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Dihydropyrimidinones and their derivatives (DHPMs) possess extensive and important biological and pharmacological activities such as antiviral, antibacterial, anticancer and antitumor properties.1–...

The thermal-activated serpentine prepared by heating natural serpentine at different temperatures was used to immobilize cadmium (Cd) in simulated contaminated soils. The results showed that the in...

In situ immobilisation zinc (Zn) in simulated polluted soil was conducted by using the thermal-activated serpentine prepared via heating natural serpentine at different temperatures as amendments. ...

Adsorption properties of nature and thermal-activated serpentines to Pb2+ in aqueous solution were investigated. The results showed that Freundlich isotherm and pseudo-second-order kinetics...

The chitosan–montmorillonite composites (CTS–MMT) were prepared by CTS in combination with Na-type montmorillonite (Na-MMT). The composites were characterized by X-ray diffraction and Fourier transform infrared spectroscopy. The effects of initial pH value of the solution, adsorbent dose, the mass ratio of CTS to Na-MMT, the adsorption temperature, and contact time on acid fuchsin (AF) removal efficiency were investigated. The results indicated that the CTS could be successfully intercalated into the interlayers of Na-MMT. With the increase in content of CTS, some of them may be distributed on the surfaces of the clay and the AF removal efficiency can reach 80.2% using CTS–MMT as adsorbent to treatment AF wastewater (the AF concentration 20 mg/L) under the condition of pH, 5; adsorbent dose, 5 g/L; the mass ratio of CTS to Na-MMT, 0.25:1; adsorption temperature, 40°C; and contact time, 90 min. Meanwhile, it was shown that the adsorption processes were better fitted by pseudo-second-order model and...

An efficient Al-Fe cointercalated bentonite composite material (Al-Fe/Bent) which is capable of removing hexavalent chromium [Cr(VI)] from aqueous solutions was prepared. The batch experiment studies were conducted to evaluate the adsorption performance of Cr(VI) contained in aqueous solution. The XRD results showed the spacing of layers of bentonite was increased due to the aluminum and iron polycation intercalated into the layer of bentonite. The removal rate of Cr(VI) from the aqueous solution could be up 87.4% under the condition of the dosage of Al-Fe/Bent 8 g/L, pH 4, and a contact time of 60 min. The equilibrium data fitted well to the Freundlich model. The adsorption process could be well described by the pseudosecond order kinetic model.

The degradation of polyacrylamide (PAM) in simulate wastewater was studied in UV/Fenton/C4H4O62− system. The factors such as molecular ratio of H2O2/Fe2+/C4H4O62−, pH, and the dosage of Fenton reagent that could affect the PAM degradation in the UV/Fenton/C4H4O62− system were investigated. The experimental results showed that adding C4H4O62− to UV/Fenton system could form photosensitive ferrous complexes, which led to higher degradation efficiency of PAM. The degradation rate of PAM could be up to 95.2% under the following conditions: the concentration of H2O2, Fe2+, and C4H4O62− were 22.5, 2.25, and 2.25 mmol/L, respectively (i.e., molecular ratio of H2O2/Fe2+/C4H4O62− was 10:1:1), the pH value was 3.0.

TiO2/bentonite composites were prepared by a sol–gel method. X-ray diffraction measurements of the samples revealed that TiO2 had intercalated into the layers of bentonite and existed in anatase phase of TiO2. Acid red 3R was used as model compounds of textile dyes in this study. The effects of operational parameters, including TiO2 content, pH, as well as catalyst dosage, on photocatalytic degradation performance were examined. The experimental results showed that the removal rate of acid red 3R can be up to 96.7% under the following conditions: the dosage of TiO2/bentonite was 2 g/L, the content of TiO2 was 30%, the pH value was 3. And the photocatalytic reaction followed pseudo-first-order kinetics models.

Na–bentonite was modified via an ion-exchange reaction with hexadecyl trimethyl ammonium bromide (CTAB). X-ray diffractometer (XRD) indicated CTAB cations had exchanged with Na+ ions in Na–bentonite and the interlayer space of bentonite was increased. Batch adsorption tests were carried out to remove phenol from model wastewater using the modified bentonite, and the effect of amount of CTAB, contact time, pH, and adding quantity of modified bentonite were evaluated. The experimental results showed that the removal efficiency of phenol can be up to 81.36% under the following conditions: the amount of CTAB was 1.5 cation exchange capacity (CEC), the dosage of organic modified bentonite was 7 g/L, the adsorption time was 60 min, and the pH value was 7. The adsorption isotherms of organic modified bentonite for phenol-based wastewater met the Freundlich adsorption equation.

Fe-pillared bentonite (Fe-Bent) was prepared by ion exchange as heterogeneous catalyst for degradation of organic contaminants in petroleum refinery wastewater. X-ray diffraction analysis showed the existence of α-Fe2O3. The effects of pH, H2O2 concentration, and catalyst dosage on the rate of lowering the chemical oxygen demand (COD) were investigated in detail. Removal efficiency of COD can be up to 92% under the following conditions: dosage of Fe-Bent 7 g L−1, pH value 3, and H2O2 concentration 10 mmol L−1. Fe-Bent showed good stability for the degradation of organics in petroleum refinery wastewater for five cycles. The adsorption of organics in wastewater onto Fe-Bent could be well described by a pseudo-second-order kinetic model.

A solid base catalyst KOH/NaY was prepared by supporting KOH on NaY and the transesterification of castor oil to biodiesel catalyzed by the KOH/NaY was studied. The effects of molar ratio of methanol to castor oil, catalyst dosage (catalyst mass/oil mass), loading amount of KOH, reaction temperature, and reaction time on the conversion rate of transesterification were investigated. Under the optimal conditions of reaction temperature 65°C, molar ratio of methanol to oil 9:1, mass fraction of catalyst 10%, loading amount of KOH 10%, and reaction time 3 h, the conversion rate of transesterification was 86.9%. And KOH/NaY catalyst could be reused at least for three cycles with a significant conversion.

In order to study the character of a Moving Bed Biofilm Reactor (MBBR) in treating petrochemical wastewater, the authors offer the comparison experiment between MBBR and activated sludge process (A...

The aromatization reaction performance of P-Zn/HZSM-5 catalyst was investigated on a fixed bed reactor using five fluid catalytic cracked (FCC) gasoline fractions (