Najnovija dostignuća u fotokatalitičkoj degradaciji organskih onečišćujućih tvari u vodama

The chemical complexity of organic contaminants (drugs, agrochemicals, and dyes) requires new, more advanced ways to remove them from water compared to the conventional treatment methods used. One such method is photocatalytic degradation. In this paper, the mechanism of degradation of harmful organic compounds using semiconductor materials with photocatalytically active properties in the presence of UV or visible radiation will be explained. Methods and selection of components for the preparation of the latest developed photocatalysts, their stability, as well as the percentage of organic contaminant removal will be discussed. The discussion will also cover the advantages and drawbacks of photocatalytic methods, as well as future research in this area.Kemijska složenost organskih onečišćujućih tvari u prirodnim vodama, poput lijekova, agrokemikalija i boja, zahtijeva primjenu novih i naprednijih načina njihova uklanjanja iz voda u odnosu na konvencionalne metode njihova pročišćavanja. Jedna od takvih metoda je fotokatalitička razgradnja. U ovom radu opisani su mehanizmi razgradnje štetnih organskih spojeva pomoću poluvodičkih materijala s aktivnim fotokatalitičkim svojstvima uz djelovanje UV ili vidljivog zračenja. Raspravljat će se o metodama i odabiru komponenata za pripravu najnovijih fotokatalizatora, o njihovoj stabilnosti te učinkovitosti uklanjanja organskih onečišćujućih tvari. Rasprava će također obuhvatiti prednosti i nedostatke fotokatalitičkih metoda, kao i buduća istraživanja u tom području

Synthesis of gel air freshener and its stability

Fragrance compounds have been used since antiquity to freshen the air or to mask the odours. Different types of air fresheners are known such as electric air fresheners with 30% market share, sprays, including aerosol air fresheners with 27%, car air fresheners with 16%, gel air fresheners with 9%, candle air fresheners and wax melts with 7 %, liquid air fresheners with 6% and others. According to research studies, in the United States, 34.7% of the population reported health problems, such as migraine headaches and respiratory problems, when exposed to fragranced products. Thus, there are numerous studies with strong evidence that fragmented products can trigger adverse health effects in the general population. Considering that air fresheners have been associated with adverse negative health effects that was the motive for proposing an alternative way of synthesis of gel air fresheners that is more green and more healthy. In this paper the gel air fresheners were synthesized by a simple and green sol-gel reaction using natural biodegradable polymer gelatin and lavender essential oil, as well as with natural banana aroma. The 3D structures of gel air fresheners of desired shapes and odours were ob-tained. The change in the 3D structure at room temperature was evident, probably as a result of thermal degra-dation and water evaporation. Anyway, the gel air freshener obtained with lavender essential oil is more accepta-ble to human health than commercially available ones. The results obtained in this study suggest that further im-provement in stability should take place

Quality assessment and health safety of natural spring water

In this paper the natural spring water was investigated. The sample of spring water was taken at the beginning of July 2019 in Tuzla, Bosnia and Hercegovina (BIH), which is consumed by the local population. The source of in-vestigated spring water is located above salt mine. All parameters of health safety were analysed by the methods of laboratory tests regulated by the State regulation on natural mineral and natural spring waters ”Official Ga-zette BiH” No. 26/10 and 32/12, i.e. physical-chemical and microbiological analysis was performed. The results of the study showed that water is not for drinking because it contains higher concentrations of ammonium ion (NH4+) which is 0.89 mg/L, nitrite (NO2-) 2.20 mg/L and sulphate (SO42-) 398.34 mg/L, and coliform bacteria are isolated. The pH value of 9.07 indicate that this spring water is alkaline. The concentrations of iron (Fe2+) 0.007 mg/L and manganese (Mn2+) 0.0144 mg/L are within the allowed limit values while the concentration of lead (Pb2+) 0.0088 is at the upper maximum allowable value. The results of this research indicate that water in this untreated state is not for drinking

The Advantages of the Use of Ion- Selective Potentiometry in Relation to UV/VIS Spectroscopy

Electro analytical methods have a long history of development. Ion-selective potentiometry is one of the electro analytical methods. There are some advantages of the use of Ion selective potentiometry (ISP) which is accurate, fast, economic and sensitive in relation to the standard method, UV/VIS spectroscopy. The development of potentiometric ion-selective electrodes is a very interesting field because it has a wide range of applications in determining ions in water and other mediums. The use of ion-selective electrodes enables the determination of ion species in a trace. Ion-selective electrodes are suitable for analysis in industry, for control processes, for physiological measurements and environmental monitoring. In recent years it was used for the determination of many ions in the food industry such as determination of calcium in milk products, fruit juice and different kinds of vegetables. In our experiment measurement of bottled water using ISP showed lower level of fluoride compared to measurement by UV/ VIS spectroscopy. This results confirmed higher sensitivity of ISE in reference to UV/VIS spectroscopy. By our experimental data we can conclude that the concentration in examined sample was within the allowed concentration according to World Health Organisation

Photocatalytic degradation of organic compounds in wastewaters

Due to the toxicity effects and endocrine disrupting properties of many organic compounds, their removal from water and wastewater has gained widespread global attention. This review summarizes photocatalytic degradation of different organic molecules present in wastewaters. This is an overview of photocatalytic deg-radation with the goal of presenting the technique as an attractive and viable process unit. This process has great potential for replacing other conventional methods for treatment of wastewaters and can be used at the advanced treatment stage. Photocatalytic degradation techniques should be more used in wastewater treatment because with this technique it is possible to decrease contaminants to certain acceptable discharge limits. However, the technique is still not being utilised on an industrial scale. This is mainly due to focus of researchers to study singu-lar contaminants such as alcohols, carboxylic acid, phenol and its derivate, chlorinated aromatic compounds, col-ours, active pharmaceutical ingredients, and different type of surface active agents. TiO2 can be used as a photo-catalyst in water purification to degrade organic pollutants

Photocatalytic degradation of organic compounds in wastewaters

Due to the toxicity effects and endocrine disrupting properties of many organic compounds, their removal from water and wastewater has gained widespread global attention. This review summarizes photocatalytic degradation of different organic molecules present in wastewaters. This is an overview of photocatalytic deg-radation with the goal of presenting the technique as an attractive and viable process unit. This process has great potential for replacing other conventional methods for treatment of wastewaters and can be used at the advanced treatment stage. Photocatalytic degradation techniques should be more used in wastewater treatment because with this technique it is possible to decrease contaminants to certain acceptable discharge limits. However, the technique is still not being utilised on an industrial scale. This is mainly due to focus of researchers to study singu-lar contaminants such as alcohols, carboxylic acid, phenol and its derivate, chlorinated aromatic compounds, col-ours, active pharmaceutical ingredients, and different type of surface active agents. TiO2 can be used as a photo-catalyst in water purification to degrade organic pollutants

Control of heavy metal content in different types of vegetables produced in the area of Zenica

In this study, concentrations of lead Pb, cadmium Cd and arsenic As were tested in 177 samples of fresh vegetables produced in the area of Zenica. This locality is exposed to the strong influence of high emissions of various pollutants primarily originating from metallurgical and thermal power plants, but also from local heating plants. The accumulation of heavy metals is followed by the types of vegetables: tuber and root, bulb, leaf, fruiting and legume from the group of fruiting vegetables. Preparation of samples was done with microwave di-gestion. The concentration of the selected metals in solutions after digestion was determined on Induced coupled plasma mass spectrometry (ICP-MS). The percentage participation of contents Pb, Cd and As, either higher or lower than the maximum allowable amount prescribed by the applicable law, was calculated in all 177 samples. The results showed that different groups of vegetables have different ability to adopt and accumulate heavy met-als. The largest number of samples containing Pb content above the maximum level (ML) was in the group of leaf vegetables, then in the roots and finally in bulb groups. Cd was at the very limit with the maximum level in the parsley sample, while all other tested samples were in compliance with the applicable regulations. Two of the tested samples of the parsley leaves group had an increased content of As according to the legal regulations

Application of polymer nanocomposite materials in food packaging

The term “nano” refers to nano particle size from 1 to 100 nanometers. The term "nanotechnology" was first introduced by Norio Taniguchi in 1974. Nanotechnology may be used to improve the taste and texture of food and for the production of packaging that maintain fresh product. The primary function of packaging is to maintain the quality and safety of products during transport and storage period, as well as to extend its viability by preventing unwanted effect agents such as microorganisms, chemical contaminants, oxygen, moisture and light. The aim of this paper is to point out the achievements of nanotechnology in terms of food packaging with an overview of polymers that are commonly used in food packaging, as well as strategies to improve the physical properties of polymers, including mechanical strength, thermal stability and barrier to gases. By studing of recently published literature, it was clear that nanomaterials such as nano polymers are trying to replace conventional materials in food packaging. Nanosensors can be used to prove the presence of contaminants, microtoxins and microorganisms in food

Influence of Agriculture on Water Quality: Significance of Heavy Metals Monitoring

Agricultural activities directly influence the quality of water systems. Investigations showed that application of various agro-technical measures results with the pollution of water streams with heavy metals and other polluters. Increased concentrations of heavy metals result with intake of heavy metals and their transfer to food chains, and for that reason it is necessary to monitor the content of heavy metals regularly. Broad investigations of bio-geochemical cycling of heavy metals in the region of Lake Modrac were performed with combined methodology of determination of heavy metal traces with the estimation of bioavailability, based on the determination of complexing constants for Pb, Cu, Cd and Zn. Monitoring was performed at the locations in the vicinity of agricultural soil. The results achieved showed that the content of organic matter in water streams presents the key factor that determines the extent of bioavailability of heavy metal traces in water systems

Control of heavy metal content in different types of vegetables produced in the area of Zenica

In this study, concentrations of lead Pb, cadmium Cd and arsenic As were tested in 177 samples of fresh vegetables produced in the area of Zenica. This locality is exposed to the strong influence of high emissions of various pollutants primarily originating from metallurgical and thermal power plants, but also from local heating plants. The accumulation of heavy metals is followed by the types of vegetables: tuber and root, bulb, leaf, fruiting and legume from the group of fruiting vegetables. Preparation of samples was done with microwave di-gestion. The concentration of the selected metals in solutions after digestion was determined on Induced coupled plasma mass spectrometry (ICP-MS). The percentage participation of contents Pb, Cd and As, either higher or lower than the maximum allowable amount prescribed by the applicable law, was calculated in all 177 samples. The results showed that different groups of vegetables have different ability to adopt and accumulate heavy met-als. The largest number of samples containing Pb content above the maximum level (ML) was in the group of leaf vegetables, then in the roots and finally in bulb groups. Cd was at the very limit with the maximum level in the parsley sample, while all other tested samples were in compliance with the applicable regulations. Two of the tested samples of the parsley leaves group had an increased content of As according to the legal regulations