In order to improve the properties of sintered MgO (80 % precipitation) obtained from seawater, an investigation was carried out with (0, 1, 2) w/% of nano-TiO2 and micro-TiO2 additions during ...sintering at a temperature of 1500 °C (1 h and 2 h). The effects of the TiO2 addition on its microstructural properties, density, porosity and chemical composition after sintering were observed. The SEM/EDS analysis confirmed the formation of a homogeneous microstructure composed mainly of periclase grains and well-distributed secondary phases. CaTiO3 and MgTiO4 are predominantly located at the inter- and intra-periclase grain boundary surfaces during cooling. The microstructure of the MgO samples with the addition of nano-TiO2 become more compact, having a positive impact on the porosity and density of the samples. The addition of 1 w/% of nTiO2 represents the optimal amount for the improvement of the properties of the MgO samples (80 % precipitation) obtained from seawater.
Poljoprivreda kao djelatnost svrstava se prvenstveno u difuzne (raspršene) izvore onečišćenja okoliša. Takvi izvori onečišćenja teže se nadziru u odnosu na točkaste, koji su vezani za ispuštanje ...otpadnih voda iz gradova i stambenih naselja. Međutim, poljoprivreda se može pojaviti istovremeno i kao točkasti (koncentrirani) izvor onečišćenja. Kod pripreme škropiva i kod vanjskog pranja strojeva za zaštitu bilja može doći do onečišćenja okoliša pesticidima. Zato treba pripremu škropiva i vanjsko pranje strojeva nakon aplikacije pesticida izvoditi na betonskoj podlozi, gdje se otpadna voda od pranja i moguća odlijevanja sredstava skuplja i dalje obrađuje jednim od biopurifikacijskih sustava. U Sloveniji su postavljena dva sustava za pročišćavanje otpadnih voda kontaminiranih pesticidima. Jedan radi na principu otparavanja vode, a drugi na način razgradnje pesticida pomoću mikroorganizama u supstratu.
Introduction/purpose: Sušica source surface water varies in natural organic and inorganic impurities, biological species and micro-organisms. This water is used instead of Vrutci lake water that has ...been stronglly affected by eutrophication. These waters need removal of pollutants with coagulants and polyelectrolyte. The aim of research was to improve the surface water treatment (coagulation and flocculation), to reduce sludge amount and to evaluate its quality, treatment and application. Methods: The physical-chemical methods are developed for determining the quality parameters of water, sludge and compost. These parameters are: turbidity, KMnO4 consumption, metals, total organic carbon, total nitrogen, and chlorophyll. Results: Surface water quality has a strong impact on sludge. The concentrations of metals in the sludge were: 72200 mgkg-1 Al, 8550 mgkg-1 Fe, and 106 mgkg-1 Zn. The metals over the maximum limit were: Ni 169 mgkg-1, Cr 69.5 mgkg-1, Pb 5.7 mgkg-1, and they have to be reduced by zeolite. The „nutrients” concentrations were: 697 mgkg-1 P, 297 mgkg-1 K, 9.6 mgkg-1 total N, and 274 mgkg-1 of dissolved organic carbon. Escherichia coli and Salamonella are important for converting sludge to compost. Conclusions: After maturation, compost can be used for Coriandrum sativum cultivation. In further work, this strategy should be applied to the water and sludge from Vrutci lake. / Введение/цель: Концентрация природных органических и неорганических примесей, биологических видов и микроорганизмов в поверхностных водах истока реки Сушица изменчива. Эта вода заменила воду из озера Врутци, на которую сильно повлияла эвтрофикация. Данные воды нуждаются в очистке от загрязнения с помощью коагулянтов и полиэлектролитов. Целью исследования являлись: улучшение очистки поверхностных вод (коагуляция и флокуляция), уменьшение количества ила, оценка его качества, обработка и применение. Методы: Разработаны физико-химические методы определения параметров качества воды, ила и компоста. Исследуемые параметры: мутность, расход KMnO4, металлы, общий органический углерод, общий азот и хлорофилл. Результаты: Качество поверхностных вод сильно влияет на содержание осадка. Концентрация металлов в иле составляет: 72200 мгкг-1 Al, 8550 мгкг-1 Fe, 106 мгкг-1 Zn. Параметры металлов, превышающие предельно-допустимую концентрацию в воде: Ni 169 мгкг-1, Cr 69,5 мгкг-1, Pb 5,7 мгкг-1 и должны быть снижены за счет цеолитов. Концентрации «питательных веществ»: 697 мгкг-1 Р, 297 мгкг-1 К, 9,6 мгкг-1 общего азота, 274 мг-кг растворенного органического углерода. Eserihia coli и Salamonella необходимы для преобразования ила в компост. Выводы: После созревания компост можно использовать для выращивания Coriandrum salivum. В следующем исследовании данная стратегия будет применяться по отношению к воде и илу из озера Врутци. / Uvod/cilj: U površinskoj vodi izvorišta reke Sušice varira koncentracija prirodnih organskih i neorganskih nečistoća, bioloških vrsta i mikroorganizama. Ova voda zamenila je vodu iz jezera Vrutci, na koju je snažno uticala eutrofikacija. Tim vodama neophodno je uklanjanje zagađivača koagulantima i polielektrolitom. Cilj istraživanja bio je da se poboljša tretman površinske vode (koagulacija i flokulacija), smanji količina mulja, proceni njegov kvalitet, tretman i primena. Metode: Fizičko-hemijske metode razvijene su za određivanje parametara kvaliteta vode, mulja i komposta. Ti parametri su: zamućenost, potrošnja KMnO4, metali, ukupni organski ugljenik, ukupni azot i hlorofil. Rezultati: Kvalitet površinske vode uveliko utiče na sadržaj mulja. Koncentracije metala u mulju su: 72200 mgkg-1 Al, 8550 mgkg1 Fe, 106 mgkg-1 Zn. Metali preko maksimalne granice su: Ni 169 mgkg-1, Cr 69,5 mgkg-1, Pb 5,7 mgkg-1, i moraju se redukovati zeolitima. Koncentracije "hranjivih sastojaka" su: 697 mgkg-1 P, 297 mgkg-1 K, 9,6 mgkg-1 ukupnog N, 274 mgkg-1 rastvorenog organskog ugljenika. Eserihia coli i Salamonella bitne su za pretvaranje mulja u kompost. Zaključak: Nakon sazrevanja kompost se može koristiti za gajenje Coriandrum salivum. U narednom istraživanju ova strategija će se primeniti na vodu i mulj iz jezera Vrutci.
Otpadni tokovi nastali tijekom proizvodnje maslinova ulja karakterizirani su niskom pH, visokom električnom vodljivošću, tamnom bojom, visokim udjelom fenola, šećera i organskih kiselina. U ovom radu ...prikazani su rezultati uklanjanja onečišćujućih tvari iz otpadne vode procesom adsorpcije i biosorpcije na aktivni ugljik i pelete Aspergillus niger te zbrinjavanje komine maslina procesom kompostiranja. Dobiveni rezultati pokazuju da je aktivni ugljik adsorbirao 35 % organske tvari i 47 % fenola, a peleti 42 % organske tvari, 57 % fenola i 39 % boje. Tijekom procesa kompostiranja komine maslina i duhanskog otpada postignuta je konverzija od 45 %.
Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna .
In this study we test the potential of the elevated temperature infrared stimulated luminescence (IRSL) signals for dating Romanian loess. The recently developed post-IR IRSL protocol is applied to ...Romanian loess using polymineral fine grains extracted from the loess-palaeosol sequence at Mircea Vodă (SE Romania). This approach is aimed at obtaining an additional age control to examine the age discrepancy obtained from previous optically stimulated luminescence (OSL) studies using different grain-sizes of quartz (4–11 μm and 63–90 μm).
Two preheat post-IR IR stimulation temperature combinations were used, 250–225 °C and 325–300 °C, respectively. The signals obtained are documented in terms of dose response curve, laboratory tests and fading. Although both post-IR IRSL signals exhibit small fading rates, dose response characteristics indicate that these rates may be laboratory artefacts. The post-IR IRSL signal stimulated at 300 °C is observed to suffer from dose dependent initial sensitivity changes as both natural and regenerated signals are observed to lie above the saturation level of the dose response curve. Uncorrected age results obtained using both post-IR IRSL signals are in general agreement with previously reported silt-sized quartz OSL ages for samples collected from the uppermost loess unit L1. For older material, the post-IR IRSL signal stimulated at 225 °C is considered to provide reliable age results, in agreement with independent age control available for this sequence.
► Post-IR IRSL investigations of polymineral fine grains, Romanian loess. ► Natural and regenerated post-IR IRSL signals were observed in saturation. ► Initial sensitivity changes at high doses for the post-IR IR stimulation at 300 °C. ► For samples in L1, uncorrected post-IR IRSL ages agree with silt-sized quartz ages. ► For older material, post-IR IR225 ages agree with independent age control.
Assessment of radiation exposure to drinking, surface, and groundwater and of the associated health risks calls for accurate and precise
Ra and
Rn measurements. One method that fits the bill is ...liquid scintillation counting (LSC), which allows measurements in one-phase (homogenous) or two-phase samples. The aim of our study was to compare the measurement efficiency with both variations in Niška Banja spa water, known for its elevated
Rn content to get a better insight into the stability and behaviour of the samples and
Ra interference in samples spiked with
Ra with
Rn measurement.
Ra interference was more evident in homogenous, one-phase and much lower in two-phase samples. However, one-phase samples offer more accurate indirect
Ra measurements. Water-immiscible cocktails (in two-phase samples) have shown a limited capacity for receiving
Rn generated by Ra decay from the aqueous to organic phase when
Rn/
Ra equilibrium is reached. We have also learned that samples with naturally high
Rn content should not be spiked with
Ra activities higher than the ones found in native samples and that calibration of two-phase samples can be rather challenging if measurements span over longer time. Further research would require much lower
Ra activities for spiking to provide more practical answers to questions arising from the demonstrated phenomena.
Treatment of the sludge from water-purification plants is becoming more and more urgent due to the inability to increase its storage area. To avoid CO2 emissions, the use of non-Portland cement ...binders is recommended. The application of geopolymerization of waste sludge (WS) from water-purification plants is a novel solution. Curing conditions including high temperature, pressure or microwaves enhance the formation of geopolymer bonds. This paper presents the results of a research on the treatment of the WS of the Thu Duc water-purification plant (Vietnam) with the geopolymerization method. Solid phases were prepared by mixing the WS and fly ash (FA). The FA proportions of the solid phases were (10, 40, 70) w/%. The alkali-activated solution (AAS) was a mixture of a 40 w/% NaOH 6M solution and 60 w/% water glass (WG: Na2O.nSiO2 with n = 1.75 and volumetric density r = 1.40 kg/L). The geopolymer materials were mixtures containing an 80 w/% solid phase and a 20 w/% liquid phase of the AAS. Geopolymer samples were formed in a cylindrical steel mold with a diameter of 10 mm at a high pressure. The samples were cured in a 112 W microwave oven for 30 s or in a dryer at 110 °C for 24 h. The compressive strength and volumetric density of both sample groups were determined and compared to each other. The formation of geopolymer bonds was investigated using XRD, FTIR and SEM.
Jaje u mitovima o stvaranju svijeta Jakovljević, Goran
Radovi Zavoda za znanstvenoistraživački i umjetnički rad u Bjelovaru,
2020, Letnik:
14, Številka:
14
Journal Article, Paper
Recenzirano
Odprti dostop
The symbolism of the Egg may be followed through cosmogonic myths in many civilisations, which are similar among themselves and show that they share the same roots in certain segments. The roots of ...the Western civilizational circle are to be found in Mesopotamia, Egypt, the Syrian and the Palestinian countries, as well as in the Aegean (Balkan-Anatolian) cultural sphere. As a result of the contact with other civilizational circles, a kind of transfer of these influences on a lot wider geographic areas took place, as well as cyclic synergy came about. By comparing various cosmogonic myths, the conclusion may be drawn that the Egg is the primordial state of Cosmos, with Chaos within, from which the first Germ of Life stems (nature; gods; humans). The meaning of the original symbol of the Egg got lost in the course of time, so that only its importance with respect to the abundance and the cyclic restoration of life in nature, and the afterlife and resurrection in religion remained.
U radu je dan opis podrijetla vode na planeti Zemlji i njezino značenje u prošlosti i sadašnjosti. Analizirani su razmjeri kretanja vode na zemlji, njihove značajke, kao i glavni izvori dostupne vode ...na zemlji izraženi kroz postotni udio na globalnoj razini. Također je razmatran nastanak vode u Svemiru i proizvodnja kisika u ranoj fazi nastanka planeta. Fokus rada bazira se na održanju kvalitete vode dostupne na Zemlji te pojavi globalne varijabilnosti intenziteta oborina koje u zadnjih nekoliko desetljeća mijenjaju značajke velikih svjetskih površina kroz procese velikih suša i poplava. Kroz rad su opisani neki od najznačajnijih primjera eksploatacije pitkih voda u svijetu kroz površinske i podzemne rezerve vode. Analizirane su mogućnosti povećanja proizvodnje hrane za ljudske potrebe u pogledu povećanja zemljišta kroz tehnološki napredne metode te zaštita vodnih resursa uslijed klimatskih promjena. Dan je osvrt na značajke kvalitete prirodne vode u medicini i industriji, poboljšanje sanitarnih uvjeta, utjecaj ljudskog zagađenje na globalnoj razini, gospodarski rast i problem smanjenja vode, kao i globalni problem ispuštanja nepročišćenih otpadnih voda u recipijente i, posljedično, ugrožavanje flore i faune.
This paper gives a description of the origin of water on planet Earth and its importance in the past and the present. The paper presents the analysis of water flow extent on Earth, its characteristics, as well as the main sources of available water on the planet, expressed through a percentage share on a global scale. It also deals with the origin of water in the Universe, as well as the production of oxygen at the early stages of the planet’s formation. The focus of the paper is based on maintaining the quality of water available on Earth and the global variability of precipitation intensity that has changed the characteristics of large world surfaces through significant drought and flood processes over the last decades. Throughout the paper, some of the most important examples of exploitation of drinking water in the world through the surface and underground reserves of water are described. The possibilities of increasing the production of food for human needs in terms of increasing land through technologically advanced methods and the protection of water resources due to climate change are analyzed. At the end of the paper, there is a review of the characteristics of natural water quality in medicine and industry, sanitary conditions improvement, the impact of global pollution on human beings, economic growth and the problem of water scarcity, as well as the global problem of discharging untreated wastewater into the recipients and consequently endangering flora and fauna.
PDF
