Wyniki wyszukiwania - BazTech

1

Agricultural Use of Natural Biostimulants – Humic Substances: a review

Kłeczek Aneta

Rocznik Ochrona Środowiska

|

2022

|

Tom 24

1--14

EN

This work presents the characteristics of humic substances, with particular emphasis on the properties of agricultural importance, i.e., the improvement of soil structure, soil properties and the availability of nutrients. Attention was also paid to the methods of introducing given substances into the soil and the possibility of direct application to the plant surface. The mechanisms responsible for the stimulating and protective effect of humic substances on plant development were explained in detail, including phytohormonal regulation, the mitigation of biotic and abiotic stresses, antioxidant properties and the influence on seed germination and the development of the plant root system. The economic and environmental importance of the application of the substances in question was also emphasized, consisting of maintaining the health of the soil and the quality of plants while reducing the share of chemical fertilizers and reducing the amount of water used. It should be noted that humic substances, like any agricultural product, should be appropriately selected for the type of cultivation, i.e., the optimal dose and method of application should be determined.

2

The Performance of Electrocoagulation Process in Removing Organic and Nitrogenous Compounds from Landfill Leachate in a Three-Compartment Reactor

Bagastyo Arseto Yekti, Sidik Fahrudin, Anggrainy Anita Dwi, Lin Jr-Lin, Nurhayati Ervin

Journal of Ecological Engineering

|

2022

|

Vol. 23, nr 2

235--245

EN

In this study, the effectiveness of the electrocoagulation (EC) process was evaluated based on the reduction of organic and nitrogenous contaminants in landfill leachate. A three-compartment electrochemical reactor as pre-treatment of stabilized landfill leachate was carried out ahead of biological treatment. The removal efficiencies of COD, BOD, ammonia, and nitrate were analyzed at pH 4, 6, and 8 with the current densities of 20.83 and 29.17 mA•cm–2. At pH 4, the highest removal of COD and NH4+ was obtained, i.e., in the range of 72–81% and 43–59%, respectively. The ratio of BOD5/COD was increased after EC, from initially 0.11 to 0.32 at pH 4. In addition, EC effectively removed humic substances in the leachate by targeting a large amount of high molecular weight humic substances, with around 103 kDa. However, the higher removal efficiency observed at higher current density leads to higher specific energy consumption. At a current density of 29.17 mA•cm–2, the specific energy consumption obtained in EC was around 10–17 Wh•g–1 COD and 99–148 Wh•g–1 NH4+. This could be decreased up to 50% at an applied current density of 20.83 mA•cm–2 with slightly lower efficiencies.

3

Removal of Humic Substances from Water by Means of Fibrous Ion Exchanger

Wasąg Henryk

Journal of Ecological Engineering

|

2020

|

Vol. 21, nr 8

229--235

EN

Natural organic substances are found in all natural waters, and especially high concentrations occur in the surface waters. Humic substances, which often constitute the majority of natural pollutants, can be the source of undesirable odor and increased color as well as may accumulate certain toxic substances through sorption or formation of complexes. Another threat connected with the presence of humic substances in water is the possibility of the trihalomethanes (THM) formation during disinfection with chlorine. Additionally, it disturbs most processes employed for treatment of water. Hence, the great interest in the development of the pretreatment methods enabling to reduce the content of humic substances prior to the further water treatment processes. According to many researchers, ion exchange is an effective method for removing humic substances from drinking water supplies. However, the obtained effects are strictly dependent on the properties of the employed ion exchangers. The paper presented the studies on the removal of humic substances from water using fibrous ion exchangers. Owing to their structure, fibrous ion exchangers are characterized by very good kinetics of the sorption process, which enables the application of thin layers with simultaneous high flow velocity. Fiban A-1 – strong base anion fibrous exchanger, synthesized in the Institute of Physical Organic Chemistry of the National Academy of Sciences of the Republic of Belarus – was employed in the presented laboratory studies on the treatment of surface water containing substantial amounts of humic substances (over 10 g/m3). The applied anion exchange resin allows for efficient elimination of humic substances from the treated water, whereas the obtained sorption value, reaching approximately 20 mg/g of ion exchanger allowed treating about 255–270 bed volumes of water under the conditions of the experiment. The exhausted Fiban A-1 ion exchanger can be successfully regenerated using 2% NaCl + 2% NaOH solution, as five consecutive operational cycles showed no reasonable decrease in the amount of purified water.

4

Ocena zmian właściwości sorpcyjnych torfu względem jonów Zn2+ w zależności od gęstości opróbowania profilu torfowego

Jezierski P.

Cuprum : czasopismo naukowo-techniczne górnictwa rud

|

2017

|

nr 4

41--48

PL

Zmienność zdolności sorpcyjnych torfu z Gór Izerskich względem jonów Zn2+ została zbadana w próbkach o grubości około 1,3 cm, uzyskanych po podziale rdzenia o długości około 45 cm. Inspiracją do podjęcia badań były doniesienia literaturowe oraz własne obserwacje autora, świadczące o tym, że torf wykazuje znaczące statystycznie zróżnicowanie cech fizykochemicznych na odcinku kilkudziesięciu centymetrów rdzenia, pod warunkiem że opróbowanie wykonane jest w odstępach 1-5 cm. Dotychczasowe badania wykonywano z wykorzystaniem zhomogenizowanych kilkunasto- i kilkudziesięciocentymetrowych próbek torfu. W opinii autora takie próbkowanie mogło uniemożliwiać uchwycenie rzeczywistej zmienności parametrów sorpcyjnych, prowadząc do ich uśrednienia. Wyniki niniejszej pracy potwierdziły postawioną tezę i wykazały ponad sześciokrotną zmianę wielkości sorpcji na badanym odcinku torfu. Dodatkowo, w celu podstawowej charakterystyki chemicznej, w tym określenia pozycji badanych torfów na diagramie Van Krevelena, wykonano analizę elementarną oraz obliczono stosunki atomowe C/N, O/C, H/C oraz parametr g (spektroskopią EPR – elektronowego paramagnetycznego rezonansu). Zbadano również charakter trwałych organicznych rodników jako produktów reakcji redoks jednostek obecnych w materii organicznej torfów, świadczących o jej właściwościach strukturalnych.

EN

The variability of sorption capacity towards Zn2+ ions of peat from the Jizera Mountains was examined for the samples with a thickness of approximately 1.3 cm obtained by cutting of the peat core which length was about 45 cm. Our studies were inspired by the literature data and the authors' own observations which revealed the statistically significant differences in physicochemical characteristics of the peat profile of several tens of centimeters length, under the condition that the sampling was performed at intervals of 1-5 cm. The previous studies were performed for the homogenized peat layers of a thickness in the range from dozen to few tens of centimeters. In the authors' opinion such sampling may prevent detection of the true volatility of sorption parameters, leading to their averaging. Therefore, as the first criterion for checking the existence of this type diversity (in profile whose dimension is the most studied) we chose the absorption capacity of Zn2 + which were analyzed for the peat layers with a resolution of a few centimeters obtained from the peat profile with a length of several tens of centimetres. The results of this study confirmed our thesis and revealed more than 6 fold change the sorption magnitude for the tested peat profile. In addition, to the basic chemical characteristics, including determining the position of the tested Van Krevelen’s peat diagram, elemental analysis was performed and the atomic ratios of C/N, O/C, H/C and g parameter (EPR – electron paramagnetic resonance spectroscopy) were calculated. The nature of persistent organic radicals formed from the structural units present in organic matter of the peat was also estimated in terms of its characteristics.

5

Ocena zdolności adsorpcyjnych granulowanego węgla aktywnego po kilkuletniej eksploatacji w zakładzie oczyszczania wody

Dąbek L., Kuśmierek K., Świątkowski A., Jaworska U.

Ochrona Środowiska

|

2016

|

Vol. 38, nr 4

53--56

PL

Przeprowadzono badania skuteczności adsorpcji wybranych adsorbatów z fazy gazowej i ciekłej na świeżym granulowanym węglu aktywnym ROW 0.8 Supra oraz zużytym po kilkuletniej eksploatacji w zakładzie oczyszczania wody. Wykazano, że adsorpcja par benzenu była proporcjonalna do dostępnej objętości porów próbek węgla świeżego i zużytego, natomiast zaadsorbowana ilość pary wodnej na węglu świeżym i zużytym była podobna. Wskazuje to, że zaadsorbowane w porach zużytego węgla wielkocząsteczkowe substancje humusowe biorą udział w adsorpcji wody. Równocześnie wykazano, że adsorpcja fenolu i 4-chlorofenolu z roztworów wodnych była ponad 10-krotnie mniejsza na węglu zużytym w porównaniu do węgla świeżego. Stwierdzono również, że adsorpcja jonów metali śladowych (Cu (II), Pb (II)), zarówno na węglu świeżym, jak i zużytym, była porównywalna. Otrzymane wyniki badań wykazały, że węgle aktywne po czasie eksploatacji w zakładach oczyszczania wody mogą być jeszcze rozważane jako potencjalne adsorbenty i znaleźć dalsze zastosowanie.

EN

Studies aimed at comparison of sorption effectiveness of selected adsorbates from vapor and liquid phases were carried out on fresh and spent granular active carbon ROW 0.8 Supra following several years of its exploitation in a water treatment plant. It was demonstrated that benzene vapor adsorption was proportional to the available pore volume of both carbons, while the adsorbed amount of water vapor on the fresh and spent carbons were similar. This would indicate that macromolecular humic substances deposited in the pores of spent granular active carbon were involved in the adsorption of water. At the same time, it was observed that phenol and 4-chlorophenol adsorption from aqueous solutions was more than 10-fold lower for the spent carbon than for the fresh one. Whereas adsorption of trace metal ions (Cu(II), Pb(II)) was similar for both carbon types. The presented results indicate that activated carbons following exploitation in water treatment stations may be still considered as potential sorbents and used in further applications.

6

Długożyciowa opóźniona luminescencja materii organicznej -nowa metoda badania substancji humusowych

Mielnik L., Prokowski Z., Mila A.

Gaz, Woda i Technika Sanitarna

|

2009

|

Nr 9

57-59