The effect of pH and initial concentration on the removal of Cu(II) and Ni(II) ions from their monocomponent and two-component aqueous solutions using Na2CO3 as a chemical precipitation agent was investigated in this paper. Monocomponent aqueous solutions  of Cu(II) and Ni(II)  ions with their initial concentrations of 50 and 500 mg/L and two-component aqueous solution with initial concentration of 500 mg/L were prepared. The precipitation was carried out by batch method at room temperature by stirring the solution at 300 rpm for 5 minutes, resulting in the formation of precipitates. The resulting precipitate was separated by filtration from the solution. The experiment proved that Na2CO3 is a good agent for removing Cu(II) and Ni(II) ions from their monocomponent water solutions of 50 and 500 mg/L concentration and two-component water solution with initial concentration of each metal 500 mg/L. The percentage of Cu(II) removal was higher at lower pH values compared to Ni(II) removal.

Wastewaters from the galvanization process contain high concentrations of heavy metals representing a great danger to human health as well as to the environment. Heavy metals in the galvanization process are used in the coating process, whereby the coatings of certain metals are formed. The treatment of wastewaters generated by the galvanization process can be conducted by a number of methods, however, today more research is being done on processes which are efficient, economical and cost-effective, but environmentally acceptable. One of those techniques is adsorption. The adsorption process of Cd2+, Ni2+ and Cr2+ions from galvanization water using brewer’s grain as the adsorbent, at different pH values and adsorbent granulation of 0.5 mm is analyzed in this paper. The percentage of moisture and ash was determined, and the FTIR analysis was performed confirming the presence of certain functional groups. Based on the obtained values, it has been shown that the brewer’s grain can be successfully used as a natural adsorbent to remove Cd2+, Ni2+ and Cr2+ ions from galvanization waters, and also that high level of efficiency is obtained at all analyzed pH values. The analysis has also shown that the affinity of adsorbents to Cd2+, Ni2+ and Cr2+ ions is in correlation with physical and chemical properties, but that the best removal efficiency is achieved at the pH 4 value

Biosensors are nowadays a powerful alternative to conventional analytical techniques for controlling the quality of not only natural water but also process water used by the food industry during the production process, as well as wastewater prior to release into natural watercourses. The goal is to provide the required quality and safety of water from the standpoint of heavy metal contamination. The basic and most important characteristics of biosensors are high sensitivity, short response time, specificity, and relatively low production cost. Biosensors can detect the presence and measure the content of various toxic substances (pesticides, heavy metals, etc.) not only in water but also in food. Detection of contaminants, primarily heavy metals in water used in food production processes, is a potential area of biosensor application in the food industry. Biosensors can be adapted for direct and continuous (online) monitoring by measuring certain analytes that can affect the quality and safety of water. This chapter will give an overview of the development and application of biosensors in order to control the quality and safety of water from the standpoint of the presence of heavy metals.

: In this paper, the extraction of phenolics from sage (Salvia Officinalis L.) which was grown in the plantations of MP Ljekobilje Trebinje, was carried out by maceration at different extraction time periods (30, 60, 90 , 120, 150 and 180 min), using different organic solvents (40%, 50% and 60% ethanol, 40%, 50% and 60% methanol) and water. The influence of each solvent on the extraction of total phenolics, flavonoids and antioxidative activity of obtained extracts was evaluated. The effect of solid-to-solvent ratio (1:7, 1:10 and 1:15) on the extraction yield of total phenolics was investigated. The influence of different extraction temperatures (room temperature, 30, 40, 50 and 60 ºC) on the content of total phenolics and flavonoids and antioxidative activity of the extract was also investigated. The content of total phenolics and flavonoids in the obtained sage extracts was determined spectrophotometrically. The radical scavenging capacity was determined by the DPPH method, wherein the extract concentration required to neutralize 50% of the initial DPPH radical concentration was also determined. The aqueous solutions of ethanol gave the highest yield of the extract, ie. the highest content of total phenolics and flavonoids in extracts obtained at room temperature and optimal extraction time of 60 minutes. Increasing the time of extraction has increased the content of the total phenolics and flavonoids in extracts, while the excessive time and temperature of the extraction had a negative effect on total phenolics, flavonoids and antioxidative activity of sage extracts.

The consequence of drastic reduction in fossil fuel reserves has forced the scientific community to find and develop new ways to exploit renewable resources and optimize the process of polymer materials production. The aim is to obtain applicable polymer whose complete life cycle is set in ecological framework. Poly(lactide) (PLA) meets these requirements as biodegradable polyester whose monomer is derived from the plant feedstock containing carbohydrates. PLA could be prepared using the different synthesis routes, but from the point of energy saving, as well as environmental protection, the microwave synthesis of PLA is the best solution. In this work, poly(L-lactide) were synthesized in microwave reactor. Reaction time was varied, while the other parameters of the synthesis were constant. The structures of obtained polymers were confirmed by Fourier – transform infrared spectroscopy (FT-IR). For determination of molar masses of poly(L-lactide) samples, the gel permeation chromatography (GPC) was applied. Thermal properties were investigated by differential scanning calorimetry (DSC).

The problem of environmental pollution is more expressed and more present by the development of the industry and the growth of the human population. Pollution of natural and wastewater is most often due to the release of heavy metals into watercourses. The greatest challenge for researchers is choosing the right biomass from a large number of low-cost biomaterials, and availability and price are very important selection factors. Microbial biomass, forestry waste and agroindustrial complexes are most frequently examined, as well as various macromolecules of natural origin. In this paper, barley straw that arises as agricultural waste product in barley production in Bosnia and Herzegovina, was used as a biosorbent. In the experimental part, physical and chemical characterization of  barley straw was performed, after which the efficiency of removing Cd(II) and Ni(II) from aqueous solutions, using barley straw, and the influence of process parameters (pH value of aqueous solution, biosorbent size, interaction of metal ions) on the biosorption capacity were tested. It can be concluded that barley straw has good adsoption characteristics for the use as a low-cost natural sorbent for the removal of heavy metals from water.