bluuebunny/crossref_metadata_2025 huggingface dataset:
Monitoring of a paper mill wastewater treatment plant using UV/VIS spectroscopy
Authors: Langergraber G. , Fleischmann N. , Hofstaedter F. , Weingartner A.
Published: May 2018

A submersible UV/VIS spectrometer was used to monitor a paper mill wastewater treatment plant. It utilises the UV/VIS range (200-750 nm) for simultaneous measurement of COD, filtered COD, TSS and nitrate with just a single instrument. The instrument measures in-situ, directly in the process. Paper mill wastewater shows typical and reproducible spectra at various process measuring points. There is a relative maximum at 280 mm due to the absorbance by dissolved organic substances, mainly ligninic acids. Comparison of absorbance spectra distinctly shows the decrease of this peak, indicating biological degradation throughout the treatment process. Summarising, one can say that paper mill wastewater cannot be monitored by a simple UV probe measuring only the absorbance at a single wavelength. The required information can only be gained from the whole spectra. Regarding plant control it is suggested that only the overall spectral information is used. Calibrations to conventional parameters are now merely carried out for purposes of reference-checking.
Disinfection of sludge using lime stabilisation and pasteurisation in a small wastewater treatment plant
Authors: Keller R. , Passamani-Franca R.F. , Cassini S.T. , Goncalves F.R.
Published: May 2018

Removal efficiency of faecal coliforms and helminth eggs was evaluated in a small wastewater treatment plant (WWTP) serving a population of 1,000. This system was formed by the association in series of a UASB reactor and four submerged aerated biofilters. The density of faecal coliforms and the count of helminth eggs were estimated in the liquid and solid phases of the system. Two different methods of disinfecting sludge were investigated: (a) chemical treatment with lime and (b) a physical treatment by pasteurisation. As expected, the association UASB + BF was very efficient at removal of helminth eggs from the final tertiary effluent, but coliforms were still present at high densities. Lime treatment and pasteurisation of sludge were very effective methods of disinfection and produced a sludge safe for final disposal.
Evaluation of electrochemically generated ozone for the disinfection of water and wastewater
Authors: Tanner B.D. , Kuwahara S. , Gerba C.P. , Reynolds K.A.
Published: May 2018

Effective wastewater treatment is critical to public health and well-being. This is especially true in developing countries, where disinfection of wastewater is frequently inadequate. People who live in these areas may benefit from wastewater disinfection using ozone. This study evaluated the ability of a new electrochemical process of ozone generation, which produced ozone continuously at high pressure and concentration by the electrolysis of water, to disinfect tap water and secondarily treated wastewater. Inactivation of Klebsiella terrigena, Escherichia coli, MS2 bacteriophage and poliovirus 1 was evaluated first in reverse osmosis (RO) treated water. Inactivation of K. terrigena (6-log), E. coli (6-log), MS2 (6-log) and poliovirus 1 (>3-log) was observed after 1min of ozonation in a 1L batch reactor. Experiments were then performed to assess the microbiological impact of disinfection using ozone on secondarily treated municipal wastewater. The effect of ozonation on wastewater was determined for total and faecal coliforms, bacteriophages and heterotrophic plate count (HPC) bacteria. Electrochemical ozone generators provided an effective, rapid and low-cost method of wastewater disinfection. Based on the results of this research, electrochemically generated ozone would be well suited to remote, small-scale, disinfection operations and may provide a feasible means of wastewater disinfection in developing countries.
The role of aquatic ecosystems as reservoirs of antibiotic resistant bacteria and antibiotic resistance genes
Authors: Biyela P.T. , Lin J. , Bezuidenhout C.C.
Published: May 2018

The widespread and indiscriminate use of antibiotics has led to the development of antibiotic resistance in pathogenic, as well as commensal, microorganisms. Resistance genes may be horizontally or vertically transferred between bacterial communities in the environment. The recipient bacterial communities may then act as a reservoir of these resistance genes. In this study, we report the incidence of antibiotic resistance in enteric bacteria isolated from the Mhlathuze River and the distribution of genetic elements that may be responsible for the observed antibiotic resistance. The resistance of the enteric bacteria isolated over a period of one year showed that resistance to the older classes of antibiotics was high (94.7% resistance to one antibiotic and 80.8% resistance to two antibiotics). Furthermore, antibiotic resistance data of the environmental isolates showed a strong correlation (r = 0.97) with data obtained from diarrhoea patients. PCR based methods demonstrated that class 1 integrons were present in >50% of the environmental bacterial isolates that were resistant to multiple antibiotics. This class of integrons is capable of transferring genes responsible for resistance to b-lactam, aminoglycoside, sulfonamide and quaternary ammonium antimicrobial agents. Conjugate plasmids were also isolated, but from a small percentage of isolates. This study showed that the Mhlathuze River (a) is a medium for the spread of bacterial antibiotic resistance genes, (b) acts as a reservoir for these genes and (c) due to socio-economic pressures, may play a role in the development and evolution of these genes along this river system.
Genetic analysis of noroviruses taken from gastroenteritis patients, river water and oysters
Authors: Ueki Y. , Akiyama K. , Watanabe T. , Omura T.
Published: May 2018

As oysters are eaten raw in Japan, their contamination with the non-bacterial agent of gastroenteritis has become a serious health problem. As it is well known that oysters tend to concentrate noroviruses (NV) in their digestive diverticula, NV may be linked with the acute gastroenteritis. However, since NV cannot be cultivated in cell cultures, and they have genetic diversity, the behaviour of NV in the aquatic environment is little known. In this study, NV samples were taken from gastroenteritis patients; from the river flowing into the oyster-farming area; and from oysters harvested from that river. Genetic identities of NV samples were analysed in capsid and RNA-dependent RNA polymerase (RdRp) regions respectively. In both regions, strains taken from patients were >96% identical with those from river and oyster samples. This proved that oysters were contaminated with NV excreted from patients with gastroenteritis.
Influence of the origin of the inoculum on the anaerobic biodegradability test
Authors: Moreno-Andrade I. , Buitrón G.
Published: May 2018

Five different sources of inocula were studied to determine its influence on biodegradability tests. Inocula were characterized determining granulometry, specific methanogenic activity, solids content, and volumetric sludge index. Also, the fermentative, aceticlastic, hydrogenophilic, OPHA, and sulfate-reducing groups were determined by the most probable number technique. Anaerobic biodegradability tests were conducted with two different substrates, one easy to degrade (glucose) and a toxic one (phenol). The best performance, in terms of percent of biodegradation and lag time, for both substrates, was obtained with the inoculum from a brewery industry UASB. The results can be explained in terms of the initial activity of the inoculum. The influence of the significant variations found in the specific methanogenic activity of the five inocula studied is discussed, in terms of the microbial composition of the samples. The results emphasized the importance of the selection of an appropriate source of inoculum in order to obtain reliable results.
Waterborne gastroenteritis outbreak in Albania
Authors: Divizia M. , Gabrieli R. , Donia D. , Macaluso A. , Bosch A. , Guix S. , Sánchez G. , Villena C. , Pintó R.M. , Palombi L. , Buonuomo E. , Cenko F. , Leno L. , Bebeci D. , Bino S.
Published: May 2018

Three different studies are reported concerning the environmental pollution caused by viruses in Albania. The first study describes an outbreak of gastroenteritis in the capital city, involving 2,722 children attending the Paediatric Unit of Tirana Hospital. The age group with the highest morbidity was 0-5 years, with 89.5%; no fatalities were recorded during the outbreak. Rotavirus was detected in 26/28 faecal samples by RT-PCR, although astrovirus, adenovirus and calicivirus were also present. The second study describes an outbreak of hepatitis A virus involving the city of Lac. Two hundred cases were recorded, with the highest incidence in the age-group 5-9 years. Phylogenetic analysis of the VP1/2A region showed the presence of a unique sequence: genotype IA. Rotavirus was identified in drinking-water samples collected during the outbreak. The third study describes the prevalence of HAV and HEV in 202 sera randomly collected from 12 different cities in Albania. HAV showed a high incidence (66.2%), whereas none was positive for HEV. The genomic analysis of the VP1/2A junction revealed the presence of only one genotype (IA) with few point mutations and just two amino acid substitutions at codons 22 and 34. Additionally, two potential antigenic variants were detected, the first at position 46 of VP3 and the second at position 23 of VP1.
Dynamic evaluation of a fixed bed anaerobic digestion process in response to organic overloads and toxicant shock loads
Authors: Dupla M. , Conte T. , Bouvier J.C. , Bernet N. , Steyer J.P.
Published: May 2018

This paper details a dynamic evaluation of a 1 m3 fixed bed anaerobic digestion reactor in response to organic overloads and toxicant shock loads. Raw industrial wine distillery wastewater was used as a reference substrate and several disturbances were applied to the process: (i) organic overloads with and without pH regulation in the feeding line, (ii) adding of ammonia in the input wastewater. The purpose of this study was to assess, using on-line instrumentation, the robustness of a fixed bed anaerobic digester. Anaerobic digestion processes have the reputation of being difficult to operate and prone to process instability due to external disturbances and the objective of this study was to demonstrate the possibility of such a reactor configuration for industrial use.
Application of HACCP principles as a management tool for monitoring and controlling microbiological hazards in water treatment facilities
Authors: Jagals C. , Jagals P.
Published: May 2018

HACCP (hazard analysis and critical control points) principles were applied to evaluate the effectiveness of two water treatment facilities to continually produce potable water free of microbiological health hazards. This paper reports a hazard analyses protocol (microbiological hazards based on faecal coliforms (FC) and turbidity (TBY) as indicators) for critical control points (CCPs) within each facility. The CCPs were raw resource water, sedimentation, filtration and chlorine-disinfection. The aim was to determine the effectiveness of each CCP to remove the indicators from the water under treatment. Arbitrary critical performance limit targets (CPLTs) were set up for each CCP to determine to what extent each contributed to effective removal and to predict what the effect would be if any of the CCPs should fail. Health-related water quality guideline limits for expected health effects were applied and compliance measured at the 90th percentile. The raw resource river water used at both treatment facilities complied with raw resource water extraction CPLTs. The treated potable water complied with health-related drinking water guidelines. Sedimentation removed the largest proportion of the indicators from the raw water, but showed failure potential that could overload the consequent system. Filtration effectiveness at both treatment facilities showed potential to break down the overall effectiveness of the entire treatment facility, since the filter systems failed to meet their respective CPLTs. This left the disinfection phase to remove the remaining portion of indicators. Faecal coliforms appeared to be completely removed from post-chlorination samples. This indicated that both chlorine disinfection phases were 100% effective in meeting their disinfection CPLTs, despite having to “clean up” the indicator organisms that spilt over from the upstream CCPs. This, nevertheless, implied a risk of unsafe water release into distribution. CCPs at these treatment facilities had some difficulties in reducing the health-related risks to meet their respective CPLTs. Applying a HACCP programme would minimise the risk of contaminated water distribution in cases of system component failure.
Investigation of opportunistic pathogens in municipal drinking water under different supply and treatment regimes
Authors: Pryor M. , Springthorpe S. , Riffard S. , Brooks T. , Huo Y. , Davis G. , Sattar S.A.
Published: May 2018

Changing regulations to lower disinfectant byproducts in drinking water is forcing utilities to switch disinfection from chlorine to monochloramine. It is generally unknown whether this will impact positively or negatively on the microbiological quality of drinking water. A utility in Florida, using water with relatively high organic carbon levels from deep wells in several wellfields, made the decision to change its disinfection regime from chlorine to chloramine in order to meet the new regulations. To assess the impacts of such a change on the microbiology of its water supplies, it undertook a number of studies before and after the change. In particular, the presence of the opportunistic pathogens Legionella and Mycobacterium, and also the composition of drinking-water biofilms, were examined. A preliminary synthesis and summary of these results are presented here. Legionella species were widely distributed in source waters and in the distribution system when chlorine was the disinfectant. In some samples they seemed to be among the dominant biofilm bacteria. Following the change to monochloramine, legionellae were not detected in the distribution system during several months of survey; however, they remained detectable at point of use, although with less species diversity. A variety of mycobacteria (21 types) were widely distributed in the distribution system when chlorine was the disinfectant, but these seemed to increase in dominance after chloramination was instituted. At point of use, only four species of mycobacteria were detected. Other changes occurring with chloramination included (a) an altered biofilm composition, (b) increased numbers of total coliforms and heterotrophs and (c) nitrification of water storage tanks. The results suggested that consideration should be given to the microbiological effects of changing disinfection regimes in drinking-water and distribution system biofilms.
Removal of natural organic matter from water using a nano-structured photocatalyst coupled with filtration membrane
Authors: Sun D. , Meng T.T. , Loong T.H. , Hwa T.J.
Published: May 2018

A study of the characteristics of a novel photocatalyst indicated that it consisted of 17.3 nm nano size (average) TiO2 in the anatase phase and porous Fe2O3. SEM results revealed that nano size TiO2 was uniformly deposited onto the surface of Fe2O3 to form a bulk photocatalyst, as TiO2/Fe2O3. The porous TiO2/Fe2O3 catalyst had a BET surface area of 168 m2/g, which is three times higher than that of commercial TiO2. The experimental results indicated that the suspended TiO2/Fe2O3 photocatalyst in a photocatalytic oxidation (PCO) reactor was effective in removing TOC at 61.58% and color400 at 93.25% at 180 min illumination time, under 0.4 g/l catalyst loading and pH 7. Experimental results also revealed that pH at 7 and TiO2/Fe2O3 loading at 0.4 g/l was the optimum condition for removal of humic acids using a PCO reactor. Experimental results clearly indicated that the permeate flux rate of the ultrafiltration (UF) membrane was improved and the filtration membrane fouling phenomenon was reduced with the addition of TiO2/Fe2O3 photocatalysts to the UF membrane system. It was found that increasing the filtration time from 40 min to 185 min, the improvement to the permeate flux rate was from 57 to 83 L/hr.m2.
Removal of chromium hexavalent from rinsing chromating waters electrochemical reduction in a laboratory pilot plant
Authors: Martínez S.A. , Rodríguez M.G. , Aguilar R. , Soto G.
Published: May 2018

In this work, experiments in a 16 L operating volume laboratory pilot plant with ring iron rotary electrodes were performed, obtaining an overall kinetic equation rate of hexavalent chromium reduction concentration and current density-dependent. Other scale-up criteria such as Reynolds' number were also evaluated to ensure a completely stirred reactor at low energy expenditure. A dimensionless NE is a relationship between liquid properties and the electric charge supplied to the system. The number, which depends on the rotation iron ring electrode speed number and the current density, is proposed to be used as scale-up criterion. It was found that at NRe = 42,179 (130 rpm rotation electrodes rate) and at NE = 9.8 × 105 (current density of 113 A/m2), complete mixing was reached at minimum energy spent and the process becomes more efficient. In addition, it was found that the higher the current density, the less treatment time and less energy spent on agitation. After the electrochemical treatment the CrVI concentration in the rinsing wastewater was less than 0.5 mg/L.
Validation of biomarkers for impact evaluation of aqueous industrial waste in mesocosms
Authors: Bassères A. , Simonet F. , Lafont M. , Coste M. , Narbonne J.-F.
Published: May 2018

The use of exposure biomarkers in measuring the impact of aqueous waste holds promise because such tools have short response times, are flexible in use and may give an indication about the type of pollution. However, their ecological significance has not yet been demonstrated. It is necessary to validate these responses under controlled conditions before using such biomarkers for biomonitoring. The TotalFinaElf company has developed a pilot scheme incorporating such controlled conditions. This pilot is a dynamic open mesocosm (16 channels 40 m in length supplied with river water). The research programme currently carried out in the “Pilot Rivers” aims at validating biochemical parameters (components of phases I and II (de)toxication metabolism and propionylcholinesterase activity), measured in a fresh water bivalve Corbicula fluminea as a biomarker of water quality. The comparison between biomarker responses and community ones (reference) gives information about the precocity and sensitivity of these biomarker responses. Pure substances (trichloroethylene (TCE), cadmium (CD) and anthracenic oil (AO)) have been injected during one month. Biomarker responses are as sensitive as the most sensitive community response in the presence of CD and AO. With TCE, community responses are more sensitive. Precocity of biomarker response is observed only in the presence of CD.
Using bioluminescent biosensors for hazard analysis and critical control point (HACCP) in wastewater control
Authors: Valat C. , Champiat D. , Degorce-Dumas J.-R. , Thomas O.
Published: May 2018

Starting from a new approach for water pollution control and wastewater treatment plant management, the hazard analysis and critical control point (HACCP) quality concept, the interest for the development of new rapid and sensitive methods such as bioluminescence-based methods is evident. After an introduction of the HACCP procedure, a bibliographic study of the bioluminescence potentiality is presented and discussed.
Using ultraviolet light for disinfection of finished water
Authors: Bukhari Z. , Abrams F. , LeChevallier M.
Published: May 2018

Ultraviolet light is now recognised to be very effective for inactivation of Cryptosporidium parvum oocysts; however, its application for disinfection of finished water necessitates validation of UV reactors prior to their installation. Although reactor performance will likely be assessed using non-pathogenic microorganisms as biodosimetry surrogates, it would be prudent for the water industry to simultaneously measure Cryptosporidium oocysts inactivation in controlled bench-scale studies using the water matrix intended for disinfection. The likelihood of that occurring is dependent upon the availability of infectivity measurement procedures that are more user-friendly than the mouse infectivity assays currently used. This study describes a modified cell culture procedure that would enable reliable measurement of changes in oocysts' infectivity following their UV treatment. Also, a number of different biodosimetry surrogates were examined and one selected for comparing the UV doses delivered between bench-scale and full-scale biodosimetry studies. Impacts of UV disinfection on production of disinfection byproducts, effects of lamp ageing on effectiveness of disinfection and the costs associated with employing this technology were also examined.
Evaluation of the purification capacity of nine portable, small-scale water purification devices
Authors: Hörman A. , Rimhanen-Finne R. , Maunula L. , von Bonsdorff C.-H. , Rapala J. , Lahti K. , Hänninen M.-L.
Published: May 2018

A test was performed to evaluate the microbial and chemical purification capacity of nine portable, small-scale water purification filter devices with production capacity less than 100 L/h. The devices were tested for simultaneous removal capacity of bacteria (cultured Escherichia coli, Clostridium perfringens, Klebsiella pneumoniae and Enterobacter cloacae), enteric protozoans (formalin-stored Cryptosporidium parvum oocysts), viral markers (F-RNA bacteriophages) and microcystins produced by toxic cyanobacterial cultures. In general, the devices tested were able to remove bacterial contaminants by 3.6-6.9 log10 units from raw water. Those devices based only on filtration through pores 0.2-0.4 μm or larger failed in viral and chemical purification. Only one device, based on reverse osmosis, was capable of removing F-RNA phages at concentrations under the detection limit and microcystins by 2.5 log10. The present study emphasised the need for evaluation tests of water purification devices from the public safety and HACCP (Hazard Analysis and Critical Control Point) points of view. Simultaneous testing for various pathogenic/indicator microbes and microcystins was shown to be a useful and practical way to obtain essential data on actual purification capacity of commercial small-scale drinking-water filters.
A simplified low-cost approach to antibiotic resistance profiling for faecal source tracking
Authors: Ebdon J.E. , Wallis J.L. , Taylor H.D.
Published: May 2018

Antibiotic resistance profiling (ARP) is a potentially useful method for distinguishing faecal bacteria according to host source. This phenotypic approach has cost benefits over genotypic methods, but existing protocols are time-consuming and manual data handling is open to human error. A simplified, low-cost approach to the ARP technique was developed that used automated data recording techniques combined with simple statistical analyses to compare isolates of the genus Enterococcus from various faecal sources. An initial battery of 21 antibiotics (at up to four concentrations) was chosen for source discrimination. Images of growth or non-growth in microplate wells were stored as bitmaps and converted to binary data to form a database of known antibiotic resistance profiles. Discriminant function analysis (DFA) showed that the average rate of isolates correctly classified by the database (wastewater vs non-wastewater) was 86%. Once the more discriminating antibiotics and their concentrations had been identified, it was possible to reduce the number of tests from 80 to 18 whilst increasing the number of correctly classified human isolates. ARP could offer a low-cost and rapid means of identifying sources of faecal pollution. As such, the technique may be of particular benefit to developing countries, where water quality may have a significant impact on health and where cost is a major factor when choosing environmental management technology.
Differentiation of faecal Escherichia coli from human and animal sources by random amplified polymorphic DNA-PCR (RAPD-PCR)
Authors: Venieri D. , Vantarakis A. , Komninou G. , Papapetropoulou M.
Published: May 2018

In this study the assessment of randomly amplified polymorphic DNA (RAPD) analysis was established as a molecular epidemiological tool. RAPD analysis was performed to differentiate faecal Escherichia coli isolates from human and animal sources. E. coli strains (128) were isolated from human and animal faeces (from cattle and sheep). Genomic DNA was extracted and randomly amplified polymorphic DNA-PCR (RAPD-PCR) fingerprinting was performed. Seven arbitrary primers were tested with a view to discriminating between E. coli isolates from humans and E. coli isolates from animals. RAPD profiles were analysed with hierarchical cluster analysis using an unweighted pair group method. RAPD profiles obtained with three of the tested primers (1247, 1290 and 1254) established a distinct differentiation between E. coli isolates from humans and E. coli from animals. Low levels of misclassification and high levels of specificity make RAPD a sensitive, efficient and reliable means of distinguishing closely related strains.
Application of a molecular method for the detection of group A rotaviruses in raw and treated water
Authors: van Zyl W.B. , Williams P.J. , Grabow W.O.K. , Taylor M.B.
Published: May 2018

Group A human rotaviruses (HRVs) are the most important aetiological agents of acute viral gastroenteritis in infants and young children in both developing and industrialised countries. Rotaviruses are resistant to many chemical disinfectants and reportedly survive well in treated tapwater and sewage. In this study a group A specific reverse transcriptase-polymerase chain reaction (RT-PCR) followed by a nested-PCR was applied for the detection of HRVs in raw and treated drinking-water samples drawn at a water reclamation plant. For a period of two years (July 2000 to June 2002), borehole, raw and treated drinking-water samples were collected weekly. Viruses were recovered from the water samples using a glass wool adsorption-elution technique followed by secondary concentration using precipitation with polyethylene glycol. In the first year of the study group A HRVs were detected in 11% sewage samples, 8% partially treated waters and 5% final treated drinking waters. The results of the second year of the study showed the presence of group A HRVs in 11% sewage and untreated surface water samples, 15% partially treated water and 6.5% final treated drinking waters. No HRVs were detected in the water samples from the boreholes. The presence of group A HRVs in treated drinking-water samples suggested that this water could be a potential source of infection to consumers. The data also implied that either the water treatment did not remove HRVs or the treated water was contaminated post-treatment.
Evaluation of virological quality of sewage from four biological treatment plants by a nested-PCR technique
Authors: Komninou G. , Vantarakis A. , Venieri D. , Papapetropoulou M.
Published: May 2018

In order to determine the virological quality of sewage from four biological treatment plants in Greece (two in the city of Athens and two in the city of Patras), 92 raw sewage samples were analysed for the presence of enteroviruses and adenoviruses during the period from October 2000 to February 2003. A nested-PCR method was used in order to increase the sensitivity of virus detection. Enteroviruses were detected in 43 samples (47%) and adenoviruses in 75 samples (81.5%) of raw sewage by nested PCR. The more frequent isolation of adenoviruses in raw sewage indicated their stability as virological indicators of the pollution of the environment and their increased persistence in sewage.
Assessment of virulence-factor activity relationships (VFARs) for waterborne diseases
Authors: Jenkins T.M. , Scott T.M. , Cole J.R. , Hashsham S.A. , Rose J.B.
Published: May 2018

Virulence-factor activity relationship (VFAR) is a concept that was developed as a way to relate the architectural and biochemical components of a microorganism to its potential to cause human disease. Development of these relationships requires specialised bioinformatics databases that do not exist at present. A pilot-scale VFAR database was designed for three different waterborne organisms: Escherichia coli, Norovirus and Cryptosporidium, to evaluate VFAR relationships. For the web-based database, each organism has separate pages containing virulence genes, occurrence genes, primer sets and probes, taxonomy, outbreaks, and serotype/species/genogroup/genotype. As the database continues to grow, it will be possible to relate the occurrence and prevalence of certain genes in various microorganisms to outbreak data and, subsequently, to establish the utility of using a combination of specific genes as markers of virulence and in establishing virulence-factor activity relationships (VFARs). The database and the VFARs established will be of use to the regulatory community as a way to assist with prioritising those organisms, which need to be regulated.
Copper corrosion kinetics and mechanisms in the presence of chlorine and orthophosphate
Authors: Zhe Y. , Pehkonen S.O.
Published: May 2018

Copper corrosion in the presence of orthophosphate and chlorine has indicated the formation of a protective scale containing either CuO or Cu2O depending on the pH. Furthermore, the scale forms relatively quickly, after 15 days of immersion EIS showed very little change. The scale is initially porous, but after prolonged immersion, the porous structure disappears, as evidenced by SEM. The equivalent circuit that is used to model the EIS spectra fits the data well and yields useful information on values, such as Rct, which varies from 2 to 10 kΩ and Rfilm, which varies from 15 to 80 kΩ when the immersion time is extended from 2 to 30 days.
Utilization of treated swine wastewater for greenhouse tomato production
Authors: Cheng J. , Shearin T.E. , Peet M.M. , Willits D.H.
Published: May 2018

An integrated system has been developed to recycle waste organics and treated wastewater from a swine farm to make value-added products and to protect the environment from potential contamination. The farm is a farrow-to-wean swine operation with approximately 4,000 sows. A high-strength wastewater (chemical oxygen demand, 18,000 mg/l; total Khejdal nitrogen, 1,600 mg/l; total phosphorus, 360 mg/l) is produced from the swine operation. An ambient-temperature anaerobic digester has been used to treat the swine wastewater and to produce biogas (from an average 475 m3/day in winter to 950 m3/day in summer). The biogas is combusted in an engine to produce electricity (around 900 kW-hr/day). The digester effluent that is rich in nutrients (N, P, and minerals) is then utilized for fertigation for greenhouse tomato production. A trickling nitrification biofilter has been developed to convert ammonium in the effluent into nitrate. The nitrified anaerobic effluent is used as both fertilizer and irrigation water for approximately 14,400 tomato plants in greenhouses. Experimental data indicate that the tomato greenhouses have used approximately 12 m3 of the effluent and 3.84 kg nitrogen per day. At the same time, the greenhouses have a daily yield of 520 kg (37 g/plant) of marketable fruit.
Combined membrane bioreactor (MBR) and reverse osmosis (RO) system for thin-Þlm transistor - liquid crystal display TFT-LCD, industrial wastewater recycling
Authors: Chen T.K. , Chen J.N.
Published: May 2018

In TFT-LCD industry, water plays a variety of roles as a cleaning agent and reaction solvent. As good quality water is increasingly a scarce resource and wastewater treatment costs rises, the once-through use of industrial water is becoming uneconomical and environmentally unacceptable. Instead, recycling of TFT-LCD industrial wastewater is become more attractive from both an economic and environmental perspective. This research is mainly to explore the capacity of TFT-LCD industrial wastewater recycling by the process combined with membrane bioreactor and reverse osmosis processes. Over the whole experimental period, the MBR process achieved a satisfactory organic removal. The COD could be removed with an average of over 97.3%. For TOC and BOD5 items, the average removal efficiencies were 97.8 and 99.4% respectively. The stable effluent quality and satisfactory removal performance were ensured by the efficient interception performance of the UF membrane device incorporated with biological reactor. Moreover, the MBR effluent did not contain any suspended solids and the SDI value was under 3. After treatment of RO, excellent water quality of permeate were under 5 mg/l, 2.5 mg/l and 150 ms/cm for COD, TOC and conductivity respectively. The treated water can be recycled for the cooling tower make-up water or other purposes.
Impact of localised dissolved iron concentrations on the biofouling of environmental wells
Authors: Stuetz R.M. , McLaughlan R.G.
Published: May 2018

Iron biofouling of wells can significantly impact the performance of a groundwater extraction system. A subsurface drainage scheme (Wakool, Australia) designed to reduce waterlogging was used to identify some of the relationships between aquifer properties and well biofouling. Piezometers drilled radially one metre from two biofouled wells showed that during normal well operation the concentration of dissolved iron (Fe2+) entering the groundwater well was highly localised around the site and with depth. CCTV survey of the biofouling on the well screens supported these findings of localised iron concentrations. Dissolved oxygen (DO) measured during pumping and under non-pumping conditions (aquifer DO) showed that oxygen was not a limiting factor, whereas stalked bacteria (Gallionella sp.) were only found in the biofouled wells. The wellhead water therefore represents only a composite of all the waters entering the well and does not indicate the possibility of localised iron concentrations in a shallow aquifer. The degree of iron biofouling within a groundwater well is therefore related directly to the presence of dissolved iron in the groundwater, as well as various oxidative processes occurring as the groundwater enters the well screen and its subsequent extraction. The distribution of iron biofilms on the well screen reflects these processes; however, the presence of well biofouling cannot always be linked to a decrease in well screen performance, but can have an impact on the overall performance of the groundwater extraction system.
Calcium carbonate scale control, effect of material and inhibitors
Authors: Macadam J. , Parsons S.A.
Published: May 2018

This paper focuses on developing a reproducible method for reducing calcium carbonate scale formation on heated surfaces where scaling can cause serious problems. It is known that calcium carbonate precipitation is sensitive to impurity ions, such as iron and zinc, even at trace concentration levels. In this paper two sets of experiments are reported. The first experiments were undertaken to investigate the effect of zinc, copper and iron dosing on CaCO3 nucleation and precipitation. Results from the experiments showed that the most effective inhibitor of CaCO3 precipitation was zinc and the effect was linked to dose levels and temperature. Copper and iron had little effect on precipitation in the dose range investigated. The second trial was undertaken to translate the precipitation data to scale formation. These tests were undertaken at 70°C. 5 mg.L-1 zinc dose reduced the scale formation by 35%. The effect of iron on calcium carbonate scaling rate was not significant. The physical nature of the material on which the scale is formed also influences the scaling. The scaling experiment was also used to investigate the effect of different surface material (stainless steel, copper and aluminium) on CaCO3 scale formation. Copper surface scaled the most.
Struvite control through process and facility design as well as operation strategy
Authors: Neethling J.B. , Benisch M.
Published: May 2018

Struvite deposition is a common problem in municipal wastewater treatment plants and can be signi?cant if not anticipated, but struvite deposits are completely manageable if properly addressed. This paper summarises experiences from a number of facilities that have dealt successfully with struvite problems, elaborates on the interrelations between secondary treatment and anaerobic digestion, and outlines an approach to control struvite and available alternatives.
Mathematical model for describing reactions of residual chlorine with organic matter in reclaimed wastewater
Authors: Funamizu N. , Iwamoto T. , Takakuwa T.
Published: May 2018

Among several applications of urban wastewater reuse, use of reclaimed wastewater to sustain stream flows has become attractive in the urban area. Since these rivers are used for recreational purposes and for restoring aquatic eco-system, the adequate control of residual chlorine is essential. Mathematical model for describing reactions between residual chlorine and organic matter in reclaimed wastewater has been developed. The model considers the effect of molecular weight distribution of organic matter on the reaction rate. Lab-scale experiments were performed to estimate reaction rates constants and to examine their temperature dependency. The experiments showed that 1) the smaller organic matter gave the larger reaction rate; 2) temperature effect on reaction rate was described by the Arrhenius formula; 3) decline of free chlorine had more temperature dependency than combined chlorine. The comparison of computed results with data from lab-scale experiments confirmed the validity of the model. We used the one-dimensional dispersion model with proposed reaction model and examined the seasonal variation of residual chlorine profile along the river sustained by reclaimed wastewater in Sapporo. Simulation showed that seasonal variation of nitrification performance in secondary treatment as well as change in temperature caused seasonal variation in residual chlorine profile along the river.
Pharmaceutical rejection by membranes for wastewater reclamation and reuse
Authors: Park G.-Y. , Lee J.H. , Kim I.S. , Cho J.
Published: May 2018

Various membranes, which have different materials and nominal molecular weight cut-offs (MWCO), were compared in terms of rejection of ibuprofen and removal of effluent organic matter (EfOM) from membrane bioreactor (MBR), because pharmaceutical compounds contain a potential risk and EfOM is the precursor of carcinogenic disinfection by-products when reusing for drinking water source. To provide equivalent comparison with respect to hydrodynamic condition, mass transfer parameter, J0/k ratio, was used. A tight-UF membrane with a molecular weight cut off of 8,000 daltons exhibited 25∼95% removal efficiencies of ibuprofen with a molecular weight of 206 with and without presence of EfOMMBR. EfOMMBR caused the reduction of ibuprofen removal efficiency for UF membrane. Rejection of EfOMMBR by UF and NF membranes ranged 29∼47% and 69∼86%, respectively. UF membrane could successfully remove ibuprofen at lower J0/k ratio range (≤1) in organic free water but could not efficiently reject ibuprofen with a relatively hydrophilic EfOMMBR (SUVA ≤3).
Modeling the fate and transport of organic and nitrogen species in soil aquifer treatment process
Authors: Kim J.-W. , Kim J. , Choi H. , Schwartz F.W.
Published: May 2018

Soil aquifer treatment (SAT) is a promising technique for wastewater reclamation and reuse. This treatment strategy takes advantage of physicochemical and biological processes in the subsurface. The model employed in this study is based on MODFLOW-SURFACT (HydroGeoLogic, Inc.), a three-dimensional model for variably saturated flow and reactive mass transport. The model accounts for reactions including the nitrification of ammonium, the denitrification of nitrate, and the oxidation of organic carbon. Concentration of dissolved oxygen and biomasses involved in aerobic and anaerobic biological reactions forms the basis for estimates of nonlinear reaction rates formulated using a multiple-Monod expression. Illustrative simulations were conducted in a two-dimensional cross-sectional domain, with unsaturated and saturated zones. They examine the effects that site and operational conditions have on the performance of a SAT system. The parameters and conditions of concern included length of the wet/dry cycle, ground surface condition, and infiltration rate. From the simulations, we found that organic carbon was effectively removed in all cases. The availability of oxygen was a key factor in predicting the production and removal of nitrate. Overall, the model successfully described the fate and transport of the key constituents during the wet/dry operational periods in both unsaturated and saturated subsurface.
Sorption behaviors of heavy metals in SAT (soil aquifer treatment) system
Authors: Lee So Young , Lee Jong-Un , Choi Heechul , Kim Kyoung-Woong
Published: May 2018

Degradation or detoxification of pollutants by SAT system was generally focused on organic contaminants although the regulation of water reuse has provisions of heavy metals. This study is to evaluate the feasibility of SAT for metals such as Cd, Cr and Pb with the pilot scaled column experiment. The desorption possibility of sorbed metals was also examined in the condition of continuous water and even acidic water (pH 4.3) injection. Fractional factorial analysis is a tool frequently used to identify factors or variables that have an effect on a certain response. A two-level fractional factorial analysis was planned to study the effect of four factors on Pb sorption from the experiments; soil particle size, TOC in solution, Pb concentration in solution and flow rate. The main effects among the factors were obtained by ANOVA based MINITAB software. The effects of four factors were also converted into coefficients; those values may build an empirical model to predict the metal sorption of soils.
Effect of irrigation water quality on organic matter, Cd and Cu mobility in soils of central Mexico
Authors: Herre A. , Siebe C. , Kaupenjohann M.
Published: May 2018

Untreated wastewater has been used for irrigation since 1912 at the Irrigation District 03, Central Mexico. Accumulated heavy metals are dominantly bound to the organic soil fraction. In a field study we evaluated the effect of wastewater irrigation on the quality of soil organic matter and the amount of water extractable Cu and Cd. In a column experiment we tested if water treatment affects the leaching of both metals and dissolved organic carbon (DOC) out of soils that have been irrigated for more than 90 years with untreated wastewater. The field study shows that long term irrigation increases the mineralizable carbon fraction and the DOC concentrations. The water extractable Cu and Cd concentrations also increase and correlate with DOC. In the column leachates the Cu concentrations also correlate with DOC, the Cd concentrations correlate with the sum of cations, chloride and DOC concentrations. Water treatment reduced Cd leaching, but it did have no substantial effect on Cu leaching.
Current status of water reuse systems in Korea
Authors: Noh S. , Kwon I. , Yang H.-M. , Choi H.-L. , Kim H.
Published: May 2018

In Korea, the current water resources will fall short by 2.6 billion tons to meet the 38 billion ton water demand in the year 2020. To overcome the future water shortage, it is desirable to minimize water consumption and to reuse treated wastewater. There are a total of 99 on-site water-recycling systems in the country. The potential capacity of the 99 systems is 429 thousands tons/day, which is 3.6% of the total service water. Compared to other industrialized countries, the number of the water recycling systems in Korea is extremely small. This is mainly due to the following reasons. First, in Korea, any building with more than 60,000 m2 of total floor space is required to install a water reuse system by law. However, only less than 0.5% of the total buildings have more than 10,000 m2. Therefore, the regulation is ineffective and merely nominal. Second, service water is supplied at low charge (0.20 US-dollar/m3 water). The inexpensive service water often discourages people to recycle treated wastewater. Third, people still think recycled water is not clean enough and can cause diseases. Therefore, they should be informed that a well-maintained recycling system does not fail to produce water with high quality.
Occurrence and control of filamentous bulking in aerated wastewater treatment plants of the French paper industry
Authors: Fourest E. , Craperi D. , Deschamps-Roupert C. , Pisicchio J.-L. , Lenon G.
Published: May 2018

The occurrence of filamentous bacteria was investigated in 15 French pulp and paper activated sludge wastewater treatment plant (WWTP). Large filamentous populations were present in most of the plants. Identification carried out with conventional methods based on morphological features and staining techniques showed that the four main filamentous bacteria encountered in these industrial WWTP and responsible for bulking belong to the genera Thiothrix sp., Type 021N, Haliscomenobacter hydrossis and Type 0092. During two years a specific survey was performed for three of these WWTP showing recurrent bulking phenomena. Data from WWTP performance, chemical data and filaments characterization were compared to correlate the presence of specific filaments with process operating conditions.
Hydrogeologic controls on the transport and fate of nitrate in ground water beneath riparian buffer zones: results from thirteen studies across the United States
Authors: Puckett L.J.
Published: May 2018

During the last two decades there has been growing interest in the capacity of riparian buffer zones to remove nitrate from ground waters moving through them. Riparian zone sediments often contain organic carbon, which favors formation of reducing conditions that can lead to removal of nitrate through denitrification. Over the past decade the National Water Quality Assessment (NAWQA) Program has investigated the transport and fate of nitrate in ground and surface waters in study areas across the United States. In these studies riparian zone efficiency in removing nitrate varied widely as a result of variations in hydrogeologic factors. These factors include (1) denitrification in the up-gradient aquifer due to the presence of organic carbon or other electron donors, (2) long residence times (>50 years) along ground-water flow paths allowing even slow reactions to completely remove nitrate, (3) dilution of nitrate enriched waters with older water having little nitrate, (4) bypassing of riparian zones due to extensive use of drains and ditches, and (5) movement of ground water along deep flow paths below reducing zones. By developing a better understanding of the hydrogeologic settings in which riparian buffer zones are likely to be inefficient we can develop improved nutrient management plans.