The use of plant materials for the synthesis of superplasticizer

The paper presents data on the synthesis of phloroglucinol-furfural modifier (1,3,5-trihydroxybenzene-2-furaldehyde oligomer) based on 2-furaldehyde (furfural) and 1,3,5-trihydroxybenzene (phloroglucinol). The synthesis of a modifier with different molar ratios of phloroglucinol/furfural was carried out. It was found that an increase in the molar ratio leads to an increase in the plasticizing ability of the modifier. The optimal concentration of the catalyst was determined to be equal to 50% by weight of phloroglucinol. Two chemical forms of the modifier were obtained: H-form and Na-form. The structure of various forms of the modifier has been studied by scanning electron microscopy. It was found that the oligomers used in the work for the synthesis of the modifier, in addition to 2-furyl methyl alcohol, do not have plasticizing properties. Purified 2-furyl methyl alcohol has weak plasticizing properties. It is shown that to achieve the best plasticizing effect, it is necessary to gradually introduce a condensing agent into the reaction mixture. With gradual introduction, a complete condensation reaction occurs between the monomers, which affects the improvement of the plasticizing properties of the resulting product. The spread of the cement mixture when using 0.3% of the additive based on the mass of cement in terms of dry matter is 19 cm.

The simultaneous removal of bisphenol A, manganese and ammonium from groundwater by MeOx: The role of chemical catalytic oxidation for bisphenol A

The iron and manganese oxide filter film (MeOx) were used to research the simultaneous removal of bisphenol A (BPA), manganese (Mn2+) and ammonium (NH4+) in a pilot-scale filter system. We found that 0.52 mg/L of BPA could be removed while consuming 5.44 mg/L of dissolved oxygen (DO). Since the oxidation process of NH4+ and BPA both consume the DO in water, the presence of NH4+ can hinder the removal of BPA. The presence of Mn2+ in water had a synergy effect on the BPA removal. The filter film was characterized by SEM, XRD and XPS. Some substances were generated to block the pores of the oxide film, and a small amount of film was found to crack and fall off. The elemental composition of C and O were both increased by about 9%, the composition of Mn was decreased from 63.48% to 44.55%, and the reduced manganese substance might affect the activity of the oxide film. The main chemical forms of MeOx are Mn6O12·3H2O, MnFe2O4 or Mn3O4. The decrease in the removal efficiency of BPA was mainly due to the C-containing intermediate [−CH2C − H(OH)]n covering the surface of the oxide film and blocking the pore size of the film.

Effect of Vermicompost Amendment on the Accumulation and Chemical Forms of Trace Metals in Leafy Vegetables Grown in Contaminated Soils

(1) Background: Trace metal (TM) contamination of farmland soil in Taiwan occurs because factories dump wastewater into irrigation ditches. Since vermicompost affects the bioavailability of TMs, the objective of this study was to evaluate its effects on the accumulation of growth of TMs in leafy vegetables. (2) Methods: Two TM-contaminated soils and different types of pak choi and lettuce were used and amended with vermicompost. Besides soil properties, the study assessed vermicompost’s influence on the growth, accumulation, and chemical forms of TMs and on the health risks posed by oral intake. (3) Results: Vermicompost could increase the content of soil organic matter, available phosphorus, exchangeable magnesium, and exchangeable potassium, thus promoting the growth of leafy vegetables. The accumulation of four TMs in crops under vermicompost was reduced compared to the control, especially for the concentration of cadmium, which decreased by 60–75%. The vermicompost’s influence on changing the chemical form of TMs depended on the TM concentrations, type of TM, and crop species; moreover, blanching effectively reduced the concentrations of TMs in high-mobility chemical forms. Although vermicompost mostly reduced the amount of cadmium consumed via oral intake, cadmium still posed the highest health risk compared to the other three TMs.