bluuebunny/crossref_metadata_2025 huggingface dataset:
A Waterborne Disease Outbreak
Authors: Andersson Y.
Published: May 2018

In Sweden 63 waterborne outbreaks occurred during the last 10 years. Even if these outbreaks include smaller family incidents, at least 10 community outbreaks involved more than 1,000 victims each, the largest being in the city of Boden in 1988. This outbreak hit 41% of the population with gastrointestinal symptoms and was preceded by the distribution of virtually untreated, fecally contaminated river water due to a transitory absence of chlorination.
Public Health Criteria for the Aquatic Environment: Recent WHO Guidelines and Their Application
Authors: Helmer R. , Hespanhol I. , Saliba L. J.
Published: May 2018

Over the past Decade, the World Health Organization has developed a series of microbiological guidelines covering different aspects of the aquatic environment. Transmission pathways of human pathogens from their faecal origin back to man via drinking-water, bathing waters, shellfish and sewage-irrigated crops were investigated and epidemiology-based health criteria established. The total and faecal coliform guideline values for drinking-water are generally complied with in urban water supplies but difficult to meet in rural areas of developing countries. The Mediterranean serves as the major study area for assessing health risks from bathing in coastal waters and from the consumption of shellfish eaten uncooked. Wastewater reuse for crop irrigation is rapidly expanding due to water shortages but poses health risks to farm workers and consumers. New guidelines for control of helminths were recently issued by a WHO Scientific Group. A comparative evaluation of the above guidelines follows.
Staphylococci in Polluted Waters and in Waters of Uninhabited Areas
Authors: Ahtiainen Jukka , Niemi Maarit , Jousimies-Somer Hannele
Published: May 2018

The aim was to study the occurrence of staphylococci in southern Finland using both the modified Vogel-Johnson (VJP) and the M-5LSMA media in the MF technique. The study involved brooks and small lakes in uninhabited areas and sparsely populated farming areas as well as effluents from sewage treatment plants. Fecal indicator bacteria were determined simultaneously in all these samples. Median colony counts on both of the staphylococcal media in 100 mL samples were 1 to 2 for uninhabited areas, 60 to 110 for agricultural areas and 1000 to 1600 for treated wastewater. The maximum values were much higher in all the environments. The M-5LSMA recovered at least as many staphylococci as the VJP medium, but was more selective. Strains isolated from pristine waters and from wastewater were identified with the API 20 Staph kit. Six different species of staphylococci were recovered on the VJP medium and ten on the M-5LSMA medium. About one third of the isolates could not be identified to species level. Only 2% of the isolates from wastewater were Staphylococcus aureus whereas 18 % of the isolates from uninhabited areas belonged to this species. The identification was confirmed with the coagulase and DNAse tests.
The Effect of Dissolved Nutrients and Inorganic Suspended Solids on the Survival of E. coli in Seawater
Authors: Milne D. P. , Curran J. C. , Findlay J. S. , Crowther J. M. , Bennett J. , Wood B. J. B.
Published: May 2018

The effect of dissolved nutrients and inorganic suspended solids on E. coli inactivation has been examined in laboratory experiments. The work employed artificial seawater with dissolved glucose and peptone, laboratory processed suspended solids and chemostat steady state E. coli cultures to establish the effect of these parameters on the viability of an E. coli population. Initial E. coli concentration was 5 × 103 100ml−1, the temperatures 5 °C and 20°C, the suspended solids concentration range was 0 - 100mgl−1, glucose concentration l.0mgl −1, peptone concentration 9.0mgl−1, salinity range 27 - 32‰ and the experimental vessels were shielded from light.

Previous work has shown that nutrient-free inorganic suspended solids, at low concentrations, markedly increased the survival of E. coli in seawater. The work presented here shows that the presence of dissolved nutrients greatly increased E. coli survival, in the absence of suspended solids. However at suspended solids concentrations of >5 - 12mgl−1survival time was greatly reduced; thereafter increasing suspended solids concentration in the range >12.5 - 100mgl−1, generally resulted in increasing survival times.
Isolation and Identification of Cryptosporidium from Water
Authors: Vesey Graham , Slade John
Published: May 2018

The efficiency of the established method for isolation and identification of Cryptosporidium was assessed and found to be as low as one percent. Each stage of the process was evaluated. Between 5 and 30 percent of the oocysts were not retained by the initial cartridge filtration. A further 2 to 30 percent could not be eluted. Subsequent stages involving centrifugation and ultrasonic disaggregation were shown to disrupt staining by the established immunofluorescence assay.
The Occurrence and Viability of Giardia spp. Cysts in UK Waters
Authors: Gilmour R. A. , Smith H. V. , Smith P. G. , Morris G. P. , Girdwood R. W. A.
Published: May 2018

Modifications of the existing methods for the isolation of Giardia spp. cysts from water enabled up to 33% of seeded cysts to be recovered. Using this method, 263 environmental samples were analysed for the presence of cysts, of which 34.4% were positive. All sewage effluents, 85% of recreational waters, 46% of raw potable water samples and 22% of treated water samples contained cysts (range 0.14 - 359/litre). A higher percentage of positive samples occurred in the summer and autumn in raw water, whereas the levels of cysts in treated waters showed little seasonal variation. A fluorogenic vital dye assay, which compares favourably with in vitro excystation, has been developed, and using this assay, viable cysts wire detected in 33% of the positive raw water samples and 42% of the positive treated water samples.
Rotavirus Detection – A Problem That Needs Concentration
Authors: Strappe Pádraig
Published: May 2018

The recovery of simian rotavirus SAl1 from dechlorinated 10l tap water samples shows a marked improvement when ultrafiltration or hydroextraction are used as second-step concentration methods. After initial adsorption of virus on to a nitrocellulose filter and subsequent elution with 3% beef broth, organic flocculation gave an average recovery of 4%. Ultrafiltration gave an average recovery of 48% while hydroextraction in crystalline sucrose gave a recovery rate of 60%. Rotavirus recovery rates were quantified by the immunofluorescence assay.
Concentration of Hepatitis a Virus in Environmental Samples
Authors: Bosch A. , Gajardo R. , Abad F. X. , Diez J. M. , Jofre J.
Published: May 2018

The cytopathogenic pHM-175 strain of hepatitis A virus was used to develop different procedures for the concentration of HAV in tap water, fresh water, seawater and raw sewage, HAV was quantified by a plaque assay in the FRhK-4 cell line. Water samples were concentrated by a modification of the adsorption to and elution from glass powder (GPAE) method, by adsorption to and elution from filter aid, and by ammonium sulfate flocculation (ASF). The GPAE method consistently yielded greater HAV recoveries than filtration through filter aid, or ASF. HAV was concentrated by GPAE from 20-litre samples with satisfactory efficiencies in all kinds of water: 100% for tap water, 80% for freshwater, 75% for seawater and 61% for sewage. Concentration efficiencies for filter aid and ASF were always lower than 25% and 40%, respectively, in any kind of water. The charge of glass powder was modified by polyethylenimine treatment. Concentration efficiencies of HAV in 20 1 samples through adsorption to and elution from positively charged glass powder (PGPAE) were 100% for tap water, 94% for seawater, and 61% for freshwater and sewage. The presence of wild-type HAV in sewage samples could be monitored by molecular hybridization with cDNA probes after GPAE concentration.
Adsorption of Viruses by Diatomaceous Earth Coated with Metallic Oxides and Metallic Peroxides
Authors: Farrah S. R. , Preston D. R.
Published: May 2018

Diatomaceous earth coated with oxides of aluminium, calcium, iron, magnesium, or manganese were not found to be useful for recovering viruses from water. The oxide coatings were not stable in water or only adsorbed viruses in small volumes of water. Further modification of coatings of magnesium oxide to make magnesium peroxide produced a modified diatomaceous earth that efficiently adsorbed viruses in water. Filters containing 3.5 g of diatomaceous earth adsorbed an average of greater than 90% of MS2, polio 1, coxsackie B5, and echo 5 in tapwater at approximately pH 8.5, even after 100 liters of tapwater had passed through the filters. From 15 to 40% of MS2 or enteroviruses could be recovered from tapwater using filters containing diatomaceous earth coated with magnesium peroxide.
The Difficulty of Using Coliphages as “Indicators” and “Index” Organisms
Authors: Karst M. , Dutkiewicz R. , Hahn T. , Botzenhart K.
Published: May 2018

Different types of coliphages (T2, T4, T7, MS2 ϕX174, coliphages from surface water) were concentrated by a MgCl2 flocculation and a filtration (Virosorb 1MDS) method. Phage type as well as water quality had an influence on recovery rates of the concentration methods. None of them were superior when single phage types were used. Also various conditions had an influence on recovery rates in the direct plaque assay. Different phage aggregates are probably responsible for the range of recovery rates. Therefore it is probably not possible to standardize methods for isolating and detecting coliphages and they may be used as “indicators” or “index” organisms not at all or only in a strictly defined system.
The Occurrence of Male-Specific and Somatic Bacteriophages in Polluted South African Waters
Authors: Kfir R. , Coubrough P. , Grabow W. O. K.
Published: May 2018

The occurrence of somatic (F') and male-specific (F') coliphages and Salmonella phages in a variety of environmental water samples was studied using different bacterial hosts. The number of plaque-forming units (pfu) of the different bacteriophages were compared and their resistance pattern to a biological treatment (humus tank) and chlorination was evaluated. The presence of the bacteriophages in shellfish was also studied. The morphology of isolate bacteriophages was examined as well as the visibility of the different plaques formed. Coliphages were found to produce larger and clearer plaques than all other bacteriophages studied. In most of the environmental water samples coliphages outnumbered all other bacteriophages, with the exception of dam water in which higher levels of F' Salmonella phages were detected. The majority of the F' Salmonella phages were shown to be RNA bacteriophages.
Detection of Poliovirus in Water By Direct Isolation of the RNA and Hybridization with Gene Probes
Authors: Tougianidou D. , Botzenhart K.
Published: May 2018

Poliovirus RNA was directly isolated by filtering water samples seeded with poliovirus through Sterivex-GS, 0.22 µm filter units (Millipore) and extracting the RNA directly out of the filter. The isolated RNA was then detected by hybridization with appropriate gene probes.
Application of Microbial Tracers in Ground Water Studies
Authors: Hötzl H. , Käss W. , Reichert B.
Published: May 2018

In situ tracing experiments have proved to be reliable tools to get direct information on subsurface flow direction and flow parameters. Beside dyes, salts, radioisotopes and drift bodies, microbes can be used as tracers. In several comparative experiments carried out in porous and karst aquifers by the International Association of Tracer Hydrology (ATH) the microbial markers (bacteria and bacteriophages) have shown promising results. They are especially suitable to explain and model the subsurface transport of microorganisms.
Field Experiments with Microbiological Tracers in a Pore Aquifer
Authors: Oetzel S. , Käss W. , Hahn T. , Reichert B. , Botzenhart K.
Published: May 2018

In our study we investigated the transport and adsorption behavior of Serratiamarcescens and the coliphage ϕX174 in a pore aquifer. We compared the results with the properties of the classical dye tracer uranine; mainly differences in the distance of the transport could be shown.
Transport of Microorganisms in the Underground – Processes, Experiments and Simulation Models
Authors: Teutsch G. , Herbold-Paschke K. , Tougianidou D. , Hahn T. , Botzenhart K.
Published: May 2018

In this paper the major processes governing the persistence and underground transport of viruses and bacteria are reviewed in respect to their importance under naturally occurring conditions. In general, the simulation of the governing processes is based on the macroscopic mass-conservation equation with the addition of some filter and/or retardation factor and a decay coefficient, representing the natural “die-off” of the microorganisms. More advanced concepts try to incorporate growth and decay coefficients together with deposition and declogging factors. At present, none of the reported concepts has been seriously validated.

Due to the complexity of natural systems and the pathogenic properties of some of the microorganisms, experiments under controlled laboratory conditions are required. A laboratory setup is presented in which a great variety of natural conditions can be simulated. This comprises a set of 1 metre columns and an 8 metre stainless-steel flume with 24 sampling ports. The columns are easily filled and conditioned and therefore used to study the effects of different soil-microorganism combinations under various environmental conditions. In the artificial flume natural underground conditions are simulated using sand and gravel aquifer material from the river Neckar alluvium.

A first set of results from the laboratory experiments is presented together with preliminary model simulations. The large variety of observed breakthrough curves and recovery for the bacteria and viruses under investigation demonstrates the great uncertainty encountered in microbiological risk assessment.
Bdellovibrio sp. – A Predator under Groundwater Conditions? A Short Communication
Authors: Filip Z. , Schmelz P. , Smed-Hildmann R.
Published: May 2018

The role of Bdellovibrio sp. in affecting the development of gram-negative bacteria under natural conditions is not yet completely understood. In our investigations, no predatory activity was observed in groundwater samples from a deep pristine aquifer. As limiting factors, temperature and pH may play a role. Their respective ambient values were T=10° C and pH 6.07. In laboratory experiments using a collection strain of B.bacteriovorus and a wild type from sewage, appreciable numbers of plaques appeared at a minimum temperature of 18° C. The optimum temperature at which more than 100 plaques were pounted was 26° C and 30° C. At pH values lower than 6 no plaques were formed but more than 100 were observed at pH 7, 8 and 9. From the individual plaques, different growth stages of Bdellovibrio sp. have been identified using a transmission electron microscope.
Chlorine Resistance of Motile Aeromonas Spp.
Authors: Knøchel Susanne
Published: May 2018

The presence of high numbers of Aeromonas spp. is undesirable in the water supply, as they may be potentially pathogenic. Furthermore, they have a strong food spoilage potential. Aeromomas spp. have also been found in chlorinated drinking water where coliform counts were low. The present study was conducted to examine the level of and variation in chlorine resistance of Aeromonas spp. Two methods were employed. Screening of relative chlorine resistance was done on 46 clinical and 41 environmental isolates of Aeromonas spp. at 30° C, using a disc assay with four concentrations of hypochlorite, and results were compared with those of E. coli (3), Ps. fluorescens (2), Klebsiella spp. (1), Ps. aeruginosa (1), and Acinetobacter (1). Resistance varied greatly between Aeromonas isolates, but they were in general more susceptible than the other bacteria tested. Inactivation studies were conducted following the survival of selected isolates in solutions of monochloramine (0, 0.5, 1.0, and 2.0 mg/l) over a period of 180 minutes at pH 7.0 and 10° C. The most resistant strain in the disc assay was also the most resistant in the inactivation study.
UV Disinfection of Secondary Effluents from Sewage Treatment Plants
Authors: Chrtek Susanne , Popp Wolfgang
Published: May 2018

Pilot plant experiments have shown that UV irradiation is a qualified and non-polluting method for disinfection of the secondary effluent from wastewater treatment plant. It is possible to reduce the load of fecal indicator bacteria below the guide values and imperative limits of the Directive of 8 December 1975 concerning the quality of bathing water, enacted by the European Communities. The bacterial concentration was reduced to an average concentration of less than 10 counts per 100 ml for coliform bacteria and fecal streptococci. Photoreactivation was observed but the increase of the density (logarithmic scale) of coliform bacteria and standard plate count was not more than 1 after four hours of light exposure. Fecal streptococci did not show any photoreactivation.
Disinfection Capability in Water for Swimming and Bathing Pools: A Simple Method for Their Evaluation in Practice
Authors: Seidel K. M. , Lopez Pila J. M. , Grohmann A.
Published: May 2018

Prevention of infectious diseases transmission in swimming and bathing pools requires that sufficient disinfection capability is constantly maintained in the bathing water. Accordingly, German regulations make mandatory that any procedure for the treatment and disinfection of those waters must guarantee a certain minimum capability to inactivate human pathogens in the water. We describe here a simple method to evaluate the disinfection capability of pool water, expressed as the inactivation rate of selected microorganisms (Pseudomonas aeruginosa,Escherichia coli and Legionella pneumophila). The test might be carried out right onsite in the pool area using simple standard laboratory equipment normally present in microbiological laboratories and might be used for the evaluation of standard disinfectants and of others to be developed in the future. Results achieved with this test show good agreement with those obtained using a sophisticated stopped flow apparatus, developed exclusively for the evaluation of disinfection capability.
Destruction of Faecal Bacteria, Enteroviruses and OVA of Parasites in Wastewater Sludge by Aerobic Thermophilic and Anaerobic Mesophilic Digestion
Authors: Carrington E. G. , Pike E. B. , Auty D. , Morris R.
Published: May 2018

A new sludge treatment plant at Harrogate South Sewage Treatment Works is designed to handle up to 4 tonnes (dry solids) daily. Sludge is thickened continuously up to 8% (ds) and is then treated in parallel anaerobic mesophilic (AD) and thermophilic aerobic digestion (TAD) plants each with a maximum working volume of 530m3. Microbiological studies were carried out to compare the destruction of pathogens and faecal indicator bacteria. The AD plant operated with a mean retention of 26 days at 34 °C and achieved 49% reduction of volatile solids. The TAD plant operated with a mean retention of 28 days at 55 °C and reduced volatile solids by 35%. Operation was on a pump in-pump out cycle, guaranteeing 4h retention for all sludge. The disinfecting ability of TAD exceeded that of AD since it reduced counts of Enterobacteriaceae, thermotolerant coliforms and faecal streptococci to below 103/100ml, rendered cytopathic enteroviruses undetectable and destroyed viability of Ascaris suum ova within 4h. The AD process reduced bacterial counts by 90% and enteroviruses by 99%, but has no effect upon viability of Ascaris ova.
Waste Stabilization Ponds in Grand Cayman, Cayman Islands
Authors: Frederick G. L.
Published: May 2018

The experience of pond performance in Grand Cayman is described. Monitoring of the system indicates that over the two years since commissioning the performance and final effluent quality have changed. This paper intends to address the contributing factors that might have caused these changes.
Survival of Pathogenic Bacteria in an Adverse Environment
Authors: Barzily A. , Kott Y.
Published: May 2018

It is known that pathogenic bacteria are sensitive to changes in environmental conditions.

This applies to Enterobacteriaeeae, as well, where optimum temperature is 37°C. Wastewater of various qualities are also hostile environments to these bacteria. The aim of the present study was to investigate the influence of temperature on the die-off of enteric bacteria in waste stabilization ponds at the temperature range 40-60°C. Survival of indicator microorganisms at the control pond effluent was higher than at increased temperature pond effluent (40°C, 50°C, 60°C). Survival percentages of the indicators at the elevated temperature pond compared to the control pond were 0.12% to 73.33%. The pathogenic bacteria Salmonella typhimurium and Shigella sonnei were introduced in dialysis bags placed in the ponds. The number of the pathogenic bacteria decreased by a few orders of magnitude within days, depending on the temperature and the strain. Following certain periods of time, the bacteria held in the heated pond and in some instances in the control pond, lost their ability to agglutinate with specific antibody. The phenomenon of bacteria showing negative specific agglutination requires further research. It is thought that this phenomenon might indicate an unknown heat survival mechanism of the pathogenic bacteria in adverse environment.
Control of Enteric Micro-Organisms by Aerobic–Thermophilic Co-Composting of Wastewater Sludge and Agro-Industry Wastes
Authors: Shuval Hillel , Jodice Roberto , Consiglio Michaele , Spaggiarri Giancarlo , Spigoni Cianluigi
Published: May 2018

A field scale, pilot plant study of aerobic-thermophilic co-composting of digested) dewatered, wastewater sludge together with the agro-industry wastes, poplar bark and grape vine stalks was carried out by A.G.A.C in Reggio-Emilia, Province of Northern Italy. The compost piles reached a temperature of over 55°C for extended periods and concentration of the bacterial indicator organisms fecal coliforms, fecal streptococcus and Salmonella were reduced drastically to acceptable levels. The mean C/N ratio of the mixture was reduced during the composting period from 25 to 17. The final compost proved effective as a soil fertility additive in plant growth experiments. The special value of co-composting sludge with ligneous-cellulose residuals, which stimulate the biological interactions essential for effective composting were revealed in this study.
A Comparison of Methods for the Isolation of a Wide Range of Viruses from Shellfish
Authors: Idema G. K. , Bateman B. W. , Kfir R. , Grabow W. O. K.
Published: May 2018

Four methods were compared for the isolation of a wide range of enteric viruses from shellfish. The comparison was aimed at finding a practical and sensitive method to be used routinely. Three of the methods (A, B and C) were based on viral adsorption and desorption using buffers at different pH values. A fourth method (D) consisted of a single homogenization step with no pH adjustments. High recoveries for polio 1 were shown with the first three methods A-C, namely 81%, 79% and 77% respectively. Recoveries for reo 1 (Lang strain) and the simian rotavirus SA11 were not satisfactory using methods A-C. By contrast, method D gave high recoveries for reo and SA11 virus (31% and 68%, respectively). A modified method D generally yielded higher recoveries as indicated by a 91%, 33% and 35% recovery for polio 1, reo and SA11 viruses respectively. Comparison of method A and modified method D for the detection of viruses from environmental shellfish samples indicated that the two methods were of equal sensitivity.
Investigation of partial and full nitrification characteristics of fertilizer wastewaters in a submerged biofilm reactor
Authors: Çeçen Ferhan
Published: May 2018

Nitrification characteristics of a high-strength fertilizer wastewater were studied in an upflow submerged biofilm reactor. The aim was the investigation of nitrogen removal rates with regard to ammonium removal and the determination of NOx-N production rates in terms of nitrile build-up and nitrate production. For this purpose the biofilm reactor was operated at various loading rates and DO levels. The system could reach high ammonium removal rates up to about 0.6 kgNH4-Nm−3d−1 (13.2 gNH4-Nm−2d−1). In a number of runs nitrification was incomplete and nitrite reached a considerable level. One of the most important factors for nitrite build-up was the relative ratio of bulk oxygen to bulk ammonium. More important than this was the ratio of bulk oxygen to bulk free ammonia. When this ratio was lower than 10, nitrite was the dominant species in the produced NOx-N. Also the increase in volumetric loading rate generally led to an increase in nitrite production. Thus, in order to achieve partial nitrification, free ammonia inhibition can be enhanced by operating at relatively low DO, high bulk ammonium and high bulk pH values. The main inhibition in the treatment of these wastes was substrate inhibition at indicated operating conditions. Since the concentration of free nitrous acid was very low, product inhibition could be disregarded.
Shrimp pond effluent: pollution problems and treatment by constructed wetlands
Authors: Sansanayuth P. , Phadungchep A. , Ngammontha S. , Ngdngam S. , Sukasem P. , Hoshino H. , Ttabucanon M. S.
Published: May 2018

An intensive shrimp culture in Thailand has rapidly expanded especially along the coast during the last decade. Excessive feed basically given during the culture causes water and sediment in the pond to contain organic matter and nutrients in high concentration. After harvesting, discharging sediment is prohibited; however, pond water is mostly discharged directly to natural water resources without any effective treatment. The nutrient load discharged from shrimp ponds can form significant source of nutrients causing pollution and eutrophication in littoral areas of Thailand. The possibility of a subsurface-flow constructed wetlands application for treating shrimp pond effluent containing high salinity was studied. An experimental-scaled model planted with Acrostchum aureum (mangrove fern) in gravel was studied by comparison with one containing only gravel. The results showed that models can reduce suspended solids, biochemical oxygen demands, total organic carbon, totel nitrogen (T-N) and total phosphorous (T-P) up to 84%, 91%, 46%, 48% and 31%, respectively. Higher removal efficiencies for TOC, T-N and T-P of the planted model compared with the gravel model were clearly found.
BOD5 removal in facultative ponds: experience in Tanzania
Authors: Mayo Aloice W.
Published: May 2018

This paper discusses the removal of BOD5 in facultative ponds under tropical conditions. Data was collected from pilot and field ponds at the University of Dar es Salaam and was compared to other ponds in Dar es Salaam. Results showed deviations of performance, in some cases, from assumptions made during the design. The permissible organic loading rate for ponds in Dar es Salaam was 450 kg BOD5/ha/d. To reduce concentration of algae in the final effluent, a sunken outlet structure was suggested.
A study of palm oil mill effluent treatment using a pond system
Authors: Chin K. K. , Lee S. W. , Mohammad H. H.
Published: May 2018

Palm oil mill effluent (POME) contains a high concentration of organic matter. COD concentration is in the range of 45,000 to 65,000 mg/l, 5-day BOD 18,000 to 48,000 mg/l and oil and grease greater than 2,000 mg/l. The COD:N:P ratio is around 750:7.3:1. The nutrient content is low for aerobic treatment processes but sufficient for anaerobic treatment processes. This paper evaluates the treatment efficiency of a pond system consisting of 8 ponds in series treating 600 cu m/day of POME. The pond system has been in operation since the mid 1980's. Effluent COD was 1,725 mg/l, BOD 610 mg/l, ammonia-N 115 mg/l, nitrate nitrogen 5 mg/l, TKN 200 mg/l and phosphate 60 mg/l. The effluent was not able to meet the discharge standard of 50 mg/l BOD.
Experimental study of high rate pond system treating piggery wastewater
Authors: Wang Baozhen , Dong Wenyi , Zhang Jinlan , Cao Xiangdong
Published: May 2018

The results of an experimental study conducted in a full-scale high rate pond system treating piggery wastewater at Jianfengshan Piggery, Panyu City, Guandong Province, are presented. The system consists of two advanced anaerobic ponds (AAP) in parallel, followed by an anaerobic transformation pond (ATP) and a five-cell algae-bacterial pond (ABP). The mechanism of the AAP is described and the hydraulic flow pattern analyzed. Fermentation pits (FP) built on the bottom performed very efficiently, operating like UASB in principle. A new concept of ATP is advanced, based on its ability to transform poorly degradable materials to more easily degradable ones. It was found in the study that the HRP system was more efficient, more reliable and saved 40% land area compared with a conventional pond system. Economic analyses of both the energy consumption and the benefit to the pond system of fish farming are also included in the paper.
Influence of environmental parameters on biomass production and nutrient removal in a high rate algal pond operated by continuous culture
Authors: Cromar N. J. , Fallowfield H. J. , Martin N. J.
Published: May 2018

High Rate Algal Ponds (HRAPs) are efficient treatment systems which minimise the effects of wastewater pollution by reduction of organic matter and inorganic nutrient content. The efficacy of these systems is well documented, however there remains little understanding of the mechanisms by which removal occurs or of the factors which may affect the efficiency of the removal process. This research attempts to elucidate the relationship between environmental parameters such as day length, pond temperature and incident surface irradiance and to relate these factors to the production of biomass and removal of nutrients within pond systems operated as continuous cultures and loaded with artificial sewage media.

Complex interactions were noted between the concentration of algal biomass in the ponds, as approximated by chlorophyll a measurements, and the efficiency of nitrogen removal which may have important implications for the management of these systems. Clear evidence of the time course of nitrification was also obtained. Equations have been developed which correlate the environmental variables with changes in pond biomass and nutrient removal. These equations can be used as a tool to aid the effective management of HRAPs as wastewater treatment systems.
Constructed wetlands for wastewater treatment in the Czech Republic the first 5 years experience
Authors: Vymazal Jan
Published: May 2018

The first full-scale constructed wetland (CW) for wastewater treatment in the Czech Republic was built in 1989. By the end of 1991 only three more CW had been put into operation. An inventory survey in 1994 revealed the presence of 41 constructed wetlands in operation or in building. All CW in the Czech Republic use the horizontal subsurface-flow configuration. With few exceptions, all systems have been designed for the secondary treatment of domestic or municipal sewage. The treatment area of vegetated beds ranges between 18 and 4493 m2 and population equivalent ranges between 4 and 1100. Common reed (Phragmites australis) is the most frequently used plant cover. The treatment efficiency is very high for organics (77–98% for BOD5, 59–91% for COD) and suspended solids (77–99%). The removal efficiency for nitrogen and phosphorus varies widely among systems and is generally lower than 60%.
Application of constructed wetlands to treat some toxic wastewaters under tropical conditions
Authors: Polprasert C. , Dan N. P. , Thayalakumaran N.
Published: May 2018

This study evaluated the potential of a free water surface constructed wetland system in treating some toxic wastewaters (i.e. phenolic and heavy metals). In a temperature range of 22–30°C, the constructed wetland units, whose hydraulic retention times (HRT) were 5–7 days, could remove more than 99% of the input phenol when they were operated at or below the organic loading rates (OLR) and influent phenol concentrations of 270 kg COD/(ha.d) and 400 mg/l, respectively. The effluent dissolved oxygen (DO) levels were 4–7 mg/l at OLR of 40–140 kg COD/(ha.d), but these DO levels decreased to 0.2–0.3 mg/l when the OLR were increased to 165–270 kg COD/(ha.d). Under similar operating conditions, the constructed wetland units could remove more than 99% of the applied chromium (Cr) and nickel (Ni), when either the Cr or Ni influent concentrations were 1–50 mg/l. The phenolic and heavy metal compounds were found to accumulate mostly at the roots of Typha, followed by the stems and leaves.
The production of activated carbon for water treatment in malawi from the waste seed husks of Moringa oleifera
Authors: Warhurst A. Michael , McConnachie Gordon L. , Pollard Simon J. T.
Published: May 2018

Moringa oleifera is a multi-purpose tree whose seeds can be used as a coagulant in water treatment. The seed husks are currently discarded as a waste, but research has shown that they can be converted into activated carbon by carbonisation at 485°C under N2 for 30 minutes, followed by activation in steam at 850°C for 5 minutes. Here we report an improved method of carbon production, using a single-stage steam pyrolysis activation that is more appropriate for the intended use. Steam pyrolysis at 750°C for between 30 and 120 minutes produced a high quality microporous activated carbon at a yield of between 11% and 17%, with increases in soak time giving improved pore development and more mesoporosity. The apparent N2 BET surface area of the M. oleifera carbon produced by soaking at 750°C for 120 minutes was 730.0 m2 g−1, similar to that of the carbon produced previously by the two-stage process, 734.3 m2 g−1. The phenol adsorptive capacities of the carbons pyrolysed at 750°C were similar to a commercial carbon. These results show that it is possible to produce high quality activated carbon from the waste seed husks of M. oleifera using a simple one-stage 750°C steam pyrolysis. This provides a low-cost method of producing activated carbon locally in developing countries for use in water treatment.
Treatment and disposal of domestic sewage sludge and nightsoil sludge for Bangkok
Authors: Stoll U. , Parameswaran K.
Published: May 2018

In the recent past, treatment and disposal of sewage sludge has become an expensive and environmentally sensitive problem in western countries. It is becoming a growing problem worldwide with its focus on the megacities in the newly developed countries, since sludge production will continue to increase as new sewage treatment plants are built and environmental quality standards become more stringent. With some traditional disposal routes coming under pressure, the challenge facing the wastewater treatment authorities is to find cost-effective and environmentally sound solutions whilst responding to increasing public awareness. This paper describes the development of a plan for integrated management of municipal sludges (sewage sludge, nightsoil/septage sludge) which has high security for medium-and long-term sludge utilization and disposal as the goal. It concludes that incineration and agricultural use should be implemented and operated in parallel as first priority options.
The effects of soil type and effluent pre-treatment on soil aquifer treatment
Authors: Kopchynski T. , Fox P. , Alsmadi B. , Berner M.
Published: May 2018

A matrix of three different levels of effluent pre-treatment and four different soil types was used in a study on the effects of soil type and effluent pre-treatment on Soil Aquifer Treatment (SAT). The objective of the study was to assess the feasibility of SAT for the recharge of groundwater and indirect potable reuse. The soils represented a wide range of hydrological and physicochemical characteristics from a proposed recharge site in Phoenix, Arizona, USA. Effluents studied included denitrified and conventional secondary effluents. These effluents contain different levels of biological oxygen demand (BOD5), organic carbon, ammonia, and nitrate. Ten 2.6 m columns were operated under different wetting/drying cycles. For the effluents studied, resultsindicate that effluent pre-treatment does not impact organic carbon removal efficiencies. Under optimal wetting/drying cycle times, BOD5 can be removed efficiently although a residual organic carbon concentration of 5–6 mg/l persists. Ammonia is effectively nitrified under most conditions but denitrification does not readily occur even when denitrified effluent is applied. Soil Aquifer Treatment appears to be a robust treatment system for denitrified effluent producing total nitrogen concentrations less than 8 mg/l and organic carbon concentrations less than 6 mg/l.
Biofilters for water reuse in aquaculture
Authors: Abeysinghe D. H. , Shanableh A. , Rigden B.
Published: May 2018

Aquaculture is a rapidly expanding industry in Australia and around the world. The majority of aquaculture operations employ flow through systems whereby residual feed and metabolic products are discharged to a nearby water body. In many countries, the discharge of nutrients rich aquaculture waters has contributed to the degradation of water quality in receiving water bodies. Aquaculture's dependency on water resources ultimately makes water recycling an attractive waste management option.

Submerged flow biofilters, utilising a filter media with specific surface area of approximately 141m2/m3, were used to remove nitrogen and phosphorus from a synthetic fish farm water. Three biofilter systems were tested for nitrification, nitrification followed by denitrification, and combined nutrients removal. Successful carbon removal and nitrification were achieved in the nitrification system. The nitrification/denitrification biofilters achieved complete denitrification and nitrogen removal. The cyclic aerated/unaerated combined nutrients removal system achieved approximately 40 percent phosphorus removal, complete nitrification and 40 percent denitrification. The study demonstrated the viability of using biofilters for nutrients removal from fish farm waters. Biofilters are readily designed and constructed in modular form which makes such systems particularly useful for water quality management in aquaculture.
Existing guidelines and regulations in Spain on wastewater reclamation and reuse
Authors: Salgot Miquel , Pascual Alba
Published: May 2018

One of the points to take into account when the implementation of a wastewater reclamation and reuse project is planned is the absence or the existence of clear regulations. In Spain, the Government issued ten years ago one Law and one Decree where wastewater reuse was indicated as a possibility, and a minimal statement appeared, indicating the need for an administrative concession and a compulsory report of the Health Authorities. An indication was made that further legal developments would be needed.

There is a bright future for wastewater reuse in Spain, but at present it is compromised, owing to the fact that the projects are appearing and a lot of difficulties arise because of the need for a more complete legal definition. In Spain there is a strong tendency to decentralise the Administration and give more power to the “Autonomous Governments” (Regional Governments: 17 in the whole country). The decisions and permissions for wastewater reuse are given now case per case depending on the Regional Administrations.

Since it is difficult to get such approvals without having definite legal health regulations, several Regional Health Authorities have decided to develop their own guidelines for wastewater reuse for irrigation. At the moment (June 1995) 3 guidelines are operative.

The authors describe these three guidelines and discuss their development and the main ideas included. The three approaches are really different in conception and a comparison is made between them as well as with regulations in the Mediterranean Basin and other countries.
The bioaugmentation of sequencing batch reactor sludges for biological phosphorus removal
Authors: Belia E. , Smith P. G.
Published: May 2018

The development of enhanced biological phosphorus removal (EBPR) through the bioaugmentation of a conventional activated sludge was studied. The objectives of the study were to evaluate the phosphorus removal capability of a sequencing batch reactor (SBR) when started with conventional activated sludge and augmented with a pure culture of Acinetobacter lwoffii. The effect of the addition of the pure culture on the reactor start up time, the settling properties of the sludge and on COD and nitrogen removal was also investigated. The effect of the removal of up to 70% of the bioaugmented biomass and its substitution with unconditioned sludge from a conventional sewage treatment plant was determined. This study has demonstrated that bioaugmentation can convert a conventional sewage works activated sludge to an EBPR sludge in 14 days. The sludge produced shows resilience to influent phosphate fluctuations, low D.O. and biomass replacement. The COD and nitrogen removal capabilities of the sludge and its settling properties are not affected by the addition of the pure culture.
Reductive dechlorination of perchloroethylene using anaerobic sequencing batch biofilm reactors (AnSBBR)
Authors: Hirl P. J. , Irvine R. L.
Published: May 2018

Chlorinated organic solvents, such as perchloroethylene (PCE) and trichloroethylene (TCE), rank in the top five of the groundwater pollutants found in the United States. During the past year, the Anaerobic Sequencing Batch Biofilm Reactor (AnSBBR) was used to select for, enrich, and modify the physiological state of one or more of the many possible microbial consortia that can participate in the reductive dechlorination of PCE. Reactors enriched on lactate or acetate were able to dechlorinate 10.5 mg (63.3 μmoles) of PCE to cis-1,2-dichloroethylene (cDCE) on a daily basis. When methanol was used as the electron donor PCE, TCE, and cDCE were detectable in the reactor at the end of a 24 hour cycle. An AnSBBR fed only H2/CO2 was able to mediate the dechlorination of PCE to TCE, cDCE, and vinyl chloride (VC). Chloride measurements provided for a reliable and accurate method for the quantification of reductive dechlorination when the sorption of the chlorinated ethylenes affected the direct measurement of these compounds.
Monitoring and control using on-line ORP on the continuous-flow activated sludge batch reactor system
Authors: Yu R.-F. , Liaw S.-L. , Chang C.-N. , Lu H.-J. , Cheng W.-Y.
Published: May 2018

On-line monitoring of ORP has been proved to be a practical and useful technique for process control of wastewater treatment systems. This paper presents the feasibility of using on-line ORP monitoring system on a laboratory scale single tank continuous-flow activated sludge batch reactor, which is capable of removing carbon, nitrogen and phosphorus pollutants. Two control strategies, fixed-time and real-time, are applied for process control. Results obtained from fixed-time control study indicate that the variations and the ORP profile can accurately represent dynamic characteristics of system; the pH profile can also indicate some of those characteristics. Also, the breakpoints, setpoints and settime on the ORP and pH profiles are used to establish the real-time control strategy to determine the transfer of operation stages. The real-time experiments show a better performance than fixed-time, thus, on-line ORP and pH monitoring and control is practical for continuous-flow batch activated sludge process control.
Dynamic mathematical modelling of sequencing batch reactors with aerated and mixed filling period
Authors: Novák L. , Goronszy M. C. , Wanner J.
Published: May 2018

Sequencing batch reactors (SBRs) can be successfully operated for both carbon and nutrient removal, including nitrogen and phosphorus. The major elements of design that accomplish population dynamics control to prevent filamentous sludge bulking, cycle time, oxygen supply, biological nitrification, denitrification, phosphorus removal and solids-liquid separation need to be set in such a way that sufficiently optimal conditions are provided to permit the reactions and processes to take place. SBR processing using cyclic activated sludge technology employs biological selectors in the inlet part of the SBR system and a minor sludge recycle stream to ensure influent wastewater is mixed with activated sludge flocs to create favourable conditions for kinetic and metabolic selection of microorganisms producing floccules. Reaction volume, in addition to the designated bottom water level volume, is variable through time fed-batch reactor mode of operation. A mathematical model that describes volume changes and simultaneously the biodegradation kinetics has been developed. The model describes theoretical behaviour of selected parameters of volume, suspended solids concentration, OUR, ammonia and nitrate nitrogen in the selector compartment and the main aerated basin in ideally mixed and filled reactors of the cyclic system during the phase of mixed-fill (selector) and aerated and non-aerated fill (main aeration reactor basin).
Biological treatment of papermill wastewater by sequencing batch reactor technology to reduce residual organics
Authors: Franta J.R. , Wilderer P. A.
Published: May 2018

Sequencing Batch Reactor (SBR) experiments have been conducted in the laboratory to study factors affecting the composition and concentration of residual organics in the effluent of biological wastewater treatment plants. Wastewater discharged by a papermill was used to feed four SBRs. The influence of process conditions, like duration of filling phase (FILL) or duration of reaction phase (REACT) could be demonstrated. The degree of elimination was dependent on the sludge age and on optimized process strategy. The highest COD removal and the best sludge settling properties for the papermill wastewater were obtained at a sludge age of 20 days with REACT period of 12 hours and duration of FILL phase of 0.5 hours. Pyrolysis GC/MS studies showed that the residual CODfrom the treated papermill wastewater consisted of refractory organic compounds such as lignins.
The effect of volatile fatty acids on enhanced biological phosphorus removal and population structure in anaerobic/aerobic sequencing batch reactors
Authors: Randall Andrew Amis , Benefield Larry D. , Hill William E. , Nicol Jean-Paul , Boman Gerald K. , Shuh-Ren Jing
Published: May 2018

Three anaerobic/aerobic sequencing batch reactors (SBRs) were operated for 5 1/2 years. Volatile fatty acids (VFAs) in influent wastewater for two of the SBRs (the Glucose 1 and 2 SBRs) resulted in optimization of enhanced biological phosphorus removal (EBPR), and a bacterial population capable of increasing phosphorus (P) removals in response to increased VFA or P concentration. Another SBR not receiving VFAs (the Starch SBR) showed marginal EBPR and was incapable of either response. All three anaerobic/aerobic sequencing batch reactors (SBRs) showed bounded oscillations in P removal that did not correspond to any operational or environmental change. The oscillations were probably associated with interspecies population dynamics intensified due to the periodic, unsteady-state, nature of the SBR process. The glucose SBRs also showed an additional type of variability associated with EBPR, probably from competition between poly-P and “G” bacteria for readily available substrate (i.e. glucose, VFAs) during anaerobiosis. The predominant bacterial isolates from the glucose SBRs were Pseudomonas and Bacillus while Aeromonas was isolated most frequently from the Starch SBR. The relatively slow growth rate of Pseudomonas may have contributed to the high variability of EBPR observed. Fractal analysis indicated overall variability may have been chaotic, but was inconclusive.