Diatomite Samples Research Articles

Regulating pore structure of diatomite with alkali dissolution and its influence on humidity control performance

Alkali dissolution is an effective method to regulate the pore structure of porous mineral material. The main chemical composition of diatomite is amorphous SiO2, which can be dissolved in alkali dissolution. The diatomite samples with alkali dissolution treatment were systematacially characterized by the particle size analysis, low temperature nitrogen adsorption, MIP, fractal theory, SEM, TEM, XRD, FTIR and surface hydroxyl density to analyze the pore structure and surface properties. And the humidity control performance of diatomite was tested under different temperatures and relative humidities. The relationship among pore structure, surface properties and humidity control performance were analyzed. The results show that alkali dissolution can regulate the mesoporous and macroporous of diatomite, and some new microporous can generate at high alkali dosage. The specific surface area, mesoporous pore volume, proportion of macroporous volume, surface roughness, heterogeneity of pore structure and number of hydroxyl groups on the surface of diatomite are important factors which determining the humidity control performance. The humidity control performance of diatomite is positively correlated with the specific surface area, mesoporous volume, surface roughness, heterogeneity of pore structure and number of hydroxyl groups on the surface, while is negatively correlated with the proportion of macroporous volume.

Geology, mineralogy, geochemistry and genesis of volcano-sedimentary hosted Lake Abiyata diatomite in central main Ethiopian Rift

The Abiyata Diatomite deposit is located in the Main Ethiopian Rift, which is characterized by strong extensional tectonics. The deposit is mostly made up of diatomaceous earth, which is a sedimentary rock made up of the fossilized remnants of diatoms, which are tiny algae. Diatomite's geological, geochemical, and mineralogical features, as well as its formation, are discussed in this research. To characterize diatomite from Abiyata, chemical, mineralogical, technological, and micro paleontological examinations were conducted on samples collected from outcrops and stream sections. The XRD characteristic peaks of diatomite demonstrate that it is primarily made up of Opal A silica, however certain crystalline phases were discovered in adequate amounts. Quartz and feldspar were the predominant crystalline phases, with lesser amounts of Calcite, Cristobalite, Illite, Mordinite, Wairakite, Halloysite, Clinoaptilolite, Adularia, and Tridymite. From SEM photomicrographs diatomites are primarily formed of benthic freshwater diatom species such as Staurosirella pinnata, Staurosira construens, Pseudostaurosira brevistriata, Epithemia Sorex and surirella pinnata. Diatom species, sedimentary profile sections and mineralogical data suggest that diatomite was deposited in lacustrine-type freshwater shallow lake environment. Chemical data obtained from 10 diatomite samples show that while silica is the bodybuilding material for diatomite. i.e., Silica (SiO2), 76.9 %; Alumina (Al2O3), 3.49 %; Sodium Oxide (Na2O), 1.52 %; Potassium Oxide (K2O), 1.107 %; Iron Oxide (Fe2O3), 1.1 %; Loss on ignition (LOI) 13.7 and other oxides are below 1 %. Studies from technological properties like physical tests, chemistry, and mineralogy and micropaleontology of Abiyata diatomite suggest that calcined diatomite can be used for waste treatment processes in the filter aid industry and as filler material.

Fluoride removal from water using Al(OH)$ _3 $-surface modified diatomite mixed with brick: optimization, isotherm and kinetic studies

<abstract><p>Excess fluoride in drinking water causes both dental and skeletal fluorosis among other problems. As such there is need to develop affordable and easily accessible techniques for fluoride removal from drinking water. This work assessed surface modified diatomite mixed with brick for fluoride removal. Diatomite samples were modified using aluminium hydroxide and the mixture was optimized for fluoride removal through response surface methodology (RSM) using the Box-Wilson central composite design. Batch experiments showed that, individually, a 28 g/L dose of the surface modified diatomite sufficiently removed fluoride to the acceptable level of 1.5 mg/L from an initial concentration of 10 mg/L fluoride while a 300 g/L dose of brick powder was required to remove an equal amount of fluoride in the same water samples. RSM optimization showed that a mixture of surface modified diatomite and brick in the mass ratio 1.8:17.8 grams per milligram of fluoride in water can be used to remove fluoride in water to an acceptable level. Adsorption of fluoride by surface modified diatomite fit better into the Freundlich adsorption isotherm (R$ ^2 $ = 0.9753) compared to the Langmuir (R$ ^2 $ = 0.8954), while adsorption by brick better fit the Langmuir adsorption mechanism (R$ ^2 $ = 0.9804) in comparison to the Freundlich adsorption (R$ ^2 $ = 0.9372). Kinetic studies revealed that chemisorption was the main mechanism for both surface modified diatomite and brick adsorbents. Conclusively, an optimal mixture of surface modified diatomite and brick can be successfully used for fluoride removal in areas for which water has high fluoride contamination.</p></abstract>

Physico-chemical properties of Russian natural aluminosilicates for purification of aqueous environment

The paper analyses and compares the physico-chemical properties of aluminosilicate green clay and bentonite and diatomite from the Russian deposits. The research determines specific surface area and the morphological features of aluminosilicates, their pore sizes, and pore distribution by volume. The surface of the green clay includes silicon and aluminum oxides, montmorillonite, kaolinite, impurities of pyrite, saponite, micas, and hydrosludes. It also contains a lot of rounded particles with a diameter of 1-2 μm. According to the research, adsorption isotherms for mesoporous green clay samples belong to type IV; the samples of bentonite and diatomite (Middle Volga regions of Russia) belong to type II. They characterize the monolayer-multilayer concentration of solution components on macroporous bodies. Also the research revealed a sufficiently high amount of adsorbate (31 ml • g-1) to cover the surface of diatomite (Ulyanovsk region, Russia) with a monomolecular layer. The source minerals of diatomite are montmorillonite and muscovite. The study of adsorption and desorption branches for a bentonite sample (Samara region, Russia) indicates the processes asymmetry. Hence, we compared the ability to adsorb iron (II) and lead ions from aqueous systems using green clay extracted in different years (2017 and 2023).

Using the sorption properties of diatomite from the Aktobe deposit in improving the quality of drinking water in Western Kazakhstan

The paper describes the results of monitoring studies of the quality of tap water in the city of Uralsk. A solution was found to use natural reserves of the mineral diatomite in the purification of drinking water. The natural sorbent diatomite was modified with hydrochloric acid before testing. Natural and modified diatomite samples were studied using X-ray fluorescence analysis and electron microscopy. In acid-activated diatomite, the specific surface area and porosity increase by 2.5 times. Xray fluorescence analysis of the elemental composition showed an increase in the silicon content in the sorbent. Organoleptic and physicochemical properties were studied in the original and diatomite-treated water: turbidity, taste, smell, color, hardness, permanganate oxidation, pH, iron and copper ions. The efficiency of sorption with respect to heavy metals was tested using the model toxicant copper sulfate. Determinations of copper and iron ions were carried out using the atomic spectrometry method. Hardness, permanganate oxidation, pH and organoleptic parameters were determined by standard methods. Treatment of water with natural and modified diatomite made it possible to significantly reduce water pollution according to the studied parameters. Filtering water with a modified diatomite sorbent allows you not only to purify water from unwanted impurities, but also to adjust its salt composition due to the intake of silicon. Based on the results of the work, we can conclude that, compared to natural, modified diatomite has higher adsorption properties in relation to copper and iron cations, increases pH, and also contributes to more effective water purification from unwanted impurities.

Characterization of Diatomite for Its use in Construction: Case Diatomite Sampled in Northern Chad

The need for energy for the purpose of thermal comfort in buildings is constantly growing. To minimize this need, we can improve the performance of the building envelope, which is the seat of several thermal stresses, which encourages us to develop, apart from renewable or alternative energies, construction materials for buildings capable of storing energy. For this, the integration of innovative passive materials in the building envelope makes it possible to reduce energy consumption and ensure thermal comfort in countries with a very hot climate such as the desert zone of Chad. We were thus interested in the characterization of diatomite which is used to build a good majority of dwellings in the Lake Chad, Kanem and BET regions. To this end, samples of diatomite used in the construction were taken from Faya, the capital of the far north of Chad, on which we carried out mineralogical analyzes as well as thermal and mechanical characterization. Observations at the SEM, analyzes by fluorescence of rays X and Diffractograms clearly confirm pure diatomite. Furthermore, the results of the various thermo-physical and mechanical tests presented a material which has a low mechanical resistance but a good thermal resistance. Therefore, the diatomite which has been the subject of this study has no negative effect on the environment, it is an excellent thermal insulation material capable of storing thermal energy in buildings.

Effect of the particle’s shape on the dynamic shear modulus and compressibility of diatomaceous soils

Diatomites are unicellular algae fossils that can be found worldwide. This paper studies the diatom's shape effect on diatomaceous soil mixtures' dynamic and compressibility properties. Physical characteristics of six diatomite samples with variable shapes and taxonomies are presented. Among these six samples, three diatomites of similar grain size distribution were mixed with kaolin, and the mechanical properties (i.e., shear modulus and damping ratio from small to large strains) were analysed. The results showed that diatom frustules increased the mixtures' compressibility and reduced the maximum shear modulus compared with pure kaolin samples. Moreover, the diatom's shape influenced the normalised shear modulus degradation curve and the damping ratio. Overall, the presence of diatomites reduces the energy dissipation capacity in soils. This research evidenced the importance of distinguishing the shape of diatom in soil mixtures when mechanical properties are analysed, a situation that has yet to be explored.

Using diatomite as a partial replacement of cement for improving the performance of recycled aggregate concrete (RAC)-Effects and mechanism

This work proposes that diatomite can be used to improve the performance of recycled aggregate concrete (RAC). A calcined diatomite sample with an amorphous silica content over 90% was added to the RAC mixture as a partial replacement of the ordinary Portland cement (OPC) at varying rates from 0 to 20 wt%. Test results show that both the strength and impermeability of RAC can be obviously enhanced with the greatest enhancement observed at a replacement level of 15 wt% for which the 28-day compressive/splitting tensile strengths were improved by 29.2% and 33.9%, respectively, and the chloride diffusion coefficient was reduced by 86.27%. The microscopic measurements confirmed the nucleation effects and the high pozzolanic reactivity of diatomite which both contributed to the more complete hydration of cement in RAC. It was also found that the proportion of large capillary pores in the new mortar was reduced by using diatomite, meanwhile the average porosity of the new interfacial transition zone (ITZ) became smaller. This work suggests that the calcined diatomite used for improving RAC performance should be no larger than 15 wt% of cement, as the scarcity of CH at a higher replacement ratio would hamper the pozzolanic reactions, meanwhile the diluted cement clinkers would have a negative effect on the pore structure of RAC.

An approach utilizing the Response Surface Methodology (RSM) to optimize Adsorption-Desorption of Natural Saudi Arabian Diatomite- with the Box- Behnken Design Technique

Saudi Arabian’s natural diatomite samples were subjected to physical adsorption–desorption characterizations using Brunauer-Emmet-Teller (BET) and the Barrett-Joyner-Halenda (BJH), performed under heating of 140 °C for different periods of hours: 6, 12, 18, and 24 h, to create a central optimization design with surface areas and total pore distributions. Seventeen experimental runs resulted in the primary composite factor design. The surface response describes 100 % variability with a determination coefficient of 1, signifying the quadratic model with an expected correlation coefficient (R2) is satisfied with a standard deviation of 0.2322, demonstrating the high predictability of the model. Moreover, the RSM results have been validated using the t-test with the observed R2 value and adjusted R2. The model selected with higher F and p values showed<0.0001, which subsequently described the significance of the developed model. The independent components were explained with the help of 3D surface and contour plots that compare the heating time, elapsed time, pressure, and relative pressure against the dependent variable. The plots revealed that the adsorbed quantities well depended on heating time, elapsed time, pressure, relative pressure for isotherm, BET surface area, Langmuir surface area, and t-plot Micropore area.

Paralia flatoniana sp. nov., a new species from the late Eocene of Texas with discussion on ecology and initial valves

A new Paralia Heiberg species, Paralia flatoniana sp. nov., is documented from a late Eocene diatomite and mudstone deposit in east central Texas. Paralia represents up to 63% of the assemblage in the diatomite samples and 34% in the mudstone. Numerous Paralia initial valves are present adding an unusual component to this assemblage as they are infrequently reported from samples containing populations of fossil Paralia. A third valve type observed attached to Paralia chains is also illustrated and discussed. Intact chains are common and preservation of the frustules is very good with limited indication of dissolution or transport. An average valve diameter of 19.0 µm (7.1–37.7 µm range), the presence of numerous initial valves and preservation of fine morphological structures suggest an environment with often high in situ productivity rather than a transported assemblage. Morphologically similar species Paralia crenulata and Paralia thybergii share many mantle characteristics with P. flatoniana while the valve face details of Paralia fausta are similar. Paleogeography and – ecology of the Eocene Gulf of Mexico and volcanism to the west provided a temperate coastal nutrient-rich shelf environment favourable for Paralia.

Study of the Effects on Mn, Pb, and Zn Solidification in Soil by a Mixed Curing Agent of Modified Diatomite.

In order to improve the application scale of diatomite in the remediation of heavy metal-contaminated soil in non-ferrous metal mining areas, the preparation of the modified diatomite-combined curing agent and its stabilizing effect on manganese (Mn), lead (Pb), and zinc (Zn) were systematically studied in non-ferrous metal tailing soil in this paper. The results showed that compared with that in natural diatomite (DE), the contents of available Mn in soil treated by acid- and alkali-modified diatomite samples (C-D and Na-D) were 18.82 and 25.93% lower, respectively, and the content of available Zn in Na-D was significantly lower, 6.71%, than that in DE. Further research showed that modified diatomite combined with quicklime (CaO) and hydroxyapatite (HAP) could significantly improve the solidification effect of soil heavy metals. Compared with that in single modified diatomite, the contents of available Mn, Pb, and Zn in the mixed curing agent-treated soil decreased by 23.59–46.32, 5.88–47.93, and 5.37–10.68%, respectively. The final pot test showed that the mixed curing agent of modified diatomite had no significant effect on the growth of plants, but it could reduce the Mn, Pb, and Zn accumulation in the upper and lower parts of plants, which is because the acid-soluble and reducible heavy metals in soil transform into an oxidizable and residual state, which reduces the mobility of heavy metals.

DIATOMITES AND LIGNINS AS MYCOTOXIN ADSORBENTS

Currently, there is a tendency to deepen the mycotoxin problem, which is associated with the global warming and environmental pollution. The results of a study of the sorption capacity of adsorbents samples based on natural materials diatomites and lignins in relation to mycotoxin T-2 are presented. The chemical composition of diatomites of the Inzensk deposit before and after modification is given and the parameters of the surface-porous structure of the samples are established. The isotherms of adsorption and desorption of nitrogen on the surface of diatomites were studied and for the first time it was shown that they belong to the type IV(a) acording to IUPAC classification. The distribution of pores by size was studied and it was established that a significant proportion of the pore space of diatomites are mesopores with an average width of 7–12 nm. The highest adsorption rates of mycotoxin T-2 were established for a diatomite sample subjected to acid modification. Data on the adsorption of mycotoxin T-2 by samples of lignins isolated from the wood of birch Betula verrucosa, stems of rye Secale sp. and cabbage Brassica oleracea are given. The results of the determination of functional groups, elemental and monomeric composition of lignins are presented. It has been established that the adsorption capacity of drugs depends mainly on the peculiarities of the chemical structure of the studied samples. The highest adsorption rates of mycotoxin T-2 are established for lignin isolated from cabbage stems. Comparison of mycotoxin T-2 adsorption, surface porous structure parameters and chemical structure of various samples leads to the conclusion that for both diatomites and lignins, the chemisorption process plays the most important role.

Effect of Chemical and Thermal Treatment Priority on Physicochemical Properties and Removal of Crystal Violet Dye from Aqueous Solution

AbstractThe release of pollutants, especially dyes, has been a significant concern as it affects the stability of ecosystems due to poor implementation of waste protocols. In this study, the diatomite samples were characterized by pHpzc, ICP, pore size distribution, XRD, TG‐DTA, BET, SEM and FTIR (before‐after). The adsorption properties of a cationically charged dye, crystal violet (CV), on the diatomite samples were investigated by varying the adsorption parameters with the aim of evaluating the adsorption mechanism. Nonlinear Langmuir, Freundlich, Dubinin‐Radushkevich and Redlich‐Peterson isotherm models, pseudo‐first and pseudo‐second order kinetic models, intraparticle diffusion and Boyd models were evaluated. The adsorption mechanism was explained by the Langmuir isotherm model and the maximum adsorption capacities for CV (at pH 7.0) of DHCl, D800 °C+HCl and DHCl+800 °C were 5.07 mg g−1 and 4.93 mg g−1 and 65.78. mg g−1 at 298 K, respectively. It was also shown that the CV adsorption was reasonable according to the second‐order kinetic model (R2=1). Adsorption occurred via two mechanisms: hydrophobic interactions and the combination of surface hydrogen bonding between the hydroxyl groups on the diatomite surface and the nitrogen atoms of the CV. The results indicated that using DHCl+800 °C would provide a simple, energy‐saving, and cost‐effective approach to removing cationic dyes from an aqueous solution.

A Novel Flux That Determines the Physico-Chemical Properties of Calcined Diatomite in Its Industrial Use as a Filler and Filter Aid: Thenardite (Na2SO4)

Diatomite needs to go through the flux-calcination process in order to increase its functionality in some specific applications such as filter aids. In this study, the effects of the thenardite, which was used for the first time as a flux in the calcination of diatomite, and widely used soda ash on the industrially important physico-chemical properties of diatomite were investigated. Samples taken from two diatomite deposits in the Aegean region of Turkey (Seydiler diatomite from Afyon and Sarayköy diatomite from Denizli) were used in this study. In raw and calcined diatomite samples, geochemical and mineralogical composition and parameters such as colour, grain size, morphology, specific surface area, permeability and wet cake density were characterized. It was found that thenardite was more effective than traditionally used soda ash in improving whiteness (L* = 98.20) and filtrate clarity (wet cake density = 0.378 g/cm3). However, higher permeability (k), i.e., higher filtration rate, was obtained in diatomite calcined with soda ash (k = 0.97 µm2). Fluxes had different effects on different diatomite species. The necessity of choosing flux type depending on the application area and the desired properties from diatomite was demonstrated.

Green technologies in energy and materials science -development prospects

Literature information about the problems in the technology of energy and ceramics is given. In the article the information about the promising directions of development of energy and firing technologies, about the influence of sintering material in the microwave field on the structure and properties of the material and the prospects of this direction in the hydrogen energy industry is considered. The results of firing samples of diatomite with additives of carbonate clay (marl) and NaCl salt in a microwave oven are considered. Microphotographs of the structures of the obtained materials are presented. For compositions of diatomite, a mixture of diatomite, marl and NaCl salt, the results of X-ray diffraction analysis and microphotographs of material structures are considered. For diatomite containing montmorillonite clay, a large exothermic effect in the temperature range 400 - 700 ° C was found upon heating. The composition based on diatomite with the addition of marl and salt passes this temperature range with endothermic effect. A promising direction of research into the technology of synthesis and storage of hydrogen is shown.

Preparation and characterization of composite scallop shell powder-based and diatomite-based hygroscopic coating materials with metal-organic framework for indoor humidity regulation

Dampness and dryness in buildings have negative effects on occupant's health, building envelope and energy usage. One promising approach is to apply hygroscopic materials with excellent moisture buffering performance in buildings to control the indoor air humidity passively. This paper proposed an innovative application of combination of metal organic frameworks (MOFs) and traditional hygroscopic materials used as passive moisture control coating materials . The scallop shell powder and diatomite, as two kind of substrates, was mixed with 20 wt% zeolite to obtain scallop shell powder-based (SZ) and diatomite-based (DZ) composite inorganic porous mineral materials, respectively. A series of novel composite hygroscopic coating materials (SZ-5, SZ-10 and DZ-5, DZ-10) were prepared by mixing the two composite porous materials with 5 wt% and 10 wt% MIL-100 (Fe) which has excellent performance of water sorption as one kind of MOFs. The microstructures of the produced samples were characterized by nitrogen adsorption/desorption technique and scanning electron microscopy while their hygrothermal properties including the thermal conductivity , the moisture adsorption/desorption performance and the moisture permeability were measured and tested. The results showed that the moisture adsorption amount and moisture adsorption rate for SZ-10 were 0.0121 g/g and 2.29 g/m 2 ·h, respectively. The diatomite-based sample DZ-10 exhibited greater moisture controlling performance with the moisture adsorption amount of 0.0201 g/g and the moisture adsorption rate of 4.62 g/m 2 ·h, which were 3 and 3.88 times those of the pure diatomite sample. The moisture buffer value (MBV) of DZ-10 were largest, indicating that this sample was the highest efficiency moisture buffering material. • A series of novel moisture buffering materials were prepared for interior coating. • Hygrothermal performance of composite materials with MIL-100 (Fe) were tested. • Composite materials with MIL-100(Fe) show better moisture buffer performance. • The relationship between microstructure and hygrothermal properties was discussed.

Characterization and efficient dye discoloration of Algerian diatomite from Ouled Djilali-Mostaganem

A series of naturally occurring diatomaceous earth samples from Ouled Djilali, Mostaganem (Lower Chelif basin, Algeria northwestern), were investigated, which are characterized by the expansion and evolution during the Messinian age. Four varieties of diatomite were distinguished, characterized, and successfully used to adsorb methylene blue dye in aqueous medium. Several properties and characteristics of diatomite have been outlined using analytical methods such as X-ray fluorescence spectrometry, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N2 adsorption–desorption (BET), and scanning electron microscopy (SEM), as well as other complementary analysis tests. Results showed that silica and calcium carbonates were the main constituents of the diatomite samples (ranging between 32.8 and 61.5% for SiO2; and 13.8–25.9% for CaO), with a slight difference in chemical composition between selected samples. Typical for all diatomite samples, the XRD analysis suggests a high mass quantity of amorphous phase (Opal); high content of crystal phase was also registered. FTIR allowed determining the basic characteristic silica bands regarding diatomite samples. While the BET and SEM investigations revealed that the studied diatomite material has a highly porous structure and was very rich in diatoms. The maximum adsorption capacity of methylene blue that was calculated from the Langmuir isotherm model was 116.59 mg/g (for Ouled Djilali: OD05 sample) at 25 °C and pH 7.0. The diatomite from Mostaganemian (Ouled Djilali) deposit may find promising applications as low-cost adsorbent for dyes removal from water.

IMPROVEMENT OF DIATOMITE CHARACTERISTICS AND ITS APPLICATION FOR WINE FILTRATION

Diatomite is widely used as a filtering material in spirit-containing systems industry. In the presented paper, different types of treatment of diatomite from the Jradzor deposit, and the effectiveness of application of the modified samples for filtering the home-made wine have been studied. It is shown that due to the treatment of the raw diatomite sample, the surface characteristics and filtration (sorption) parameters of raw diatomite are improved. At first, raw diatomite from Jradzor deposit was water treated to remove the clay additives, then thermally treated at 900 0C and after it some samples were γ-irradiated by 500 Gr- a dose, which is acceptable for foods. Based on nitrogen adsorption-desorption isotherms, the values of the specific surface by the methods of BET and BJH have been determined. Also, the values of microporous and total pore volume, humidity and bulk density have been determined for the treated samples of diatomite. The effectiveness of home-made wine filtration capability for two modified samples of diatomite have been studied. The effect of the filtering material amount and the filtering material-filtrate shaking time on the effectiveness of filtration has been studied by the photocolorimetric method. It is established that the γ-irradiated samples, which pass the water and thermal treatments at 900 0C, are more effective than the filtering materials

Diatomite – evaluation of physico-mechanical, chemical, mineralogical and thermal properties

Diatomite is one of the most intensively examined raw materials in the materials industry with a broad range of various applications. The diatomite sample, collected from Vitačevo plateau in the vicinity of Kavadarci, was fully characterized by means of physical-mechanical, chemical, XRPD, SEM, TEM, DTA/TGA and IR techniques. The physical-mechanical features pointed out to soft, light, white to gray rock with shell-like structure exhibiting compressive strength from 4.65–4.88 MPa in dry form, whereas the total porosity ranges 70–72% and the density is 2.06–2.09 g/cm3. The chemical analysis of the diatomite revealed that SiO2 content exceeds 91%. The results from the X-ray powder diffraction indicate predominant amorphous SiO2 phase associated with minor presence of crystalline quartz, muscovite, chlorites and plagioclase. The IR spectrum of the diatomite manifested characteristic bands for amorphous silica at 799 cm–1 and 1101 cm–1. DTA/TGA results display great thermal stability of the sample remaining amorphous up to 1050ºC whereas the SEM analysis determined the morphology, surface characteristics and the nanometric pores in the raw material. Thus, the studied diatomite is classified as a natural nanomaterial that is suitable for broad application in various construction materials, refractory ceramics, special oxide ceramics, and also finds potential use in filtering, adsorbent, catalysts, food and pharmaceutical industries.

Design and optimization of Zn (Ii) adsorption conditions from aqueous solutions by Fe/Mn-Diatomite material

Environmental issues such as the wastewater have influenced each aspect of our lives. For human and environmental health protection, it is necessary to remove excess zinc in industrial wastewaters before discharging them to environment. Modified diatomite displayed larger surface area and pore volumes in comparison with untreated natural diatomite, which favored heavy metals sorption behavior. In this study, the removal of Zn(II) ions from aqueous solution was studied using Fe/Mn modified diatomite sample at different adsorption parameters such as contact initial metal ions concentration, dosage of Fe/Mn-Diatomite and ionic strength Na2CO3 on ionic Zn2+ adsorption capacity of diatomite modified. The residual zinc concentration in the solution was determined using flame atomic absorption spectroscopy. The results showed that: the gravitational increase increases with increasing time and then becomes almost stable, with 120 minutes timeliness; absorption increases when Fe/Mn-Ditomite is increased, absorption reaches 89.48% at a dose of 1.5 g/l; additional different concentrations Na2CO3 ranged from 0 ppm to 80 ppm the results showed that performance treatment Zn2+ of correspond 94,85%. This study could lay an essential foundation to develop modified diatomite for heavy metal removal from wastewater.