Elution and reconcentration of polioviruses adsorbed on coal from water samples.

Viruses adsorbed on coal particles in the form of coal bed could efficiently be recovered with elution of 6% beef extract solution in Mcllvaine buffer at pH 7.1. Significant reduction in large volume of eluate could be achieved by employing modified organic flocculation technique to obtain virus concentrate. Modified organic flocculation technique involves addition of 0.02% bovine albumin in eluate. Enteroviruses were adsorbed to flocs which were formed at pH 3.5 and were recovered by centrifugation followed by solublization of flocs in a small volume of 0.15 M disodium hydrogen phosphate solution at pH 9.5. The recovery of viruses ranged from 87.9% to 97.3% with an average of 92.2%.

Use of bituminous coal for concentration of enteroviruses from sewage and effluent.

A method has been developed for concentration of enteroviruses from untreated and treated domestic wastewater using bituminous coal bed as a virus adsorbent. A bed made from 1.5 g of 120 mesh coal powder was used for concentrating enteroviruses from 100 ml of clarified sewage at different pH values with and without addition of AlCl3. To enhance the adsorption of viruses, requisite quantities of aluminium chloride were added so that a final concentration of 0.0005 M could be achieved. At pH 3.0 maximum adsorption (82.8%) of poliovirus type 1 from artificially contaminated clarified sewage was observed without addition of AlCl3. However, at pH 5.0 maximum virus adsorption of 98.7% was achieved after addition of aluminium chloride. An average recovery of 86.9% of adsorbed viruses at pH 5.0 was achieved from coal bed with 3% flocculating beef extract at pH 9.5. This method for concentration of enteroviruses incorporating use of coal was compared with that of Millipore membrane filter method applied to raw sewage and clarified sewage. The results obtained from the methodology using coal as adsorbent was subjected to Student's "t" test and it was observed that its efficiency is confirmed for recovery of enteroviruses from raw and nonclarified sewage. These results are also comparable with that obtained with MF method. The results presented in this paper are indicative of the potential of this method for both treated and raw sewage.

Methodology for recovery of indigenous viruses from primary sludge.

Freon extraction method for recovery of viruses from primary sludge has been studied with sonication and the beef extract eluation methods. Several variables within the freon extraction method were worked out and it was observed that equal volume of 10% buffered beef extract (pH 7.0), as that of the sludge sample, was required for optimum virus elution. Eluate decontamination with antibiotics, dilution and plaquing over BGM cell cultures using the overlay medium without phenol red, fortified with 1.7% milk powder resulted in best recoveries without any cytotoxicity to the cell cultures. A sample volume of 20 ml primary sludge was sufficient for quantification of viruses.