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.     

Removal of viruses from water by sorption on coal

The objective of this research was to investigate the potential of bituminous coal as sorbent for removing viruses from water and to delineate the sorption mechanism(s). This study was undertaken in view of the increasing use of coal in water and wastewater treatment. Bacteriophage T4 against Escherichia coli BB was used as a model virus and coal samples from Neyveli and Giridih were used as sorbents. A sampling method for rapid separation of unsorbed viruses from the sorbent was standardized which consisted of filtering the sample containing coal and viruses through a Whatman filter paper soaked in beef extract. Effects of the following parameters on virus sorption were investigated: pH, ionic strength, temperature, and presence of proteinaceous matter.Maximum virus sorption (about 70%) was observed at pH 8·0 with input virus concentration 1·44 × 10⁴ PFU ml⁻¹, coal size 350 μm and ionic strength 0·02. Optimum ionic strength for virus sorption was found to be 0·015. Higher temperatures increased the sorption capacity and the activation energy was found to be 30·3 kcal/mole. This and low desorption values (6–10%) suggested irreversible chemisorption. Effect of carbon content of coal on sorption-desorption was studied using pure graphite which showed negligible desorption. Effect of proteinaceous matter was investigated using 5% domestic wastewater and the culture broth. Proteinaceous matter appeared to compete with virus for sorption sites on coal and reduced sorption by about 12%.Kinetics and equilibria of sorption on Neyveli coal at pH values 5·5, 7·1 and 8·0 were studied in a non-flow agitated system. Equilibrium sorption was attained in 90 min, the bulk of it being over in 45 min. Sorption data followed Langmuir type isotherm plots and suggested L2 type plot according to Gile's classification (J. Chem. Soc. Part 3, p. 3973, 1960). Isotherm plot with 5% domestic wastewater gave an S curve, suggesting moderate to large intermolecular attraction and implying strong competition for substrate sites from molecules of the solvent. Monomolecular coverage to the extent of only 0·1% of total surface area agreed with the assumptions of isotherm plot and penetration into micropores and macropores of coal was ruled out.     

Methods for concentrating viruses from large volumes of estuarine water on pleated membranes

The efficiency of cartridge filters with pleated membranes was determined for the recovery of poliovirus from large volumes of seawater. Flow rates of about 6 gal min⁻¹ were obtained when a combination of a 3- and a 0.45-μm pleated filter were incorporated into the Wallis—Melnick virus concentrator. The filters adsorbed poliovirus when water was acidified at pH 3.5 and aluminum chloride added at a final concentration of 0.0015 m. The filters retained their capacity to adsorb virus particles, even after 600 gal (22681.) of very turbid estuarine water had been filtered. Viruses were eluted from the pleated filters with pH 11.5 glycine buffer and reconcentrated by precipitation with ferric chloride or aluminum chloride. Virus from 100-gal samples was concentrated into a final eluate volume of 20–100 ml, with virus recovery of about 50% being achieved in the material that had been concentrated 20,000–100,000 times.     

Use of dyes and proteins as indicators of virus adsorption to soils

Outbreaks of viral diseases have been associated with contamination of ground water sources by viral migration from septic tanks. A better understanding of virus adsorption to soils might help elucidate the possible mechanism of subsurface virus migration and ultimate contamination of ground water sources. The present investigation sought a simple test that could predict virus adsorption to soils. Two dyes, methylene blue (positively charged) and amaranth (negatively charged), and three proteins, ferritin (p¹ 4.5), myoglobin (p¹ 7.3) and cytochrome-c (p¹ 9.3), were evaluated as potential indicators of virus adsorption to 20 different soils. The results indicated that no single indicator could predict the adsorption pattern for the different viruses which were evaluated with the soils tested. However, the viruses could be divided into two groups based on their similarities to adsorption of ferritin and cytochrome-c to soils. The other three indicators, myoglobin, methylene blue and amaranth did not significantly correlate with virus adsorption. Therefore, it is proposed that a two protein indicator system could be used to evaluate soils to predict virus adsorption.     

The effectiveness of chlorine residuals in inactivation of bacteria and viruses introduced by post-treatment contamination

The protection afforded the water consumer by the maintenance of a free or combined chlorine residual in water distribution systems was evaluated in a laboratory system provided with a simulated cross connection. Tap water, adjusted to the appropriate pH, temperature and chlorine residual, was challenged with varying levels of autoclaved sewage seeded with Shigella sonnei, Salmonella typhimurium, a coliform (IMVIC⁺⁺⁻⁻), poliovirus 1 and f2 bacterial virus. Comparative survivals of these microorganisms were evaluated over 2 h periods. As expected, microbial inactivation was increased by lower pH, higher temperature, higher initial chlorine concentration and lower sewage concentration. An initial free chlorine residual was more effective than an equivalent initial combined chlorine residual. Generally, S. sonnei, S. typhimurium and the coliform organism were inactivated at the same rate but poliovirus 1 was more resistant and f2 was the most resistant. At pH 8, with an initial free chlorine residual of 0.7 mg 1⁻¹, and added sewage levels of up to 1% by vol, 3 logs or greater bacterial inactivation was obtained within 60 min. Viral inactivation under these conditions was less than 2 logs.     

Viral association with suspended solids

Laboratory models and field sewage samples were used to study viral association with particulates in suspension. Poliovirus and coliphages T2, T7 and f2 were tested for their adsorption to and elution from both organic and inorganic suspended solids at a variety of pH values and in both the presence and absence of a divalent cation. The results indicate that no one of the viruses tested can be used to describe a general pattern of adsorption. T2 and f2 readily associated with the clays used in the presence of divalent cation, while T7 and poliovirus adsorbed equally well to both organic and inorganic particulates. All viruses varied in the degree to which they associated with naturally-occurring suspended solids in primary and final sewage effluents; maximal association occurred at the pH extremes of 4.0 and 10.0 for all systems. Regardless of the conditions used to effect adsorption, all viruses tested, with the exception of f2, were infective by plaque assay in their adsorbed form. These data suggest that no one coliphage system can acceptably model the behavior of poliovirus in laboratory or field conditions. Furthermore, the results reaffirm and broaden the findings that viruses associated with suspended particulates are infective. Therefore, any system used to monitor virus levels in the environment must adequately account not only for free virus, but also for those which are solids-associated.     

Viral pollution determination of superficial waters (river water and sea-water) from the urban area of Barcelona (Spain)

Various surface water systems in the metropolitan area of Barcelona (Spain), including two rivers and three beaches, were analysed for human viruses using glass powder as adsorbent to concentrate them. The method used allows concentration of large volumes (up to 2001), of water in a single step. Values obtained varied from 18.4 to values higher than 55 MPNCU 1⁻¹in the Besôs river and 0.44-44 MPNCU 1⁻¹in the Llobregat river. Viruses were isolated from approx. 70% of sea-water samples, the values ranging from 0 to 1.60 MPNCU 1⁻¹. Findings are discussed in terms of correlation between virus pollution and bacterial indicators of fecal contamination. Also, the suitability of glass powder adsorption to concentrate viruses in sea-water is discussed.     

Adsorption of mercury(II) by coal fly ash

Coal fly ash, an industrial solid waste, was found to have a good adsorption capacity for mercury(II). Adsorption of mercury(II) on coal fly ash conforms to Freundlich's adsorption model. Several parameters such as time of equilibration, effect of pH, effect of initial concentration of solute, effect of fly ash dose etc. were studied. The maximum adsorption was observed after shaking for 3 h. Solution pH was the most important parameter affecting the adsorption. The optimum pH range was 3.5–4.5. There was total adsorption of mercury below 10 mg l⁻¹. The performance of coal fly ash as an adsorbent was found to be significant when compared with activated powdered charcoal.     

The effect of polysaccharidic gums on activated carbon treatment of textile wastewater

The activated carbon treatment of wastewater originating from the Celanese Canada Ltd., Carpet plant at Sorel, Quebec, was tested in this study. Typical plant effluent was characterized and prepared. Soluble organics in the synthetic effluent varied between 75–185 mg TOC 1⁻¹, consisting of dyes (10%) process chemicals (75%) and the soluble guar gum (15%) used as a viscosity adjusting additive in the newly installed continuous dyeing process.The activated carbon adsorption of the guar gum from its pure solution was examined in laboratory tests. Improved adsorption was observed at low pH values and at elevated adsorption temperatures. Lignite-based carbon out-performed bituminous coal-based carbon. At 30 mg TOC 1⁻¹ of soluble guar gum, low carbon loading in the range of 3–8 mg TOC g^–1 was recorded for various types of carbon at 20°C and neutral pH.Activated carbon adsorption of the typical conventional prepared dyehouse wastewater resulted in non-adsorbable residues in the range of 9–18 mg TOC 1⁻¹. Presence of 50–100 mg of polysaccharidic guar gum per liter of conventional wastewater mixture had a pronounced positive effect on the adsorption process. This is reflected in an increase in both the carbon loading at initial concentration and the adsorption isotherm slope.     

Use of talc-celite layers in the concentration of enteroviruses from large volumes of potable waters

The talc-Celite technique has now been adapted for the recovery of enteroviruses from potable waters. Layers containing a 3:1 mixture of talc and Celite 503 were sandwiched between two sheets of Whatman 114 filter paper with an AP 25 (Millipore) prefilter disc on top. For the processing of 1-1 volumes, layers (300 mg talc and 100 mg Celite) were held in a 47 mm diameter filter holder. Layers containing 1.2 g talc and 0.4 g Celite were prepared in 142 mm diameter metallic (Sartorius) holders for experiments with larger (10 to 1000 l) sample volumes. Before experimental contamination and passage through the layer, conditioning of dechlorinated water was carried out by adjusting its pH to 6.0 and the addition of Earle's balanced salt solution (EBSS) to a final concentration of 1:100. For 1-1 volumes, layer-adsorbed virus was elutedin situ with 10–20 ml of 10% fetal calf serum in normal saline (pH 9.0). Because 100 ml amounts of the same eluent were required when working with the larger layers, a 10-fold reduction in the volume of the eluate was achieved by placing it in a dialysis sac and subjecting it to overnight (4°C) hydroextraction with polyethylene glycol 6000.When working with poliovirus (type 1, Sabin)-contaminated sample volumes of 1- to 20-1, between 83–95% of the input virus could be recovered with this technique. In experiments with 100 to 1000 litre amounts, containing as little as 1.2 plaque forming units (PFU) of poliovirus 1⁻¹, between 58–64% of the added virus could be recovered with a sample concentration of up to 100,000-fold. In 1- to 20-1 volume experiments with echovirus 6 and coxsackieviruses A9 and B5, 81–92% of the input PFU could be recovered.     

Disinfection of viruses in sewage by ozone

The action of ozone on poliovirus was examined employing two different methods. In the first, the filtered sewage together with a virus inoculum was added to a buffer solution which contained known concentrations of ozone. The most outstanding finding was the complete disappearance of the ozone immediately after the addition of the effluent. At the same time, there was a rapid reduction in virus titer. However, after the initial reduction, the virus titer remained unchanged. The degree of virus inactivation was dependent on ozone concentration and on the amount of organic matter in the effluent. With increased ozone concentration and decreased organic matter, a larger percentage of viruses were inactivated. With the second method, ozone was bubbled into filtered sewage containing a virus inoculum. Inactivation of the virus started after a lag period of about 30 s. even before ozone residual in the sewage was detected. Inactivation of 99.999% of the virus was obtained when the ozone residual was about 0.6 mg l⁻¹. In similar experiments performed with buffer instead of sewage, the entire process took place at a much faster rate. When ozone concentrations reached about 1.0 mg l⁻¹. 99.999% of the virus was inactivated. In conclusion, ozone was found to be a very potent viral disinfectant, even in contaminated water.     

Enteric virus survival in algal-bacterial wastewater treatment systems—I : Laboratory studies

The survival of a representative enteric virus, poliovirus type 1, in laboratory models of algal-bacterial sewage treatment systems and the interactions of poliovirus with stabilization pond water was studied. In laboratory reactors a fraction of the total poliovirus present rapidly adsorbed to stabilization pond water solids by a reversible process, conforming to a Freundlich adsorption isotherm. In laboratory cultures the growth of Scenedesmus quadricauda and Bacillus megaterium in sterile sewage had no detrimental effect on poliovirus survival, whereas the growth of heterogeneous populations of stabilization pond bacteria in the same medium resulted in substantial virus inactivation. Appreciable poliovirus inactivation occurred in laboratory cultures of mixed algal-bacterial populations obtained from stabilization ponds. Because the degree of antiviral activity in these cultures was greater than that in cultures of stabilization pond bacteria alone, additional microbial factors must contribute to this virus inactivating phenomenon. The results of this study suggest that in algal-bacterial treatment systems both virus adsorption to solids and virus inactivation due to microbial activity play a role in reducing the enteric virus concentration in wastewater.     

Removal of poliovirus and rotavirus from tapwater by a quaternary ammonium resin

A quaternary ammonium-type anion exchange resin was tested as a contact water viral disinfectant. Suspensions of tapwater containing approx. 10⁴ plaque-forming units ml⁻¹ of poliovirus type 1 and Simian rotavirus SA-11 were passed through 1 ml beds of resin, at flow rates of 10–12 ml min⁻¹. With resin 14-1.91 − > 99.9% of the input virus was removed. The beds were effective in removal of virus even after passage of 1500 ml of tapwater. Less than 10% of the virus associated with resin 14-1 could be recovered as compared to 100% for control resin. Kinetic studies indicated that virus adsorbed to the resins were being inactivated.     

Comparison of electrocoagulation and chemical coagulation pretreatment for enhanced virus removal using microfiltration membranes

This research studied virus removal by iron electrocoagulation (EC) followed by microfiltration (MF) in water treatment using the MS2 bacteriophage as a tracer virus. In the absence of EC, MF alone achieved less than a 0.5-log removal of MS2 virus, but, as the iron-coagulant dosage increased, the log virus removal increased dramatically. More than 4-log virus removal, as required by the Surface Water Treatment Rule, was achieved with 6-9 mg/L Fe³⁺. The experimental data indicated that at lower iron dosages and pH (<∼8 mg Fe/L and pH 6.3 and 7.3) negatively charged MS2 viruses first adsorbed onto the positively charged iron hydroxide floc particles before being removed by MF. At higher iron dosages and pH (>∼9 mg Fe/L and pH 8.3), virus removal was attributed predominantly to enmeshment and subsequent removal by MF. Additionally, the experimental data showed no obvious influence of ionic strength in the natural water range of 10⁻⁷-10⁻² M on MS2 virus removal by EC-MF. Finally, EC pretreatment significantly outperformed chemical coagulation pretreatment for virus removal. The proposed mechanism for this improved performance by EC is that locally higher iron and virus concentrations and locally lower pH near the anode improved MS2 enmeshment by iron flocs as well as adsorption of MS2 viruses onto the iron floc particles.     

Adsorption des acides humiques sur charbon active en poudre. Influence du triphosphate de sodium

The use of activated carbon beds for the removal of natural humic and fulvic substances found in water supplies, has recently received considerable attention in water treatment operation (Lee et al., 1980; Le Cloirec et al., 1983). Moreover, the use of carbon adsorption for the reduction of haloform precursors (Anderson et al., 1981) and trihalomethanes produced by chlorination process, has contributed to a comprehensive investigation of adsorption characteristics of natural organic compounds (McCreary and Snoeyink, 1981). Many recent works showed the influence of adsorption system characteristics, such as pH, salt type, salt concentration and ionic heterogeneity in multicomponent adsorption systems, on the removal efficiency of humic and fulvic substances by activated carbon (McCreary and Snoeyink, 1980; Randtke and Jepsen, 1982; Weber et al., 1983). The purpose of this study is to examine the effect of a main component of domestic detergents, sodium triphosphate (STP), on the adsorptive capacities of powdered activated carbon (PAC) for commercially supplied humic acids, at different pH values in distilled water. Also, the effect of STP concentration and pH on the adsorption affinity of the PAC for humic acids, is discussed in relation with electrokinetic properties of carbon particles (zeta potential measurements).A first batch equilibrium study (Figs 1 and 2), showed an effective enhancement of adsorption capacity for humic acids as a function of STP concentration, in a non buffered media (pH of distilled water, close to 5.0). For example, visible absorption analysis of humic acids indicates an increase of 93% (500 mg l⁻¹ PAC) and 133% (1000 mg l⁻¹ PAC) in the carbon adsorption efficiency for a STP concentration from 0.2 to 1.0mM. A second batch equilibrium study (Figs 3 and 4) led to adsorption isotherms for humic acids in distilled water, as a function of STP concentration and initial pH value of the non buffered multicomponent system. Freundlich isotherms showed an increase in the adsorption capacity of the PAC for humic acids, with a decrease in pH and an increase in STP concentration. However, the adsorption capacity for humic acids is quite reduced at high pH values in presence of STP, in comparison with results obtained with distilled water.Electrokinetic measurements on PAC suspensions (Fig. 5) indicates that both humic acids and STP induce a negative variation of the zeta potential of carbon particles. In such a binary system, the zeta potential is a linear function of the pH; the negative surface charge of the carbon increasing with an elevation of pH (Fig. 6). Therefore, it appears that some adsorption of triphosphate polyanion from solution could occur, contributing then to the apparent negative surface charge of PAC particles.It has been previously showed that the type of anion in sodium salts, had little effect on the enhancement of adsorptive capacities of activated carbon for humic substances (Lafrance and Mazet, 1985), due to Na⁺ ions. However, adsorption of TP anions on the carbon surface may produce a source of repulsive charges, unfavourable to the co-adsorption of humic acids as the pH of the binary system reach more basic conditions. The influence of possible electrostatic interactions between adsorbates at the carbon surface, on the adsorption efficiency for humic acids, could then be studied by zeta potential measurements of PAC particles during the adsorption process.     

Batch metal removal by peat. Kinetics and thermodynamics

Peat moss, a natural inexpensive material, is able to play an important rôle in treatment processes of metal-bearing industrial effluents since it adsorbs, complexes or exchanges various metal cations. This paper presents kinetics and thermodynamics of batch metal removal reactions by 50 g l⁻¹ (dry wt) eutrophic or oligotrophic peat particles using Cu²⁺, Cd²⁺, Zn²⁺ and Ni²⁺ concentrations ranging from 0.01 to 100 mM.Metal cation removal reactions are moderately rapid in 10 mM metal unbuffered solutions: the forward kinetic constant ranges between 0.005 and 0.17 M⁻¹s⁻¹, and equilibrium is reached within about 1 h. Under these conditions of pH (2.2–4.2) and concentrations, apparent binding equilibrium constants were found to range between 2 and 3150 M⁻¹ depending upon the peat origin and the metal cation.In 0–6.5 pH-buffered metal cation solutions, the four cations binding reactions behaved differently demonstrating that metal binding equilibrium constant decrease in the order Ni²⁺ > Cu²⁺ > Cd²⁺ = Zn²⁺. When pH is higher than 6.7, more than 90% of a 10 mM metal cation solution is removed by 50 g 1⁻¹ peat particles and metal binding capacities equal 200 mmol kg⁻¹ dry wt, whatever the metal nature and the peat origin. Except for nickel cation which is very strongly bound to peat, all metal cations are completely released when pH is fixed below 1.5.     

A new and simple method for recuperation of enteroviruses from water

A new and simple method for recuperation of enteroviruses from water is described here. The sample to be analyzed, with a volume arbitrarily fixed to 101, is adjusted to pH = 3.5 with hydrochloric acid. It is then injected under low pressure (0.15 bar) by the lower end of a column containing glass powder (50 g). The calibration of the water's upward speed enables the glass powder to remain in dynamic suspension. Under these conditions, poliovirus is quantitatively adsorbed on the glass powder. The virus is then eluted from the glass powder with 50 ml of a glycine buffer (pH = 11.5) and thus concentrated 200 times in the final eluate. The total duration of operation does not exceed 2 h 30 mn. The recuperation efficiency is about 40–60% and does not depend on initial virus concentration in sample, and this, for virus concentrations ranging from 1 to 10⁴PFU/1.     

Phosphate adsorption onto hydrous manganese(IV) oxide in the presence of divalent cations

Alkaline earth cations, Ba²⁺, Sr²⁺, Ca²⁺, Mg²⁺ and transition metal ions, Mn²⁺, Co²⁺, Ni²⁺, cause hydrous manganese(IV) oxide (HMO) to strongly adsorb phosphate between pH 6 and 9 depending on the cation. The effectiveness of the alkaline earth cations to cause P adsorption was Ba²⁺ > Sr²⁺ > Ca²⁺ > Mg²⁺, which is the same order as their affinities for the oxide. Changes with time were found in the abilities of the transition metals to cause P adsorption onto HMO and this may be due to conversion of the adsorbed cation to its oxide. A new potential role for HMO as an adsorbent of phosphate in natural waters was indicated.     

Occurrence of rotaviruses and enteroviruses in recreational waters of Oak Creek, Arizona

Recent epidemiological studies have shown a relationship between swimming in recreational waters meeting bacteriological standards and gastroenteritis with a suggested viral etiology. No previous studies have been conducted in the United States on the occurrence of human pathogenic enteric viruses in freshwater recreational areas. The presence of enteroviruses and rotaviruses was investigated in Oak Creek, Arizona, a heavily used recreational area. Water samples were filtered through positively charged filters (168–1555 I.), eluted with beef extract, and assayed for human enteroviruses and rotaviruses. Eighteen of the 41 recreational water samples were positive for enterovirus or rotavirus. Of these, nine samples exceeded the Arizona State recommended limit of 1 PFU 40 l⁻¹ for full body contact in effluent dominated recreational waters. Several virus positive samples met the recommended fecal coliform standards (200 CFU 100 ml⁻¹) for recreational waters indicating the inadequacy of bacterial standards for monitoring viral water quality. The isolation of the pathogenic enteric viruses (i.e., poliovirus 1, echovirus 1, coxsackievirus B1 and B6 and rotavirus) from this popular recreational water demonstrates the potential for transmission of viral disease.     

The loss of poliovirus 1 infectivity in marine waters

The loss of infectivity (LOI) of poliovirus 1 in marine water from the Gulf of Mexico was studied. Typically, three logs of infectivity were lost in 5–6 days at 24°C. Experiments described in this report suggested that this LOI was not a result of container adsorption or virion aggregation: nor was a resistant component within the stock virus found that would have explained the two-component curves often observed with the virus loss. Viral infectivity loss occurred in raw, filter-sterilized, and autoclaved marine water. Loss was also observed when the virus was suspended in artificial seawater of 1, 10 and 20 g kg⁻¹ salinity. No explanation for the LOI other than true inactivation of the virion was found. The specific component(s) of marine water responsible for virion inactivation remains to be ascertained.