scholarly journals Carbon-Bonded Alumina Filters Coated by Graphene Oxide for Water Treatment

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2006
Author(s):  
Ondřej Jankovský ◽  
Michal Lojka ◽  
Adéla Jiříčková ◽  
Christos G. Aneziris ◽  
Enrico Storti ◽  
...  

The aim of this paper is to prepare nano-functionalized ceramic foam filters from carbon-bonded alumina. The carbon-bonded filters were produced via the Schwartzwalder process using a two-step approach. The prepared ceramic foam filters were further coated using graphene oxide. Graphene oxide was prepared by the modified Tour method. The C/O of the graphene oxide ratio was evaluated by XPS, EDS and elemental analysis (EA). The amount and type of individual oxygen functionalities were characterized by XPS and Raman spectroscopy. The microstructure was studied by TEM, and XRD was used to evaluate the interlayer distance. In the next step, filters were coated by graphene oxide using dip-coating. After drying, the prepared composite filters were used for the purification of the water containing lead, zinc and cadmium ions. The efficiency of the sorption was very high, suggesting the potential use of these materials for the treatment of wastewater from heavy metals.

Author(s):  
E. A. Olajubu ◽  
Gbemisola Ajayi ◽  
Isaiah Adesola Oke ◽  
Franklin Oladiipo Asahiah

Rapid industrialization has contributed immensely to the discharge of heavy metals into receiving water bodies untreated. The quantity of heavy metals prediction in industrial wastewater is very essential before treatment so that the quantity is precisely removed. This article formulates, simulate and evaluate a predictive model that mimics electrochemical treatment of lead and cadmium ions present in paint industrial wastewater using artificial neural network. The predictive model was formulated using Fuzzy Logic toolbox in MATLAB and the simulation was done in the environment. The prediction of the model was evaluated by comparing the predicted quantity of lead ions and cadmium ions with the result of the experimental work in the laboratory. The article concludes that the developed prediction model demonstrated very high prediction accuracy in predicting the percentage of lead and cadmium ions present in paints wastewater.


Chemosensors ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 53
Author(s):  
Erik W. Nunes ◽  
Martin K. L. Silva ◽  
Ivana Cesarino

The development of electroanalytical sensors for heavy metals detection in complex matrices holds great interest. Herein, a sensor based on a reduced graphene oxide (rGO) modified with antimony nanoparticles (Sb) was developed for the electrochemical detection of divalent cadmium ions (Cd2+) and lead ions (Pb2+). The simultaneous determination of both metals covered a range of 0.1 to 3.0 µmol L−1, with limits of detection (LOD) of 70.03 and 45.50 nmol L−1 for Cd2+ and Pb2+, respectively. For the individual detection, LOD of 20.50 nmol L−1 (Cd2+) and 2.01 nmol L−1 (Pb2+) were found. The analytical performance of this new sensor in detecting both metals in chamomile tea samples was satisfactorily evaluated.


Author(s):  
E. A. Olajubu ◽  
Gbemisola Ajayi ◽  
Isaiah Oke ◽  
Franklin Oladiipo Asahiah

Rapid industrialization has contributed immensely to the discharge of heavy metals into receiving water bodies untreated. The quantity of heavy metals prediction in industrial wastewater is very essential before treatment so that the quantity is precisely removed. This article formulates, simulate and evaluate a predictive model that mimics electrochemical treatment of lead and cadmium ions present in paint industrial wastewater using artificial neural network. The predictive model was formulated using Fuzzy Logic toolbox in MATLAB and the simulation was done in the environment. The prediction of the model was evaluated by comparing the predicted quantity of lead ions and cadmium ions with the result of the experimental work in the laboratory. The article concludes that the developed prediction model demonstrated very high prediction accuracy in predicting the percentage of lead and cadmium ions present in paints wastewater.


2019 ◽  
Author(s):  
V.B. Kalmanova

В статье представлены результаты исследования экологогеохимического состояния снежного покрова как индикатора качества атмосферного воздуха г. Биробиджана. Выявлены основные природные и антропогенные факторы, предопределяющие экологическое состояние городской территории в зимний период (климатические, планировочная структура, стационарные и мобильные источники загрязнения). Определено, что выбросы основных загрязнителей во время отопительного сезона превышает летний в 6,5 раз. Проведены геохимические исследования снежного покрова на 60 экспериментальных площадках, заложенных в различных функциональных зонах города. Выявлено значительное превышение тяжелых металлов над фоновым уровнем: железа до 60, марганца до 50, меди до 40, цинка до 20, никеля до 12, свинца до 10, кобальта до 6 раз. С 2003 по 2018 годы содержание химических элементов в снеге увеличилось в 2 раза за счет мобильных источников загрязнения, ТЭЦ, котельных. Проведена сравнительная характеристика накопления тяжелых металлов в снеге за 2003 и 2018 годы и установлен ранжированный ряд загрязняющих токсичных веществ. Разработана шкала оценки загрязнения депонирующих сред по суммарному показателю концентрации тяжелых металлов, согласно которой в Биробиджане выявлено 5 уровней загрязнения снежного покрова. В целом экологическое состояние урбанизированной территории признано неудовлетворительным (8 площади территории относится к очень высокому, 14 к высокому, 21 к выше среднему, 27 к среднему уровням загрязнения, 30 к относительно чистым районам города). По полученным результатам разработана карта в программе ArcView GIS Экологогеохимическое районирование территории г. Биробиджана по уровню загрязнения снежного покрова с выделением наиболее загрязненных участков (70 от общей площади города является загрязненной). По результатам проведенных исследований предложены конструктивные методы планирования урбанизированной территории с целью улучшения ее экологического состояния: проведение геомониторинга (контроль загрязнения снежного покрова и своевременный его вывоз на специально оборудованные полигоны). Snow cover is taken as an indicator of air quality using Birobidzhan, a middlesize city in the Russian Far East, as a case study. The main natural and manmade determinants influencing the ecological state of the urban area in winter are identified: climate, a planning structure, and the stationary and mobile sources of pollution. During the heating season the emission of major pollutants exceeds the summer level by 6.5 times. The geochemical study of snow cover was performed at 60 experimental sites in different functional urban areas. A significant excess of heavy metals over the regional background level was revealed: iron up to 60 times, manganese up to 50, copper up to 40, zinc up to 20 , nickel up to 12, lead up to 10, cobalt up to 6 times. From 2003 to 2018 the content of chemical elements in snow increased in 2 times due to the mobile sources of pollution, thermal power plants, and boilers. The comparative characteristic of accumulation of heavy metals in snow for 2003 and 2018 is carried out, and the ranked number of polluting toxic substances is established. The scale of pollution assessment in depositing environments was developed using the cumulative indicator of heavy metal concentration. Five levels of snow cover pollution are found in Birobidzhan: low, moderate, above moderate, high and very high. As a whole, the ecological state of the urban area is considered as unsatisfactory (8 of the area with a very high level of pollution, 14 with high, 21 above moderate, 27 a moderate level of pollution, 30 a relatively clean area). According to the results, a map was developed in the ArcView GIS program Ecological and geochemical zoning of Birobidzhan, using the level of the snow cover pollution with the allocation of the most polluted areas (70 of the total area of the city is polluted). According to the results, a constructive method of planning in an urban area is proposed in order to improve its environmental condition: geomonitoring as a control of pollution in snow cover and its prompt removal to specially equipped landfills.


1999 ◽  
Vol 39 (2) ◽  
pp. 201-208 ◽  
Author(s):  
C. Dierkes ◽  
W. F. Geiger

Runoff from highways contains significant loads of heavy metals and hydrocarbons. According to German regulations, it should be infiltrated over embankments to support groundwater-recharge. To investigate the decontaminating effect of greened embankments, soil-monoliths from highways with high traffic densities were taken. Soils were analyzed to characterize the contamination in relation to distance and depth for lead, zinc, copper, cadmium, PAH and MOTH. Lysimeters were charged in the field and laboratory with highway runoff to study the effluents under defined conditions. Concentrations of pollutants in roadside soils depend on the age of embankments and traffic density. Highest concentrations were found in the upper 5 cm of the soil and within a distance of up to two metres from the street. Concentrations of most pollutants decreased rapidly with depth and distance. Lead and cadmium could not be detected in lysimeter effluent. Zinc and copper were found in concentrations that did not exceed drinking water quality limits.


2021 ◽  
Vol 11 (7) ◽  
pp. 3123
Author(s):  
Haroon Mahmood ◽  
Laura Simonini ◽  
Andrea Dorigato ◽  
Alessandro Pegoretti

In this work, a novel nanomaterial deposition technique involving the triboelectrification (TE) of glass fibers (GF) to create attractive charges on their surface was investigated. Through TE, continuous GF were positively charged thus, attracting negatively charged graphene oxide (GO) nanoparticles dispersed in a solution. The electrical charges on the glass fibers surface increased with the intensity of the TE process. The deposited GO coating was then chemically treated to obtain reduced graphene oxide (rGO) on the surface of GFs. The amount of coating obtained increased with the GO solution concentration used during the deposition process, as revealed by FESEM analysis. However, the same increment could not be noticed as a function of the intensity of the process. Both uncoated and coated GF were used to obtain single fiber microcomposites by using a bicomponent epoxy matrix. The fiber/matrix interfacial shear strength was evaluated through micro debonding tests, which revealed an increment of fiber/matrix adhesion up to 45% for rGO coated GF in comparison to the uncoated ones. A slight improvement in the electrical conductivity of rGO coated fibers through TE compared to conventional dip coating was also observed in terms of volumetric resistivity by a four-point probe setup.


2008 ◽  
Vol 37 (4) ◽  
Author(s):  
Mirosław Skorbiłowicz ◽  
Elżbieta Skorbiłowicz

The distribution of lead, zinc, and chromium in fractions of bottom sediments in the Narew River and its tributariesThe purpose of the paper was to evaluate the distribution of lead, zinc and chromium contents in different grain fractions of bottom sediments in the Narew River and some of its tributaries. This study also aimed to determine which fractions are mostly responsible for bottom sediment pollution. The studies of the Narew and its tributaries (the Supraśl, Narewka, and Orlanka) were conducted in September 2005 in the upper Narew catchment area. The analyzed bottom sediments differed regarding grain size distribution. The studies revealed the influence of the percentage of particular grain fractions present on the accumulation of heavy metals in all bottom sediments.


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