Batch and Column Adsorption of Phosphorus by Modified Montmorillonite

Phosphorus pollutants are a crucial component of water eutrophication. In this study, montmorillonite modified by Keggin Al-13 and hexadecyltrimethyl ammonium (Al-13-O-MMt) was used as an adsorbent to remove phosphorus from solutions and thus simulate the practice of a field trial, such as in wastewater. The ammonium molybdate spectrophotometric method was used to determine the concentrations of phosphorus in samples. In the batch experiment, phosphorus was adsorbed by original montmorillonite (MMt) and Al-13-O-MMt at various pH values (6-9) to identify the effect of pH during the adsorption process. The batch adsorption results demonstrate that Al-13-O-MMt can adsorb up to 93% of phosphorus at pH = 8. Six graduated amounts (0.01-0.25 g) of montmorillonite were tested at three different temperatures to determine the most suitable temperature and the minimum dosage of Al-13-O-MMt needed for the adsorption of 200 mg/L phosphorus in a 30 mL solution, which was 0.1 g at 25 degrees C. Therefore, the adsorption capacity of Al-13-O-MMt was found to be 60 mg/g. Subsequently, a column experiment was conducted. The results showed that the optimized dosage of Al-13-O-MMt was 6.667 g for phosphorus adsorption with a concentration of 200 mg/L in 2000 mL solution, and the breakthrough time was 4794.67 min.

Automated summary

In this study, modified montmorillonite was used as an adsorbent to remove phosphorus from solutions. The batch experiment demonstrated that the modified montmorillonite could adsorb up to 93% of phosphorus at pH = 8. The column experiment showed that the optimized dosage for phosphorus adsorption in a 2000 mL solution with a concentration of 200 mg/L was 6.667 g, and the breakthrough time was 4794.67 minutes.