Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników
Powiadomienia systemowe
  • Sesja wygasła!

Znaleziono wyników: 9

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  organic contaminants
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
EN
The main purpose of the article is to develop a multifactorial model for rapid assessment of the efficiency of biological wastewater treatment reactors. A mathematical model of the process of biological wastewater treatment has been developed based on: changes in the concentration of organic contaminants in the bioreactor over time, taking into account the uneven flow of wastewater to the treatment plant, the process of substrate entering the bioreactor (different amounts may enter at different times). The software implementation of the proposed algorithm for solving the corresponding model problem in Python is carried out. The results of computer experiments on the study of the efficiency of wastewater treatment in biological treatment reactors for different operating conditions of facilities are presented. In particular, such processes were considered with taking into account the unevenness of the load, because the maximum cleaning loads are in the morning and in the evening. The task was solved to simulate a real situation and show how cleaning takes place at the maximum load at a certain time of the day. The results obtained will be useful for calculations in the design of biological treatment facilities or in the reconstruction of existing bioreactors for their prospective operation under new operating conditions.
EN
The aim of the study was to use regenerated activated carbon to adsorb phenol from a river. Coconut shell activated carbon was derived from used tap water filter cartridges. The activated carbon was carbonised and then activated with KOH at 200°C, under a nitrogen atmosphere. The resulting adsorbent was characterised on the basis of nitrogen adsorption by Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM) analysis and point of zero charge (pH PZC). The study of periodic adsorption included kinetic and equilibrium modelling, determined the effect of solution pH on efficiency and the possibility of regeneration and reuse of the adsorbent. The efficiency of phenol removal from model water was evaluated, followed by the possibility of their adsorption from a polluted river in Silesia Province. Phenol adsorption followed pseudo-second-order kinetics. The adsorbents showed high adsorption abilities, as determined by the Langmuir isotherm model. The model fits the experimental data well. The concentration of phenol in the river was in the range of 0.45-0.77 mg∙dm-3, which means that its value was at least five times higher than the standard values. The use of regenerated activated carbon from waste filter cartridges removed phenol from the river by 78% using optimal test parameters.
EN
The use of aluminum sulfate (Al2SO4) coagulant in water treatment plants generates large amount of sludge residues containing the alum hydroxide precipitates and organic matter. Due to its amphoteric characteristic, this sludge by-product offers alum coagulant recovery by using electrochemical process, before safe disposal to the environment. This study is aimed at evaluating the efficiency of membrane-based electrochemical processes to recover aluminum from the filtrate of the acidified sludge. The dried alum sludge was acidified using sulfuric acid at pH 3, and then centrifuged to obtain the filtrate. Organic content of the filtrate was measured by means of Total Organic Carbon (TOC) and Chemical Oxygen Demand (COD), i.e., 295.8 mg/L and 9,666.7±942.81 mg/L, respectively. In addition, the concentration of Al, Fe, Cu, and Cr was 1,194 mg/L, 515 mg/L, 0.559 mg/L, and 0.217 mg/L, respectively. The two-compartment electrochemical reactor was separated by using Cation Exchange Membrane (CEM) and Anion Exchange Membrane (AEM), and operated in a batch system for 10 hours with an electrical current of 300 mA. The results showed that the use of CEM in electrolysis with the electrodes distances of 1 cm increased the aluminum recovery up to 66.74% with the TOC removal of 24.04% compared to the use of AEM. An electrochemical process using CEM can be suggested to obtain organic-free recovery stream containing higher recovery of alum.
EN
The research was carried out in order to identify and assess groundwater contamination in the area of the former factory of paints and varnishes “Polifarb” in Gdańsk. A network of temporary boreholes allowed specifying the size of the active sources of contamination and estimating the volume of contaminated rocks and the amount of polluted water. Two zones of polluted water have been identified, with different specific substances. In the first zone, located in the area of the former “Polifarb” factory and close behind it, the water contained polycyclic aromatic hydrocarbons (PAH), volatile aromatic hydrocarbons (BTX), phenols, petrol and mineral oils. In the second zone, chloroorganic compounds (VOC) were detected. Diagnostic modelling and prognostic simulations allowed a preliminary evaluation of the rate of pollutants migration towards the wells of the “Czarny Dwór” groundwater intake.
PL
Ksenobiotyki, a szczególnie pestycydy, farmaceutyki oraz związki endokrynologicznie czynne to zróżnicowane grupy związków chemicznych stanowiące zagrożenie dla środowiska naturalnego i zdrowia człowieka. Ze względu na ich trwałość, toksyczność, odporność na warunki atmosferyczne i biochemiczne oraz zdolność do bioakumulacji w tkankach organizmów żywych, zasługują na szczególną uwagę w ochronie środowiska i zdrowia ludzkiego. Oznaczanie śladowych ilości zanieczyszczeń w próbkach środowiskowych, a szczególnie wodnych jest zatem problemem ważnym i ciągle aktualnym. Jest to zadanie trudne ze względu na złożoność analizowanych matryc. Niezbędne jest bowiem wyodrębnienie analitów i pozbycie się z matrycy substancji przeszkadzających oraz ich zatężenie przed oznaczaniem metodami chromatograficznymi, w celu uzyskania odpowiednich, niskich limitów detekcji. W prezentowanej pracy omówione będą najważniejsze sposoby wyodrębniania, wzbogacania i oznaczania śladowych ilości zanieczyszczeń organicznych w próbkach środowiskowych.
EN
Xenobiotics, especially pesticides, pharmaceuticals and endocrinologically active compounds are different organic compounds mostly toxic for the environment and human health. Due to their durability, toxicity, resistance and bioaccumulation in animal tissues it is necessary to determined this compound in complex environmental matrices. Moreover, it is necessary to consider that these compounds occur in very low concentrations and their direct analysis with available chromatographic and/or electrophoretic techniques is rather impossible. According to this fact, there is a need to apply specific pre-treatment methods that would allow for easy and effective isolation, concentration and determination of xenobiotics in trace amount. Therefore in this paper the important pretreatment and determination methods for xenbiotics trace analysis are presented.
EN
We examine the composition and levels of organic contaminants (PAHs, PCB, HCB) in four sediment cores collected from the Barents Sea. We assess the influence of temporal variations in contaminant supplies and post-depositional reworking on contaminant distribution. Anthropogenic levels of Σ12 PAH reached 95 ng g-1, higher inventories dominated by BKF were observed at southern stations, while northern stations exhibited lower inventories with PHE as the dominant compound. The PCB composition was similar at all stations dominated by CB 101, 138 and 153. Σ7 PCB concentrations were higher at northern stations. The observed composition and spatio-temporal pattern of organic contaminants is in accordance with long-range transport supplies.
PL
Przedstawiono przegląd danych literaturowych dotyczących zastosowania naturalnych sorbentów oraz niektórych materiałów odpadowych do eliminacji ze środowiska zanieczyszczeń organicznych, a także metali ciężkich poprzez sorpcję oraz (w przypadku substancji biodegradowalnych) mineralizację. Wykazano, że kora sosny i włókna naturalne, takie jak wełna, bawełna czy lignina, mogą być dobrymi sorbentami dla zanieczyszczeń ropopochodnych. Za pomocą kory uzyskano także efektywną sorpcję chloroorganicznych pestycydów z wody, a zastosowanie sorbentów mineralnych, takich jak perlit czy glinki, umożliwiło eliminację pentachlorofenolu, WWA i ropy naftowej z wody, gleby i ścieków. Materiały naturalne i odpadowe, np. kora, lignina, biomasa, bawełna, chitosan, glinki i zeolity, mają bardzo dobre właściwości sorpcyjne wobec metali ciężkich. Liczne dane literaturowe mówią o skutecznym wykorzystywaniu takich materiałów, jak torf, kompost, muszle ostryg, granulat lawy jako wypełnienia biofiltrów do oczyszczania powietrza. Naturalne sorbenty i niektóre materiały odpadowe służą także jako nośniki do unieruchamiania mikroorganizmów aktywnych w rozkładzie zanieczyszczeń. Zachodzące procesy biodegradacji umożliwiają samoregenerację sorbentu. Liczne badania udowadniają, że ww. materiały mogą z powodzeniem zastąpić węgiel aktywny i kosztowne sorbenty syntetyczne w technologiach związanych z usuwaniem zanieczyszczeń ze środowiska.
EN
The paper contains a review of literature data comprising results of laboratory investigations on sorption of organic contaminants as well as heavy metals by means of natural sorbents and some waste materials. There are also some examples of use elaborated technologies on a technical scale. There are many examples of using pine bark for sorption of fatty acids emulsions and petroleum derivative products from wastewater. Bark may be also an effective sorbent for chlororganic compounds, especially pesticides. Natural materials like lignin, sawdust, wool and cotton may be used for decontamination of water and soil from petroleum products. Composite settings, composed from clay bonded to sand, showed high capacity for removing benzo(a)pirene and pentachlorophenol (PCP) from wastewater. Natural and waste materials like bark, lignin, seaweed, cotton, chitosan, clay and zeolites have high sorption properties for heavy metals. Natural sorbents can be modified by means of physical and chemical methods in order to enhance their sorptive capacity. The use of natural as well as waste sorbents as elements of biofilters to remove organic and odour-generating contaminants from the air was also presented. Items of literature present numerous uses of biofilters filled with natural and waste materials such as compost, oyster shells, lava granulate. Very promising method for the contaminants elimination is the application of sorbents containing immobilized active microorganisms. High effectiveness of such a system is possible thanks to the following two mechanisms: adsorption of the contaminants on the sorbent, and biodegradation of organic substances. Immobilized microorganisms are widely used in environmental biotechnology for the air, water, wastewater and soil purification, especially to eliminate hardly degraded contaminants. The immobilization of biomass in sorbents is a factor enhancing the biodegradation by supporting high metabolic activity of microorganisms. The review of literature presented in this paper suggests that activated carbon and costly synthetic sorbents may be successfully replaced by natural and even waste materials of sorptive properties, namely: bark, natural fibers (wool, cotton, cellulose), mineral sorbents (zeolites, clay), sawdust, straw, lignin, oyster shells, chitin, and biomass. It is to be supposed that these materials will soon be used in technologies connected with removing contaminants from the environment.
PL
Zmiany zawartości biomasy i wskaźników zanieczyszczeń organicznych w powierzchniowych wodach trzech rzek: Odry, lny i Regi obserwowano przez trzy lata hydrologiczne (od października 1993 r. do września 1996 r.). Jako wskaźnik zawartości biomasy obumarłego fitoplanktonu przyjęto zawartość feofityny_a (Feo_a), a wskaźnikami ogólnego zanieczyszczenia substancjami organicznymi w wodach były: pięciodobowe biochemiczne zapotrzebowanie tlenu (BZT 5) oraz chemiczne zapotrzebowanie tlenu chromianowe (ChZT-Cr). W lnie i Redze zawartość Feo_a była porównywalna, średnie roczne zawartości wynosiły odpowiednio 4,2 i 5,0 mg . m-3, natomiast w rze_e Odrze były znacznie wyższe i wynosiły 23 mg . m-3. Średnie roczne wskaźniki zanieczyszczenia substancjami organicznymi we wszystkich rzekach były porównywalne, ChZT-Cr wahało się w przedziale 31,6-39,8 mgO2 . dm-3, a BZT5 w przedziale 4,1-4,56 mgO2 . dm-3. Dodatkowo w rzece Odrze odnotowano sezonowość zmian zawartości Feo_a oraz BZT5 i ChZT-Cr, w sezonie wegetacyjnym osiągały one wartości maksymalne, a w sezonie zimowym wartości minimalne. W dwóch pozostałych rzekach zaobserwowano sezonowość zmian jedynie w przypadku Feo_a. Przeprowadzone badania wskazują, że w rzece Odrze zanieczyszczenia organiczne mogą w znacznym stopniu pochodzić z rozkładu obumarłych glonów, natomiast w lnie i Redze ze źródeł allochtonicznych.
EN
Changes of biomass and dissolved organic compounds content in surface water of 3 rivers: Odra, Ina and Rega during hydrological year were analysed during period 1994-1996. The content of pheophytine_a (Feo_a) served as an indicator of the dead phytoplankton, and as indexes of the total pollution of water by organic substances were used: 5-day biochemical oxygen demand (BOD5) and chromate chemical oxygen demand (COD-Cr). The content of Feo_a in Ina and Rega was comparable - 4.2 and 5.0 mg. m -3, respectively. The average yearly indexes of pollution by organic substances were similar in all three rivers, COD-Cr was 36.9-39.8 mgO2 . dm-3, and BOD5 was in the range of 4.1-4.56 mgO2 . dm-3. Additionally, in the Odra river there were seasonal changes of all three indexes, during the vegetation season they were the highest, and during winter the lowest. In the two other rivers seasonal changes were observed only for Feo_a. This study have shown that organic pollutants in the Odra river can to a great extent be traced to dead algae, whereas in Rega and Ina to other sources. Comparable levels of the indexes of pollution by organic substances found in the rivers, so different as far as the biomass production was concerned, may be due to the fact that the self-cleaning processes in Ina and Rega are less active then in the Odra river.
9
Content available remote Modelowanie transportu i sorpcji związków organicznych zawartych w odciekach
PL
W artykule przedstawiono zanieczyszczenia organiczne obecne w odciekach ze składowisk odpadów komunalnych oraz generalne równanie bilansu masy z uwzględnieniem członów odpowiedzialnych za adwekcyjny i dyfuzyjny transport jak również sorpcję i strącanie warstwy wodonośnej. Metody obliczeniowe dla przewidywania współczynników rozdziału gleba/woda i oktanol/woda oraz rozpuszczalności związków organicznych w wodzie są przedstawione rozpoczynając od najprostszej Π metody dla współczynników oktanol/woda. Podsumowane są również metody przewidywania rozpuszczalności związków organicznych w wodzie i rozpuszczalnikach organicznych takich jak metoda Yalkowskiego, metody bazujące na teorii regularnych roztworów oraz równaniu Margulesa.
EN
Organic contaminants present in leakage from municipal landfills have been characterized and general mass balance equation including terms responsible for advective and diffusive transport as well as sorption and precipitation in groundwater aquifer have been described. Computing methods of prediction soil/water and octanol/water partition coefficients and solubility of organics in water briefly summarized starting from the simplest Π method for octanol/water npartition coefficients through some methods based on structure of considered molecules. Methods of predicting solubility of organic compounds in water and in organic solvents have been briefly summarized, such as the Yalkowsky's method, methods based on the regular solutions theory, and the Margules equation.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.