Removal of enteric viruses from surface water at eight waterworks in The Netherlands.

Eight waterworks in The Netherlands, which use surface water as their raw water source, were sampled repeatedly between November 1978 and June 1981. At five waterworks , 30 of 45 samples of raw water contained viruses. Of 55 samples of partially purified water, 11 were virus positive, including 8 after coagulation, sedimentation, and rapid sand filtration, 2 after storage, coagulation, sedimentation, transport chlorination, and rapid sand filtration, and 1 after storage in open reservoirs for 5 months. No viruses were detected in 100 samples of drinking water of 500 liters each from six waterworks . Most isolated viruses were typed, and a great variety of human enteroviruses were found, reflecting both pollution of raw water sources with sewage and vaccination with oral polio vaccine in neighboring countries.     

Selective removal of molybdenum traces from growth media of N2-fixing bacteria

A new method for the selective removal of traces of molybdenum from growth media of N2-fixing bacteria (Rhodobacter capsulatus and Klebsiella pneumoniae) was developed. This method is based on the filtration of nutrient solutions through a layer of activated carbon (pulverized charcoal). The adsorption of Mo (molybdate) to activated carbon was optimal if a charcoal suspension (50 g/liter) was degassed by boiling before use and if the pH of the solutions, which had to be purified, was adjusted to values between 1.5 and 4. In this pH region no or only negligible amounts of other metal ions were adsorbed. The activated carbon method was compared with other Mo-eliminating procedures, including 8-hydroxyquinoline/dichloromethane extraction, Chelex 100 chromatography, and treatment with Mo-starved Azotobacter vinelandii cells. The activated carbon filtration appeared to be the most effective, specific, and rapid method. Whereas the untreated Rhodobacter growth medium was contaminated with 1.2 ppb Mo, as analyzed by inductively coupled plasma mass spectrometry (ICP-MS), the activated carbon-treated medium was below the ICP-MS detection limit (less than 0.05 ppb). A similarly effective removal of Mo impurities was obtained by the Azotobacter treatment. Even at low optical densities (2-5 at 436 nm) Mo traces were removed very rapidly within 10-15 min. However, because the Mo uptake/Mo adsorption capacity of A. vinelandii depended on freshly cultivated cells and on the growth phase at which the cells were harvested, this microbiological method was generally more time-consuming and less reproducible than the activated carbon method.(ABSTRACT TRUNCATED AT 250 WORDS)     

Rapid detection of bacterial endotoxins in drinking water and renovated wastewater.

A pilot study was conducted to determine the feasibility of using the Limulus endotoxin assay to detect endotoxins in potable waters and from reclaimed advanced waste treatment (AWT) plant effluents. Water samples were tested using both Limulus lysates prepared in our laboratory and a commercial product, Difco Pyrotest. The Limulus assay procedure was easily adapted to the testing of water samples for endotoxin. Measured endotoxin concentrations varied from 0.78 ng/ml to 1,250 ng/ml. Levels of endotoxin were not predictable based on whether the water was drinking water or AWT water, i.e., some AWT water samples had less endotoxin activity than some samples of drinking water, and some AWT waters had greater endotoxin activity than drinking water. Only three of the water samples tested were free of any detectable endotoxin. Breakpoint chlorination procedures seemed to reduce measurable endotoxin content, whereas passage through activated carbon columns was associated with greater final endotoxin concentrations in test waters.     

Simple Method for Repurification of Endotoxins for Biological Use

A method for obtaining highly purified endotoxin (lipopolysaccharide [LPS]) in a few hours by repurification of commercial or laboratory preparations was devised. It avoids the use of phenol, which is not suitable for phenol-soluble lipopolysaccharides nor for some industrial purposes. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and matrix-assisted laser desorption ionization mass spectrometry analysis confirmed the integrity of the purified LPSs. The purified products did not activate Toll-like receptor 2 (TLR2), nuclear oligomerization domain 1 (NOD1), or NOD2 but did activate TLR4. Applied to different lipopolysaccharides, the method also improved their mass spectra, thus facilitating their structural analysis.     

Influence of temperature and process technology on the occurrence of Aeromonas species and hygienic indicator organisms in drinking water production plants

The occurrence of Aeromonas spp. and hygienic indicator organisms in raw and treated waters of five drinking water production plants in Flanders (Belgium) was surveyed over a period of 17 months. Aeromonads were isolated on ampicillin-dextrin agar (ADA) and further identified by gas-liquid chromatographic analysis of their cellular fatty acid methyl ester (FAME) content. ADA medium was found to be highly specific for the enumeration of Aeromonas spp. In general, Aeromonas counts were very low in untreated groundwater but numbered 10⁴–10⁶ colony-forming units per liter in open storage reservoirs for surface water. Aeromonas spp. were seasonally distributed with maximal densities occurring during the summer. The ecology of Aeromonas in the different waters was studied in relation to the physical, chemical, and microbiological water characteristics. Strongly positive correlations were observed between Aeromonas densities and heterotrophic plate counts, whereas a clearly negative relationship was found with dissolved oxygen. On average, 99.7% of the aeromonads were removed by flocculation-decantation followed by breakpoint chlorination, whereas 98.9% were removed by slow sand filtration. Flocculation-decantation without breakpoint chlorination did not reduce the microbial numbers. At three of four drinking water production plants tested, rapid sand filtration decreased the number of aeromonads and hygienic indicator organisms. At one plant, however, the numbers of Aeromonas and hygienic indicator organisms were high in the sand filter effluents. Increased numbers of aeromonads were also counted in the effluent of the activated carbon filters. Hence, inactivation of Aeromonas spp. by the current process technology appears not sufficient to exclude postchlorination. The survival of aeromonads in certain filter systems may be due to the growth of these bacteria on biodegradable organic material, provided by the decomposition from bacteria, algae, or other sources. Correspondence to: W. Verstraete     

Simple method for repurification of endotoxins for biological use

A method for obtaining highly purified endotoxin (lipopolysaccharide [LPS]) in a few hours by repurification of commercial or laboratory preparations was devised. It avoids the use of phenol, which is not suitable for phenol-soluble lipopolysaccharides nor for some industrial purposes. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and matrix-assisted laser desorption ionization mass spectrometry analysis confirmed the integrity of the purified LPSs. The purified products did not activate Toll-like receptor 2 (TLR2), nuclear oligomerization domain 1 (NOD1), or NOD2 but did activate TLR4. Applied to different lipopolysaccharides, the method also improved their mass spectra, thus facilitating their structural analysis.     

Influence of water quality on enteric virus concentration by microporous filter methods.

Four enteric viruses, poliovirus type 1, echovirus type 1, reovirus type 3, and simian adenovirus SV-11, were concentrated from seeded 1.3-liter volumes of raw, finished, and granular activated carbon-treated waters by adsorption to 47-mm-diameter (17 cm2), electropositive ( Virosorb 1MDS ) filters at pH 7.5 or electronegative ( Filterite ) filters at pH 3.5 with and without 5 mM added MgCl2, followed by elution with 0.3% beef extract in 50 mM glycine at pH 9.5. Removal of particulates from raw and finished waters by 0.2-micron prefiltration before virus addition and pH adjustment had little effect on virus concentration efficiencies. Soluble organic compounds reduced virus adsorption efficiencies from both raw and finished waters compared with granular activated carbon-treated water, but the extent of interference varied with virus type and adsorption conditions. For electropositive 1MDS filters, organic interference was similar with all virus types. For Filterite filters, organic interference was evident with poliovirus and echovirus, but could be overcome by adding MgCl2. Reovirus and SV-11 were not adversely affected by organics during adsorption to Filterite filters. Elution of reovirus and adenovirus was inefficient compared with that of poliovirus and echovirus. None of the three adsorption schemes ( 1MDS at pH 7.5 and Filterite with and without 5 mM MgCl2 at pH 3.5) could be judged superior for all viruses and water types tested.     

Influence of water quality on enteric virus concentration by microporous filter methods

Four enteric viruses, poliovirus type 1, echovirus type 1, reovirus type 3, and simian adenovirus SV-11, were concentrated from seeded 1.3-liter volumes of raw, finished, and granular activated carbon-treated waters by adsorption to 47-mm-diameter (17 cm2), electropositive ( Virosorb 1MDS ) filters at pH 7.5 or electronegative ( Filterite ) filters at pH 3.5 with and without 5 mM added MgCl2, followed by elution with 0.3% beef extract in 50 mM glycine at pH 9.5. Removal of particulates from raw and finished waters by 0.2-micron prefiltration before virus addition and pH adjustment had little effect on virus concentration efficiencies. Soluble organic compounds reduced virus adsorption efficiencies from both raw and finished waters compared with granular activated carbon-treated water, but the extent of interference varied with virus type and adsorption conditions. For electropositive 1MDS filters, organic interference was similar with all virus types. For Filterite filters, organic interference was evident with poliovirus and echovirus, but could be overcome by adding MgCl2. Reovirus and SV-11 were not adversely affected by organics during adsorption to Filterite filters. Elution of reovirus and adenovirus was inefficient compared with that of poliovirus and echovirus. None of the three adsorption schemes ( 1MDS at pH 7.5 and Filterite with and without 5 mM MgCl2 at pH 3.5) could be judged superior for all viruses and water types tested.     

Potentiation of the virucidal effectiveness of free chlorine by substances in drinking water

At 5 degrees C, poliovirus 1 was inactivated by free chlorine (FC) at pH 9.0 more than 10 times as rapidly in drinking water as in purified water. Because ions that comprise many salts potentiate the virucidal effectiveness of FC, we believe that ions and possible other substances in the drinking water potentiated the virucidal effectiveness of FC. Since viruses may be much more sensitive to chlorination in drinking waters than laboratory tests in purified waters have heretofore led us to believe, it may be possible to reduce the amounts of FC applied to many water supplies for disinfection and thereby perhaps reduce the quantities of halomethanes and other toxic compounds produced in these supplies by the chlorination process.     

Potentiation of the virucidal effectiveness of free chlorine by substances in drinking water.

At 5 degrees C, poliovirus 1 was inactivated by free chlorine (FC) at pH 9.0 more than 10 times as rapidly in drinking water as in purified water. Because ions that comprise many salts potentiate the virucidal effectiveness of FC, we believe that ions and possible other substances in the drinking water potentiated the virucidal effectiveness of FC. Since viruses may be much more sensitive to chlorination in drinking waters than laboratory tests in purified waters have heretofore led us to believe, it may be possible to reduce the amounts of FC applied to many water supplies for disinfection and thereby perhaps reduce the quantities of halomethanes and other toxic compounds produced in these supplies by the chlorination process.     

Relation between substrate feeding pattern and development of filamentous bacteria in activated sludge processes: Part III. applications with industrial waste waters

Summary Laboratory scale activated sludge systems were operated under regimes of continuous or intermittent feeding of the waste water. Industrial waste waters from breweries, a dairy plant and a petro-chemical plant were investigated. The systems were started up with sludge from a municipal waste water plant or more often with sludges obtained from the corresponding industrial waste water treatment plants. It was found that intermittently fed systems produced sludges with better settleability characteristics than systems that were continuously supplemented with waste water. Our previous hypothesis that in intermittent systems floc forming bacteria become dominant as a result of higher substrate uptake rates was confirmed and may thus be extended to waste waters containing readily available substrates such as carbohydrates (brewery-and dairy waste water) or acids (petro-chemical waste water). Supplementation of brewery waste water with urea had a negative influence on sludge settleability, especially in continuously operated systems.     

A new colchicine binding assay for tubulin

A simple and sensitive procedure is described for assaying tubulin, the subunit protein of microtubules. Tubulin is equilibrated with [³H]colchicine after which the remaining free colchicine is removed by adsorption to activated charcoal. Values for the amount of tubulin in various rat tissues have been determined by both the charcoal method and by gel filtration on Sephadex G-100, and in all cases the values determined by the two methods correspond closely.     

Removal of chromium from industrial waste by using eucalyptus bark

Several low cost biomaterials such as baggase, charred rice husk, activated charcoal and eucalyptus bark (EB) were tested for removal of chromium. All the experiments were carried out in batch process with laboratory prepared samples and wastewater obtained from metal finishing section of auto ancillary unit. The adsorbent, which had highest chromium(VI) removal was EB. Influences of chromium concentration, pH, contact time on removal of chromium from effluent was investigated. The adsorption data were fitted well by Freundlich isotherm. The kinetic data were analyzed by using a first order Lagergren kinetic. The Gibbs free energy was obtained for each system and was found to be -1.879 kJ mol(-1) for Cr(VI) and -3.885 kJ mol(-1) for Cr(III) for removal from industrial effluent. The negative value of deltaG0 indicates the feasibility and spontaneous nature of adsorption. The maximum removal of Cr(VI) was observed at pH 2. Adsorption capacity was found to be 45 mg/g of adsorbent, at Cr(VI) concentration in the effluent being 250 mg/l. A waste water sample containing Cr(VI), Cr(III), Mg, and Ca obtained from industrial unit showed satisfactory removal of chromium. The results indicate that eucalyptus bark can be used for the removal of chromium.     

Bioindication of mutagenic and carcinogenic pollutants in waters of the O?awa River

Samples of raw waters from the O?awa River, chlorinated raw water, raw water filtered through activated charcoal and treated and chlorinated water before and after ozonization were examined with the use of the Ames test for potential carcinogenic activity. Positive results were obtained for raw water with Salmonella typhimurium strains TA 98 and TA 1535 and for chlorinated raw water with strain TA 1537.     

PURIFICATION AND PROPERTIES OF CHOLINE ACETYLTRANSFERASE FROM TORPEDO CALIFORNICA

Abstract— Choline acetyltransferase (ChAT), the enzyme responsible for the biosynthesis of acetylcholine in nervous tissue, has been purified to apparent homogeneity from the electric organ of the electric fish Torpedo californica using ion-exchange, gel filtration, and hydroxyapatite chromatography. The final preparation had been purified 8570-fold to a specific activity of 30μmol ACh formed/min/mg protein. The purified protein has a pH optimum of 6.8 (phosphate buffer), is activated by low concentrations (ca. 10 m m ) of ammonium or alkylammonium ions, and is strongly inhibited by a sulfhydryl blocking reagent (DTNB). ChAT has a mol. wt. of 63000 when measured by SDS-polyacrylamide gel electrophoresis or gel filtration.
A new method for the rapid assay of ChAT activity is described in which unreacted substrate ([³H]acetyl-CoA) is removed from reaction mixtures by adsorption to charcoal: some advantages of this technique are discussed.     

Genotoxic activity of organic chemicals in drinking water

The information summarized in this review provides substantial evidence for the widespread presence of genotoxins in drinking water. In many, if not most cases, the genotoxic activity can be directly attributed to the chlorination stage of drinking water treatment. The genotoxic activity appears to originate primarily from reactions of chlorine with humic substances in the source waters. Genotoxic activity in drinking water concentrates has been most frequently demonstrated using bacterial mutagenicity tests but results with mammalian cell assay systems are generally consistent with the findings from the bacterial assays. There is currently no evidence for genotoxic damage following in vivo exposures to animals. In some locations genotoxic contaminants of probable industrial and/or agricultural origin occur in the source waters and contribute substantially to the genotoxic activity of finished drinking waters. The method used for sample concentration can have an important bearing on study results. In particular, organic acids account for most of the mutagenicity of chlorinated drinking water, and their recovery from water requires a sample acidification step prior to extraction or XAD resin adsorption. Considerable work has been done to determine the identity of the compounds responsible for the mutagenicity of organic concentrates of drinking water. Recently, one class of acidic compounds, the chlorinated hydroxyfuranones, has been shown to be responsible for a major part of the mutagenic activity. Strategies for drinking water treatment that have been evaluated with respect to reduction of genotoxins in drinking water include granular activated carbon (GAC) filtration, chemical destruction, and the use of alternative means of treatment (i.e., ozone, chlorine dioxide, and monochloramine). GAC treatment has been found to be effective for removal of mutagens from drinking water even after the GAC is beyond its normal use for organic carbon removal. All disinfectant chemicals appear to have the capacity of forming mutagenic chemicals during water treatment. However, the levels of mutagenicity formed with the alternative disinfectants have been generally less than those seen with chlorine and, especially in the case of ozone, highly dependent on the source water.(ABSTRACT TRUNCATED AT 400 WORDS)     

Effects of manufacturing conditions on the adsorption capacity of heavy metal ions by Makino bamboo charcoal

The objective of this study was to investigate the effects of manufacturing conditions on the adsorption capacity of heavy metal ions by Makino bamboo charcoal. Results show that the specific surface area and iodine number of bamboo charcoal activated at 900 degrees C were larger than those of bamboo charcoal activated at 800 degrees C. The specific surface area of bamboo charcoal activated at 800 degrees C by carbon dioxide was larger than that of charcoal activated by steam. However, a contrary result was observed when the activation temperature was 900 degrees C. The total volume and proportion of micropores in bamboo charcoal activated by carbon dioxide were greater than those in the other sample groups. However, the total volume and bulk volume of meso- and macropores, and average pore diameter for bamboo charcoal activated by steam were greater than those in the other sample groups. Using 5g bamboo charcoal (10-30 mesh) with a soaking time of 24h, a better adsorption effect on Pb2+ (100%), Cu2+ (100%), and Cr3+ (88-98%) was found. However, medium frequencies were observed for the adsorption of Cd2+ (40-80%) and Ni2+ (20-60%). Very limited adsorption of As5+ was detected in this study. For the same charcoal grain sizes, the adsorption capacity of 0.5g of charcoal was better than that of 0.1g. The improved adsorption effect of the sample group activated by steam was compared with the sample group activated by carbon dioxide.     

THE EFFECT OF CHARCOAL ON THE GROWTH OF LEGUMINOUS PLANTS IN SAND CULTURE

The addition of small proportions (0.5-2.0 %) of activated charcoal to the rooting medium of inoculated peas in nitrogen-free sand culture resulted in marked increases in dry weight of the plants and in nitrogen fixation. Wood charcoal in larger proportions had a similar effect, while animal charcoal severely inhibited growth. The number of nodules was greatly reduced in the presence of activated charcoal, but such nodules as formed were much larger and the nodule tissues per unit weight were more active in nitrogen fixation. Activated charcoal also led to an increase in dry weight of non-inoculated peas supplied with inorganic combined nitrogen. It is tentatively suggested that these favourable effects arise from the adsorption by the charcoal of harmful excretions from roots or micro-organisms or of excess nutrients, and from the maintenance of a more favourable pH in the rooting medium. The examination of barley intersown with the peas, and the results of Kjeldahl analyses on the rooting media, provided no evidence that the enhanced fixation in the presence of activated charcoal was attended by any considerable excretion of fixed nitrogen.     

Occurrence of Cryptosporidium oocysts in sewage effluents and selected surface waters

An existing method for the detection of Cryptosporidium oocysts in water was modified to investigate oocyst prevalence in large volumes of water. Surface waters and sewage effluents were filtered, eluted from the filter, and concentrated using centrifugation. The resultant pellet was then homogenized, sonicated, and placed on a sucrose gradient to separate oocysts from the sediment. The uppermost gradient layer was then examined by immunofluorescence using a labeled monoclonal antibody. Using this technique, average numbers of oocysts detected in raw and treated sewage were 5.18 X 10(3) and 1.30 X 10(3)/L, respectively. Filtered sewage effluents had significantly lower numbers of oocysts (10.0/L). These data show that sand filtration may reduce the concentrations of this parasite in waste waters. Highly variable oocyst numbers were encountered in surface waters. Since Cryptosporidium oocysts are frequently present in environmental waters, they could be responsible for waterborne outbreaks of disease.     

Advective Mixing of Pore Waters and Ecology of Sandy Sediments of the Ocean Shelf

Sand sediments are widely distributed in the shelf zone of the World Ocean. The main physical and ecological peculiarity of marine sands is the mobility of pore waters and their mixing with the near-bottom waters of the sea. The mixing is closely related to turbulent processes in the water column; the most important of these processes is wave mixing. This causes filtration of seawater through the sand, ensuring therefore, perhaps, the most large-scale filtration process on the Earth. Advective mixing redistributes dissolved oxygen and nutrients between the pore waters of the sand and the bulk of the seawater column and determines redox conditions in the sediment column, which usually are either oxidative or suboxic; the metals with variable valence, mostly iron, serve as a redox buffer. The regeneration of nutrients and nitrification of ammonia also take place in the sand column. The instability of advective mixing is considered as the major difficulty for qualitative assessment of energetic metabolism and regeneration of nutrients in sands as well as for revealing the ecological role of marine sands in coastal ecosystems.