Asghar Alahyari Solokloei; Mohammad Ali Baghapuor; Abooalfazl Azhdarpoor; Mohammad Reza Shirdarreh
Abstract
Background:Background: Diclofenac is one of the drug compounds that is known as an emerging contaminant in aqueous solutions. Studies have shown that biological treatment is not sufficient to treat these compounds and new methods such as adsorption should be used to prevent contamination of aquatic environments. ...
Read More
Background:Background: Diclofenac is one of the drug compounds that is known as an emerging contaminant in aqueous solutions. Studies have shown that biological treatment is not sufficient to treat these compounds and new methods such as adsorption should be used to prevent contamination of aquatic environments. One of the native absorbers in this regard is the pumice. This study aimed to investigate the removal of diclofenac from aqueous solutions using magnesium chloride modified pumice.
Methods: In this experimental study, with a practical approach, the required adsorbent was prepared from pumice. Magnesium chloride was used for pumice modification. The experiments were performed in a closed system at laboratory temperature. In this study, the effect of variables, adsorbent dose, contact time, and pH on diclofenac removal was investigated. Diclofenac was analyzed by KNAUER model HPLC at a wavelength of 254 nm.
Results: Modified pumice by magnesium chloride was able to remove 95.83% of diclofenac (20 mg/l) at a concentration=1 g/l for 15 minutes at pH=5. Comparison of modified and natural pumice performance in 5, 10, 15, 30, 40 minutes with an average of 89.52% of modified pumice removal, compared to 48.15% of natural pumice removal, which was 1.86 times more efficient.
Conclusion: Pumice can be used as a cheap, available, and highly effective adsorbent for the removal of diclofenac from aqueous solutions.
Nasim Salehi; Abooalfazl Azhdarpoor; Mohammadreza Shirdarreh
Abstract
Background: Pyrene is one of the polycyclic aromatic hydrocarbons that has carcinogenic, mutagenic and teratogenic effects for living organisms. Landfill leachate is another environmental pollutant that covers a wide range of pollutants, especially heavy metals. The simultaneous presence of two types ...
Read More
Background: Pyrene is one of the polycyclic aromatic hydrocarbons that has carcinogenic, mutagenic and teratogenic effects for living organisms. Landfill leachate is another environmental pollutant that covers a wide range of pollutants, especially heavy metals. The simultaneous presence of two types of pollutants with organic and inorganic structures can increase their toxicity. Methods: In this experimental study, the single and simultaneous effect of Landfill leachate and pyrene on plant growth parameters and the number of heterotrophic soil bacteria was investigated. The study was conducted for 90 days at concentrations of 150, 300, 500, 750 and 1000 mg/kg-1 of pyrene and percentages 0, 30, 50, 70 and 100% of landfill leachate. Results: The results showed that after 90 days, the highest dry stem and root biomass were obtained in irrigation treatment with pyrene and Landfill leachate (Blank)-non-contaminated municipal water with quantities of 8.2 and 3.5 g, respectively; moreover, the lowest stem and root biomass related to the treatment were observed in the simultaneous presence of 30% leachate and pyrene with a concentration of 300 mg/kg-1 with quantities of 5 and 1.8 g, respectively. Leachate did not produce any biological toxicity at any of the surfaces used, but the use of pyrene at concentrations of 1500 mg/kg-1 and above reduced the number of heterotrophic bacteria. Conclusion: According to the results, the simultaneous presence of the two pollutants, pyrene and leachate, exacerbates the phytotoxicity due to possible interactions between them. Pyrene as a carbon source is decomposed by bacteria at low concentrations, but it inhibits metabolism and growth at high concentrations.