Exploitation of Nano-Bentonite, Nano-Halloysite and Organically Modified Nano-Montmorillonite as an Adsorbent and Coagulation Aid for the Removal of Multi-Pesticides from Water: A Sorption Modelling Approach

• Published in: Water, air, and soil pollution air, and soil pollution, 2015-03, Vol.226 (3), p.1-14, Article 41
• Main Authors: Shabeer, T. P. Ahammed, Saha, Ajoy, Gajbhiye, V. T., Gupta, Suman, Manjaiah, K. M., Varghese, Eldho
• Format: Article
• Language: English
• Subjects: Adsorbents; Adsorption; Agriculture; Analysis; Atmospheric Protection/Air Quality Control/Air Pollution; Bentonite; Chloride; Chlorides; Clay; Climate Change/Climate Change Impacts; Coagulants; Coagulation; Combined treatment; Drinking water; Earth and Environmental Science; Efficiency; Environment; Environmental monitoring; Flocculation; Fourier transforms; Hydrogeology; Isotherms; Montmorillonite; Nanomaterials; Nanostructure; Oxidation; Particle size; Pesticides; Pollutant removal; Pollutants; Pollution; Polyaluminium chloride; Research centers; Sedimentation & deposition; Soil adsorption; Soil Science & Conservation; Soil sciences; Studies; Surface water; Water; Water Quality/Water Pollution; Water treatment
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/s11270-015-2331-8

The objective of this study was to investigate the removal of multi-pesticides through a combined treatment process with coagulation–adsorption on nano-clay. Nano-clays like nano-bentonite, nano-halloysite and organically modified nano-montmorillonite were used as the adsorbent, and alum and polyaluminium chloride (PAC) were used as the coagulants. The coagulation method alone was not sufficient to purify water, whereas coagulation plus adsorption methods provided superior purification. Amongst the nano-clays used, organically modified nano-montmorillonite gave the best result in terms of pesticide removal from water. In order to evaluate the effect of coagulant addition on the removal efficiency of nano-clay, the respective adsorption isotherms were also calculated in the presence and absence of coagulants. Freundlich isotherm constants have shown that adsorption of pesticides on different nano-clay depends on the type of clay, presence and absence of coagulants as well as the properties of pesticides. The treatment combination having the maximum removal capacity was used efficiently for the removal of pesticides from natural and fortified natural water. The results indicated that alum–PAC coagulation aided by nano-clay as an adsorbent was the superior process for the simultaneous removal of multi-pesticides from water.