The Physico-Chemical and Mineralogical Characterization of Mg-Rich Synthetic Gypsum Produced in a Rare Earth Refining Plant

The physical, chemical and mineralogical characterization of the constituents of magnesium-rich synthetic gypsum produced in a rare earth-refining plant located in Gebeng, Pahang, Malaysia was conducted through elemental chemical analysis, scanning electron microscopy with Energy Dispersive X-ray (EDX)-analyzer, thermal analysis, X-ray fluorescence and X-ray diffraction. The crystalline nature of the by-product was studied using FTIR spectroscopy. Elemental analysis confirmed the presence of Ca and Mg, which are essential macronutrients required by plants and this Ca alongside the high pH (9.17) of MRSG may confer on the material a high acid neutralization capacity. From the result, it was observed that the studied by-product is a heterogeneous crystalline material comprising of gypsum (CaSO4.2H2O) and other major components such as calcium (magnesium) compounds (hydroxide, oxide, silicates, and carbonate) and sulfur. These aggregates may contribute to give an acid neutralization capacity to MRSG. The XRD study of MRSG indicated a high content of gypsum (45.4%), shown by the d-spacing of 7.609 Å (2-theta 11.63) in the diffractogram. The infrared absorption spectra of MRSG indicate close similarities to mined gypsum. The results of the characterization indicated that MRSG has valuable properties that can promote its use in amending soil fertility constraints on nutrient-deficient tropical acid soils.

Neutralization effect of slag on the acid rock drainage

Aims/hypothesis Pohang Tertiary mudstone presents the issue of acid rock drainage. This study analyzed the capacity of a mixed slag (70% steel slag + 30% blast furnace slag) to neutralize Pohang Tertiary mudstone’s acid rock drainage. Methods Element analysis, acid neutralization capacity (ANC) test, and net acid generation (NAG) test were conducted on Pohang Tertiary mudstone samples and the mixed slag. The XRF analysis and the XRD analysis on the mixed slag were conducted to measure the CaO content, which indicates the potential of the mixed slag as an acid-neutralizing agent. Results According to the analysis results on the Pohang Tertiary mudstone samples, the total sulfur content was high, which indicates a high risk of acid rock drainage generation. Although there were slight deviations between the samples, overall, the mudstone exhibited a high acid rock drainage generation capacity. The XRF analysis of mixed slag results showed high amounts of CaO content. From the XRD analysis graph, it was clear that a high proportion of minerals with Ca- compounds consisting of basic substances were present. The neutralization capacity of the mixed slag on Pohang Tertiary mudstone was determined by the relationship between maximum potential acidity (MPA) and acid neutralization capacity (ANC). For instance, the mixed slag of 4.5% effectively neutralizes a sulfur content of 1%.

Feasibility of Stabilized Zn and Pb Contaminated Soils as Roadway Subgrade Materials

The authors have developed a new binder, KMP, which is made from oxalic acid-activated phosphate rock, monopotassium phosphate (KH2PO4), and reactive magnesia (MgO). This study explores the acid neutralization capacity, strength characteristics, water-soaking durability, resilient modulus, and pore size distribution of KMP stabilized soils with individual Zn, Pb, or coexisting Zn and Pb contaminants. For comparison purpose, Portland cement (PC) is also tested. The results show that KMP stabilized soils have a higher acid buffering capacity than PC stabilized soils, regardless of the soil contamination conditions. The water stability coefficient and resilient modulus of the KMP stabilized soils are found to be higher than PC stabilized soils. The reasons for the differences in these properties between KMP and PC stabilized soils are interpreted based on the stability and dissolubility of the main hydration products of the KMP and PC stabilized soils, the soil pore distribution, and concentration of Mg or Ca leached from the KMP and PC stabilized soils obtained from the acid neutralization capacity tests. Overall, this study demonstrates that the KMP is effective in stabilizing soils that are contaminated with Zn or Pb alone and mixed Zn and Pb contaminants, and the KMP stabilized soils are better suited as roadway subgrade material.

Acid neutralizing capacity, an important waste management parameter

The paper presents the influence of acid neutralization capacity in industrial waste samples as a decision indicator. For the analysis of the acid neutralization capacity, six samples of wastes from different sectors of activity were subjected. A successful method that can be applied to determine the properties of waste is acidneutralizing capacity. The acid-neutralizing capacity was evaluated with HCl 1 N by neutralizing the excess with NaOH 0.5 N after 15 min stirring. From the results obtained it is found that the acid neutralization capacity can provide essential information for the subsequent management of the waste.

Acid Neutralizing Capacity of Selected Antacid Suspensions Available in the Ghanaian Market

Antacids are substances commonly used by patients to obtain fast symptomatic relief from dyspepsia. They are weak bases which neutralize excess gastric acid and subsequently raise the pH of the gastric contents. The potency of the antacids depends mainly on their acid neutralization capacity (ANC) and this can vary from one brand to another. Several dosage forms of antacids are available for use by patients. However, In Ghana, suspensions are the commonest dosage form of antacids which is preferred by patients. The objective of this study was to determine the acid neutralizing capacity of six (6) randomly selected brands of antacid suspensions on the Ghanaian market using potentiometric acid-base titration. The samples were coded A-F to avoid any bias in the study. All the sampled brands had more than one year to expiry as indicated on their label. Brand D had the highest ANC of 29.70 mEq/dose whiles brand A had the lowest ANC of 11.25 mEq/dose. From the results obtained, it can be inferred that acid neutralization can be more effective and rapidly achieved with liquid antacids containing a high amount of magnesium hydroxide and aluminium Hydroxide. Hence, for acute symptomatic relief from dyspepsia, antacids containing a higher concentration of magnesium hydroxide and aluminium hydroxide would be most beneficial to patients.

Formulation, Development and Evaluation of Chewable Bi-layered Tablets for Treating Gastro Esophageal Reflux Disease

The purpose of this research work was to formulate raft-forming chewable bilayer tablets of sodium alginate using a raft-forming agent along with gas-generating agents. Tablets were prepared by wet granulation and evaluated for raft strength, acid neutralization capacity, weight variation, % drug content, thickness, hardness, friability and in vitro drug release. Various raft-forming agents were used in preliminary screening. The amount of sodium alginate, amount of calcium carbonate and amount sodium bicarbonate were selected as variables. Raft strength, acid neutralization capacity and drug release at 30 min were selected as responses.Tablets containing sodium alginate were having maximum raft strength as compared with other raft-forming agents. Acid neutralization capacity and in vitro drug release of all factorial batches were found to be satisfactory. Prepared tablets were found to be pharmaceutically equivalent to the marketed product. It was concluded that raft-forming chewable bilayer tablets prepared using an optimum amount of sodium alginate, calcium carbonate and sodium bicarbonate could be an efficient dosage form in the treatment of gastro oesophageal reflux diseases. Keywords: Chewable bilayer tablet, Sodium alginate, Raft forming agent, Acid Neutralizing capacity

Investigation of the Role of the Alkalizing Agent in Sodium Alginate Liquid Anti-reflux Suspension

Background: Anti-reflux formulation is one of the popular formulations across the globe in the pharmaceutical industry used specifically for the management of gastro-oesophageal reflux disease. But, this formulation is less explored with respect to research. Anti-reflux formulation has challenges to show its antacid functionality, which could have synergies in the management of refluxes in gastro-oesophageal reflux disease. Alkalizing agents act as antacid and improve the acid neutralization capacity in the anti-reflux formulation, and can be used appropriately as they affect raft strength beyond certain (optimum) limits. Objective: The objective of this work is to investigate the significance of alkalizing agent in sodium alginate based on oral liquid anti-reflux suspension for the management of Gastro-oesophageal Reflux Disease (GERD). Methods: In the present study, the formulation was prepared using sodium alginate along with different alkalizing agents like calcium carbonate and sodium bicarbonate at different levels. The formulation was further studied for in-vitro characterization like pH, viscosity, Acid Neutralization Capacity (ANC), thickness, formation speed, flotation, and raft strength. Results: The formulation with a higher level of calcium carbonate as the alkalizing agent showed a positive effect on the acid neutralization capacity (20.83mEq) and raft strength (16.95g) as well. Whereas, the formulation with a higher level of sodium bi-carbonate (4.01%) showed improved acid neutralization (22.31mEq) but showed a negative effect on raft strengths (10.08g). Conclusion: Based on the study, the optimum levels include 5% sodium alginate, 1.6% calcium carbonate and 2.67% sodium bicarbonate to achieve good liquid suspension formulation possessing good acid neutralization capacity as well as raft strength.

Behavior of metallic trace elements containing in stabilized and solidified oily petroleum sludge

The present work examines the influence of the leaching conditions on the release of various chemical elements from a cementitious material obtained by solidification of an industrial waste rejection of Algeria. Toxicity Characteristic Leaching Procedure (TCLP), X-ray diffraction (XRD) and Scanning electron microscopy coupled with energy dispersive X-ray microanalysis SEM-EDX analyses were employed to characterize the waste and the stabilized/solidified materials. Than several formulations were prepared with different percent of waste ranging from 0 % to 30 %. To evaluate the influence of leaching conditions on the release of chemical ions (Zn2+, Pb2+, Cl-, Mg2+, Ca2+, Na+, K+ and SO42−) contained in the stabilized and solidified materials, the Acid Neutralization Capacity (ANC), the Pore Water (PW) and Monolith Leaching Tests (MLT) have been carried out. The leaching tests (ANC, PW and MLT) have shown a low metal leachability. However, the lowest released amount was observed for the MLT.

In vitro Antacid Screening of the Aqueous and Ethanolic Leaf Extracts of Ixora Coccinea (Linn). and Mimosa Pudica (Linn.)

Ixora coccinea L. (santan) and Mimosa pudica L. (makahiya) ethanolic and aqueous extracts were screened for their in vitro antacid potentials using the preliminary antacid test, determination of acid neutralization capacity, acid neutralizing effect, duration of consistent neutralization, and buffering capacity. Phytochemical screening and quantification of alkaloids were also done and the alkaloid content was correlated to the in vitro antacid potentials of the extracts. Among the extracts, the M. pudica aqueous extract gave the best preliminary antacid test result (1.0066±0.0083 pH) and acid neutralization capacity (0.0711±0.0038 mmol H+). Its aqueous extract showed comparable acid neutralizing effect (3.507% acid neutralized) on gastric juice with that of its ethanol extract (3.509% acid neutralized). On the other hand, the I. coccinea aqueous extract had the highest acid buffering capacity (0.0701±0.0020 mmol H+/pH). Both aqueous extracts gave the longest duration of neutralization with 9±1.732 minutes. All the extracts were tested positive for flavonoids, indoles, tannins, anthraquinones, anthrones, and alkaloids, with the I. coccinea aqueous extract having the highest alkaloid content (18.0282±1.2607% w alkaloid/w extract). This study provides the first reported proof of the antacid activities of I. coccinea and M. pudica. Further tests, including mouse model assays, are suggested to determine the efficacy of the extracts in vivo.