Influence of Wooden Sawdust Treatments on Cu(II) and Zn(II) Removal from Water

Organic waste materials and semi-products containing cellulose are used as low-cost adsorbents that are able to compete with conventional sorbents. In addition, their capacity to bind heavy metal ions can be intensified by chemical treatments using mineral and organic acids, bases, oxidizing agents, and organic compounds. In this paper, we studied the biosorption capacity of natural and modified wooden sawdust of poplar, cherry, spruce, and hornbeam in order to remove heavy metals from acidic model solutions. The Fourier transform infrared spectroscopy (FTIR) spectra showed changes of the functional groups due to the alkaline modification of sawdust, which manifested in the considerably increased intensity of the hydroxyl peaks. The adsorption isotherm models clearly indicated that the adsorptive behavior of metal ions in treated sawdust satisfied not only the Langmuir model, but also the Freundlich model. The adsorption data obtained for studied sorbents were better fitted by the Langmuir isotherm model for both metals, except for spruce sawdust. Surface complexation and ion exchange are the major mechanisms involved in metal ion removal. We investigated the efficiency of the alkaline modified sawdust for metal removal under various initial concentrations of Cu(II) and Zn(II) from model solutions. The highest adsorption efficiency values (copper 94.3% at pH 6.8 and zinc 98.2% at pH 7.3) were obtained for poplar modified by KOH. For all types of sawdust, we found that the sorption efficiency of modified sorbents was higher in comparison to untreated sawdust. The value of the pH initially increased more in the case of modified sawdust (8.2 for zinc removal with spruce NaOH) and then slowly decreased (7.0 for Zn(II) with spruce NaOH).This research was funded by Scientific Grant Agency of the Ministry of Education, Science, Research, and Sport of the Slovak Republic and the Slovak Academy of Sciences, grant number 1/0419/19 and grant number 1/0326/18

Discontinuities of Plastic Deformation in Metallic Glasses with Different Glass Forming Ability

AbstractThe metallic ribbons Fe40Ni40B20, Cu47Ti35Zr11Ni6Si1 and Zr65Cu17.5Ni10Al7.5 with different microhardness and glass forming ability were studied at different loading rates from 0.05 to 100 mN/s. We describe in details the differences in elemental discontinuities on the loading curves for the studied alloys. It was found that the discontinuities began at a certain local deformation independently on the macroscopic mechanical properties of a ribbon. More developed discontinuities at higher deformations are created for the materials with lower microhardness and so lower strength

Study of Inorganic Pollutants Removal from Acid Mine Drainage by Hemp Hurds

Sulphates in wastewaters have an origin as the by-products of a variety of industrial operations. A specific and major producer of such effluents, which contained sulphates and heavy metals, is the mining industry. These contaminants should be removed from wastewater using an adequate process of treatment

Removal of Copper from Water Solutions by Adsorption on Spruce Sawdust

Pollution of water by toxic elements is one of the major factors of concern for human health, as well as for environmental quality, and draws a large amount of scientific attention. New and cheaper methods of wastewater treatment are increasing the quality of the environment and reducing the negative impacts on fauna, flora, and human beings. The sorption technique is considered a cost effective method for effectively removing heavy metals. During the past few years, there have been increasing studies dedicated to using low-cost adsorbents like bark, tannin-rich materials, lignin, chitosan peat moss, and sawdust. The presented paper describes the adsorption behavior of spruce wood sawdust. In order to determine its applicability for wastewater treatment, copper removal from model solutions was studied

Removal of copper, zinc and iron from water solutions by spruce sawdust adsorption

The water pollution by toxic elements is one of the major problems threatening human health as well as the quality of the environment. Sorption is considered a cost-effective method that is able to effectively remove heavy metals. During past few years, researches have been researching usage of low-cost adsorbents like bark, lignin, chitosan peat moss and sawdust. This paper deals with the study of copper, zinc and iron adsorption by adsorption of spruce sawdust obtained as a by-product from locally used wood. Raw spruce sawdust was used to remove heavy metal ions from the model solutions with ion concentration of 10 mg/L during 24 hours or 5, 10, 15, 30, 45, 60, 120 min, respectively. Fourier-transform infrared spectroscopy was applied to determine functional groups of sawdust. Sorption efficiency was higher than 67% in short-time experiments and higher than 75% for one day experiments in all tested cations

The removal of sulphate ions from model solutions and their influence on ion exchange resins

There is a growing tendency for industries around the globe to diminish the contents of pollutants in industrial wastewaters to an acceptable level. Conventional methods are unfavourable and economically unacceptable, especially for large volumes of wastewaters with a high content of undesirable compounds. In contrast, ion–exchange is a very powerful technology capable of removing contamination from water. This paper analyses a study of ion exchange in Amberlite MB20 and Purolite MB400 resins after sulphate removal from a model solution. For the characterisation of ion exchange in resins, infrared spectroscopy was used. The IR spectra of both ion exchange resins show a similar composition after adsorption. Experiments that are due to this same used matrix in producing. The efficiency of sulphate ion removal and pH changes were also measured. Amberlite MB20 has proven to be a suitable ion exchange resin due to its high effi ciency (about 86%) for the removal of sulphates from solutions with initial concentrations of 100 and 500 mg.L-1, respectively

The Impact of Anthropogenic Activity on the Quality of Bottom Sediments in the Watershed of the Delňa Creek

This paper is focused on evaluating the quality of bottom sediments and water in the watershed of the Delňa creek, where gold, antimony and mercury were mined in the past. The results showed that the biggest source of pollution was a heap of mining material, where the limit values of Sb, As, Hg and Pb concentrations in the sediments were exceeded. Other sources of pollution in the river basin were the right-hand tributaries. A comparison of the dependencies of the concentrations of potentially toxic metals in the water and sediments shows that while the concentrations of pollutants in the waters react to the current state of water quality in the basin and tributaries (pH, concentration, discharge), the sediments exhibit a stable concentration character

Metal Pollution Indices of Bottom Sediment and Surface Water Affected by Acid Mine Drainage

Sediments are normally the final pathway of both natural and anthropogenic components produced or derived from the environment. Sediment quality is a good indicator of pollution in the water column, where heavy metals and other organic pollutants tend to concentrate. Metals are introduced in aquatic systems as a result of the weathering of soils and rocks, from volcanic eruptions, and from a variety of human activities involving the mining, processing, or use of metals and/or substances that contain metal pollutants. Heavy metal concentration in the water column can be relatively low in some cases, but the concentrations in the sediment may be elevated. The presented work aimed to investigate the pollutant levels of some heavy metals (Fe, Mn, Al, Cu, Zn, As, Cd, Pb) in the water and sediments related to acid mine drainage (AMD) produced from an abandoned sulphide mine in Smolnik in Eastern Slovakia. A metal pollution index was used to compare the total content of metals at five sampling stations. The level of partitioning of the metals between the surface water and sediments in the area was calculated using Partition coefficients and the correlation coefficients between the metal pairs in both media were calculated by a Pearson coefficient

Sorption isotherm study of manganese removal from aqueous solutions by natural and MnO2-coated zeolite

The applicability of the natural and MnO2-coated zeolite as sorbent for the removal of Mn(II) from synthetic solutions has been investigated. Batch experiments were carried out to determine the influence of pH and Mn(II) concentration on the sorption process. A maximum removal efficiency (98.9%) was observed for modified zeolite with the concentration of 10 mg/dm3 of manganese in solution. The equilibrium data showed a very good correlation for both Langmuir and Freundlich sorption models and this suggests both monolayer adsorption and a heterogeneous surface existence. Maximum sorption capacity calculated from the Langmuir model constituted 5.57 mg/g for natural zeolite and 13.41 mg/g for modified zeolite

The Influence of Phosphogypsum Addition on Phosphorus Release in Biochemical Treatment of Sewage Sludge

The paper is focused on the research of biochemical treatment of sewage sludge and phosphogypsum under sulphate-reducing conditions with a phosphorus release process. The theoretical foundations of the work were based on the biochemical formalization using the principles of autocatalysis of natural systems. During the experimental research for the control of physicochemical parameters of the process spectroquantic, X-ray fluorescence analysis and other techniques were used. A schematic model of the dephosphatation process under anaerobic stabilization of sewage sludge and phosphogypsum was developed. The increase of phosphogypsum dosage had a close correlation with the release of phosphate ions. At the stimulating action of the phosphogypsum additive, a 2.5–5.0-fold increase in soluble phosphate concentration was observed. The rational dose of phosphogypsum was determined. Along with an increase the ratio of COD (Chemical Oxygen Demand)/phosphogypsum to 0.1, an increase in the phosphate ions in solution was observed. A further increase in the ratio of COD/phosphogypsum did not affect the concentration of phosphate ions in solution