The Removal of Bacteria by Modified Natural Zeolites

Abstract

The removal effect of natural and modified zeolites containing different heavy metals (Ni2+, Zn2+, Fe3+ and Cu2+) on pure cultures of Escherichia coli and Staphylococcus aureus in a solid medium was evaluated in this work. These experiments were carried out in a continuous mode treating municipal wastewater. Faecal coliform species and Pseudomonas aeruginosa were identified. The rate constants of heavy metal lixiviation were determined using a first order kinetic model. The removal effect of modified natural zeolites in both a solid medium and in continuous mode showed an increased elimination of the bacterial population. The results established a decreasing order of the removal effect as follows: Cu2+ > Fe3+ > Zn2+ > Ni2+. The best performance of columns was obtained for inlet bacterial concentrations below 10(6) cells/100 ml. Most of the identified bacterial species were affected by copper modified zeolites, although Serratia marcescens presented the highest sensitivity and Klebsiella pneumoniae the greatest resistance.

Antibacterial behavior of silver-modified clinoptilolite–heulandite rich tuff on coliform microorganisms from wastewater in a column system

“…Under this context, Mila´n et al (2001) used metallic (Ni 2+ , Zn 2+ , Fe 3+ and Cu 2+ ) modified natural zeolites as disinfectant agents in a column system. The best results were obtained when the initial bacterial concentration in the municipal wastewater was 10 6 NVC/100 mL.…”

Kinetics and thermodynamics studies of silver ions adsorption onto coconut shell activated carbon

“…[2] When water disinfection is applied using chlorine, different toxic and carcinogenic by-products are formed. However, ozone utilization is limited because of its cost; and UV requires previous water treatment for solids removal and membrane filters do not last long, having also a high energetic cost.…”

Silver-Modified Mexican Clinoptilolite-Rich Tuffs With Various Particle Sizes as Antimicrobial Agents Against Escherichia coli

“…Disinfection of water can be achieved using chemical and physical agents such as chlorine and its derivatives, ozone or ultraviolet light [1][2][3][4][5][6]. Silver or zinc modified natural zeolites have been proposed as water disinfectants [7][8][9][10]. A study by Rivera-Garza [11] found that a silver modified clinoptilolite-heulandite-rich tuff releases silver ions into water, causing elimination of coliform microorganisms after a 2 h treatment.…”