Diatomite from Tuy An district, Phu Yen province, with different purities and diatom integrity as catalyst carriers, were adopted to prepare TNTs/g-C3N4 composite catalysts by a sol-gel method, with an optimal weight ratio of 1:1 for TNTs/g-C3N4 and diatomite. Compared with pure TNTs, g-C3N4, and TNTs/g-C3N4, the obtained composite photocatalysts exhibited lower photocatalytic performance under the same conditions and NO removal within 30 min under visible light. The NO gas treatment efficiency under the same conditions with different catalyst supports only decreases by approximately 18% at a reaction rate of 0.0950 min-1. This research on composite photocatalysts is a promising step towards practical environmental remediation. The use of diatomite as a carrier for photocatalytic materials is particularly noteworthy, as it is a naturally available and cost-effective source of materials. However, further improvements in the photocatalytic performance of the composite material are necessary to fully realize its potential in environmental remediation, including removing NOx and other pollutants. Overall, this study provides valuable insights into the influence of carriers on the photocatalytic activity of composite photocatalysts and lays the foundation for future research in this field.

S-TiO2 typically exhibits high photocatalytic activity, but its powdered form makes it difficult to apply practically in environmental treatment. Diatomite from different locations varies in purity and integrity of the diatomaceous earth, making it a suitable catalyst support for synthesizing mixed-phase S-TiO2 catalysts using the sol-gel technique. The synthesized photocatalyst exhibits similar photocatalytic activity to S-TiO2. The NO gas treatment efficiency under the same conditions with different catalyst supports only decreases by approximately 3% within 30 minutes at a reaction rate of 0.0950 min-1, with an optimal mass ratio of 70:30 for S-TiO2 and diatomite. This composite material holds promise for addressing the application of photocatalytic materials in practical environmental treatment, including NO removal and the treatment of other environmental pollutants, as diatomite is a naturally available and environmentally friendly material.

Heavy metal pollution is a major problems in the environment. The impact of toxic metal ions can be minimized by different technologies, viz., chemical precipitation, membrane filtration, oxidation, reverse osmosis, flotation and adsorption. But among them, adsorption was found to be very efficient and common due to the low concentration of metal uptake and economically feasible properties. In this review paper, Fe–Mn binary oxide incorporated into diatomite (Fe/Mn-diatomite) was prepared by a simple coating method , and removal of Cu(II) from aqueous solutions. The effects of three independent variables including initial ion concentration, removal time, and adsorbent dosage were investigated on the maximum adsorption of Cu (II). The optimum conditions for the adsorption of Cu(II) was obtained: 75 ppm of initial ion concentration, 150 min of removal time and 1.5 g/l of adsorbent. The maximum removal efficiencies of Cu(II) was obtained 86.25%. The results showed that Fe/Mn-diatomite was apable of treating copper metal in wastewater.

Environmental issues such as the wastewater have influenced each aspect of our lives. For human and environmental health protection, it is necessary to remove excess zinc in industrial wastewaters before discharging them to environment. Modified diatomite displayed larger surface area and pore volumes in comparison with untreated natural diatomite, which favored heavy metals sorption behavior. In this study, the removal of Zn(II) ions from aqueous solution was studied using Fe/Mn modified diatomite sample at different adsorption parameters such as contact initial metal ions concentration, dosage of Fe/Mn-Diatomite and ionic strength Na2CO3 on ionic Zn2+ adsorption capacity of diatomite modified. The residual zinc concentration in the solution was determined using flame atomic absorption spectroscopy. The results showed that: the gravitational increase increases with increasing time and then becomes almost stable, with 120 minutes timeliness; absorption increases when Fe/Mn-Ditomite is increased, absorption reaches 89.48% at a dose of 1.5 g/l; additional different concentrations Na2CO3 ranged from 0 ppm to 80 ppm the results showed that performance treatment Zn2+ of correspond 94,85%. This study could lay an essential foundation to develop modified diatomite for heavy metal removal from wastewater.