bluuebunny/crossref_metadata_2025 huggingface dataset:
The relationship between musty-odor-causing organisms and water quality in Lake Biwa
Authors: Kajino M. , Sakamoto K.
Published: May 2018

Musty odor has occurred annually in Lake Biwa since 1969. Osaka municipal waterworks, which is located downstream of Lake Biwa, has made many efforts to treat musty-odor compounds produced in Lake Biwa from spring through autumn. With the development of analytical methods for the determination of musty-odor compounds, we have been able to confirm that planktonic blue-green algae are the major causes of the musty-odor occurrences. The relationship between the growth of blue-green algae and the water quality was not so apparent. However, through our data analysis focusing on the relationship between musty-odor occurrences due to Phormidium tenue or Oscillatoria tenuis and some nutrients in Lake Biwa, we found that the concentration of nitrate in water may be an important parameter for the estimation of growth of the algae and the musty-odor behavior.
Chemical perception and behavioral response of freshwater fish to 2-methylisoborneol
Authors: Kawamura G. , Anraku K. , Hisatomi Y. , Matsuoka T. , Motohiro T.
Published: May 2018

The substance 2-methylisoborneol (MIB) often affects aquatic organisms and causes problem of off-flavours in fish. In order to know how fish become tainted with MIB, response and chemical sensitivity of three freshwater fishes to MIB were examined behaviorally and electrophysiologically. The electrocardiographic tests showed that the threshold of detection for this compound was 4.8 × 10−5 ngl−1 for the Nile tilapia and 2.1 × 10−5 ngl−1 for the rainbow trout. Fish whose olfactory rosettes were removed also showed the cardiac response to MIB, but the threshold increased by 3 and 5 orders of magnitude in the Nile tilapia and rainbow trout respectively. The recordings of neural response of the olfactory tract of the carp to MIB solutions showed the olfactory threshold at a concentration of 4 × 10−8 ngl−1. In behavioral tests in tanks, MIB solutions did not attract these fishes and evoked no avoidance in these fishes. It was concluded that, while freshwater fishes are extremely sensitive to MIB, they would not escape from waters contaminated with MIB and thus easily be tainted with MIB.
Biology of Oscillatoria cf. chalybea, a 2-methylisoborneol producing blue-green alga of Mississippi catfish ponds
Authors: van der Ploeg M. , Dennis M. E. , de Regt M. Q.
Published: May 2018

Relative abundance of Oscillatoria cf. chalybea was monitored during May-November, 1993, in 40 ponds at four catfish farms located 50-100 km apart in west central Mississippi, USA. The occurrence of O. cf.chalybea coincided with the period that water temperatures remained above 20°C. In 70% of ponds, O. cf.chalybea was present for a period of 2-20 weeks. The alga recurred in all ponds where it had been present in 1990 and 1991. The effects of temperature and light availability on growth rate and 2-methylisoborneol (MIB) production of O. cf. chalybea were studied in continuous cultures. At 28°C, maximum specific growth rates were 0.8 d−1 (24 h light) and 0.6 d−1 (14 h light :10 h dark). Algal cells contained less MIB when adapted to the shorter light cycle than when grown under continuous light. Specific growth rate of O. cf.chalybea dropped from 0.3 to 0.1 d−1 when temperature was changed from 21 to 19.5°C (14 h light).
The identification of odorous metabolites produced from algal monocultures
Authors: Cotsaris E. , Bruchet A. , Mallevialle J. , Bursill D. B.
Published: May 2018

Four algal species commonly found in the River Seine were cultured for a comprehensive investigation of their odorous metabolites. Closed loop stripping analysis (CLSA), open stripping analysis (OSA) and steam distillation extraction (SDE) were used to extract and concentrate a wide range of metabolites. The odour causing compounds were identified by a combination of chemical (gas chromatography-mass spectrometry (GC-MS)) and sensory (sensory-gas chromatography (sensory-GC), flavour profile analysis (FPA)) analyses. The compounds found responsible for unpleasant odours were alkenes, saturated and unsaturated aliphatic alcohols, aldehydes, ketones, sulphides and pyrazines. Some of the odorous compounds responsible for septic and muddy/musty odours may have been of bacterial or fungal origin as the cultures were non-axenic. Sensory-GC was found to be a valuable tool in identifying compounds of very low odour thresholds, which were present at or below the detection limits of the GC-MS.
Characterization and pollution profile of leather tanning industry in Turkey
Authors: Tünay Olcay , Kabdasli Isik , Orhon Derin , Ates Esra
Published: May 2018

Leather tanning industry as a significant polluting source is exposed to stringent effluent limitations. On the other hand, leather processing has a very complex structure in terms of both production and waste streams. A systematic subcategorization approach is required to assess the pollution characteristics and control measures. In this study, a procedure is defined for the development of subcategories for the industry. Results of a detailed review on the amount and the quality of wastewaters originating from the industry are given and six different subcategories are defined to reflect the structure of the leather processing industry in Turkey. Solid and hazardous waste profiles are also given.
Heavy metal availability to plants in soils irrigated with wastewater from Mexico City
Authors: Siebe Christina
Published: May 2018

The relationship between three different heavy metal fractions in soils irrigated for long periods of time with untreated wastewater from Mexico City and the metal uptake by alfalfa (Medicago sativa) was studied in order to evaluate actual accumulation levels in soils, as well as to establish which extracting solution characterizes most precisely the availability of selected heavy metals to plants. Cd, Pb, Cu and Zn were analyzed in aqua regia, 1 M NH4NO3 and water extracts from 50 soil samples and correlated with total contents in alfalfa tissue collected at the same sites. Heavy metal contents of the 3 fractions increase significantly with irrigation time, but European tolerance limits are slightly exceeded only for Cd at some sites. Plant uptake of Cd and Pb also increases the longer the soils have been irrigated and correlates best with aqua regia extracts from soils.
Computational fluid dynamic modelling of wastewater ponds to improve design
Authors: Wood M. G. , Greenfield P. F. , Howes T. , Johns M. R. , Keller J.
Published: May 2018

Wastewater ponds are a popular treatment alternative in Australia, especially in the meat industry. However, increasingly stringent Australian environmental legislation is raising questions about the continued viability of ponds. Traditional design methods do not address the hydrodynamic problems (i.e. short-circuiting) nor can they predict the effects of measures like baffles or repositioning inlets or outlets to improve performance. This is because the microscale interactions between the fluid and solids, and the biological reactions are ignored. This paper presents a tool -- computational fluid dynamic (CFD) modelling and explores its potential as a new design tool for wastewater ponds. FIDAP, a finite element CFD program, is one of the new generation of commercial CFD packages available. This program has been used to qualitatively investigate the hydrodynamics of four pond systems. These models are limited to 2-dimensional (D), steady-state simulations in a laminar flow regime. They form the first step in the process to address the microscale fluid flow, mixing and biology in wastewater ponds. Considerably more modelling and validation work is yet to be done.
Microbiological performance and salmonella dynamics in a wastewater depuration pond system of southeastern spain
Authors: Emparanza-Knörr Ana , Torrella Francisco
Published: May 2018

The Salmonella presence and the microbiological quality indicators, total and fecal coliforms and coliphages of E. coli C, have been studied in a overloaded wastewater lagoon system treating urban wastewatrers of the village of Guardamar del Segura (Alicante, Spain). Classical microbiological technology to detect salmonellae was used, including pre-enrichment, enrichment, selective media plating and biochemical and serological confirmation. Water was physicochemically characterized according to COD, SS, temperature, pH and dissolved oxygen. The selective migration step through Rappaport-Vassiliadis semisolid agar medium was essential for the consistent detection of Salmonella in the different lagoon effluents. Total and fecal coliform levels of up to 105-106 MPN/100 ml were detected in the final effluent. High coliphage concentrations of 103-104 pfu/ml were also found in the effluent waters. Salmonella was always detected in 100 ml samples and eventually reached an order of value of 103 MPN/100 ml. Total coliform reduction was higher in the anaerobic ponds whereas fecal coliforms were more efficiently eliminated in the facultative (mostly “anoxic”) lagoons. Coliphage reduction was higher in the facultative lagoons when compared to the anaerobic ponds. On many occasions, no reduction or eventual increment of the concentration of salmonellae was detected in the effluents from the anaerobic ponds compared to concentrations of the patohogen in the influent raw wasterwaters. The possibility exists for a capacity of Salmonella to multiply in the anoxic phase of the wastewater treatment, but the presence of microorganisms in raw sewage waters which could maskSalmonella detection with the enrichment methodology employed cannot be ruled out.
Evaluation of a tropical single-cell waste stabilization pond system for irrigation
Authors: Ceballos B. S. O. , Konig A. , Lomans B. , Athayde A. B. , Pearson H. W.
Published: May 2018

A single full-scale primary facultative pond in Sapé, north-east Brazil was monitored for performance and efficiency. The pond had a hydraulic retention time of 61 days and achieved a 95% BOD5 removal efficiency and had no helminth eggs in the effluent. The effluent failed to meet the WHO faecal coliform guideline for unrestricted irrigation. The pond was dominated by the cyanobacterium Microcystis and gave better than predicted orthophosphate removal. Details of how the system could be simply upgraded utilizing the same land are discussed.
Removal of pathogenic organisms from the effluent of an upflow anaerobic digester using waste stabilization ponds
Authors: Dixo N. G. H. , Gambrill M. P. , Catunda P. F. C. , van Haandel A. C.
Published: May 2018

A series of four pilot-scale, shallow waste stabilization ponds (WSPs), comprising one facultative followed by three maturation ponds with a total design retention time of 20 days, was monitored to observe its ability to remove pathogenic organisms from the effluent of an upflow anaerobic sludge blanket (UASB) digester. The UASB reactor received strong domestic wastewater from the shanty district of a city in north-east Brazil. The raw wastewater had a very high concentration of intestinal nematode eggs of which, on average, 89.6 percent were removed in the UASB reactor. No intestinal nematode eggs were recovered in the effluent of the first maturation pond, making it suitable for restricted irrigation. The removal of eggs in the first pond exceeded predictions made using a recently published model. Faecal coliforms (FC) were reduced by 4.7 log units on average in the pond series -- the final effluent being suitable for unrestricted irrigation. pHs exceeding 10 were attained in the final maturation pond at the sunniest time of day. There was a significant correlation between levels of pH and FC in the ponds, the latter being ≤ 1000 per 100 ml when the former was ≥ 9.1. The removal of FC in the ponds was linear over the range of pH encountered. The findings are consistent with recent work by others suggesting that FC removal in ponds is multi-factorial. The UASB reactor, with a retention time of 7 h, is an efficient primary treatment alternative to an anaerobic pond in a WSP series receiving an extremely strong domestic wastewater. There are potential advantages of using the former in preference to the latter in a series of ponds.
Upgrading pond effluents: an overview
Authors: Middlebrooks E. J.
Published: May 2018

A synopsis of the performance data and design concepts for methods used to upgrade wastewater stabilization pond effluents is presented. The following methods are discussed: intermittent sand filters, rock filters, microstrainers, constructed wetland systems, water hyacinths and duckweed, land application, hydrograph controlled release technique, and others. Cost information is given for the most commonly used methods.
The bacterial quality of salad crops drip and furrow irrigated with waste stabilization pond effluent: an evaluation of the who guidelines
Authors: Bastos R. K. X. , Mara D. D.
Published: May 2018

Field- and glasshouse-grown lettuces and radishes were drip- and furrow-irrigated with waste stabilization pond effluent and with trickling filter effluent diluted with clean water. Crop contamination levels varied considerably. Under dry weather conditions they were at worst of the orders of 103 and 104E. coli per 100 g (fresh weight) for radishes and lettuces, respectively; salmonellae were always absent. The bacterial quality of experimental lettuces was similar to those of lettuces on sale in local markets. When rainfall occurred E. coli numbers increased and salmonellae were isolated from lettuce surfaces. These results are interpreted as partially, substantiating the current World Health Organization bacteriological guideline for unrestricted wastewater reuse, but suggest the need for further assessment on the variation in crop contamination caused by climatic conditions.
An attempt to understand dissolved air flotation using multivariate data analysis
Authors: Krofta Milos , Herath Banda , Burgess David , Lampman Larry
Published: May 2018

In order to optimize the dissolved air flotation (DAF) process, a mathematical relationship should be established between the operating variables and the quality of the effluent water. In this study, operating parameters, including influent wastewater characteristics, were related to suspended solid (SS), COD, BOD5 and turbidity of the effluent via an empirical mathematical model.

The data presented in this study were obtained from a pilot plant DAF study carried out on municipal wastewater at Lee, Massachusetts to determine the operating conditions for the wastewater clarification. Response surface methodology was used to determine optimal conditions and to study the variations of flotation behaviour with varying operating conditions.

The multivariate technique used in this study is an extremely valuable tool to analyze data obtained from actual wastewater treatment processes where the characteristics of the wastewater are constantly changing. Without such a tool it may not be possible to draw valid conclusions. In addition, this technique requires comparatively fewer experiments when compared to traditional methods.

Addition of more flocculant and recycle water over what is required actually decreases the effluent water quality. Tests carried out with the same DAF unit at Little Rock, Arkansas and Birmingham, Alabama have confirmed the accuracy of the predictions from the model.
Urban wastewater treatment by electrocoagulation and flotation
Authors: Pouet M.-F. , Grasmick A.
Published: May 2018

In waste water treatment, the use of a physico-chemical process by flotation would present some advantages compared to a separation by settling. However like each physico-chemical process, a separation by flotation needs a chemical destabilization. We have studied the use of an electrochemical destabilization coupled to a process of flotation (DAF). This paper presents the results obtained on an urban waste water treated by electrocoagulation and dissolved air flotation (DAF). To show the interest of coupling flotation and electrocoagulation, we have studied each process separately. Then we have combined the two processes. The role of each operation on pollution removal is presented. An effect of synergism between the two processes on the pollution abatement is shown. A reduction of 75% of the global COD is obtained. The results of the coupling are compared to the performance of an intensive treatment by flocculation-lamellar settler.
The relationship between health effects in triathletes and microbiological quality of freshwater
Authors: Medema G. J. , van Asperen I. A. , Klokman-Houweling J. M. , Nooitgedagt A. , van de Laar M. J. W. , Havelaar A. H.
Published: May 2018

This pilot study was carried out to determine the relationship between microbiological water quality parameters and the occurrence of health complaints among triathletes. Data were collected at an Olympic distance triathlon (n=314) and a run-bike-run (n=81; controls for exposure to fresh water). At the time of the triathlon, the concentrations of Escherichia coli , thermotolerant coliforms, faecal streptococci, entero- and reoviruses, F-specific RNA phages, Salmonella, Campylobacter, Aeromonas, Plesiomonas shigelloides, Pseudomonas aeruginosa and Staphylococcus aureus were examined over the swimming course. Information on the occurrence of health complaints during the competition and in the week thereafter was collected through a written questionnaire.

The results show that triathletes and run-bike-runners are comparable with respect to factors other than water exposure (age, sex, training history, physical stress, lower intestinal health complaints during the competition) that may influence the occurrence of health complaints in the week after the competition.

Triathletes and run-bike-runners reported gastro-intestinal (7.7% vs 2.5%), respiratory (5.5% vs 3.7%), skin/mucosal (2.6% vs 1.2%), general (3.5% vs 1.2%) and total symptoms (14.8% vs 7.4%) in the week after the event. The health risks for triathletes for all symptom groups are not significantly higher than for run-bike-runners. The geometric mean concentration of faecal indicator bacteria is relatively low: E. coli 170/100 ml; faecal streptococci 13/100 ml, enteroviruses were present at concentrations of 0.1/l. The group of triathletes was homogeneusly and relatively intensely exposed to water; they all swam in the same body of water at the same time and 75% reported to have swallowed freshwater.

It was concluded that this study design is suitable to study the relationship between health complaints and microbiological water quality. In the summers of 1993 and 1994, a study will be carried out concerning several run-bike-runs and triathlons in freshwaters of different quality.
Causes of waterborne outbreaks in community water systems in Finland: 1980-1992
Authors: Lahti K. , Hiisvirta L.
Published: May 2018

Finland is known as a country with thousands of unpolluted lakes and pristine groundwaters. For this reason treatment processes applied in the drinking-water industry are quite simple. These kinds of water supplies, as well as private wells, are vulnerable for accidental pollution, leading to twenty-four reported waterborne epidemics outbreaks in Finland in 1980-1992. About 40 per cent of these outbreaks were due to contaminated water from community drinking-water supplies. The number of people affected in these outbreaks was around 7 700. Contaminated groundwater was a more common cause than surface water. The majority of Finnish groundwater supplies distribute water without any treatment or only with alkalization. In most outbreaks leakage and blockage of a sewage pipe in the vicinity of a groundwater well resulted in the contamination of drinking-water. The largest of these outbreaks affected some 5 000 people. The etiologic agents in these epidemics were most probably viruses; faecal indicator bacteria and enteric viruses were detected in water samples during the epidemics. Contamination of water distribution networks due to cross-connection caused two restricted epidemics. Inadequate disinfection of surface water was the reason for three outbreaks. Two of these were caused by the same water supply in subsequent years. The raw water source for this supply was of quite a high quality, for which reason the treatment consisted only of rapid sand filtration and chlorination. For fear of the chlorinated organic compounds formed during disinfection the amount of chlorine in water treatment was reduced to a level where disinfection was inadequate, and some hundred people became ill. The etiologic agent in these outbreaks remained unknown.
Microbiological quality of residues from drinking water preparation
Authors: Würzer M. , Wiedenmann A. , Botzenhart K.
Published: May 2018

In Germany the application of procedures such as flocculation and filtration in the preparation of drinking water results in the annual production of an estimated 500,000 t of sediments and sludges. Some of these residues have a potential for being reused, for example in agriculture, forestry, brickworks or waste water treatment. To assess the microbiological quality of residues from waterworks methods for the detection of enterobacteria, Escherichia coli, Salmonella, Pseudomonas aeruginosa, Legionella, poliovirus, Ascaris suis eggs and Cryptosporidium have been evaluated regarding their detection limits and were applied to various residues from German waterworks. Results show that sediments and sludges may contain pathogenic bacteria, viruses and protista. When residues from waterworks are intended to be reused in agriculture or forestry the microbiological quality should therefore be considered.
Designing a research programme to promote river basin management
Authors: Breen C. M. , Biggs H. , Dent M. C. , Görgens A. , O'Keeffe J. , Rogers K. H.
Published: May 2018

Growing perceptions that ecological research is failing to meet the needs of resource managers has prompted a review of the structure and management of research programmes.

In this paper we identify principles, frameworks and approaches to guide the restructuring of research programmes. Their application is discussed in relation to the restructured research programme on the rivers flowing through the Kruger National Park. A preliminary evaluation after one year of operation of this programme indicated beneficial changes in research and in stakeholder and client attitudes to research.
Efficacy of a combined system of copper and silver and free chlorine for inactivation of Naegleria fowleri amoebas in water
Authors: Cassells J. M. , Yahya M. T. , Gerba C. P. , Rose J. B.
Published: May 2018

Electrolytically generated copper and silver ions (400:40 and 800:80 μg/l) were evaluated, separately and combined with 1.0 mg/l free chlorine, for their efficacy in reducing the viable numbers of Naegleria fowleri amoebas in water (pH 7.3 and 23-25°C). Inactivation rates (k = log10 reduction/min) and T99 values (exposure time required to achieve a 99% or a 2 log10 reduction) of the disinfectants were determined. Copper and silver alone, at ratio of 400:40 to 800:80 μg/l caused no significant inactivation of N. fowleri even after 72 hours of exposure (k = 0.00017 and 0.00013, respectively). Addition of 1.0 mg/l free chlorine to water which contained 400:40 or 800:80 μg/l copper and silver resulted in enhanced inactivation rates (k = 0.458 and 0.515, respectively) compared to either chlorine alone (k = 0.33) or the metals alone. Water containing 800:80 μg/l copper and silver with 1.0 mg/l chlorine showed a T99 value of 3.9 minutes, while chlorine alone showed a T99 of 6.1 minutes. Enhanced inactivation of N. fowleri by a combined system of free chlorine and copper and silver may be attributed to the different mechanism that each disinfectant utilizes in inactivating the amoebas, and may suggest a synergistic effect.
Comparative survival of hepatitis A virus, poliovirus and indicator viruses in geographically diverse seawaters
Authors: Callahan Kathleen M. , Taylor Douglas J. , Sobsey Mark D.
Published: May 2018

The presence and persistence of enteric viruses in sewage contaminated seawater is an important public health concern for bathing, surfing and shellfishing. In an effort to find suitable indicators of enteric viruses in seawater, we compared the survival of two groups of enteric bacteriophages, F-specific coliphages (FRNA phages) and somatic Salmonella bacteriophages (SS phages), to the survival of two human enteric viruses, hepatitis A virus (HAV) and poliovirus type 1 (PV-1), in coastal seawater from three geographic areas (So. California, Hawaii, and North Carolina) at 20°C. Concentrations of all four viruses decreased over 30 days from their initial titers and there was little difference in the survival of a particular virus among the three seawaters. However, the extent of reduction varied among the four viruses. Survival was greater for the SS phages than for any of the other viruses, with an estimated 4 log10 reduction time of about 10 weeks. FRNA phages and PV-1 were inactivated rapidly, with 4 log10 reductions in ~ 1 week. HAV reductions were intermediate between SS phages and FRNA phages, with 4 log10 reductions in about 4 weeks. The observed differences in virus survival suggest that SS phages are more persistent in seawater than other viruses and hence may be good indicators for enteric viruses in seawater.
Comparative reductions of hepatitis A virus, enteroviruses and coliphage MS2 in miniature soil columns
Authors: Sobsey Mark D. , Hall Richard M. , Hazard Ruth L.
Published: May 2018

The reduction of viruses in wastewater and other contaminated waters in the subsurface or soil environment is an important public health consideration for land disposal of wastes and the use of ground sources as water supplies. Because of the lack of information on the comparative reductions of different viruses in soils receiving wastes, we determined the reductions of hepatitis A virus (HAV), poliovirus 1, echovirus 1 and the indicator virus MS2 in 10-cm deep, miniature soil columns dosed twice weekly with 2.5 cm of water or wastewater and incubated at 5 or 25°C for 16 weeks. The soils studied were coarse sand, loamy sand, clay loam and organic muck. By examination of column effluents, few or no viruses were detected in clay loam column effluents, with >99.98% virus reductions under all conditions tested. In organic muck columns virus reductions ranged from 30-98%, with greater reductions at 25°C than at 5°C and greater reductions of enteroviruses than either HAV or MS2. In the sandy soil columns viruses were retained generally better in loamy sand than in coarse sand. Overall, poliovirus was reduced the most and echovirus the least. In coarse sand, mean virus reductions ranged from a low of about 50% for echovirus at 5° to a high of about 99.4% for poliovirus at 25°. In loamy sand, mean virus reductions ranged from a low of about 60% for echovirus at 5° to a high of 99.997% for poliovirus at 25°. Virus reductions were greater in sandy soil columns dosed with groundwater than with wastewater. The appreciable breakthroughs of viruses in column effluents of organic muck and coarse sand soils indicate that these soil types may be unsuitable for land application of wastewater under some hydrogeological conditions.
Detection of small round structured viruses in clinical and environmental samples by polymerase chain reaction
Authors: Wolfaardt M. , Moe C. L. , Grabow W. O. K.
Published: May 2018

Norwalk (NV) and other small round structured viruses (SRSVs) have been identified as common causes of gastroenteritis. Outbreaks of Norwalk gastroenteritis have been associated with contaminated drinking water and food such as oysters and salads. The cloning and sequencing of the NV genome has made it possible to detect NV and related viruses by the reverse transcription-polymerase chain reaction (RT-PCR). We applied RT-PCR to detect SRSVs in faecal specimens from two gastroenteritis outbreaks in South Africa, designated “Christmas” and “Grootbrak” and were able to detect SRSVs in all of the three specimens from the Christmas outbreak and in two of 16 specimens from the Grootbrak outbreak. The RT-PCR procedure used appeared to be more sensitive for the detection of SRSVs in patient stool specimens than immune electron microscopy and NV antigen detection by enzyme linked immunosorbent assay. The RT-PCR procedure proved suitable for the detection of SRSVs in seeded samples of sewage, sewage sludge, river water, and tap water. However, sensitivity was lower for seeded samples of sewage and sludge than for tap water, which indicates interference by high levels of organic matter. The RT-PCR procedure was also used to show that small numbers of SRSVs can successfully be recovered from large volumes of water by means of a glass wool adsorption-elution method. Since no practical method is available for quantitation of the small numbers of SRSVs concerned, it was not possible to evaluate the efficiency of recovery. Although no SRSVs have been detected by direct testing of sewage and sludge samples, the results obtained in this study show that RT-PCR detection of SRSVs in sewage and polluted water environments is feasible, and that small numbers of the viruses can, like many other enteric viruses, successfully be recovered by means of a glass wool adsorption-elution method.
Evaluation of different filtration techniques for the concentration of cryptosporidium oocysts from water
Authors: Shepherd K. M. , Wyn-Jones A. P.
Published: May 2018

The relative performances of different filter matrices were assessed for the concentration of Cryptosporidium oocysts in water. Cartridge filtration methods were examined and compared with membrane filtration and a flocculation method using seeded tap and river water to determine the most efficient and consistent method of sample concentration. From 10L samples, calcium carbonate flocculation gave the most consistently high recovery rate of Cryptosporidium oocysts (tap water mean 72.9%; river water mean 41.9%), followed by membrane filtration using 1.2μm cellulose acetate membranes (tap water mean 37.8%; river water mean 26.6%). For filtration of larger volumes (>100L) of water the Cuno Microwynd II cartridge filter provided the highest recovery rate of oocysts (tap water mean 13.3%; river water mean 10.8%) when compared with the Vokes cartridge and Balston filters. All recoveries fell dramatically when sucrose flotation techniques were applied.
Differential accumulation and depuration of human enteric viruses by mussels
Authors: Bosch A. , Pintó R. M. , Abad F. X.
Published: May 2018

The tissue distribution of adenovirus 40 (ADV) and human rotavirus, serotype 3 (HRV) was determined after feeding the common mussel (Mytilus spp.) with high levels of clay-associated virus. At different time intervals, individual tissues were carefully dissected and assayed for infectivity. Viruses were detected in contaminated mussels after 1-hour contact, and maximum levels were observed after 6 hours. Most infectious viruses were located in the gills and in the digestive tract. Decreasing virus numbers were found in the mantle lobes.

Mussels contaminated with poliovirus 1 (PV), hepatitis A virus, strain HM-175 (HAV), ADV, HRV, and bacteriophages of Bacteroides fragilis (B40-8) were depurated in 50-1 tanks with a continuous flow of ozonated marine water. After 96 hours, HAV and HRV suffered less than 2 Log10 titre reduction (LTR), while ADV showed a 2.7 LTR. PV showed a 3 LTR after 48 hours and became undetectable thereafter. Bacteriophage B40-8 suffered less than 2 LTR after 96 hours, suggesting that it could be an appropriate indicator of the efficiency of virus elimination during shellfish depuration.
Effects of an anaerobic zone in a textile wastewater treatment plant
Authors: Bortone G. , Cech J. S. , Bianchi R. , Tilche A.
Published: May 2018

High concentration of textile industries represents a serious environmental problem in the Como area in Northern Italy. The Seveso treatment plant was formerly performing biological removal of nitrogen by means of a modified Ludzack-Ettinger configuration. Being the plant overloaded, nitrification was not achieved. Therefore the plant flow sheet has been modified. The former predenitrification tank has been changed in an anaerobic compartment, since the internal recycle was stopped.

The efficiency of the anaerobic reactor for COD removal, the selective pressure on the microbial community and the enhanced biological phosphorus removal were evaluated.

In the anaerobic tank 40% of the influent COD was removed with a reaction time of only 45 minutes. The activated sludge showed a very high presence of Poly-P bacteria; anaerobic P release was noticed during the anaerobic phase. Sludge settleability was always good (contrary to a similar activated sludge treatment plant, also treating textile wastewater but without an anaerobic selector, that suffers heavy filamentous bulking and Nocardia foaming). The final effluent PO4-P concentration was always lower than 1 mg L−1.
Integrated waste disposal strategy for the Orkney Islands - a case study
Authors: Chambers B. , Chapman R. E. , Cross R. T.
Published: May 2018

The Orkney Islands are situated several miles off the north east coast of Scotland and comprise about 40 separate islands, of which about 16 have a significant number of inhabitants. The total population is about 20,000 with 7,500 living in Kirkwall, the main town.

The EU Urban Waste Water Treatment Directive (UWWTD) has presented the Orkney Islands Council with an opportunity to develop an integrated waste disposal strategy for the entire group of islands. The problems which must be overcome are common to many island communities with limited land availability and seasonal industries based on agriculture and fishing.

The waste disposal strategy developed by Orkney Islands Council provides an integrated solution to a complex problem and takes into account the shortage of available land for sludge disposal and the effect of effluent treatment costs on the economics of interdependent island industries.

The strategy involves the construction of a new sewerage system to intercept the Kirkwall outfalls and deliver the sewage to a new treatment site prior to long sea outfall discharge. The most significant industrial discharges each contain a very high proportion of soluble BOD. As a result, primary treatment alone cannot achieve the reductions is SS and BOD required by the UWWTD. Some industrial effluents will therefore be pre-treated before discharge to sewers. The sludge disposal strategy has been developed to provide sustainability and outlet security. Accordingly two disposal routes have been proposed. These are land disposal or drying and co-incineration with domestic waste in a new incineration complex. Sludge from the outlying communities will be dewatered using a mobile centrifuge before being transported to Kirkwall for ultimate disposal.
Dynamic simulation of sludge blanket movements in a full-scale rectangular sedimentation basin
Authors: Göhle F. , Finnson A. , Hultman B.
Published: May 2018

Bromma sewage treatment plant in Stockholm is the second largest plant in Stockholm and will in the near future have requirements for nitrogen removal. This means that a higher sludge age must be used in the aeration basin. This may be accomplished by an increase of the sludge concentration up to values until the limiting solids flux is exceeded. Measurement of the sludge blanket level is a possibility for better control of the sedimentation basin. Different measurements were performed to evaluate the main factors influencing the level.

Dynamic simulation studies were performed at Bromma sewage treatment plant in Stockholm of the sludge blanket level and the return sludge concentration in a full-scale sedimentation basin. The simulations were performed with the help of a Danish simulation package, EFOR (1992), in which both reactions in the aeration basin (mainly based on the IAWPRC model) and separation processes in the sedimentation basin (both clarification and thickening) can be studied. The thickening model is based on the solids flux theory and the Vesilind formula (1979). Different methods were compared for determination and use of characteristic parameters in the Vesilind formula.
Biological nutrient removal in a sequencing batch reactor treating domestic wastewater
Authors: Bernardes R. S. , Klapwijk A.
Published: May 2018

This investigation aims to monitor a strategy for biological nutrient removal (nitrogen and phosphorus) in a Sequencing Batch Reactor (SBR) treating domestic wastewater. For this, the performance of an SBR with nitrification, denitrification, carbon oxidation and phosphorus removal is evaluated.

During this study the influent used was pre-settled domestic wastewater from Bennekom-Municipal Treatment Plant (The Netherlands). The average influent COD, TKN and phosphate were 443 mg COD/1, 71 mg N/1 and 7 mg P/1, respectively. Acetic acid was added to this influent from a feed solution, to increase the COD by an extra 100 mg COD/1.

In this study, a pilot plant SBR was operated during 5 months in order to have: i) a mixed culture able to perform carbon oxidation, nitrification, denitrification and biological phosphorus removal and ii) long term assessment of the biological nitrogen and phosphorus removal processes. Pilot plant SBR consists of two cylindric polystyrene vessels, the first with total volume of 0.35 m3 (Reactor 1) and the second with total volume of 1.3 m3 (Reactor 2).

The effluent had, in average, phosphate concentration lower than 1 mg P/1 and nitrogen concentration lower than 12 mg N/1.
Quality improvement of biosolids by ferrate(VI) oxidation of offensive odour compounds
Authors: Chao Allen C. , de Luca Sergio J. , Idle Carlos N.
Published: May 2018

Studies concerning the treatment, stabilization and final disposal of biosolids, one of the by-products of wastewater treatment, in environmental recovery, have been intensified by the sanitary and environmental effects of land disposal. The careful assessment of biosolid quality shows that, when appropriately managed, the environmental risks of their uses can be minimized by chemical stabilization, and biosolids could even be used as fertilizer and soil conditioner.

A research study of biosolid stabilization was performed using lime as a standard process compared to potassium ferrate (VI). The chances of leaching and solubilization of metals were tested, simulating conditions for disposal in the environment. The sanitary effectiveness in terms of pathogens (bacteria, fungi and helminth eggs) were also evaluated.

Experiments were performed on the lime and ferrate(VI) treatment of compounds such as ammonia, nitrate, soluble sulphides, and total sulphates, indicators of odouriferous offensive compounds which might occasionally prevent some uses of the solids, and the results are presented in this paper.

Wastewater Treatment Plants emit offensive odours generated during the sewage treatment process, as well as during the treatment and the management of biosolids. This occurs in the drying beds and the spreading of biosolids on land, due to the high concentrations of sulphur compounds, nitrogen compounds, acids and organic compounds (aldehydes and ketones).

The potassium ferrate(VI) utilized in the research is a powerful oxidizing agent throughout the pH scale, with the advantage of not generating by-products which will cause toxicity or mutagenicity (DE LUCA, 1981). The ion ferrate(VI) has greater oxidizing power than permanganate, e.g., it oxidizes reduced sulfur forms to sulphate, ammonia to nitrate, hypochlorite to chlorite and chlorite to chlorate(DE LUCA et al., 1992; CHAO et al., 1992).

This paper shows that, as expected, the potassium ferrate (VI) treatment replaces several chemical products utilized for odour control of sludges, mainly aggressive odours caused by ammonia and sulphides, through the formation of precipitates with iron compounds. Ferrate (VI) has often been shown to destroy soluble sulphides, transforming them into sulphate. The generation of oxygen in the decomposition of ferrate(VI) increases its oxidizing power. Ferrate(VI) applied to sludges also has the double effect of transforming ammonia into nitrates, such that this product takes the place of sulphates, acting as an electron acceptor, thus preventing the development of further odours when biosolids are utilized.
Improving the effluent quality of facultative stabilization ponds by means of submerged aerated biofilters
Authors: Gonçalves R. F. , de Oliveira F. F.
Published: May 2018

This paper describes the use of a submerged aerated biofilter (BF) in the tertiary treatment of effluent from facultative stabilization ponds (FSP). The results, obtained over four months of tests, confirm the ability of the BF to remove algae and, principally, to achieve tertiary nitrification. For hydraulic loading rates of 2m3/m2.h, the mean efficiency of the process in the removal of algae (SS) and COD was 58% and 63% respectively. Concentrations above 70 mg SS/1 and 195 mg O2/1 (COD) in the effluent from the ponds was reduced to 30 mg SS/1 and 70 mg O2/1 (COD) in the effluent from the BF. In addition to the removal of organic forms of nitrogen and phosphorus, the biofilter also reaches the soluble COD and ammonia. Tertiary nitrification was achieved with a mean efficiency of 86% for volumetric loads of up to 0.7 kg N-NH4+/m3.day (27°C). For concentrations above 20 mg n-NH4+/1 in the feed, the process can produce with safety effluents with less than 1 mg N-NH4+/1. The period of operation between the 2 successive washings of the bed filter was in the order of three days.
Treatment of wastewater transported by vacuum trucks
Authors: Ingallinella A. M. , Sanguinetti G. , Vazquez H. P. , Fernández R. G.
Published: May 2018

This paper presents the results obtained during the evaluation of a system of stabilization ponds in which exclusively liquids transported by vacuum trucks are treated. The liquids proceed from the emptying of cesspools and from septic tanks and have different characteristics from fresh sewage. Information is provided about the efficiency achieved in the reduction of BOD and faecal coliform bacteria. Comments are made on the results obtained in batch tests to determine the BOD(k) and faecal coliform bacteria (kb) removal constants and they are compared to the values of constants obtained from data about the functioning of the ponds. The conclusion is that a system of stabilization ponds is efficient for the treatment of this kind of wastewater, if it is designed bearing in mind its particular features, and with this purpose a treatment scheme is recommended.
Patterns of roof runoff contamination and their potential implications on practice and regulation of treatment and local infiltration
Authors: Förster Jürgen
Published: May 2018

Roof runoff water was sampled from an experimental roof system and from house roofs in the city of Bayreuth, Germany. Samples were analysed for organic micropollutants, heavy metals and sum parameters. The pollution level and the shape of the runoff profiles are dependent on the individual properties of the precipitation event and the roof, but patterns with high concentrations at the beginning of the event and a subsequent decrease (first flush effect) are very typical. For dissolved substances, the profile can often be well described by a negative exponential function. Metal surfaces on the roofs cause extreme runoff pollution with heavy metals (Cu, Zn) that constitutes an environmental hazard. It is concluded that there is a need for the development of flexible drainage strategies for surface runoff and that metal surfaces should be avoided on roofs.
Toxicity of phenolic wastewater to luminescent bacteria photobacterium phosphoreum and activated sludges
Authors: Kahru A. , Kurvet M. , Külm I.
Published: May 2018

Ash-heap water (AHW - phenolic wastewater of local oil-shale industry) was analyzed for its phenolic composition using HPLC and for its relative toxicity using MicrotoxTM and BiotoxTM tests where inhibition of natural luminescence of photobacteria is used as toxicity endpoint. Most abundant components in AHW were phenol (84 mg/L) and p-cresol (70 mg/L). The 5-min EC50 values for AHW (the concentration of AHW, %, which reduces the light output of bacteria by 50% after being in contact with bacteria for 5 minutes) for BiotoxTM and MicrotoxTM tests were 1.5% and 0.6%, respectively.

Also, the toxicity of AHW towards two different activated sludges (acclimatized and not acclimatized to phenolic wastewater) was evaluated using decrease of adenosine triphosphate (ATP) content of the sludge as toxicity endpoint. AHW was relatively non-toxic to activated sludges, especially to the acclimatized sludge. The respective 60-min EC50 value for AHW (the concentration of AHW, %, which decreases the ATP level of activated sludge compared to the non-exposed control by 50% after being in contact with sludge for 60 minutes) was 20-30% for non acclimatized sludge and 50-60% for acclimatized sludge. Therefore, the biopurification of AHW using an adapted activated sludge process could be considered feasible.
Study of toxicity of pesticides using luminescent bacteria Photobacterium phosphoreum
Authors: Kahru A. , Tomson K. , Pall T. , Külm I.
Published: May 2018

The relative toxicity (expressed as 5-min EC50 value - the concentration of chemical which reduces the light output of bacteria by 50% after contact for 5 minutes) of 13 pesticides (e.g., 2,4-dichlorophenoxyacetic acid, atrazine, coumarin, glyphosate, paraquat, pentachlorophenol, lindane, malathion) and 14 solvents was evaluated using BiotoxTM test that is based on reconstituted freeze-dried viable Photobacterium phosphoreum. The most toxic of the 13 pesticides analyzed using BiotoxTM was pentachlorophenol (5-min EC50=0.55 mg/L) and the less toxic was paraquat (5-min EC50=14800 mg/L). The 5-min EC50 data for BiotoxTM were compared to the respective data for MicrotoxTM test (also based on freeze-dried P. phosphoreum) and rodent oral LD50 values. For BiotoxTMvs MicrotoxTM the log-log correlation coefficients for the whole data set (pesticides+solvents, pesticides, solvents) were 078, 0.37 and 0.95, respectively. The less toxic solvents to BiotoxTM were ethylene glycol, DMSO, methanol, ethanol, acetone and acetonitrile and, therefore, these solvents could be used for increasing the solubility of lipophilic compounds, e.g., for testing the toxicity of pesticides.

In order to analyze toxic effects of pesticides in complex mixtures the EC50 values of pentachlorophenol, coumarin and glyphosate as pure substances and in their mixtures were compared: the toxic effects of the above-mentioned pesticides in their mixtures were not additive.
Testing the biodegradability of wastewater treatment plant outfalls: role of bacterial inocula
Authors: Percherancier Hélène , Volat Bernadette , Montuelle Bernard
Published: May 2018

A simple procedure of batch experiments is described allowing the determination of the Biodegradable Dissolved Organic Carbon (BDOC) content of different effluent outfalls from wastewater treatment plants. The bioassay is based on the DOC reduction of treated wastewater samples inoculated with natural consortia of bacteria taken from river sediments or aquarium filters. This test allows routine determination of BDOC within a short period of time (less than 8 days). BDOC represents a still significant proportion of the treated effluent DOC: from 50% to about 70%, depending on the effluent. The origin of bacterial inocula have no influence on these proportions, but are the main parameter for the rate of biodegradation. Testing the biodegradability at 10°C and 20°C appears to be significant as it influences biodegradation processes and must be done for a complete ecological evaluation of the biodegradability of wastewater treatment plant effluents.