Decolorization of Textile Azo‐metal Complex Dyes by a Halophilic Bacterium Isolated from Çamaltı Saltern in Turkey

The decolorization of some of azo‐metal complex dyes used in textile industry was investigated in this study. The halophilic prokaryotes isolated from a solar sea‐saltern (Çamalt?) in Turkey were screened for resistance to five commercial azo and mixture of azo‐metal complex dyes. Only one bacterium was found to be resistant against two of dyes, namely Lanaset Navy R and Lanaset Brown B. The bacterium was identified as Halobacillus sp. C‐22 according to 16S rRNA gene sequence analyses. Decolorization experiments were carried out at 120 mg/L concentration of both dyes, at room temperature, and with an acidic pH of 4.5. Lanaset Brown B was decolorized at a high adsorbance ratio (96.12%) at the 78th hour. However, Lanaset Navy R was rapidly decolorized in 10 min (46.67%) and showed the highest adsorbance ratio (60.66%) at the third hour. Freundlich and Langmuir equilibrium isotherm models were used to evaluate the adsorption of dyes and Freundlich isoterm was more suitable for biosorpsiyon of both azo dyes. The functional groups on Halobacillus sp. C‐22 for decolorization were characterized by FT‐IR. This is the first study to reveal potential of Halobacillus sp. for decolorization of textile azo‐metal complex dyes.     

Detection of Toxoplasma gondii in Turkish River and Drinking Water Samples by Different PCR and LAMP Methods

In this study, we investigated the occurence of Toxoplasma gondii and checked the sequencing in 56 samples collected from in the Ordu province, Middle Black Sea, Turkey. The samples were collected from drinking and river water and DNA was extracted from all samples. After DNA isolation, the 18S rRNA target gene and B1 gene of T. gondii were amplified by conventional PCR, nested PCR, and loop‐mediated isothermal amplification (LAMP) assay, respectively. Twenty out of 56 samples (35.7%) were Toxoplasma positive by LAMP. The conventional PCR and nested PCR confirmed that 12 and 16 out of 56 samples (21.42 and 28.57%) were positive for Toxoplasma, respectively. All drinking water samples were negative by all three methods. Thirteen Toxoplasma nested PCR products were successfully sequenced. This study achieved detection and sequencing of Toxoplasma from water supplies in the Middle Black sea area in Turkey.     

Optimization of constitutive parameters of foundation soils k-means clustering analysis

The goal of this study was to optimize the constitutive parameters of foundation soils using a k-means algorithm with clustering analysis. A database was collected from unconfined compression tests, Pr...     

Response Surface Modeling and Optimization of Microwave‐Activated Persulfate Oxidation of Olive Oil Mill Wastewater

Olive oil mill wastewater (OMW) is environmentally hazardous not only because it contains high recalcitrant and toxic compounds, but also due to its high organic load and turbidity. In this study, oxidation of OMW by microwave (MW)‐activated persulfate is investigated. Box–Behnken design is applied to investigate the effects of operating conditions on operating cost, organic matter, and color removal. Multi response optimization is performed according to minimum operating cost, maximum organic matter and color removal efficiencies. At optimum conditions (persulfate anion dose of 266 g L^?1, oxidation duration of 23.58 min, MW power of 567 W, and initial pH 2), chemical oxygen demand (COD) removal of 63.38%, color removal of 94.85%, and operating cost of 0.0633 Euro/g total organic carbon (TOC) removal are found. The biochemical oxygen demand (BOD₅)/COD ratio is increased from 0.144 to 0.285. Results of Pareto analysis show individual effect of MW power is 92.81% for TOC removal, 15.52% for color removal, 68.99% for operating cost, respectively. According to the results, it is not recommended to use this process as an ultimate treatment unit due to the high amount of oxidizing agent consumed. Instead, it is recommended to be used as a pre‐ or post‐treatment step.     

Strength and structure of laterites and lateritic soils

Ten soils from Puerto Rico representing various states of weathering were subjected to engineering index tests, strength and density measurement, mineralogic analyses, and scanning electron microscopy.Engineering classification systems used for temperate soils tend to underestimate the engineering behavior of these undisturbed lateritic soils and in the undisturbed state the soils exhibit low densities and high strengths.The engineering properties of the undisturbed soils show systematic trends in relation to the degree of weathering and the parent rock. For a given rock, the void ratio is decreased and cohesion increased as weathering proceeds. This is the result of increasing crystallization and cementation by the sesquioxides.The specific gravity of the solid particles is a promising index property to characterize these lateritic soils insofar as it reflects iron oxide content. The decrease in void ratio and increase in cohesion with increasing specific gravity suggests a model for the engineering classification of tropical soils.     

Analysis of dam-induced cyclic patterns on river flow dynamics

This paper investigates the impact of the Hungry Horse Dam on streamflow dynamics in the South Fork of the Flathead River, Montana, USA. To this end, pre- and post-dam periods of raw and naturalized streamflow data were analysed. Pettitt’s change point analysis indicated a significant change point in streamflow dynamics due to dam construction. Complexities in the pre- and post-dam periods were evaluated by sample and multi-scale entropy analyses, and the entropies of the post-dam period were found to be higher than those of the pre-dam period. Possible reasons for this, unrelated to the natural hydrological cycle caused by the dam, were analysed using wavelet analyses. The wavelet analyses showed a clear change in the phase relationship between precipitation and streamflow. Finally, weak positive trends found in the hydrological variables indicated the effects of human activities (e.g. dam construction). The results also revealed distorted lead times, which can improve the streamflow forecasts for different lead times.     

Crushed recycled glass as a filter medium and comparison with silica sand

The objective of this work was to evaluate crushed recycled glass as a medium for rapid filtration. In the first part of this work, physical and hydraulic characteristics of the glass medium were studied. In the second part, pilot scale inline filtration experiments were carried out using raw waters from three different water sources. Two physically identical filter columns were operated in parallel in all the experiments. One filter contained a silica sand medium that is widely used in Turkey, whereas the other filter contained crushed recycled glass. Experiments were repeated five times as follows: (i) Without the use of a coagulant, (ii–iii) with 5 mg/L and 10 mg/L of alum, and (iv–v) with 5 mg/L and 10 mg/L of ferric chloride. Turbidity, particle counts, and head losses were measured and compared as functions of time. The following were observed: (1) Provided that a coagulant was used, the filter containing crushed glass produced effluent turbidities and particle counts similar to those obtained with the sand filter. (2) The crushed glass medium generated both a smaller clean‐bed head loss and smaller clogging head losses than those of the sand filter. It is concluded that crushed glass shows significant promise as an alternative to silica sand in rapid filtration.     

Impact of soil compaction and irrigation practices on salt dynamics in the presence of a saline shallow groundwater: An experimental and modelling study

Soil salt accumulation is a widespread problem leading to diminished crop yield and threatening food security in many regions of the world. The soil salinization problem is particularly acute in areas that lack adequate soil water drainage and where a saline shallow water table (WT) is present. In this study, we present laboratory-scale column experiments, extending over a period of more than 400 days that focus on the processes contributing to soil salinization. We specifically examine the combined impact of soil compaction, surface water application model and water quality on salt dynamics in the presence of a saline shallow WT. The soil columns (60 cm height and 16 cm diameter) were packed with an agricultural soil with bulk densities of 1.15 and 1.34 g/cm⁻³ for uncompacted and compacted layers, respectively, and automatically monitored for water content, salinity and pressure. Two surface water compositions are considered: fresh (deionized, DI) and saline water (~3.4 mS/cm). To assess the sensitivity of compaction on salt dynamics, the experiments were numerically modelled with the HYDRUS-1D computer program. The results show that the saline WT led to rapid salinization of the soil column due to capillarity, with the salinity reaching levels much higher than that at the WT. However, compaction layer provided a barrier that limited the downwards moisture percolation and solute transport. Furthermore, the numerical simulations showed that the application of freshwater can temporarily reverse the accumulation of salts in agricultural soils. This irrigation strategy can help, in the short-term, alleviate soil salinization problem. The soil hydraulic properties, WT depth, water quality, evaporation demand and the availability of freshwater all play a role in the practicability of such short-term solutions. The presence of a saline shallow WT would, however, rapidly reverse these temporary measures, leading to the recurrence of topsoil salinization.     

Development of a GIS-based monitoring and management system for underground coal mining safety

Coal mine safety is of paramount concern to mining industry. Mine accidents have various causes and consequences including catastrophic failure of mine, substantial economic losses and most notably loss of lives. Therefore, any initiative in mine monitoring is of vital importance for progressing safety surveillance and maintenance.This paper presents the development of a geographic information system (GIS)-based monitoring and management system for underground mine safety in three levels as constructive safety, surveillance and maintenance, and emergency. The developed model integrates the database design and management to the monitoring system implementation which encompasses query and analysis operations with the help of web and desktop applications. Interactive object-oriented graphical user interfaces (GUIs) were developed to visualize information about the entities gathered from the model and also to provide analysis operations based on the graphical representations and demonstrations using data tables and map objects.The research methodology essentially encompasses five main stages: (i) designing a conceptual database model; (ii) development of a logical model in terms of entity-relationship (ER) diagrams; (iii) development of a physical model based on physical constraints and requirements; (iv) development of GUIs and implementation of the developed model, analysis and queries; (v) verification and validation of the created model for Ömerler underground coal mine in Turkey. The proposed system is expected to be an efficient tool for improving and maintaining healthy standards in underground coal mines which can possibly be extended to a national GIS infrastructure.