scholarly journals Lead and Cadmium Immobilization by Polymeric Sponges Coated with Hydroxyapatite

2008 ◽  
Vol 396-398 ◽  
pp. 561-564 ◽  
Author(s):  
Elena Mavropoulos ◽  
Nilce C.C. da Rocha ◽  
M.L.F.M. Kede ◽  
Marcelo Henrique Prado da Silva ◽  
Josino C. Moreira ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Bone Tissue ◽  
Cadmium Uptake ◽  
Sorption Experiment ◽  
Lead And Cadmium ◽  
Hydroxyapatite Powder ◽  
Before And After ◽  
Metal Incorporation

Polymeric sponges coated with hydroxyapatite were used in lead and cadmium uptake experiments in order to mimetizes heavy metal incorporation by bone tissue. The hydroxyapatite-coated sponges (S-HA) were obtained by hydrothermal alkali conversion from monetite. The results showed that S-HA were efficient in immobilizing Pb and Cd. The uptake experiments using hydroxyapatite powder (HA) removed almost 100% of Pb2+ and 59% of Cd2+. When polymeric sponges coated with hydroxyapatite were used, the removal of Cd2+ and Pb2+ decreased, respectively, to closely 14 % and 74%, after 24 hours sorption. Before and after sorption experiment MEV analysis indicated precipitation of pyromorphite on hydroxyapatite-coated sponges.

scholarly journals The Potential of Heavy Metal Incorporation into Clay Precursors

2019 ◽  
Vol 8 (3) ◽  
pp. 4839-4845
Keyword(s):  
Heavy Metal ◽  
Environmental Pollution ◽  
Industrial Activities ◽  
Lead And Cadmium ◽  
Metal Waste ◽  
Global Issue ◽  
Good Potential ◽  
Copper Zinc ◽  
Metal Incorporation ◽  
Heavy Metal Waste

High amount of heavy metal waste produced from the industrial activities has become an important global issue for several decades due to its hazardous effect on the human and environment. Since heavy metal is highly toxic and cannot be eliminated easily, the application to reuse the heavy metal waste without harming the environment must be investigated thoroughly. This paper reviews the incorporation of heavy metal into clay precursors as a good potential for the reduction of environmental pollution. The results from the previous studies show the transformation of heavy metal such as copper, zinc, lead and cadmium into less hazardous species when incorporating into clay precursors. These transformations have reduced the mobility of heavy metal as a crystalline structure is formed after the thermal treatment. It is found that the immobilization process successfully stabilizing heavy metal and increases the metal’s resistance against the acidic attack through the formation of low permeable structure in the clay precursors. Hence, the incorporation of heavy metal into clay precursors is proven to be a great prospect in reducing environmental pollution.

HYDROXYAPATITE, ALGINATE, AND CHITOSAN FOR BONE SCAFFOLDS: SPECTROSCOPY STUDY

2016 ◽  
Vol 19 (2) ◽  
pp. 93-100
Author(s):  
Lalita El Milla
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Functional Groups ◽  
Bone Growth ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Tissue Engineering Scaffolds ◽  
Hydroxyapatite Powder ◽  
Materials Used

Scaffolds is three dimensional structure that serves as a framework for bone growth. Natural materials are often used in synthesis of bone tissue engineering scaffolds with respect to compliance with the content of the human body. Among the materials used to make scafffold was hydroxyapatite, alginate and chitosan. Hydroxyapatite powder obtained by mixing phosphoric acid and calcium hydroxide, alginate powders extracted from brown algae and chitosan powder acetylated from crab. The purpose of this study was to examine the functional groups of hydroxyapatite, alginate and chitosan. The method used in this study was laboratory experimental using Fourier Transform Infrared (FTIR) spectroscopy for hydroxyapatite, alginate and chitosan powders. The results indicated the presence of functional groups PO43-, O-H and CO32- in hydroxyapatite. In alginate there were O-H, C=O, COOH and C-O-C functional groups, whereas in chitosan there were O-H, N-H, C=O, C-N, and C-O-C. It was concluded that the third material containing functional groups as found in humans that correspond to the scaffolds material in bone tissue engineering.

Researches Concerning the Phenomena at the Interface for the Sintered Compacts of Titan-Hydroxyapatite

2013 ◽  
Vol 856 ◽  
pp. 164-168 ◽  
Author(s):  
Diana Irinel Băilă
Keyword(s):  
Specific Surface ◽  
Bone Tissue ◽  
Contact Zone ◽  
Cellular Differentiation ◽  
Selective Laser Sintering ◽  
Important Process ◽  
Sintering Process ◽  
Cellular Processes ◽  
Hydroxyapatite Powder ◽  
Ti Powder

The behaviour of metallic powders is very important for manufacturing parts and for realize the prototypes. Manufacturing of the orthopaedic implants by selective laser sintering process can be used in medicine. The powders necessary for SLS process are biomaterials who must assure a good osteointegration of endobone implants like the Ti powder (Ti-6Al-4V) and the hydroxyapatite powder. The conditioned powders is a very important process and is necessary in SLS to obtain medical prothesis and influence the final properties of prothesis. Materials must present a gradient for porosity and one for composition (presents of a bioactive phase in titan matrix). The exterior porosity, in the contact zones with the bone tissue, favors the incipient cellular processes (the adhesion and attachment of osteoblastes, proliferation and cellular differentiation and nucleation of mineral bone). The pores must be open and with a specific surface more great. Its preferred the exterior intercommunicating porosity. The presence of phosphates of calcium in the contact zone of the implant with bone favors the mineral kernel on bone. The report Ca/P of phosphates mineral bone has an ascending evolution towards 10/6 according to hydroxyapatite.

scholarly journals Relationship between heavy metal exposure and type 2 diabetes: a large-scale retrospective cohort study using occupational health examinations

BMJ Open ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. e039541
Author(s):  
Jun Ho Ji ◽  
Mi Hyeon Jin ◽  
Jung-Hun Kang ◽  
Soon Il Lee ◽  
Suee Lee ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Type 2 Diabetes ◽  
Heavy Metal ◽  
Cohort Study ◽  
Retrospective Cohort ◽  
Metal Exposure ◽  
Heavy Metal Exposure ◽  
Lead And Cadmium

ObjectivesTo investigate the associations between heavy metal exposure and serum ferritin levels, physical measurements and type 2 diabetes mellitus (DM).DesignA retrospective cohort study.SettingChangwon, the location of this study, is a Korean representative industrial city. Data were obtained from medical check-ups between 2002 and 2018.ParticipantsA total of 34 814 male subjects were included. Of them, 1035 subjects with lead exposure, 200 subjects with cadmium exposure and the 33 579 remaining were assigned to cohort A, cohort B and the control cohort, respectively. Data including personal history of alcohol and smoking, age, height, weight, the follow-up duration, haemoglobin A1c (HbA1c), fasting blood sugar (FBS), ferritin levels, and lead and cadmium levels within 1 year after exposure were collected.Primary outcome measureIn subjects without diabetes, changes in FBS and HbA1c were analysed through repeated tests at intervals of 1 year or longer after the occupational exposure to heavy metals.ResultsIn Cohort A, DM was diagnosed in 33 subjects. There was a significant difference in lead concentrations between the subjects diagnosed with DM and those without DM during the follow-up period (3.94±2.92 mg/dL vs 2.81±2.03 mg/dL, p=0.002). Simple exposure to heavy metals (lead and cadmium) was not associated with DM in Cox regression models (lead exposure (HR) 1.01, 95% CI: 0.58 to 1.77, p 0.971; cadmium exposure HR 1.48, 95% CI: 0.61 to 3.55, p=0.385). Annual changes in FBS according to lead concentration at the beginning of exposure showed a positive correlation (r=0.072, p=0.032).ConclusionOur findings demonstrated that simple occupational exposure to heavy metals lead and cadmium was not associated with the incidence of DM. However, lead concentrations at the beginning of the exposure might be an indicator of DM and glucose elevations.

Slip Casting Used as a Forming Technique for Hydroxyapatite Processing

2016 ◽  
Vol 720 ◽  
pp. 219-222 ◽  
Author(s):  
Rubens Lincoln Santana Blazutti Marçal ◽  
Daniel Navarro da Rocha ◽  
Marcelo Henrique Prado da Silva
Keyword(s):  
Slip Casting ◽  
Ceramic Materials ◽  
Processing Route ◽  
Ceramic Suspension ◽  
Polyethylene Glycol 400 ◽  
Density Measurements ◽  
Hydroxyapatite Powder ◽  
Heat Treated ◽  
Thermal Phase ◽  
Before And After

Ceramic materials have particular properties when compared to other classes of materials, exhibiting poor ductility as an example. Slip casting is a widely used ceramic forming technique, and already established in the literature and in the ceramic industry. This study aims to present slip casting as a processing route for producing hydroxyapatite (HA) struts, and show the thermal phase stability. The ceramic suspension was produced and stabilized with hydroxyapatite powder, deionized water and polyethylene glycol 400. The slip was poured into gypsum mold. The green bodies were heat treated at 900 and 1100°C. Hydroxyapatite was the only phase present in all samples, before and after heat treatments. Density measurements showed that the densification was higher for the ceramic bodies sintered at 1100°C, when compared to the ones calcined at 900°C.

scholarly journals Deciphering lead and cadmium stripping peaks for porous antimony deposited electrodes

2016 ◽  
Vol 34 (2) ◽  
pp. 233-241 ◽  
Author(s):  
Aqeel Ahmad Taimoor
Keyword(s):  
Heavy Metal ◽  
Photoelectron Spectroscopy ◽  
Metal Ion ◽  
Porous Electrodes ◽  
Electrochemical Sensing ◽  
Ex Situ ◽  
Electrochemical Tests ◽  
Diffusion Limitations ◽  
Lead And Cadmium ◽  
Cadmium And Lead

AbstractCadmium and lead are generally taken as model heavy metal ions in water to scale the detection limit of various electrode sensors, using electrochemical sensing techniques. These ions interact with the electrochemically deposited antimony electrodes depending on the diffusion limitations. The phenomenon acts differently for the in-situ and ex-situ deposition as well as for porous and non-porous electrodes. A method has been adopted in this study to discourage the stripping and deposition of the working ions (antimony) to understand the principle of heavy metal ion detection. X-ray photoelectron spectroscopy (XPS) technique was used to establish the interaction between the working and dissolved ions. In addition to the distinct peaks for each analyte, researchers also observed a shoulder peak. A possible reason for the presence of this peak was provided. Different electrochemical tests were performed to ascertain the theory on the basis of the experimental observations.

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