Virus Removal by Diatomaceous‐Earth Filtration–Part 2

Abstract

The removal of viruses from drinking‐water supplies is not a long‐established practice, but it is an issue of major concern. Diatorhaceous‐earth filtration has been demonstrated to remove viruses from water effectively; however, as this article emphasizes, more research of and experimentation with this process is necessary. Part 1, involving the study of the bacteriophage T2 for E. coli, appeared in JOURNAL AWWA, 66:2:98 (Feb. 1974).

Nanostructured surface modification of microporous ceramics for efficient virus filtration

“…Various approaches have been presented in the literature which have taken up this challenge: diatomaceous earth (DE) modified with polyelectrolytes, 5-7 DE modified with salts/hydroxides of aluminum, iron, magnesium and calcium, 5,6,8 fiberglass and cellulose modified with salts of Al, Fe, Mg and Ca, 9 fiberglass and cellulose modified with alumina-coated colloidal silica, 10 sand modified with Fe-and Al-hydroxide, 11 and granular anthracite and granular activated carbon coated with nanoporous Al 2 O 3 . 12 These and other studies of electropositive filter media 13,14 generally show that the strongest contribution to the adsorption process is made by electrostatic forces, i.e.…”

Performance and Cost-Effectiveness of Ferric and Aluminum Hydrous Metal Oxide Coating on Filter Media to Enhance Virus Removal

“…An alternate approach is to modify the surface properties of the filter media, e.g., by coating with an electropositive material. The first investigators of this approach (Brown et al, 1974a, Brown et al, 1974bFarrah et al, 1988;Farrah et al, 1991) found that iron aluminum hydroxide coating increased removal of viruses by diatomaceous earth from less than 30% to greater than 80%. Subsequently, Lukasik et al (1996Lukasik et al ( , 1999) tested removal of viruses by columns filled with fine sand (less than 0.3 mm) coated with iron aluminum hydroxide.…”

Environmental health sciences center task force review on halogenated organics in drinking water

“…Recently there has been considerable concern about virus diseases in drinking water (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25). It has been suggested that a variety of pathogenic viruses, including the causative agents for such wellknown diseases as poliomyelitis and hepatitis, may be transferred via water.…”

“…Primary and secondary treatment removes 93 to 99%o of the bacteria (13) and 90 to 99.9Wo of the viruses (23) in domestic wastewater, but large concentrations of bacteria still remain. Physical-chemical treatment processes such as coagulation, filtration, and carbon adsorption remove various amounts of pathogens (15,18,23,26). Coagulation followed by settling or filtration has been shown to be one of the most effective means of virus removal; it is more effective than chlorination.…”

“…Morris (93) has defined the relative importance of these chlorinating species. The net relative reactivities r under a given set of conditions is a sum of the products of the estimated temperature dependent specific seactivity (ri) and the fraction (fi) of the total chlorine-containing species and is given by: r = I rfi (15) The net relative activities for chlorine products in water at pH 7.0 and 15°C are shown in Table 5. The variation in the electrophilic behavior of a chlorinating species will depend on the nucleophilicities of the substrate.…”