bluuebunny/crossref_metadata_2025 huggingface dataset:
Fenton oxidation with ethanol to degrade anthracene into biodegradable 9,10-anthraquinon: a pretreatment method for anthracene-contaminated soil
Authors: Lee Byung-Dae , Hosomi Masaaki , Murakami Akihiko
Published: May 2018

The anthracene (ANT), and the large amounts of soil contaminated by this hazardous polycyclic aromatic hydrocarbon (PAH), necessitate developing a practical treatment method to prevent further environmental damage. Here, we describe a method for effectively pretreating soil highly contaminated with ANT (≈500 mg ANT/kg soil), i.e., we apply Fenton oxidation in which ethanol is added to increase ANT removal. In addition to determining the optimum amounts of ethanol, Fe2+, and H2O2 needed to achieve maximum removal efficiency of ANT from simulated soil (andesol particles), i.e., ≈97%, we also employ GC-MS and HPLC to determine the main oxidation product generated by the optimized Fenton reaction: 9,10-anthraquinon (ANTQUI). The biodegradability of ANTQUI is subsequently confirmed to be much more rapid than that of ANT, i.e., biodegradability of 90 versus 30% over 30 days, results demonstrating that the proposed treatment method can be effectively applied to remove ANT prior to disposal at industrial waste sites.
Assessment of leaching tests on construction material made of incinerator ash (sewage sludge): investigations in Japan and Germany
Authors: Wiebusch Bernd , Ozaki Masaaki , Watanabe Haruki , Seyfried Carl Franz
Published: May 2018

Heavy metal release from bricks or blocks made of sewage sludge considerably decreases by sintering or cement consolidation. With such treatment, the enviromnental compatibility of recycled material can be ensured. In the framework of joint German-Japanese research, two types of leaching tests were introduced to develop a standardized test for construction material made of sewage sludge. One type is considered as a worst-case-test with low pH-values of 4-5 which describes the leaching availability under strong natural conditions (e.g. acid rain). The other type is a standardized test without pH-control. Both types of tests are investigated by using crushed samples of blocks.

Generally, there are two different ways for a sustainable assessment of the enviromnental compatibility. One way is to use a test with a low pH-value like the worst-case-tests. The other way is to crush the sample in small particles to produce large surfaces when using a standardized test. The smaller the particle size is, the higher is the concentration of heavy metals in the eluate. From the Japanese point of view, blocks are usually utilized in original shape, small particles are not appropriate as samples. That is why medium-sized particles are used for the leaching tests. But using “bigger” particles, lower pH-values can be used. Therefore, a modified Swiss method is assumed to be suitable as a new standardized test for the effect of acid rain. This method is discussed from the point of view of sample diameter. From the German point of view, crushed samples with diameter <10 mm are used in combination with a standardized test. The heavy metal release from Japanese re-products is very low, and it has a close relationship with the release of the alkaline and alkaline earth metals. This effect can be shown on ash bricks from Germany also. Considering recommended limits in Germany, higher firing temperatures of >1100°C should be used.
The use of stress proteins in Mytilus edulis as indicators of chlorinated effluent pollution
Authors: Lawrence A. J. , Nicholson B.
Published: May 2018

This study was performed to examine the use of stress proteins in Mytilus edulis as biomarkers of low level chlorine residual oxidant pollution in the environment. Mussels were exposed to chlorine, heat and heat and chlorine treatments over 14 days. At intervals mussels were removed from each treatment, gill and mantle tissue dissected out and the tissue proteins separated by SDS polyacrylamide gel electrophoresis. The concentration of sample proteins was determined by scanning densitometry and compared to the levels found in control animals. In addition, western blot analysis was performed using monoclonal hsp 70 primary antibody to qualitatively assess stress 70 protein level in each treatment after 14 days. Chlorine residual oxidants in the region of 0.01-0.07 mgl−1 induced significant changes in protein expression in the gill of treated mussels. Chlorine treatment was the strongest inducer of 68-72 kDa stress proteins over 14 days and also increased synthesis of 29 kDa protein. Temperature alone increased 43-47 kDa proteins. Each treatment also reduced synthesis of 78 kDa protein (grp 78) and 52-67 kDa proteins. Clear differences were observed in protein synthesis between gill and mantle tissue. The results indicate that stress proteins can be used as indicators of chlorinated effluent pollution in natural populations.
Bioleaching of metals from soils or sediments
Authors: Tichy R. , Rulkens W. H. , Grotenhuis J. T. C. , Nydl V. , Cuypers C. , Fajtl J.
Published: May 2018

Bioleaching can be one of few techniques applicable for the removal of toxic metals from polluted soils or sediments. Its principle is a microbial production of sulphuric acid and leaching of metals with it. The use of bioleaching can benefit from the use of low-cost substrates and from a possible coupling to other processes of microbial sulphur cycle, like sulphate reduction to treat spent bioleaching liquor, or partial sulphide oxidation to recycle sulphur. For the evaluation of bioleaching, the existence of different leaching strategies is considered, i.e. intensive or extensive extraction. The intensive extraction uses high concentrations of acid at short extraction times, whereas low acid additions and long treatment times are used in extensive processes. On a reference study with wetland sediment receiving mine drainage we demonstrated that the bioleaching is a typical extensive process. The bioleaching experiments involved the use of the different sulphur substrates, i.e. orthorhombic sulphur flower and microbially produced, recycled sulphur from partial sulphide oxidation process. The latter type of sulphur substrate performed considerably better.
Pollution prevention and restoration in the golden horn of Istanbul
Authors: Inanç Bülent , Kinaci Cumali , Öztürk Izzet , Sevimli Mehmet Faik , Arikan Osman , Öztürk Mustafa
Published: May 2018

The pollution in the Golden Horn is one of the most important environmental problems of Istanbul. Alluvium carried by Alibey and Kagithane creeks, and domestic and industrial wastewater discharges are the major sources of the pollution. In the upstream, a part of 3 to 4 km long is almost completely filled with debris and organic solids. There is a high anaerobic activity in the sediment resulting in a heavy odor problem. Sea traffic is impossible since the depth of water is less than 10 cm at this part. A restoration feasibility project has been carried out for pollution prevention and evaluation of the restoration alternatives. For this purpose, first, characteristics of water quality and bottom sediment were determined. Second, pollution prevention measures and the alternatives for the dredging and disposal of the bottom sediment were evaluated. Istanbul Metropolitan Municipality has already started the dredging work by early 1997, and has completed the diversion of all domestic and industrial wastewater discharges out of the Golden Horn. This paper summarizes the studies for determining current status, evaluating the restoration alternatives, and also the progress of the on-going dredging work.
Application of biofilm kinetics to the sulfur/lime packed bed reactor for autotrophic denitrification of groundwater
Authors: Wang Zhishi
Published: May 2018

To evaluate the engineering feasibility of autotrophic denitrification, a program of theoretical and experimental investigations of the granular sulfur/lime packed bed autotrophic denitrification system was planned and completed. This program evaluated the stoichiometric, kinetic and physical characteristics of the process. This paper will focus on the results of that project which are concerned with the kinetics of autotrophic denitrification of groundwater.
Upgrading of waste water treatment plants by cloth-filtration using an improved type of filter-cloth
Authors: Grabbe U. , Seyfried C. F. , Rosenwinkel K.-H.
Published: May 2018

In order to reach in the effluents of wastewater treatment plants values for phosphorous below 0,5 mg P/l and for the suspended solids below 5 mg SS/1, a filtration stage is necessary in almost all instances. Apart from conventional deep-bed porous media filters (gravity filters), cloth filtration systems offer a viable alternative because of the low head loss, and their low price. The use of pile fabrics instead of conventional needle felt solves the crucial problem of cloth filtration: the considerable increase of cloth resistance due to the irreversible soiling. Cloth filtration plants equipped with this filter media allow for considerably higher hydraulic strains and for higher surface loads with a separation performance on the same level as reached by conventional systems. If the problem of clogging is solved as well, it should be possible to use pile fabrics with even finer filaments on a pile of micro-fibres, which would further increase the effluent quality.
Intermittent addition of external carbon to enhance denitrification in activated sludge
Authors: Hasselblad S. , Hallin S.
Published: May 2018

Efficient nitrogen removal in a pre-denitrifying activated sludge process strongly depends on the amount and nature of the carbon source in the wastewater. If denitrification has to be supported at periods, the response to a supplemental carbon source should be immediate and substantial. The aim of this work was to study how intermittent addition of ethanol affects process performance and the denitrifying capacity of the biomass in a pre-denitrifying activated sludge process. The investigated intermissions simulated a possible operational situation with a short stop of ethanol addition or a strategy with addition only at weekends. The long-term effect of intermittent addition was also studied. Experiments were performed in a pilot-scale activated sludge plant. Effluent nitrate was measured on-line and potential denitrification rates were determined with the acetylene inhibition technique. Once the bacteria were adapted to the external carbon source, the studied intermission of 24 hours as well as an intermission of six days showed no severe effect on denitrification capacity of the sludge. In order to maintain process stability with intermittent addition, the denitrifying bacteria had to sustain a high capacity at each stop. Five weeks of intermittent addition of ethanol did not change the level of nitrate reduction in the system during periods of ethanol addition. Denitrification potential was, however, negatively affected. The results suggest that it is possible to use an intermittent strategy when adding ethanol as an external carbon source in a pre-denitrifying system and for instance only support the denitrifying bacteria during weekends.
Coagulation and flocculation on water quality matrix
Authors: Tambo Norihito , Kamei Tasuku
Published: May 2018

The effective working zones of various separation processes have characterized by the author on the water quality conversion matrix of a two-dimensional diagram with coordinates of impurity size and chemical nature. In this paper the author describes behaviors of the various water quality components on the matrix with the operations of precipitation, coagulation and flocculation. The formation mechanisms and procedures of various types of flocs from various impurity components are discussed in connection with the structures of various flocs generated from the various components. The nature of flocs are defined mainly by the kinds of the matrix components and selected coagulation operations, and controls performance of the following solid-liquid separation processes.
Enhanced flocculation/sedimentation process by a jet mixed separator
Authors: Watanabe Yoshimasa , Kasahara Shinsuke , Iwasaki Yoshihiko
Published: May 2018

This paper deals with the performance of a jet mixed separator (JMS) which has a series of porous plates inserted in the channel perpendicular to a flow. The water passes through holes in the plates, thus creating jets which gently mix the water on itself. Simultaneous flocculation of suspended particles and sedimentation of grown-flocs occur in the JMS, because large-scale eddies in the vertical plane are almost absent in it. The JMS incorporated with inclined tube settlers was applied to the rapid sand filtration system instead of the combination of mechanical flocculator and sedimentation basin. The turbidity of JMS effluent was constantly below 1 TU at the hydraulic retention time of about 1 hour. The JMS without inclined tube settlers was used as physico-chemical pretreatment process for the rotating biological contactors. The BOD and suspended solids concentration of JMS effluent were around 50 and 40 mg/L, respectively at the hydraulic retention time of 45 min.
Virus removal in a membrane separation process
Authors: Otaki Masahiro , Yano Kazuyoshi , Ohgaki Shinichiro
Published: May 2018

Recently, membrane technology has been considered an alternative to conventional water purification. To study the fate of viruses in membrane processes, indigenous coliphages in pilot scale membrane processes located in the eastern part of Tokyo Metropolitan area have been surveyed for 6 months. This plant used river water as its resource and had two microfiltration membrane processes which had different pore sizes (0.2 μm and 0.1 μm) and one ultrafiltration process which had 13,000 nominal molecular weight cut off. To detect indigenous coliphages, E. coli K12 F+(A/λ) and E. coli C were used as host bacteria. E. coli K12 F+(A/λ) can detect both DNA and RNA phages and E. coli C can only DNA phage. The resource water contained E. coli K12 phages at 200∼1500 PFU/100 mL and the removal ratio of these DNA and RNA phages was lower than that of DNA phage by E. coli C in both MF membrane processes through 6 months. It is thought to be caused by difference of phage size, because DNA phage is bigger than RNA phage in general. The removal ratio of E. coli K12 and E. coli C phages reached 100% in the UF membrane process. According to the comparison of the concentration of phages in solution and eluted from suspended solid in resource and drain, it is thought that most phages concentrated in the drain were absorbed in suspended solids. To make certain of the removal ratio in UF and NF (nanofiltration) processes, high concentrations of coliphage Qβ and poliomyelitis virus vaccine were fed into these processes. The removal ratio of coliphage Qβ in UF and NF processes are 10−8.3 and 10−6.3 respectively, and the ratio of poliomyelitis virus vaccine in UF and NF are <10−6.7 and <10−7.3 respectively.
Optimised lamellae settling process for run off water treatment
Authors: Bridoux G. A. , Villeroux A. , Riotte M. , Huau M. C.
Published: May 2018

Since the more stringent new french standard of the 3rd of January 1992 relating to water and embracing Urban Run Off Water Discharges during wet weather, some research works have been carried out to treat run off water. In particular, processes based on lamellae settler have been studied.

The study presented in this paper describes optimal conditions achieved on a lamellae settler prototype and the results obtained. Parameters investigated were as follow:– injection of coagulant (ferric chloride) controlled by the Suspended Solids (SS) flow feeding the lamellae settler– energy input in the flocculator to improve flocs polymerisation– sludge scraped in the thickened area– optimum adjustment of extracted sludge.

Sludge recirculation combined with on line monitoring of Suspended Solids in the flocculator allowed the maximum sludge loading to be established.

Those optimisations were applied with an hydraulic load of 150 m.h−1. Removal efficiency were 70% for Suspended Solids and 60% for Chemical Oxygen Demand (COD). The concentration of extracted sludge was 30 g.l−1.
Far field modeling of the Mamala Bay outfalls
Authors: Roberts Philip J. W.
Published: May 2018

The results of far field modeling of the wastefield formed by the Sand Island, Honolulu, ocean outfall are presented. A far field model, FRFIELD, was coupled to a near field model, NRFIELD. The input data for the models were long time series of oceanographic observations over the whole water column including currents measured by Acoustic Doppler Current Profilers and density stratification measured by thermistor strings. Thousands of simulations were made to predict the statistical variation of wastefield properties around the diffuser. It was shown that the visitation frequency of the wastefield decreases rapidly with distance from the diffuser. The spatial variation of minimum and harmonic average dilutions was also predicted. Average dilution increases rapidly with distance. It is concluded that any impact of the discharge will be confined to a relatively small area around the diffuser and beach impacts are not likely to be significant.
A rationale for using local and regional point rainfall data for design and analysis of urban storm drainage systems
Authors: Mikkelsen P. S. , Madsen H. , Arnbjerg-Nielsen K. , Jørgensen H. K. , Rosbjerg D. , Harremoës P.
Published: May 2018

The Danish measuring network for high-resolution rainfall data consists of approximately 70 tipping bucket rain gauges of which 41 have been operated for more than 10 years. The gauges are separated by one to 300 km and cover an area of 43,000 km2. Significant geographical variations of extreme rainfall characteristics have been observed. Part of these variations can be explained by correlation with the mean annual rainfall and the existence of a metropolitan effect in the Greater Copenhagen area. The remaining variation may be attributed to sampling errors and small-scale spatial variations close to the gauges. Engineering methodologies all require rain data of some kind, ranging from design storms based on idf-curves for use in simple calculations to high-resolution time series for use in detailed simulation studies. A comprehensive regional analysis was carried out to account for the geographical variation and to improve estimation for large return periods exceeding the actual length of the measured time series. Ideally, rainfall data used as input to urban drainage calculations should always be based on regional rain information. Regional design storms can be made readily available based on theory developed in this study. However, a satisfactory framework for generating synthetic rain series from regional rain information is not yet available. Thus, there will still be a need for using historical rain series in the near future. To improve the basis for choosing representative historical rain series all the Danish gauges have been classified according to their deviations from the regional distribution.
Regional estimation of short duration rainfall extremes
Authors: Nguyen V. T. V. , Nguyen T. D. , Wang H.
Published: May 2018

The present study proposes a method for estimating the distribution of short-duration (e.g., 1 hour) extreme rainfalls at sites where data for the time interval of interest do not exist, but rainfall data for longer-duration (e.g., 1 day) are available (partially-gaged sites). The proposed method is based on the recently developed “scale-invariance” (or “scaling”) theory. In this study, the scaling concept implies that statistical properties of the extreme rainfall processes for different temporal scales are related to each other by a scale-changing operator involving only the scale ratio. Further, it is assumed that these hydrologic series possess a simple scaling behaviour. The suggested methodology has been applied to extreme rainfall data from a network of 14 recording raingages in Quebec (Canada). The Generalised Extreme Value (GEV) distribution was used to estimate the rainfall quantiles. Results of the numerical application have indicated that for partially-gaged sites the proposed scaling method is able to provide extreme rainfall estimates which are comparable with those based on available at-site rainfall data.
Costs and benefits of water quality: Massachusetts as a case example
Authors: Isaac Russell A.
Published: May 2018

Economists have long argued for economic principles to play a major role in pollution control as the most efficient way to achieve goals. To date, there has been limited use of such principles for several reasons including the difficulty of placing a value on intangibles such as environmental quality or, specifically in this case, clean water. However, as financial resources have become more limited, some thought is being given to fuller use of marginal (as opposed to total) benefit-cost analysis as a component rather than the absolute arbiter in evaluating environmental improvements. The present paper explores some of the background for such an analysis, areas where data exist, where they are needed and draws information from the state of Massachusetts for a case example. The results suggest that overall in the United States and in Massachusetts specifically, a point of economic inefficiency may be near based on available tools. However, existing tools are likely to be deficient and protocols for assessing benefits as well as costs need to be verified and a consensus reached on their use; also, the pertinent data need to be collected before great reliance is placed on benefit-cost techniques as a principal component in decision making.
Integrated waste water management for a small river basin - a case study
Authors: Fenz R. , Zessner M. , Kreuzinger N. , Kroiss H.
Published: May 2018

In Austria approximately 70% of the population is connected to sewerage and to biological waste water treatment plants. Whereas the urban areas are already provided with these facilities to a very high extent, effort is still needed in rural areas to meet the requirements of the Austrian legislation. The way, this task should be solved has provoked much controversy. It is mainly the question, whether centralised or decentralised sewage disposal systems are preferable from the ecological and economical point of view, that became a political issue during the last 5 years. The Institute for Water Quality and Waste Management was asked to elaborate a waste water management concept for the Lainsitz River Basin, a mainly rural area in the north of Austria discharging to the Elbe river. Both ecological and economical aspects should be considered. This paper presents the methodology that was applied and the criteria which were decisive for the selection of the final solution.
Spatial distribution of heavy metals in bottom sediment of Yenshui river, Taiwan
Authors: Chang Jing-Song , Yu Kuang-Chung , Tsai Li-Jyur , Ho Shien-Tsong
Published: May 2018

Distribution of heavy metals in bottom sediments from heavily polluted section of Yenshui river, located in the southern Taiwan, are presented. Sediment cores of seven sites were separated into several cuts and analyzed with both sequential extraction procedure (SEP) to realize the heavy metal contents (including Cr, Co, Zn, Ni, Pb, Cu and Cd) among binding fractions of different sediment depth and multivariate analysis (MA) to conduct the correlations of heavy metal variation in depth profile. Results show that distribution of heavy metals in depth profile of sediment is not identical among different sites. Levels of Zn, Cr, Cu and Ni were higher than other metals, and within the ranges of 30–200 mg/Kg, 8–160 mg/Kg, 5–130 mg/Kg, 10–100 mg/Kg, respectively. The major binding forms of Zn, Cr and Cu in sediment were ‘bound to carbonates’, ‘bound to Fe oxides’ and ‘bound to organic matter’ respectively. And, the percentages of different heavy metal binding forms were not significantly varied in depth profile. Results of principal component analyses (PCA) demonstrate that Cr, Ni and Cu were clustered, which indicate these metals had similar loadings in sediment profile, and might be discharged from the same pollution source of electroplating industry.
High resolution model simulation of precipitation and evaluation with Doppler radar observation
Authors: Wei Yu , Lin Charles A. , Benoit Robert , Zawadzki Isztar
Published: May 2018

Surface precipitation is a key input parameter for hydrologic models. Validation of the precipitation field simulated by an atmospheric model is a first step in the development of a coupled atmospheric-hydrologic model. The objective of the present study is to simulate the surface precipitation using MC2 (Mesoscale Compressible Community Model) in a self-nesting mode. Two heavy rain cases in Quebec are examined. Using the first case (October 14-15, 1995), model parameters are adjusted to obtain a good simulation of the precipitation, when compared with that retrieved from Doppler radar measurements. The model is then applied to the second case (November 8-9, 1996) with no further tuning. The highest resolution used in both studies is 6 km. The spatial distribution of the simulated precipitation is very similar to that retrieved from radar measurements. The difference between the magnitude of the MC2 precipitation and radar estimates is of the same order as the uncertainty of the latter. A time shift is found in the simulated precipitation fields, which increases with the forecast lead time.
Development of a new, applied environmental engineering degree program
Authors: Cunnington P. J.
Published: May 2018

Funds to develop new training initiatives are scarce, if not non-existent. This degree program reflects the commitment made by the staff of its originating department and the vision of Dr. A.R. Barren, P. Eng., who made it happen. This particular degree is one of a new breed, significantly incorporating industry in both its development and its presentation. Its success to date indicates that there was a need for this approach to providing an alternative educational program for current and future professionals. Developing a new degree completion program at the same time as the introduction of a new government approval procedure, presented some challenges. On reflection, both the internal and external approval processes were appropriate. It minimised duplication and verified justification to proceed. This paper outlines the process from identifying the target audience, through the development and approval process and concluding with its implementation. This Bachelor of Technology degree was a new credential in the Province of British Columbia, Canada. Its broad range of major elective studies allows individuals to gain knowledge in any four of nine topic areas. The balance of the program provides a general knowledge of engineering and science principles, integrates management topics and requires completion of an industry sponsored project. The applied nature of the course content, combined with the industry professionals that present it, ensures that the material is relevant and appropriate for the individuals from this sector who are participating. The ease of registration into the program, the frequency and modular format of courses that are offered provides a very high degree of flexibility to the participants. Accreditation of environmental degree programs for professional registration is still evolving.
RT-PCR evaluation of viral contamination in five shellfish beds over a 21-month period
Authors: Le Guyader F. , Miossec L. , Haugarreau L. , Dubois E. , Kopecka H. , Pommepuy M.
Published: May 2018

Five shellfish beds were sampled for 21 months and evaluated for microbial contamination. Viral extraction was performed on dissected tissues and the clinically most important enteric viruses (hepatitis A virus, small round structured virus, rotavirus and enterovirus) were searched for by RT-PCR and hybridization. Among the 104 samples analysed, 66% were contaminated by at least one virus and 34% were negative for any virus. The two sites regularly contaminated by faecal coliforms had the highest percentage of viral contamination and HAV was detected only in these sites. However, sampling sites meeting the criteria for commercialisation showed occasional viral contamination and viruses were detected in samples with no faecal coliform contamination.
Distribution of Giardia and Cryptosporidium in natural water systems in New Zealand - a nationwide survey
Authors: Ionas G. , Learmonth J. J. , Keys E. A. , Brown T. J.
Published: May 2018

This study aimed to determine the distribution of Giardia cysts and Cryptosporidium oocysts in New Zealand's natural water systems.
Occurrences of Giardia cysts in beach water
Authors: Ho B. S. W. , Tam T.-Y
Published: May 2018

A total of 64 beach water samples with various bacteriological quality (Grades 1 to 4) were analysed for their bacteriological and parasitological contents (E coli and Giardia cysts respectively). Results indicated that Giardia cysts were detected in less than 10% of the Grade 1 beach water samples with E coli concentrations of <24/100mL. For Grades 2, 3 & 4 beach water samples, Giardia cysts were found, respectively, in 85, 50 and 64% of the samples. Except for one beach water sample which had an unusually high concentration of Giardia cysts (23 cysts/L), they were generally present at moderate concentrations (<10 cysts/L) in all other beach water samples. Despite moderate levels of Giardia cysts present in beach water of different grades, the potential health risk faced by swimmers bathing in local beach water needs to be carefully assessed as Giardia is known to have a low infectious dose.
Improvements in the RT-PCR detection of enteric viruses in environmental samples
Authors: Schwab K. J. , Neill F. H. , Estes M. K. , Atmar R. L.
Published: May 2018

Current methods for the detection of nucleic acid from enteric viruses in environmental samples usually involve extensive concentration and purification of target viruses followed by RT-PCR amplification using two enzymes, reverse transcriptase and Taq polymerase. We have developed a modified method that improves RT-PCR assays by: (i) the use of an RT-PCR internal standard control RNA to identify potential false negative results caused by inhibition of RT-PCR enzymes; (ii) the use of rTth (Perkin-Elmer, Foster City, CA), a heat-stable enzyme that functions as both a reverse transcriptase and DNA polymerase in a single-tube, single-buffer, elevated-temperature reaction; and (iii) the use of thermolabile uracil N-glycosylase (HK-UNG) (Epicentre Technologies, Madison, WI) to prevent PCR product carryover contamination. The new method was compared to the traditional two-enzyme, RT-PCR method for detection of Norwalk virus (NV) and hepatitis A virus (HAV) in buffer, stool, clam and oyster samples. The new method was at least as sensitive in NV and HAV detection compared to the traditional two-enzyme method. The internal standard control successfully detected inhibitors to RT-PCR amplification. NV and HAV PCR products generated with dUTP replacing dTTP during amplification were seeded into subsequent samples to test the prevention of PCR product carryover contamination by HK-UNG. The new method successfully eliminated PCR product carryover contamination in contrast to the traditional two-enzyme method. These improvements to viral nucleic acid detection have the potential to improve sensitivity, specificity and confidence in RT-PCR results.
Automatic monitoring of denitrification rates and capacities in activated sludge processes using fluorescence or redox potential
Authors: Isaacs S. , Mah Terry , Maneshin S. K.
Published: May 2018

A novel method is described to automatically estimate several key parameters affecting denitrification in activated sludge processes: the nitrate concentration, the denitrification capacity, and the maximum (substrate unlimited) and actual denitrification rates. From these, the concentration of active denitrifying microorganisms and the quality of available organic substrate pool can be estimated. Additionally, a modification of the method allows the determination of the efficacy of various carbon substrates to enhance denitrification, and this can be used to determine optimal dosing rates of an external carbon source. The method is based on measurements of either fluorescence or redox potential (ORP) in an isolated mini-reactor, the Biological Activity Meter (BAM), situated in the anoxic zone of the wastewater treatment plant. Advantages of the method are that it is in situ, operating at the same temperature as in the measured anoxic zone, requires no pumps or pipes for mixed liquor sampling, consumes little or no reagents, and uses measurement signals which are instantaneous and low maintenance, one of which provides a direct measure of biological activity.
Survival and transfer of faecal indicator organisms of wastewater effluents in receiving lake waters
Authors: Rajala R. L. , Heinonen-Tanski H.
Published: May 2018

Water of Lake Kallavesi, which receives wastewater effluents, is used for abstraction of drinking water, for swimming and fishing. It is also used directly for washing and drinking water, both for humans and cattle, especially in summer time. These are the reasons for the present study to follow survival and transfer of faecal indicators downstream from the wastewater treatment plant. Samples were collected in winter and summer from the bottom of the lake at deep sites. At some of the sites the vertical distribution of microbes in summer was also studied. Indicators determined were faecal coliforms, enterococci, sulphite-reducing clostridia and coliphages. The farthest point was 35km for bottom samples. All the indicators could be found in sampling sites near to the discharge point with relatively high numbers. At distant sample sites, coliphages or enterococci were the most abundant. In the winter, coliphages were found up to 18km from the discharge point. In summer, indicators survived well. The results suggest that the direct use of lake water could be considered a health risk.
Use of dynamic models to study secondary clarifier performance
Authors: Hasselblad S. , Björlenius B. , Carlsson B.
Published: May 2018

Efficient separation of solids and supernatant is crucial in an activated sludge system since performance of the system depends on the return of active biological solids. A simple discrete linear dynamic model is applied to secondary clarifier performance. Dynamic modelling could accurately predict movement of the sludge blanket height in secondary clarifiers and also indicate the level of the current limiting solids flux. Change in model parameters may indicate either altered sludge composition and settling characteristics, or disturbances in the sedimentation process.
Towards a simulation-benchmark for evaluating respirometry-based control strategies
Authors: Spanjers Henri , Vanrolleghem Peter , Nguyen Khanh , Vanhooren Henk , Patry Gilles G.
Published: May 2018

Many respirometry-based control strategies have been proposed in the literature but few successful practical implementations or even simulation-based evaluations have been reported. The state-of-the-art provides insufficient justification for the development of a how-to-do procedure for such control strategies in full scale. It is, therefore, expected that carefully conducted simulation studies will greatly support the evaluation of proposed strategies and, eventually, the implementation in practice. These studies should be based on a rigorous methodology including simulation model, plant layout, controller and test procedure. This paper describes the development of such a methodology, termed “benchmark”. The benchmark is evaluated on the basis of a respirometry-based control strategy from the literature. Some simulation results are shown and modifications to the strategy imperative to the implementation in the benchmark are discussed. It is concluded that the benchmark provides a convenient means to perform a number of tests with the implemented control strategy. The benchmark should be further developed and tested.
A hybrid respirometric method for more reliable assessment of activated sludge model parameter
Authors: Vanrolleghem Peter A. , Spanjers Henri
Published: May 2018

A novel hybrid respirometric principle is proposed that is particularly suited to sludge and wastewater characterisation in the context of activated sludge process models. Advantages of two respirometric principles are combined and their disadvantages eliminated to increase measuring frequency and precision. Emphasis is put on decreasing the bias in parameter estimates that results from the use of unreliable sensor constants in the calculation of respiration rates. To this end checks for dissolved oxygen probes, aeration systems and pumps are built into the respirometer's operation. Checks are to be run while the respirometric batch experiment is conducted so that between-experiment variation is eliminated and within-experiment variation is minimised. It is also stressed that a combined sensor/process model should be used to estimate the process parameters rather than a sequential procedure in which the sensor constants are first used to calculate respiration rates, that are subsequently used for sludge and wastewater characterisation. Finally, three possible practical implementations of the new principle are discussed in relation to maximising parameter estimation accuracy.
Remote turbidity measurement with a laser reflectometer
Authors: Johnson Mark
Published: May 2018

A simple, laser-based reflectometer is described for the measurement of water turbidity via 180° optical scattering. Applications exist both in clean source waters (0-1000NTU) with a minimum detectable turbidity better than 1NTU, and in dense wastewater primary-clarifier sludges. The non-contact measurement is performed from a distance at least up to 10m, substantially avoiding the usual window fouling problems of optical instruments. By measuring directly in the process, through a free water surface or on the side of a flowing water stream, the difficulties of transporting sample to the instrument are also avoided. Extensions to be described allow measurement also of water colour.
Using iron-coated spent catalyst as an alternative adsorbent to remove Cr(VI) from water
Authors: Liu J. C. , Huang J. G.
Published: May 2018

The feasibility of utilizing iron-coated spent catalyst to adsorb Cr(VI) from aqueous solution was studied. Various factors, such as types and concentrations of iron salt, pH, and initial Cr(VI) concentration were investigated. A significant increase in Cr(VI) removal capacity can be achieved through iron-coating. The maximum adsorption was found at pH of 3.0-4.0. The presence of chloride and sulfate ions were found to suppress Cr(VI) adsorption. Langmuir adsorption isotherm was utilized to describe the adsorption reaction. Results from zeta potential measurement indicate that Cr(VI) is adsorbed largely through electrostatic interaction onto iron-coated spent catalyst. This study shows that spent catalyst can be converted to a useful adsorbent for Cr(VI) removal.
Gradients in the taxonomic composition of different microbial systems: comparison between biofilms for advanced waste treatment and lake sediments
Authors: Röske I. , Röske K. , Uhlmann D.
Published: May 2018

The application of in situ hybridization with group specific oligonucleotide probes detected by epifluorescence microscopy and confocal laser scanning microscopy was tested to identify spatial gradients in the distribution of bacteria in biofilms of plug flow reactors and in the bottom sediment layer of a drinking water reservoir. The two tubular biofilm reactors were fed with the effluent from a full scale biological wastewater treatment plant to which were added the chlorophenols whole degradation was being investigated. One was operated as a continuous-flow reactor and the other as a sequencing batch reactor.

The vertical gradients in the microbial colonization of the sediment were analyzed by means of glass slides exposed to the sediment.

In the biofilms of both reactors the beta-Proteobacteria dominated. The Cytophaga-Flavobacterium group and the Gram-positive bacteria were also abundant. Only small amounts of gamma-bacteria could be detected. This is contrary to findings using traditional cultivation methods. Unlike the biofilms in the reactor, the bacterial Aufwuchs on the glass slides in the sediment presented a surprising diversity of morphological types and size classes of bacteria.
Modeling of turboflo - a novel biofilm reactor for wastewater treatment
Authors: Mousseau Fabien , Liu Sean X. , Hermanowicz Slawomir W. , Lazarova Valentina , Manem Jacques
Published: May 2018

A mathematical model of a novel industrial-scale biofilm reactor - TURBOFLO - was developed. The reactor is an internal circulating airlift with rectangular cross-section. High density polyethylene granules with a density of less than 1 g/cm3 were used to support bacterial growth. The reactor was used for several months for nitrification of secondary effluent. The mathematical model consisted of three differential mass balance equations for ammonia, dissolved oxygen (DO) and biomass. Description of gas-liquid mass transfer was the critical part of the model. The most successful approach was based on Higbie's penetration theory and Kolmogorov's isotropic turbulence.
Simultaneous nitrification/denitrification in an aerobic biofilm system
Authors: Helmer Christine , Kunst Sabine
Published: May 2018

In the biological pretreatment of landfill leachate in Mechernich (Germany) a loss of inorganic nitrogen of up to 90% was observed in the nitrification step (rotating biological contactor) under low DO conditions. Ammonia was removed but only small amounts of nitrate were produced. Nitrite accumulation did not occur. In aerobic batch tests nitrogen loss was confirmed without any addition of organic substrate, even when homogenizing the biofilm mechanically to destroy possible anoxic microzones. N2 was measured as the gaseous end product of the process. From results presented it can be assumed that a largely autotrophic microorganism population performed this aerobic nitrification/denitrification.
Impact of catalytic ozonation on the removal of a chelating agent and surfactants in aqueous solution
Authors: Vel Leitner N. Karpel , Gombert B. , Legube B. , Luck F.
Published: May 2018

The present work consisted in the study of the oxidation yield induced by catalysts during ozonation of sodium gluconate, toluene sulfonic acid and Triton X100 in dilute aqueous solution (TOC ≈ 8 mg C/L). Two operating conditions have been used to demonstrate the enhancement brought about by catalytic ozonation: continuous filtration experiments and batch tests.

Dynamic filtration experiments have been performed on catalysts previously saturated to simulate the behavior of the catalyst over a long period of use.

Batch experiments which allowed us to distinguish the part due to adsorption, ozonation and catalytic effect were carried out on three catalysts with intent to test their efficiency.
The removal and recovery of copper (II) ions from wastewater by magnetite immobilized cells of Pseudomonas putida 5-X
Authors: Chua H. , Wong P. K. , Yu P. H. F. , Li X. Z.
Published: May 2018

Magnetite-immobilized cells of Pseudomonas putida 5-X can be used as biosorbent in copper removal from aqueous solutions. Dilute HCl pretreated magnetite-immobilized cells of Pseudomonas putida 5-X were used in this study for the treatment of wastewater streams containing copper (II) concentrations as high as 100 mg/L. The biosorbent removal and recovery operations were carried out using a series of three batch type biosorption reactors. It was observed that the dilute HCl pretreated magnetite-immobilized cells of Pseudomonas putida 5-X had higher biosorption capacity than that observed on the fresh cells of magnetite-immobilized cells of Pseudomonas putida 5-X. The removal and recovery rates of biosorbent were 96% and 95%, respectively. The process was reversible. The concentrations of copper ion (II) in the recovery solution could be as high as 1.4 g/L and could be successfully recovered using 0.6 N HCl.
Combined biological and chemical treatment of highly concentrated residual dyehouse liquors
Authors: Krull R. , Hemmi M. , Otto P. , Hempel D. C.
Published: May 2018

The combined biological and chemical treatment of highly concentrated reactive azo dye-containing residual dyehouse liquors with recalcitrant compounds was investigated in a sequencing batch reactor (SBR). The plant consists of a batch reactor in which the anoxic and aerobic phases are carried out by sequenced steps. Water-soluble reactive dyes were reductively cleft and decolorized by a facultative anaerobic bacterial mixed culture under anoxic conditions. Complete decolorization was observed up to concentrations of nearly 20 g dye/L without addition of an external auxiliar substrate. Mineralization of the cleavage products occurs with the same bacterial mixed culture in the same reactor under aerobic conditions. The biomass used for the anoxic treatment is grown in this aerobic phase by the use of split flows with readily biodegradable compounds. Because of the recalcitrant toxic character of some remaining substances, further aerobic mineralization was initiated by partial oxidation with ozone. Partial ozonization in a circulated stream with biological post-treatment of the transformed substances led to an increased reaction selectivity, to a better biological degradation and not least to a lower consumption of ozone. Due to this purification procedure involving highly concentrated residual dyehouse liquors a total decolorization and an overvall degradation of nearly 90% in DOC was achieved.
Optimizing chemical treatment of a power plant water softener
Authors: Nurdogan Y. , Goldman E. , Dawes S. S.
Published: May 2018

The Piñon Pine Plant of Sierra Pacific Power Company near Reno, Nevada is a zero discharge facility. To maintain zero discharge operation a side-stream softener is used to control circulating cooling water (circ-water) and discharge pond water quality. During plant startup, this softener was not performing to its design objectives, which specified maximums of 30 ppm calcium as Ca, 10 ppm magnesium as Mg, and 20 ppm silica as SiO2 in the softened water. Jar tests were conducted to determine the best chemicals and optimum dosages for the side-stream softener. The optimum pH range for softening was in the range of 11.3–11.5. Replacing the Polyaluminum Hydroxychlorosulfate (PAC) coagulant with 25–50 mg/L of Mg(OH)2 greatly improved flocculation. In addition to Mg(OH)2 solution, MgSO4 was required at a dosage of 50 mg/L as Mg to reduce the silica concentration to 20 mg/L as SiO2. The optimum dosage of Na2CO3 (soda ash) was 750 mg/L to reduce the calcium concentration to 30 mg/L as Ca. The optimum dosage of flocculent (a Polyacrylamide based anionic polymer) was 10–15 mg/L. Dispersant addition was adversely effecting the softening process.
Impact of different substrates on biomass protein composition during wastewater treatment investigated by two-dimensional electrophoresis
Authors: Huber Sylvia , Minnebusch Sabine , Wuertz Stefan , Wilderer Peter A. , Helmreich Brigitte
Published: May 2018

The influence of different influent substrates on biomass protein composition was examined by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). Activated sludge from six sequencing batch reactors (SBRs) was investigated; four reactors were fed with model substrates and two received effluents from a wood milling process and a paper production process, respectively. Our investigations showed that in 2D-PAGE complex substrates caused a less diverse protein pattern than model wastewater composed of simple and low molecular weight compounds. This may be caused by complex formation by high molecular weight compounds of substrate with proteins. A more likely explanation is the presence of a more diversified microbial population resulting in a lower concentration of individual proteins, so that detection limits after staining were too high to observe discrete spots.