Optimized chemical preconditioning of Philippine natural zeolites

Clay Minerals ◽  
2019 ◽  
Vol 54 (4) ◽  
pp. 401-408
Author(s):  
Eleanor M. Olegario ◽  
Kathrina Lois M. Taaca ◽  
John Christopher Lawrence Morillo ◽  
Herman D. Mendoza
Keyword(s):  
Surface Area ◽  
Acid Treatment ◽  
The Philippines ◽  
Exchange Capacity ◽  
Natural Zeolites ◽  
Copper Uptake ◽  
Uptake Capacity ◽  
Preconditioning Techniques ◽  
Structure And Morphology ◽  
Environmental Mitigation

AbstractNatural zeolites in the Aksitero sedimentary formation of the western Luzon area of the Philippines were evaluated. The natural washed zeolite (NW-Z) was preconditioned with acid to purify it and increase its surface area. Acid treatment with 3 M HCl for 12 h yielded optimum acid treatment of the NW-Z, causing increases in the Si/Al ratio, the specific surface area by 32.5% and the porosity of the acid-treated zeolite (HC-Z). The HC-Z was washed with 4 M NaCl for 3, 6, 12, 18, 24, 48 and 72 h to improve its cation-exchange capacity for copper. The sodium-treated zeolite (Na-Z) was immersed in 100 ppm CuSO4 solution to test the copper-uptake capacity. Pretreatment of HC-Z with 4 M NaCl for 24 h is optimal for sodium treatment of the preconditioned HC-Z. The preconditioning techniques did not significantly alter the structure and morphology of the zeolite samples. It is suggested that the preconditioned Philippine natural zeolite samples are readily available for further functionalization that will enhance their antibacterial, catalytic and adsorption properties, with various useful applications in the field of catalysis, biomedicine, environmental mitigation and wastewater treatment.

scholarly journals Effect of Low Zeolite Doses on Plants and Soil Physicochemical Properties

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2617
Author(s):  
Alicja Szatanik-Kloc ◽  
Justyna Szerement ◽  
Agnieszka Adamczuk ◽  
Grzegorz Józefaciuk
Keyword(s):  
Plant Growth ◽  
Physicochemical Properties ◽  
Cation Exchange ◽  
Surface Area ◽  
Cation Exchange Capacity ◽  
N Fertilization ◽  
Exchange Capacity ◽  
First Year ◽  
Soil Physicochemical Properties ◽  
Water Holding

Thousands of tons of zeolitic materials are used yearly as soil conditioners and components of slow-release fertilizers. A positive influence of application of zeolites on plant growth has been frequently observed. Because zeolites have extremely large cation exchange capacity, surface area, porosity and water holding capacity, a paradigm has aroused that increasing plant growth is caused by a long-lasting improvement of soil physicochemical properties by zeolites. In the first year of our field experiment performed on a poor soil with zeolite rates from 1 to 8 t/ha and N fertilization, an increase in spring wheat yield was observed. Any effect on soil cation exchange capacity (CEC), surface area (S), pH-dependent surface charge (Qv), mesoporosity, water holding capacity and plant available water (PAW) was noted. This positive effect of zeolite on plants could be due to extra nutrients supplied by the mineral (primarily potassium—1 ton of the studied zeolite contained around 15 kg of exchangeable potassium). In the second year of the experiment (NPK treatment on previously zeolitized soil), the zeolite presence did not impact plant yield. No long-term effect of the zeolite on plants was observed in the third year after soil zeolitization, when, as in the first year, only N fertilization was applied. That there were no significant changes in the above-mentioned physicochemical properties of the field soil after the addition of zeolite was most likely due to high dilution of the mineral in the soil (8 t/ha zeolite is only ~0.35% of the soil mass in the root zone). To determine how much zeolite is needed to improve soil physicochemical properties, much higher zeolite rates than those applied in the field were studied in the laboratory. The latter studies showed that CEC and S increased proportionally to the zeolite percentage in the soil. The Qv of the zeolite was lower than that of the soil, so a decrease in soil variable charge was observed due to zeolite addition. Surprisingly, a slight increase in PAW, even at the largest zeolite dose (from 9.5% for the control soil to 13% for a mixture of 40 g zeolite and 100 g soil), was observed. It resulted from small alterations of the soil macrostructure: although the input of small zeolite pores was seen in pore size distributions, the larger pores responsible for the storage of PAW were almost not affected by the zeolite addition.

Thermal stability and heavy metal (As5+, Cu2+, Ni2+, Pb2+ and Zn2+) ions uptake of the natural zeolites from the Philippines

2019 ◽  
Vol 6 (8) ◽  
pp. 085204 ◽  
Author(s):  
Eleanor Olegario ◽  
Christian Mark Pelicano ◽  
Jenichi Clairvaux Felizco ◽  
Herman Mendoza
Keyword(s):  
Thermal Stability ◽  
Heavy Metal ◽  
The Philippines ◽  
Natural Zeolites

scholarly journals Effect of Sulfuric Acid Treatment and Calcination on Natural Zeolites of Indonesia

2016 ◽  
Vol 28 (1) ◽  
pp. 11-14 ◽  
Author(s):  
Ady Mara ◽  
Karna Wijaya ◽  
Wega Trisunaryati Mudasir
Keyword(s):  
Sulfuric Acid ◽  
Acid Treatment ◽  
Natural Zeolites ◽  
Sulfuric Acid Treatment

Characteristics of variably saturated granular bentonite after long-term storage at near-field relevant temperatures

Clay Minerals ◽  
2013 ◽  
Vol 48 (2) ◽  
pp. 343-361 ◽  
Author(s):  
M. Valter ◽  
M. Plötze
Keyword(s):  
Physicochemical Properties ◽  
Cation Exchange ◽  
Surface Area ◽  
Cation Exchange Capacity ◽  
Elevated Temperatures ◽  
Near Field ◽  
Exchange Capacity ◽  
Hydraulic Permeability ◽  
Cation Composition ◽  
Retention Capacity

AbstractBentonite is a potential material for use in the engineered barrier of radioactive waste repositories because of its low hydraulic permeability, self-sealing capability and retention capacity. It is expected that bentonite would react at the elevated temperatures accompanying the radioactive decay in the nuclear waste. The presented study was started in order to improve understanding of the coupled influence of temperature and (pore) water on the physicochemical and mineralogical properties of bentonite during thermal treatment under near-field relevant conditions. Granular Na-bentonite MX-80 was differently saturated (Sr = 1–0.05) and stored at different temperatures (50–150°C) in a closed system. Upon dismantling after different periods of time (3 to 18 months), mineralogical characteristics, cation exchange capacity and content of leachable cations, as well as physicochemical properties such as surface area and water adsorption were investigated.The results showed a high mineralogical stability. A slight conversion from the sodium to an earth alkali form of the bentonite was observed. However, considerable changes in the physicochemical properties of the bentonite were observed, particularly by treatment above the critical temperature of 120°C. The cation exchange capacity decreased during heating at 150°C by approximately. 10%. The specific surface area dropped by more than 50%. The water uptake capacity under free swelling conditions showed a slight tendency to lower values especially for samples heated for more than 12 months. The water vapour adsorption ability in contrast drops by 25% already within three months at T = 120°C. These changes are mostly related to the variations in the interlayer cation composition and to smectite aggregation processes. The observed alterations are rather subtle. However, temperatures ⩾ 120°C had a remarkable negative influence on different properties of MX-80.

Study of the pozzolanic activity and hydration products of cement pastes with addition of natural zeolites

Clay Minerals ◽  
2011 ◽  
Vol 46 (2) ◽  
pp. 241-250 ◽  
Author(s):  
V. Lilkov ◽  
O. Petrov ◽  
V. Petkova ◽  
N. Petrova ◽  
Y. Tzvetanova
Keyword(s):  
Surface Area ◽  
Cement Paste ◽  
Chemical Reactions ◽  
Natural Zeolite ◽  
Early Stage ◽  
Pozzolanic Activity ◽  
Large Surface Area ◽  
Natural Zeolites ◽  
Hydration Products ◽  
Cement Pastes

AbstractThis paper presents results from comparative thermogravimetric, calorimetric and pozzolanic activity analyses of five natural zeolite samples from Bulgaria, Slovakia, Philippines, USA and North Korea. The zeolites actively participate in the hydration processes of cement. Their activity in the early stage of hydration is based mainly on the large surface area of the particles while, in the later stages of activation, chemical reactions occur between the products of the hydration of cement and the soluble SiO2 that is present in the bulk of the zeolites. It has been shown that in all cement pastes which contain zeolite additives, the quantity of portlandite is lower than that in pure cement paste or is even totally absent. The amounts of hydration products are greater when 30% zeolite is used than when 10% zeolite is added (excluding the sample with chabazite). The lowest pozzolanic activity is shown by chabazite, which possessed the lowest SiO2/Al2O2 ratio.

Copper removal by polymer immobilised Rhizopus oryzae

2000 ◽  
Vol 42 (7-8) ◽  
pp. 345-352 ◽  
Author(s):  
M. S. Al-Hakawati ◽  
C. J. Banks
Keyword(s):  
Adsorption Capacity ◽  
Room Temperature ◽  
Shake Flask ◽  
Rhizopus Oryzae ◽  
Polymer Matrices ◽  
Copper Uptake ◽  
Uptake Capacity ◽  
Copper Adsorption ◽  
Copper Solution ◽  
Erroneous Result

Rhizopus oryzae, strain IMI 057412, was immobilised by inclusion in six different polymers: polyvinlformal, polysulfone, polyurethane, alginate, polyacrylamide, k-carrageenan, polyethyleneimine(PEI). It was also grown on a seventh, polyurethane. The biomass/polymer matrices were formed into equal size units (4 mm spheres or cubes) and the resulting biomass/polymer matrices were used to uptake copper at 2 mg/l from a laboratory-formulated copper solution in shake flask experiments at room temperature and initially neutral pH. Results showed that the copper uptake capacity of immobilised biomass was either equal to or less than that of free biomass. Biomass immobilised in polyurethane gave a capacity equal to that of free biomass, while other matrices hindered the uptake to different degrees. The k-carrageenan matrix proved to be unstable in the copper solution and dissolved during the experiment releasing the biomass and leading to an erroneous result. The polymer matrices without biomass, with theexception of alginate and polysulfone, showed no measurable copper adsorption capacity. All the experiments were conducted in duplicate with a maximum variation between them of 7%.

Study and Fabrication of Acid-Modified Diatomite

2012 ◽  
Vol 512-515 ◽  
pp. 2175-2178
Author(s):  
Yan Jiang ◽  
Hua Ye ◽  
Li Na He
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Acid Treatment ◽  
Great Increase ◽  
Acid Modification ◽  
Catalyst Carrier ◽  
Modification Process ◽  
Large Mesopores ◽  
Potential Use ◽  
Modified Diatomite

This paper presents an investigation of the purification and activation of a raw diatomite by acid treatment. In the acid modification process, the SiO2 gel powder was adsorbed partially into the pure diatomite, blocking macropores and large mesopores of diatomite, which resulted in great increase of the specific surface area and SiO2 content of diatomite. Thus, the as-prepared diatomite has potential use in the fabrication of catalyst carrier.

scholarly journals Pre-Treatment Methods for Regeneration of Spent Activated Carbon

Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4561
Author(s):  
Sang Youp Hwang ◽  
Gi Bbum Lee ◽  
Ji Hyun Kim ◽  
Bum Ui Hong ◽  
Jung Eun Park
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Acid Treatment ◽  
Chemical Activation ◽  
Fixed Carbon ◽  
Treatment Methods ◽  
Positive Effects ◽  
Area Increase ◽  
Pre Treatment ◽  
Surface Area Increase

Spent activated carbon (SAC) usually exhibits a low specific surface area due to its high ash contents. In this study, pre-treatments, such as heat and acid treatments, were optimized to improve this feature. The heat pre-treatment did not reduce the ash content, nor did it increase the surface area. Because metallic ions adsorbed in SACs turn into ash upon the heat treatment. In the acid pre-treatment, the volatiles and fixed carbon were increased with decreasing ash contents. In this study, it was found that the surface area increase was correlated with the ratio between fixed carbon and ash. Among the pre-treatment methods, the combined heat and acid pre-treatment method highly increased the ratio, and therefore led to the surface area increase. Additionally, the acid pre-treatment was carried out using different types of acid (organic and inorganic acids) solutions to further improve the surface areas. The organic acid treatment caused a significant structural collapse compared to the inorganic acid treatment, decreasing the surface area. In particular, H3PO4 effectively removed ashes adsorbed on the activated carbon surface and regenerated the exhausted activated carbon. Both the heat and acid pre-treatments before chemical activation resulted in the positive effects such as strong desorption of pollutants and ashes within the internal structure of the activated carbon. Therefore, the regeneration introduced in this study is methodically the best method to regenerate SAC and maintain a stable structure.

Influence of Acid Treatment on the Loading and Release Behavior of Halloysite with 2-Mercaptobenzothiazole

2019 ◽  
Vol 19 (11) ◽  
pp. 7178-7184 ◽  
Author(s):  
Xuteng Xing ◽  
Jihui Wang ◽  
Qiushi Li ◽  
Wenbin Hu
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Acid Treatment ◽  
Gas Adsorption ◽  
Treatment Time ◽  
Halloysite Nanotubes ◽  
Tubular Structure ◽  
Internal Diameter ◽  
Release Behavior

Halloysite nanotubes (HNTs) are natural clay minerals with a tubular structure. They have attracted considerable attention as a potential nanocontainer due to their abundance, biocompatibility and nontoxicity. In this study, HNTs were handled with H2SO4 at 70 °C. The morphology and structure of these acid-treated and original HNTs were investigated by scanning electron microscopy (SEM), energy dispersion spectrum (EDS), transmission electron microscope (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR), and their specific surface area was determined by automatic gas adsorption analyzer. The loading efficiency and release behavior of acid-treated HNTs for 2-Mercaptobenzothiazole (MBT) were investigated by UV-vis spectrophotometer. Results show that acid-treated HNTs retained their tubular structure, but their internal diameter expanded by 35–37 nm after 32 h of acid treatment. After 72 h of acid treatment, HNTs can be transferred into amorphous silica nanotubes. Moreover, the specific surface area of these HNTs samples initially increased with the increase in acid treatment time but then started to decrease after 32 h. The specific surface area of acid-treated HNTs at 32 h can reach 251.6 m2/g, which was much higher than that for untreated HNTs (55.3 m2/g). In addition, the loading capacity of acid-treated HNTs can reach 32.1% for HNTs-32, which is about three times higher than that of original HNTs. The acid treatment has slight effect on the release behavior.

Role of Extracellular Components in Microbial Biosorption of Copper and Lead

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2153-2156 ◽  
Author(s):  
A. A. Pradhan ◽  
A. D. Levine
Keyword(s):  
Metal Removal ◽  
Chloride Ions ◽  
Metallic Ions ◽  
Copper Uptake ◽  
Uptake Capacity ◽  
Inhibiting Effect ◽  
Removal Capacity ◽  
Microbial System ◽  
Microbial Systems

Binding of metal ions to extracellular components of microbial systems plays an important role in biosorption processes. Besides pH and temperature, type of anionic system and concentration of the metallic ions are some of the governing factors determining the maximum uptake capacity of the microbial system. Actinomycetes show an ability to selectively scavenge metals from aqueous systems. A biosorption system was tested using a bimetallic solution containing lead and copper. Uptake of Pb was observed to increase with concentration. Chloride ions had an inhibiting effect on the metal removal capacity of the actinomycetes system.

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