bluuebunny/crossref_metadata_2025_split huggingface dataset:
Odour emission estimates and control strategies using models and sampling for East Bay Municipal Utility District's collection sewage system and wastewater treatment plant
Authors: Witherspoon J. R. , Sidhu A. , Castleberry J. , Coleman L. , Reynolds K. , Card T. , Daigger G. T. 
Published: May 2018

For several years, public complaints regarding odours generated by East Bay Municipal Utility District's (EBMUD's) wastewater treatment plant and sewage collection system (SCS) have been increasing. In response, an Odor Control Master Plan was completed to develop near- and long-term odour abatement strategies for their wastewater system. The plan's strategies include using an advisory committee to assist in setting odour threshold levels, prioritizingodour sources, issuing an odour-status newsletter, and reviewing odour control options. The objective is to provide an odour-free community environment at least 99 percent of the year.
This paper provides innovative approaches to estimate odour emissions and identify viable odour control options for SCSs through complete wastewater treatment. This paper also presents a CH2M HILL SCS odour model comparison to a comprehensive EBMUD sewage system corrosion study, illustrating that areas having high predicted odours also have high corrosion rates.
Northumbrian Water coastal programme: nine scrubbers for the price of eight!
Authors: Lloyd T. C. 
Published: May 2018

Under the EU Urban Wastewater Treatment Directive, Northumbrian Water have to provide full sewage treatment at eight coastal sites for 1999/2000 deadlines. As part of the consequent standardisation programme, NWL appointed Entec to co-ordinate odour containment, ventilation and abatement at all eight sites. Following trials and a review of options, NWL specified the ICI “Odorgard” catalytic single stage scrubber as the standard abatement method.
Tenders were sought using ECC Option A (activity schedules) conditions of contract from the three licensees. Costs were identified for anticipated odour loads/installation programmes to maximise “bulk discount” opportunities, culminating in simultaneous contracts being let to ERG for all eight sites. This represents the largest known multi-site odour abatement award in the water industry to date effectively giving discounts equivalent to the cost of the ninth scrubber.
Further advantages of the bulk purchase included common operational procedures/spares and the ability to apply lessons being learnt from commissioning of prior scrubber installations.
Operation of modern day process plants – minimising Cryptosporidium risk
Authors: Edwards D. 
Published: May 2018

Closer examination of basic water treatment processes, “source to tap”, is one of the evident supplier responses to new quality constraints and increasing resource pressures.
More recently, with the release of DWI Incident Reports and UKWIR documentation on the organism Cryptosporidium, the focus has been extended to defining and operating at “optimal” conditions within treatment processes.
As a result the Water Industry is currently re-evaluating “due diligence” guidance of operational procedural practices on treatment streams, in order to consistently produce potable water to an ever increasing standard, and thus lowering the public health risk.
Thermophilic anaerobic digestion and pasteurisation. Practical experience from Danish wastewater treatment plants
Authors: Nielsen B. , Petersen G. 
Published: May 2018

Increasing sludge disposal costs have highly intensified the interest in reducing the sludge quantities from Danish wastewater treatment plants. By upgrading existing mesophilic digesters to the thermophilic temperature range, the retention time can be halved and many digesters designed only for primary sludge will have sufficient capacity to treat also the biological excess sludge.
At the moment, eight full-scale thermophilic digesters are in operation in Denmark and five are under construction. This paper describes the full-scale experience gained from digestion of biological excess sludge as well as a mixture of primary and biological sludge.
Thermophilic digestion has proven to be a good and stable process for solids reduction and pathogen removal. The digested sludge can be dewatered to a high solids content and thereby the sludge quantity for disposal can be reduced by 30-40% depending on the type of wastewater treatment plant. A drawback of the process is that the polymer costs for sludge dewatering may be increased depending on the sludge type.
The efficacy of long-lasting residual drinking water disinfectants based on hydrogen peroxide and silver
Authors: Pedahzur R. , Katzenelson D. , Barnea N. , Lev O. , Shuval H.I. , Fattal B. , Ulitzur S. 
Published: May 2018

The aim of the present work was to evaluate the disinfectant capacity and the possible fields of application of a combined silver and hydrogen peroxide (HP) water disinfectant. The findings demonstrated the high bactericidal action of silver (on E. coli) and its relatively ineffective virucidal effect (on MS-2 phage).
HP was found to have a small bactericidal effect and a mild virucidal one. When combined, silver and HP usually exhibited a synergistic action on the viability of E. coli and on the luminescence of recombinant luminescent E. coli. In some instances, the combined bactericidal effects were 1000-fold higher than the sum of the separate ones. No increased virucidal action was observed. The biocidal action of the combination generally increased with increasing temperature and pH, and decreased in secondary and tertiary effluents. The physiological effects and mechanisms of toxicity of HP, silver and their combinations, were assessed by monitoring the induction of stress promoters upon exposure to the active agents, and by assessing the sensitivity of E. coli mutated in major stress responses to HP, silver and their combinations. The results showed that HP induced a wide array of stress responses, that both silver and HP induced promoters regulated by the heat shock response, and that the dnaK promoter (regulated by the heat shock response) was synergistically induced. The mutant sensitivity tests showed that bacteria deficient in the ability to activate central cellular stress responses (SOS, heat shock, stationary phase, oxidative) were hypersensitive to both HP and silver. These results imply that cellular proteins, and possibly the DNA, are the cellular moieties chiefly affected. The above findings suggest that the potentiated effect of HP and silver is a metabolically dependant/related process that stems from a combination and/or accumulation of physiological effects exerted by the active ingredients.
The physico-chemical properties of the combined disinfectant, and its disinfection capacity, points to its potential application as a long-term secondary residual disinfectant for water of relatively high quality.
Mass transfer phenomena in biofilm systems
Authors: Wäsche S. , Horn H. , Hempel D.C. 
Published: May 2018

Mathematical models allow the simulation of microorganism growth and substrate transport in biofilm systems. Nevertheless there is still a lack of knowledge about the mass transfer of substrate in the boundary layer between biofilm and bulkphase.
Several biofilms were cultivated under different substrate and hydrodynamic conditions in a biofilm tube reactor. Oxygen concentration profiles were measured with oxygen microelectrodes in the biofilm and in the boundary layer. The thickness of the concentration layer was found to depend on surface structure which depends on the substrate loading and the hydrodynamic conditions during the growth phase of the biofilm. Biofilm density and maximum substrate flux were also influenced by growth conditions. An empirical function for the concentration layer thickness was formulated for biofilms grown under different conditions to describe transport phenomena in the boundary layer.
Optimising the A/O cycle for phosphorus removal in a submerged biofilter under continuous feed
Authors: Gonçalves R.F. , Rogalla F. 
Published: May 2018

This work describes laboratory scale research about Enhanced Biological Phosphorus Removal (EBPR) in a submerged biofilter under Anaerobic/Oxic (A/O) alternation and continuous feed. Its main purpose is to detail the behaviour of the reactor throughout the anaerobic and the aerobic phases of the A/O cycle, to study the importance of the anaerobic phase in the selection of the EBPR bacteria in the biofilm and to evaluate the consumption and the importance of the organic substrate during the anaerobic phase. The mass balance over the Phosphorus (P) element indicates that long anaerobic phases (6 h) are more efficient than short ones (3 h) as a selector of EBPR bacteria in biofilms.
In both comparisons, thespecific mass of P released in a 6 h period represents almost 50% more than the amount of P release in the shorter period (3 h). However, the presence of rapidly biodegradable COD in the influent of the anaerobic phase is a more effective selector, more important than the duration of the anaerobic phase: by doubling the amount of acetic acid in the influent, a similar 50% increase of P-release can be achieved at short anaerobic periods of 3 h. The effect of the strategy adopted in this study, focusing on selecting EBPR bacteria in biofilm, is shown by the P levels of 4% (total P/SST) in the sludge removed from the BF by backwashing in all periods.
Endogenous respiration rate in vapour phase biological reactors (VPBRs) during volatile organic compound (VOC) degradation
Authors: Villaverde S. , Fdz-Polanco F. , García Encina P.A. 
Published: May 2018

Endogenous respiration rates within Pseudomonas putida biofilms growing on toluene and ethanol as sole external carbon source were evaluated using oxygen microelectrodes in a Flat Plate Vapour Phase Biological Reactor (FPVPBR). The endogenous respiration was experimentally evaluated in Pseudomonas putida 54G biofilm cultures growing on toluene and ethanol, by measuring the flux of oxygen through the liquid-biofilm interface in absence of any external carbon source. Two fluorescent probes, 2,4-diamidino-2-phenylindole (DAPI) and 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) were used to evaluate the number of total and respiring cells within the biofilm, respectively. Biofilm samples were also analysed for viable and VOC-culturable cells by spread plating on non-selective and selective media, respectively.
Results suggest that endogenous respiration rate may contribute significantly to the oxygen requirements of the overall process and, consequently, affect the performance of the VPBR degrading VOCs. In the time the biofilm growing process at expenses of VOCs may deviate towards serious cryptic growth and endogenous metabolism. The endogenous respiration within the biofilm is a function of the VOC concentration and in last term of the injury phenomena that may act as regulatory mechanism of the biofilm thickness and density, which might justify the absence of plugging phenomena in VPBR. As the VOC concentration increases, the injury increases, meaning increasing intracellular material leakage and injured cell death resulting in lysis products. These observations can justify the unusually long operation periods characterizing VOC vapours biofiltration units.
Flow, stock and destination of radioactive fallout Cs-137 in the global environment
Authors: Morisawa S. , Shimada Y. , Yoneda M. 
Published: May 2018

Environmental fate of radionuclide caesium-137 (Cs-137), which was released for more than 30 years since 1945 to the global environment by the atmospheric nuclear detonation tests, was analyzed from an aspect to determine the transport rate between environmental media, the accumulation and mass distribution in each media and the final destination. The mathematical model was developed and validated by comparing the model estimation with the monitoring data, and the final distribution of Cs-137 and its overall decreasing rate were evaluated together with the health risks to the reference Japanese.
The mass distribution simulation showed that the final destination of the fallout Cs-137 is the deeper land and the ocean bottom, and that the apparent decreasing rate of Cs-137 in the humans' living environment is larger than the physical half-life of Cs-137 due to the environmental acceleration of radionuclide transportation.
Two approaches to indirect potable reuse using membrane technology
Authors: Lozier J. 
Published: May 2018

A pilot study was conducted at McAllen, Texas to evaluate two microfiltration technologies, Memcor and ZeeWeed, to treat secondary effluent from the city of McAllen south WWTP. The objectives of the study were to compare the ability of Memcor and ZeeWeed to pretreat secondary effluent for subsequent processing by RO and to evaluate the ability of the ZenoGem membrane bioreactor process to directly treat screened, de-gritted wastewater to a quality suitable for direct processing by RO.
The results showed both Memcor and ZeeWeed to be competitive in their ability to produce a high quality filtrate from secondary effluent. The results also indicated that the ZenoGem process is capable of producing a filtrate suitable for RO treatment while meeting the City's current wastewater effluent discharge requirements. Additionally, the ZenoGem treated McAllen's raw wastewater to a quality comparable to the city's existing WWTP effluent.
EU policy on nutrients emissions: legislation and implementation
Authors: Blöch H. 
Published: May 2018

After 25 years of EU water legislation the European Union has just thoroughly restructured its water policy. The European Parliament and the Council, following a tough conciliation procedure between the two legislators, have in summer 2000 agreed a proposal by the European Commission for a Water Framework Directive. This legislation will have the following main objectives:integrated river basin management across borders, with coordinated programmes of measuresprotection of all waters, surface waters and groundwater, in quality and quantity with a proper ecological dimensionemissions and discharges controlled by a “combined approach” of emission limit values and quality standards, plus the phasing out of particularly hazardous substancesintroducing water pricing policiesstrengthening public participation
This new Water Framework Directive adopted in September 2000 will complement existing EU water legislation on nutrients reduction - the 1991 Directive on nitrates pollution from agricultural sources and the 1991 Directive on urban waste water treatment. These Directives will remain main pillars of EU water policy whilst at the same time being integrated into the river basin management in a coherent way.
Overview: full scale experience of the SHARON® process for treatment of rejection water of digested sludge dewatering
Authors: van Kempen R. , Mulder J. W. , Uijterlinde C. A. , Loosdrecht M. C.M. 
Published: May 2018

A SHARON® system has been constructed at the Utrecht WWTP and at the Rotterdam Dokhaven WWTP. In the SHARON® process rejection water from dewatering of digested sludge is treated for N-removal. It concerns a high active process operating without sludge retention. Due to differences in growth rate nitrite oxidisers can be washed out of the system while ammonia oxidisers are maintained, resulting in N-removal over nitrite. The SHARON® process was selected in competition with several other techniques.
The feed of a SHARON® system is concentrated, with ammonia concentrations ranging from 0.5 to 1.5 g N/l. The results show that conversion rates of 90% are well possible with N-removal mainly via the nitrite route. The process was shown to be stable. Due to the high ammonium influent concentrations pH control is of great importance, preventing process inhibitions. The acidifying effect of nitrification can be compensated completely by CO2 stripping during aeration and by denitrification. Heat production by biological conversions is significant, due to the high inlet concentrations, and contributes to the optimal operating temperature of 30-40°C.
Study on endocrine disrupting chemicals in wastewater treatment plants
Authors: Nasu M. , Goto M. , Kato H. , Oshima Y. , Tanaka H. 
Published: May 2018

From July 1998 to March 1999, a study was made of a total of 27 treatment plants for the principal purpose of understanding the actual condition of endocrine disrupting chemicals (EDCs) in sewage, and the behavior of EDCs in wastewater treatment plants.
The results showed actual levels of influent and effluent concentrations of EDCs in sewage. Substances detected above the minimum limit of determination were 15 for wastewater influent and 6 for effluent. Similarly, nonyl phenol ethoxylate and 17β-estradiol, which are highlighted as pertinent substances, were detected. It was confirmed that the reduction ratio of EDCs in treatment plants was 90% or more for almost all substances.
The behavior of EDCs in general in treatment plants was also studied. As a result, the EDCs reduction effect was recognized in both the primary settling tank and biological reaction tank, though the trend varies among substances.
Towards sustainable development: catalysts for change in industrial water management
Authors: Ayers Robert L. 
Published: May 2018

“Business as usual is not an option.” Water management practices are changing too slowly and the global 'fresh water gap' continues to grow. Actions as must be taken by government and civic leaders. Industry also has a responsibility to act, but its inability to adequately meet the challenge to date points to the need for additional stimuli.
The current water crisis can be mitigated by changes in behaviour and perceptions. This presentation will argue that specific catalysts are required to encourage and support a dramatic shift of behaviours and perceptions by industry leaders. The catalysts include: establish clear and objective rules; introduce water pricing; recognize 'life cycle' costs; prioritize needs; reward small-scale solutions; nurture innovations; spread global best practices.
With the help of the catalysts described herein, industry can take its place as a leader in effective water management in the 21st Century. In partnership with governments, international organizations and civic organizations, industry leaders can help meet the challenge of the water crisis while creating sustainable economic growth.
Performance indicators in water and sanitation for developing areas
Authors: Pybus P. , Schoeman G. 
Published: May 2018

There is a move throughout the developed world to introduce benchmarking techniques to the management of water and sanitation systems. The indicators that are being considered for benchmarking purposes tend to cover a broad band of activities that are part of the scope of management of large organisations. Most of the lists that have been prepared do not really cater for the implementation and operation of small rural schemes. The greatest need is the implementation of sustainable schemes for this category of consumer.
The implementation of a rural water and sanitation scheme involves the negotiation in the initial stages with the local community representatives of what the community wants and how it will be provided and operated. This may have to be preceded by a period of empowerment so that the negotiations can be conducted by informed people. At the conclusion of the negotiations a business plan can be prepared that should be implemented in association with the community. The project is at this stage mainly in the control of a professional engineer, responsible for the technical interpretation of the business plan and the management of the construction phase. Finally, after commissioning, a water service provider will be responsible for the operation, management and maintenance of the scheme on a sustainable basis.
The key actions and activities are identified and performance criteria defined. As communication at the beginning of the project is a critical component, the success of this is confirmed by examination and discussion as to how much has in fact been communicated and understood correctly. Other performance indicators for the operational phase are derived from the conventional ones used in the developed world. Finally, it is important that the participants, do not see the measurement of performance as a threatening situation, but rather a stepping stone to improvement of not only performance, but also of subsequent reward.
Urban catchment management in a developing country: the Lotus River project, Cape Town, South Africa
Authors: Grobicki A. M.W. 
Published: May 2018

This paper describes a 2-year pilot project undertaken in an urban catchment in Cape Town, South Africa. The impermeable area of the Lotus River catchment has doubled over 15 years, from 17% in 1983 to 34% in 1997. Following the abolition of urban influx control in 1990, informal settlements in the catchment grew rapidly and now house about 90,000 out of the catchment's total population of 380,000 people. The informal areas are still largely unserviced, despite a commitment from local government to speed up service delivery to the poorest areas of the city.
Within the Lotus River project, hydrological and ecological assessments of the urban watercourses were undertaken, through physico-chemical and microbiological sampling programmes, macro-invertebrate counts, and vegetation sampling. All available information regarding the catchment was integrated within a GIS platform, including demographic and socio-economic data on the various communities, and hydrogeological information on the underlying aquifer obtained from earlier studies. The integrated nature of the project allows a number of conclusions and recommendations to be drawn, regarding the management of this particular catchment. However, important general lessons have also been learned which can be applied by local authorities responsible for urban catchments in developing countries. The necessity of providing the required institutional structures cannot be overemphasised.
The influence of biosolids treatment files on the mobility of metal trace elements
Authors: Maisonnave V. , Montrejaud-Vignoles M. , Bonnin C. , Revel J.-C. , Vignoles C. 
Published: May 2018

The production of sludge in France is estimated to be about 900,000 metric tons dry matter per year and 60% of this is recycled onto agricultural land. At present, the long term future of this procedure is open to question and among the different arguments being put forward are the levels of metallic trace elements and the risk of accumulation in soils.
This study presents the behaviour of metallic trace elements in sludges from three different treatment procedures: thickened liquid sludges, dewatered sludges and dried sludges. These biosolids are mixed with a clay soil and then placed in a temperature and humidity controlled glasshouse. Several containers are seeded with ryegrass and compared with controls. For the three harvests, covering all the amendments studied (including non-amended soil), the differences are not really representative. Absorption by the ryegrass is low in all cases. For the cadmium, the chromium, the nickel and the lead, the roots are 5 to 10 times more concentrated than the leaves. The majority of these elements stay absorbed in the roots, regardless of the amendment used.
The addition of the sludges has considerably reduced the uptake of water in ryegrass throughout its growth cycle. Quite apart from their fertilizing qualities, wastewater treatment plant sludges could offer important implications for irrigation.