Gulsen Tozsin

Using marble wastes as a soil amendment for acidic soil neutralization.

One of the most important factors limiting plant growth is soil pH. The objective of this study is to determine the effectiveness of marble waste applications on neutralization of soil acidity. Marble quarry waste (MQW) and marble cutting waste (MCW) were applied to an acid soil at different rates and their effectiveness on neutralization was evaluated by a laboratory incubation test. The results showed that soil pH increased from 4.71 to 6.36 and 6.84 by applications of MCW and MQW, respectively. It was suggested that MQW and MCW could be used as soil amendments for the neutralization of acid soils and thus the negative impact of marble wastes on the environment could be reduced.

Removal of textile dye Reactive Black 5 from aqueous solution by adsorption on laccase-modified silica fume

AbstractTextile wastewater with the dye is released in various ways into the environment and it causes significant environmental problems. Due to the stability of modern dyes, conventional biological treatment methods for industrial wastewater are ineffective, resulting in an intensively colored discharge from the treatment facilities. Thus, there is a need for developing more effective treatment methods to eliminate dyes from the waste stream at its source. The most effective methods of dye removal from wastewater are adsorption and the use of enzymes. In this study, the removal of Reactive Black 5 (RB5) from aqueous solutions has been studied using silica fume (SF) waste material after its modification with laccase from Russulaceae (Lactarius volemus). Laccase was purified by using saturated precipitate (NH4)2SO4, DEAE-cellulose and immobilized on SF. Batch adsorption experiments have been performed as a function of pH, contact time, temperature, and adsorbent dosage. The optimum results were obtained a...

Inhibition of acid mine drainage and immobilization of heavy metals from copper flotation tailings using a marble cutting waste

Acid mine drainage (AMD) with high concentrations of sulfates and metals is generated by the oxidation of sulfide bearing wastes. CaCO3-rich marble cutting waste is a residual material produced by the cutting and polishing of marble stone. In this study, the feasibility of using the marble cutting waste as an acid-neutralizing agent to inhibit AMD and immobilize heavy metals from copper flotation tailings (sulfide- bearing wastes) was investigated. Continuous-stirring shake-flask tests were conducted for 40 d, and the pH value, sulfate content, and dissolved metal content of the leachate were analyzed every 10 d to determine the effectiveness of the marble cutting waste as an acid neutralizer. For comparison, CaCO3 was also used as a neutralizing agent. The average pH value of the leachate was 2.1 at the beginning of the experiment (t = 0). In the experiment employing the marble cutting waste, the pH value of the leachate changed from 6.5 to 7.8, and the sulfate and iron concentrations decreased from 4558 to 838 mg/L and from 536 to 0.01 mg/L, respectively, after 40 d. The marble cutting waste also removed more than 80wt% of heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn) from AMD generated by copper flotation tailings.

Changes in the chemical composition of an acidic soil treated with marble quarry and marble cutting wastes

Soil acidity greatly affects the availability of plant nutrients. The level of soil acidity can be adjusted by treating the soil with certain additives. The objective of this study was to determine the effect of marble quarry waste (MQW) and marble cutting waste (MCW) on the chemical composition and the acidity of a soil. Marble wastes at different rates were applied to an acid soil. Their effectiveness in neutralizing the soil pH was compared with that of agricultural lime. The changes in the chemical composition of the soil were also evaluated with column test at the end of a 75-day incubation period. The results indicated that the MQW and MCW applications significantly increased the soil pH (from 4.71 up to 6.54), the CaCO3 content (from 0.33% up to 0.75%), and the exchangeable Ca (from 14.79 cmol kg(-1) up to 21.18 cmol kg(-1)) and Na (from 0.57 cmol kg(-1) up to 1.07 cmol kg(-1)) contents, but decreased the exchangeable K (from 0.46 cmol kg(-1) down to 0.28 cmol kg(-1)), the plant-available P (from 25.56 mg L(-1) down to 16.62 mg L(-1)), and the extractable Fe (from 259.43 mg L(-1) down to 55.4 mg L(-1)), Cu (from 1.97 mg L(-1) down to 1.42 mg L(-1)), Mn (from 17.89 mg L(-1) down to 4.61 mg L(-1)) and Zn (from 7.88 mg L(-1) down to 1.56 mg L(-1)) contents. In addition, the Cd (from 0.060 mg L(-1) down to 0.046 mg L(-1)), Ni (from 0.337 mg L(-1) down to 0.092 mg L(-1)) and Pb (from 28.00 mg L(-1) down to 20.08 mg L(-1)) concentrations decreased upon the treatment of the soil with marble wastes.

Evaluation of a Turkish Lignite Coal Cleaning by Conventional and Enhanced Gravity Separation Techniques

ABSTRACT The use of low-rank coals as an energy source may cause environmental problems. Washability of a Turkish lignite sample was evaluated by conventional methods with sink-and-float tests and a Reichert spiral. Also, the fine size fractions were cleaned with enhanced gravity separation techniques, a multigravity separator (MGS), and a Falcon concentrator. The as-received lignite sample was sieved into five size fractions (-100 +25.4 mm; -25.4 +12.7 mm; -12.7 +1.2 mm; -1.2 +0.15 mm; -0.15 mm) and the washability characteristics of the first three fractions were separately investigated with sink-float tests. The -1.2 +0.15 mm size fraction was cleaned using a Reichert spiral. Tests with the MGS and the Falcon concentrator were conducted with a -0.15 mm fine size fraction. Sink-float tests results showed that the tested coal can be classified as difficult-to-clean coal due to the presence of high near-gravity material at lower separation densities than 1.7 g/cm3. However, the production of cleaner coal was easier at finer size fractions due to further liberation. Enhanced gravity separation techniques presented better results in terms of combustible recoveries.

Use of waste pyrite as an alternative to gypsum for alkaline soil amelioration

The reclamation of alkaline soils is of great interest especially in arid and semi-arid climatic regions of the world. The aim of this study was to investigate the application of pyrite from the waste materials of a copper concentration plant as an alternative to gypsum application for alkaline soil amelioration. The second aim was to assess heavy metal contamination. Waste pyrite (FeS2) obtained from a copper concentration plant and pure gypsum (CaSO4·2H2O) were added to soil within the columns and pots. Column-leaching tests were performed to determine the effectiveness of waste pyrite application on alkaline soil characteristics as compared with gypsum application. Greenhouse pot experiments were also conducted for evaluating the effects of these soil additives on plant growth. The results indicated that the pH and exchangeable sodium percentage of the experimental soil significantly decreased (p < 0.01) upon waste pyrite and gypsum applications. While waste pyrite was very effective in increasing the levels of essential plant micro-nutrients and dry matter weight of wheat, it did not cause pollution or toxicological problems in the soil. The results of this study clearly indicated that waste pyrite is a good ameliorating agent and an alternative to gypsum in reclamation of alkaline soils.

Pyritic Tailings as a Source of Plant Micronutrients in Calcareous Soils

Pyrite (FeS2) is usually a waste from complex sulfide ores. Yet, it may be a remediation additive for calcareous soils deficient in iron (Fe) and other micronutrients such as copper (Cu), zinc (Zn), and manganese (Mn). In this study, leaching experiments were conducted under laboratory conditions and a 30-day pot trial (with wheat) to evaluate the effect of applying different amounts of pyritic tailings on micronutrient and heavy-metal concentrations in a calcareous soil and on crop growth (dry-matter production). The application of pyritic tailings to the calcareous soils improved the levels of Fe, Cu, Zn, and Mn, and dry-matter biomass of wheat also significantly increased. The heavy-metal contents in soil and plant were well below the permissible limit for soil and plants.