Ispitivanje koagulacione aktivnosti prirodnih koagulanata ekstrahovanih iz različitih sorti pasulja

Coagulation and flocculation by adding chemicals are the methods that are usually used for removal of water turbidity. This study is concerned with the coagulation activity of extracts of various strains of bean. The aim was to ascertain if bean varieties influence coagulation activity. Active components were extracted from 1 g of ground sample with 100 ml distilled water. Contents of dry matter and nitrogen were specified in the solid samples, and the content of soluble nitrogen was determined in the extracts. These data were used to calculate the efficiency of extraction of nitrogen-containing compounds. The coagulation activity was assessed by jar test using synthetic turbid water, of the initial pH 9 and turbidity 35 NTU. The jar test was carried out by adding different amounts of extracts to model water, and stirring the content. After sedimentation for 1 h, residual turbidity was determined by turbidimeter and coagulation activity was calculated. The increment of organic matter concentration after the coagulation was also determined. These experiments confirmed that extracts of all investigated strains of bean could be used successfully as natural coagulants.Koagulacija i flokulacija predstavljaju najčešće primenjivane metode za bistrenje vode, i uglavnom se izvode dodatkom hemijskih koagulanata. U ovom radu je ispitivana koagulaciona aktivnost ekstrakata dobijenih iz semena različitih sorti pasulja, a s ciljem da se utvrdi mogućnost njihove primene kao prirodnih koagulanata za uklanjanje mutnoće vode, i da se utvrdi uticaj sorte pasulja na koagulacionu aktivnost. Ekstrakcija aktivnih komponenti je izvedena sa 100 ml destilovane vode iz 1 g samlevenog uzorka. U čvrstim uzorcima je određen sadržaj suve materije i azota, a u ekstraktima sadržaj rastvorljivog azota, na osnovu čega je određena efikasnost ekstrakcije jedinjenja sa azotom. Za određivanje koagulacione aktivnosti ekstrakata izveden je džar-test, dodavanjem različitih doza ekstrakata model vodi, čiji je pH 9 i početna mutnoća 35 NTU. Nakon mešanja u određenom vremenskom intervalu, čaše su ostavljene da se njihov sadržaj istaloži, a zatim je u bistrom delu određivana mutnoća, i preko nje koagulaciona aktivnost. Takođe je utvrđen doprinos svakog od ekstrakata porastu sadržaja organskih materija u vodi nakon njenog bistrenja u odnosu na slepu probu, a preko permanganatnog broja. Ovim eksperimentima potvrđeno je da se ekstrakti svih ispitivanih sorti pasulja mogu uspešno primeniti kao prirodni koagulanti

Chemical parameters of oxidative stress adaptability in beech

e antioxidant activity, lipid peroxidation, and contents of free proline and soluble proteins were investigated on six-year-old beech plants. Provenance Avala, in Serbia, had the best adaptability to environmental factors on locality Fruska Gora due to low lipid peroxidation, high FRAP value, and free proline and soluble proteins contents. Provenances Scharnstein and Mitterndorf, in Austria, had the best adaptability to environmental factors on locality Debeli Lug due to high FRAP value and free proline and soluble proteins contents. FRAP values in majority of provenances from locality Debeli Lug were higher. Correlations parameters were much higher between provenances in locality Debeli Lug, situated at higher altitude, which is the consequence of better adaption to environmental factors in�uence

Social media and disasters: human security, environmental racism, and crisis communication in Hurricane Irma response

Social media has been widely recognized as key communication channel in disaster situations. However, there is limited empirical investigation on how the intersecting issues of social order, environmental impacts, and crisis communication unfold from the perspective of a social media user. This study examines 60,449 tweets to and from the news media in Florida during and immediately after Hurricane Irma in September, 2017. Based on a critical review of the literature coupled with an eight-category coding scheme (including second-hand reporting, reporting on self-experience, requesting help, coordinating relief efforts, and expressing well wishes), the article assesses the content and timing of tweets before, during, and after the storm. It finds that thematically, twitter coverage not only covers the storm itself but pressing social issues such as looting, price gouging, the privileging of elites in rebuilding efforts, environmental vulnerability, and abandoning pets. Temporally, the volume of different tweets peaked and dropped at different stages; for example, tweets about personal experience peaked when the hurricane hit the ground while requests for help peaked in the days after the hurricane. The study allows for a better understanding of the sociological, environmental, and even social justice impacts and related disaster response through the use of social media

Honesty above all else? Expectations and perceptions of political conduct in three established democracies

The authors gratefully acknowledge financial support from the ESRC (grant number RES-000-22-3459) and British Academy (grant numbers SG-101785 and SG-52322). They would also like to thank two anonymous reviewers for their helpful comments and suggestions

The kinetics of chromium(VI) adsorption from water on some natural materials

This paper is concerned with the kinetics of chromium(VI) adsorption by wood sawdust, pulp, and Kraft lignin. In our previous works we determined adsorption efficiency of these adsorbents. In this paper we focused our attention on the influence of contact time on chromium(VI) adsorption from water by the same adsorbents. The analytical data were approached from the following kinetic models: First-order kinetic model, Parabolic diffusion model, Elovich model, and Modified Freundlich model. Elovich model was shown to be the best fit for the description of chromium(VI) adsorption. It was found that adsorption was the fastest on pulp and slowest on Kraft lignin

Investigation of coagulation activity of natural coagulants from seeds of different leguminose species

The ability of seeds of plants: Phaseolus vulgaris, Robinia pseudoacacia Ceratonia siliqua and Amorpha fruticosa, to act as natural coagulants was tested using synthetic turbid water. This water was prepared by adding kaolin into tap water, just before the test. Active components were extracted from ground seeds with distilled water. The coagulation ability of this extract was assessed by the use of standard jar test measurements in water with various initial turbidity. Investigation of these natural coagulants was confirmed their positive coagulation activity. Of all plants that have been examined, the seed extract from Ceratonia siliqua appeared to be one of the most effective coagulants for water treatment. A dose of 20 mg/l of this coagulant resulted in 100% coagulation activity for clarification of water with 17.5 NTU initial turbidity

Improvement of production of high-yield poplar varieties seedlings by mycorrhiza application

Research related to the effects of treatment by mycorrhiza preparations Ectovit, Rhodovit (preparations Symbio-m Ltd., Czech Rep.) and their combination on growth of four high-yield poplar clones of Populus deltoides and one variety of Populus x euramericana are presented in this paper. In order to make more accurate assessment of mycorrhiza effect, soil characteristics such as morphology, texture and chemical composition were determined. The study results indicate that mycorrhized cuttings had the same or the better survival in all the study clones compared to the control. The application of the preparation Ectovit and Rhodovit resulted averagely in the first class planting stock of all the study clones. The combination of the preparations Ectovit and Rhodovit produced averagely the first class planting stock only of the clone Populus x euramericana