The use of bacterial indole-3-acetic acid (IAA) for reduce of chemical fertilizers doses

The standard technology of seed processing uses mainly chemical products. Recent researches showed that toxic materials from chemical fertilizers can be harmful to humans, animals and the environment. Currently the attention of researches is shifting away from chemical fertlizers and toward alternative that consumers perceive to be natural, Plant Growth Promoting bacteria (PGP). PGP bacteria could be a way to reduce chemical fertilizer doses. This was the reason to test the ability of Bacillus megaterium, Azotobacter chroococcum to produce hormone auxin (IAA). Bacterial strains were identified by PCR amplification and sequencing of the 16S rRNA gene. Indole-3-acetic acid (IAA) was detected and quantified by MRM experiment. This study conducted that maize seed inoculation with IAA from species mentioned above showed positive effects. They had statistically significantly higher root and steam height compared to control seedlings. Bacterial strains tested in this study may be recommended as PGP (Plant Growth Promoting) bacteria, due to their positive effects and eventually can be used to reduce chemical fertilizers doses

Innovative aproach for wireless electrochemical remediation of cyanotoxins based on bipolar electrochemistry

Bipolar electrochemistry (BPE) is an unconventional method to address conducting and semiconducting particles in a wireless manner. Unique features of BPE when compared to conventional electrochemical setup where electrochemical reactions take place at the surface of two different electrodes both connected to a potentiostat, allow us to address bipolar electrode electrochemically in a wireless fashion because there is no direct connection with the power supply (see Figure 1.). Herein, we used the concept of BPE as a straightforward way for the site selective deposition of materials on bipolar electrodes. Furthermore, we use these materials for the electrochemical remediation of cyanotoxins, a potential global health problem, exploiting the versatility of bipolar electrochemistry. Due to the high toxicity of cyanotoxins, highly efficient remediation methods have been under development in recent years, with advanced oxidation processes focused on mineralization as major target. Electrochemical remediation arose as an interesting alternative with few reported protocols to date

Water quality of the North Banat basal aquifer system

North Banat, an area of about 2329 km2 administered by six municipalities, is the extreme northeastern part of the Republic of Serbia and located in the southeastern margin of Pannonian depression. Drinking water is supplied under artesian or sub artesian pressure of Lower Pleistocene (Q1) or Upper Pliocene (Pl3) from confined aquifers. Tapped water-bearing beds in Banat dip from northeast to the south, reaching a depth of some 300 m at surrounding of Kikinda. Chemically, these 'uncommon' waters are a natural rarity controlled by geological and hydro geological characters of the water-bearing strata. The quality of water, periodically tested and examined, is discussed in this paper and its chemical composition is interpreted in terms of the regional geology

Freshwater Cyanobacterial blooms and Cyanotoxin production in Serbia in the past 25 years

Since 1980 cyanobacterial blooms occurred in a large number of reservoirs lakes and water flows (rivers and channels) in Serbia. Among 83 water ecosystems examined, 58 were found in blooming condition almost every year during last 2 decades. All natural lakes, accumulations, rivers and canals in Vojvodina province (agricultural part) proved to be sites with frequent cyanobacterial proliferation. During the summer 2005-spring 2006 microcystin-LR survey in Vojvodina, the toxin was permanently present in all examined ecosystems and the highest value of 362.68 μgL-1 was detected in Ludoš Lake. The part of Central Serbia is very problematic for ground water supply. For that reason more than 20 reservoirs serve as drinking water suppliers. Significant and persistent cyanobacterial blooms have been recognized in 9 of them. Samples for cyanotoxin analyses were taken during and after blooms in Ćelije Reservoir and in drinking water in Kruševac town 2 days later. Concentration of microcystin-LR was 650 μgL-1 in the reservoir while the tap water contained 2.5μgL-1

Geological effect on the Grlište reservoir water quality

This work presents analytical data for copper (Cu), zinc (Zn) and manganese (Mn) of the Grlište storage reservoir that was built for water supply to Zaječar and the nearby communities. Because there was not any industry of military work that could be a source of heavy metals, the research focused on the geology of the area drained to the impounded lake. Occurrences and deposits of minerals in the area were registered and concentrations of copper, zinc and manganese in the lake analyzed and graphically represented. Water samples the analyses were taken at the upstream and downstream ends and the middle of the lake, each from three depths: lake surface, mid-depth and near the floor. Measurements spanned the period from 1991 to 2004. The copper and zinc concentrations had a gently rising trend in all sections, and manganese only in the upstream end of the lake

Geohemijsko kartiranje obalskih profila u slivnom području reke Ibar - uloga u uspostavljanju geohemijske osnove za procenu antropogenog uticaja na životnu sredinu

Geochemical mapping of riverbank profiles of the basin area of the river Ibar was performed in the purpose of making regional geochemical map of Serbia 1:1000000. In this area, deposits of lead and zinc are located, and they are characterized by very complex geological composition. Sampling net at chosen locations of riverbank profiles was adjusted to the morphological and hydrographic characteristics of the terrain. At every profile, samples were collected from A-horizon, Ob-overbank sediment and S-active stream sediment, while tracking the changes of lithological members, in accordance to the WEGS methodology (Western European Geological Surveys). The preserved geochemical track in the overbank sediment is of special significance for correlation the results of chemical elements in the surface part of (A-horizon) and active contemporary stream sediment. In the analytical process, beside determining contents of Pb, Zn, Cu, Co, Ni, Cr, Sb, V, Cd and other elements, the radiometric examinations of contents of U238, Th232 and K40, were also conducted as well as the appropriate sedimentological analyses. On the basis of geochemical prospection results, a data base was formed which represents a foundation for estimation of anthropogenic influence on the living environment of rural settlements in the basin area of the river Ibar. In accordance to the geological- structural and morphological characteristics of the terrain, the results are applicable in the research of mineral raw materials, in agriculture, forestry, geomedicine, etc.Kartiranje obalskih profila u slivnom području reke Ibar vršeno je u cilju izrade geohemijske karte Srbije 1:1000000. U ovom području se nalaze ležišta olova i cinka, a karakteriše ga veoma složen geološki sastav. Mreža uzorkovanja na izabranim lokacijama obalskih profila prilagođena je morfološkim i hidrografskim karakteristikama terena. Na svakom profilu prikupljeni su uzorci iz Ahorizonta, overbank sedimenta i aktivnog strim sedimenta, prateći promene litoloških članova, u skladu sa metodologijom WEGS (Western European Geological Surveys). Sačuvani geohemijski zapis u overbank sedimentu je od posebnog značaja za korelaciju rezultata hemijskih elemenata u površinskom delu (A-horizont) i aktivnog savremenog strim sedimenta. U analitičkom postupku, pored određivanja sadržaja Pb, Zn, Cu, Co, Ni, Cr, Sb, V, Cd i drugih elemenata, vršena su radiometrijska ispitivanja sadržaja U238, Th232 i K40, kao i odgovarajuće sedimentološke analize. Na bazi rezultata geohemijske prospekcije formirana je baza podataka koja čini osnovu za procenu antropogenog uticaja na životnu sredinu ruralnih naselja u slivnom području reke Ibar. U skladu sa geološko-strukturnim i morfološkim karakteristikama terena, rezultati su primenjivi u istraživanju mineralnih sirovina, u poljoprivredi, šumarstvu, geomedicini i sl

Reduction of Trihalomethanes Forming Potential by Adsorption of Natural Organic Matter on Ionic Exchange Resins

In a sanitation process of drinking water, carbon from the organic matter reacts with chlorine, forming by-products, among which are trihalomethanes (THM). These substances are carriers of mutagenic and can-cerogenic potential and hence should be removed in drinking water treatment. Since the natural organic mat-ters are precursors of THM formation, their removal from the water decreases the concentration of THMs. The THM forming potential is the most reliable indicator in evaluation of organic matter removal during drinking water treatment processes. The results have shown that the reaction producing THMs follows sec-ond order kinetics. The second order rate constant ranged from 0.024 M-1s-1 to 0.065 M-1s-1 at 22 °C and pH = 8.2 for 96 hours. The removal of 78.4% of natural organic matter, by adsorption on anionic exchange res-ins, resulted in the THM forming potential reduction by 63.1%. Various fractions of natural organic matter differ in their reactivity with chlorine, which is important when it comes to selection of the adsorption me-dium in the drinking water treatment processes

Odredjivanje adsorpcionog kapaciteta u statičkim uslovima

The adsorption process are more and more frequently applied in water treatments. The choice of the adsorption medium depends on the adsorption capacity. The adsorption capacity in statical conditions should always preceeds the determination of the adsorption capacity in dynamic conditions, because it represents one of the main indicators of the proper determination of technological parameters in the process of water purification. The aim of this paper is to present a method for determination of specific adsorption capacity according to linear form of Freundlich`s equation and adsorption capacity in accordance with Lengmuir`s equation and its linear form.Adsorpcioni procesi se sve češće primenjuju u tretmanima prečišćavanja vode. Izbor adsorpcionog medijuma zavisi od adsorpcionog kapaciteta. Adsorpcioni kapacitet u statičkim uslovima treba uvek da predhodi odreĎivanju adsorpcionog kapaciteta u dinamičkim uslovima, jer je on jedan od glavnih pokazatelja za pravilno odreĎivanje tehnoloških parametara u tretmanima prečišćavanja vode. U ovom radu prikazan je način odreĎivanja specifične adsorpcije prema linearizovanom obliku Freundlichove-ove jednačine i adsorpcionog kapaciteta u skladu sa Lengmuir-ovom jednačinom i njenim linearizovanim oblikom.7 Medjunarodna konferencija Vodovodni i kanalizacioni sistemi / 7th international conference Water Supply and Sewerage Systems, Jahorina - Pale (Bosnia and Herzegovina), 10-12 May 2007