Using Modified Clinoptilolite Zeolite to Remove Pollutants and Salt from Agricultural Drainage Water in a Model Drainage System

• Published in: International Journal of Environmental Research 2021-10, Vol.15 (5), p.859-873
• Main Authors: Sadeghi, Sara, Albaji, Mohammad, Golabi, Mona, Boroomand Nasab, Saeed
• Format: Article
• Language: English
• Subjects: Adsorbents; Adsorption; Ambient temperature; Clinoptilolite zeolites; Drainage systems; Drainage water; Drains; Earth and Environmental Science; Efficiency; Environment; Environmental Engineering/Biotechnology; Environmental Management; Experiments; Farms; Feasibility studies; Fertilization; Geoecology/Natural Processes; Landscape/Regional and Urban Planning; Mathematical models; Natural Hazards; Nitrate removal; Nitrates; Nutrient removal; Parameters; pH effects; Phosphate; Phosphates; Phosphorus removal; Plant roots; Pollutant removal; Pollutants; Research Paper; Retention; Retention time; Salinity; Salinity effects; Salts; Subsurface drainage; Water purification; Zeolites
• ISSN: 1735-6865; 2008-2304
• DOI: 10.1007/s41742-021-00359-5

This study examined the feasibility of using zeolite clinoptilolite to removal nitrate, phosphate pollutants, and salt from the agricultural drainage water. To that end, significant pollutant absorption parameters, such as adsorbent particle size, pollutant concentration, salinity, temperature, retention time, pH, and adsorbent concentration, were optimized in the batch condition. Having optimized the parameters, the researchers conducted adsorption experiments on an experimental model, similar to the subsurface drainage systems applied in farms. Adsorption experiments were carried out at the optimized parameter levels on four models, namely a reference model (D0), a model with adsorbents around the drains (D1), a model with adsorbents around the plant roots (D2), and a model with adsorbents on the soil surface (D3). These models were fed with untreated drainage water from the farms in the south of Khuzestan during the fertilization season. In the batch adsorption experiments, the results showed 63% nitrate removal efficiency, 39% phosphate removal efficiency, and 79% salt removal efficiency using 30 g.L -1 of 1000 µm adsorbent particles for a pH of 5, and initial pollutant concentration of 80 mg.L -1 nitrate and 10 mg.L -1 phosphate in 12 dS/m salinity during a 90-min retention time period at 50 °C ambient temperature. These parameter levels led to nitrate, phosphate, and salt removal efficiencies of 59.72, 29.28, and 77.47%, respectively, in the model with clinoptilolite adsorbents around the drains (D1). Article Highlights Using zeolite clinoptilolite to filter nitrate, phosphate, salt from agricultural drainage water. The results were suggestive of a 76% pollutant and salt-removal efficiency. TThe nitrate -removal efficiency was 59.72% in the model with clinoptilolite adsorbents. The phosphate-removal efficiency was of 29.28% in the model with clinoptilolite adsorbents. The salt-removal efficiency was 77.47% in the model with clinoptilolite adsorbents.