the seminal DNA from the IMI-8 group, but it was much less obvious in the IMI-2 one. IMI exposure resulted in elevation of all fatty acids analyzed, but the increases were significant only in stearic, oleic, linoleic and arachidonic acids. The ratios of 20:4/20:3 and 20:4/18:2 were decreased and 16:1n-9/16:0 ratio was increased. In conclusion, the present animal experiments revealed that the treatment with IMI at NOAEL dose-levels caused deterioration in sperm parameters, decreased T level, increased apoptosis of germ cells, seminal DNA fragmentation, the depletion of antioxidants and change in disturbance of fatty acid composition. All these changes indicate the suppression of testicular function.     

Toxaphen in der Umwelt

Toxaphene is a mixture of more than 200 polychlorinated C₁₀-terpenes. Due to its persistence and long-range transport, it is distributed all over the world. Many of the components are very stable under environmental conditions, while others are easily degraded by UV-light or microorganisms. The main conversion pathway is reductive dechlorination and dehydrochlorination; oxidative degradation possibly occurs only after previous dechlorination. Accumulation especially in the aquatic environment has led in many cases to high residue levels in fish, marine mammals, and sea birds of the northern hemispere. Toxaphene is mutagenic in the Ames test and of high toxicity for fish, but few data are available on the toxicity of single components or their mode of action.     

Characterization of soil erosion and its implication to forest management

Forests have traditionally been managed to maximize timber production or economic profit, completely neglecting other forest values. Nowadays, however, forests are being managed for multiple uses. The basic requirement of multiple use forestry is to identify and quantify forest values and to determine management objectives. The priorities of management objectives, however, must be decided. In this study, a model predicting the soil loss for multi objective forest management was developed. The model was based on data from remeasurement of permanent sample plots. The data were gathered from 132 sample plots. Approximately 80% of the observations were used for model development and 20% for validation. The model was designed for even aged and uneven aged forests, as well as for forests with mixed and pure species composition. The explicatory variables in the model were mean diameter and number of trees. All parameter estimates were found highly significant (p < 0.001) in predicting soil loss. The model fit and validation tests were fairly good. The soil loss model presented in this paper was considered to have an appropriate level of reliability. It can be used in the overall multi-objective forest management planning, but, it should be limited to the conditions for which the data were gathered.     

Unprecedented total mineralization of atrazine and cyanuric acid by anodic oxidation and electro-Fenton with a boron-doped diamond anode

This article reports the complete mineralization of atrazine. Atrazine has been the most widely used s-triazine herbicide. Atrazine occurs in natural waters and presents a potential danger for public health because atrazine is considered as an endocrine disruptor. The use of chemical, photochemical and photocatalytic advanced oxidation processes (AOPs) to decontaminate waters containing atrazine only allowed its conversion into the cyanuric acid as ultimate end products, since it cannot be completely degraded by hydroxyl radicals (^•OH) produced by these techniques. The same behavior was previously reported for anodic oxidation and electro-Fenton with Pt anode, although better performances were found using boron-doped diamond (BDD) anode but without explaining the role of generated ^•OH. Here, the oxidative action of these radicals in such electrochemical AOPs has been clarified by studying the mineralization process and decay kinetics of atrazine and cyanuric acid in separated solutions by anodic oxidation with BDD and electro-Fenton with Pt or BDD anode using an undivided cell with a carbon-felt cathode under galvanostatic conditions. Results showed that electro-Fenton with BDD anode was the more powerful treatment to degrade both compounds. Almost total mineralization, 97% total organic carbon (COT) removal, of atrazine was only feasible by this method with a faster removal of its oxidation intermediates by ^•OH formed at the BDD surface than that formed in the bulk from Fenton reaction, although the latter process caused a more rapid decay of the herbicide. Cyanuric acid was much slowly mineralized mainly with ^•OH produced at the BDD surface, and it was not degraded by electro-Fenton with Pt anode. These results highlight that electrochemical advanced oxidation processes (EAOPs) using a BDD anode are more powerful than the classical electro-Fenton process with Pt or PbO₂ anodes.     

Valorization of spent coffee grounds recycling as a potential alternative fuel resource in Turkey: An experimental study

In this study, recycling of spent coffee grounds (SCG) as a potential feedstock for alternative fuel production and compounds of added value in Turkey was assessed. The average oil content was found (≈ 13% w/w). All samples (before and after extraction) were tested for scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), calorific value, surface analysis and porosity, Fourier transform infrared (FT-IR), and elemental analysis to assess their potential towards fuel properties. Elemental analysis indicated that carbon represents the highest percentages (49.59% and 46.42%, respectively), followed by nitrogen (16.7% and 15.5%), hydrogen (6.74% and 6.04%), and sulfur (0.851% and 0.561%). These results indicate that SCG can be utilized as compost, as it is rich in nitrogen. Properties of the extracted oil were examined, followed by biodiesel production. The quality of biodiesel was compared with American Society for Testing and Materials (ASTM) D6751 standards, and all the properties complied with standard specifications. The fatty acid compositions were analyzed by gas chromatography. It was observed that coffee waste methyl ester (CWME) is mainly composed of palmitic (35.8%) and arachidic (44.6%) acids, which are saturated fatty acids. The low degree of unsaturation provides an excellent oxidation stability (10.4 hr). CWME has also excellent cetane number, higher heating value, and iodine value with poor cold flow properties. The studies also investigated blending of biodiesel with Euro diesel and butanol. Following this, a remarkable improvement in cloud and pour points of biodiesel was obtained. Spent coffee grounds after oil extraction is an ideal material for garden fertilizer, feedstock for ethanol, biogas production, and as fuel pellets. The outcome of such research work produces valuable insights on the recycling importance of SCG in Turkey.

Implications: Coffee is a huge industry, and coffee has been widely used due to its refreshing properties. This industry generates large quantities of waste. Therefore, recycling of spent coffee grounds for producing alternative fuels and compounds of added value is crucial. Elemental analysis indicated that coffee waste can be utilized as compost, as it is rich in nitrogen. Coffee waste after oil extraction is an ideal feedstock for ethanol and biogas production, garden fertilizer, and as fuel pellets. The low degree of unsaturation provides excellent oxidation stability. Its biodiesel has also excellent cetane number, higher heating value, and lower iodine value.