bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microbial cycling of volatile organic sulfur compounds in anoxic environments
Authors: Lomans B.P. , Pol A. , Op den Camp H.J.M. 
Published: May 2018

Microbial cycling of volatile organic sulfur compounds (VOSC) is investigated due to the impact these compounds are thought to have on environmental processes like global temperature control, acid precipitation and the global sulfur cycle. Moreover, in several kinds of industries like composting plants and the paper industry VOSC are released causing odor problems. Waste streams containing these compounds must be treated in order to avoid the release of these compounds to the atmosphere. This paper describes the general mechanisms for the production and degradation of methanethiol (MT) and dimethyl sulfide (DMS), two ubiquitous VOSC in anaerobic environments. Slurry incubations indicated that methylation of sulfide and MT resulting in MT and DMS, respectively, is one of the major mechanisms for VOSC in sulfide-rich anaerobic environments. An anaerobic bacterium that is responsible for the formation of MT and DMS through the anaerobic methylation of H2S and MT was isolated from a freshwater pond after enrichment with syringate as a methyl group donating compound and sole carbon source.
In spite of the continuous formation of MT and DMS, steady state concentrations are generally very low. This is due to the microbial degradation of these compounds. Experiments with sulfate-rich and sulfate-amended sediment slurries demonstrated that besides methanogens, sulfate-reducing bacteria can also degrade MT and DMS, provided that sulfate is available. A methanogen was isolated that is able to grow on DMS as the sole carbon source. A large survey of sediments slurries of various origin demonstrated that both isolates are commonly occurring inhabitants of anaerobic environments.
Regeneration of process water containing surfactants by nanofiltration - investigation and modelling of mass transport
Authors: Wendler B. , Goers B. , Wozny G. 
Published: May 2018

The mechanisms in nanofiltration of aqueous solutions of different anionic surfactants and of mixture solutions of surfactants and NaCl are investigated. The surfactants used are sodium dodecylether sulfate, sodium dodecyl sulfate and sodium alkyl benzene sulfonate. High retentions in the range of 95% up to 99.9% referring to the feed concentration are found to depend on the solvent flux. If additional salt is present in the solution, the permeate quality is deteriorating because of lower solvent flux and of mass transfer due to the electrical potential.
The experimental results show that convective mass transfer of surfactant through the nanofiltration membrane occurs. Consequently, an extended solution-diffusion model is used for modelling of the process. Depending on the feed composition, concentration polarisation has to be considered in the model. The calculated surfactant flux through the membrane is in good agreement with the experimental results.
A novel approach to pathogen reduction in biosolids: the enzymic hydrolyser
Authors: Mayhew M.E. , Le M.S. , Ratcliff R. 
Published: May 2018

Revision of the Sludge (Use in Agriculture) Regulations in the UK has resulted in the requirement of a final product standard in terms of E coli per gram of dry solids. Conventional mesophilic digestion including 14-day secondary storage should normally provide adequate treatment to meet the Treated Sludge Standard. Any process capable of greater pathogen reduction would ensure more process security and compliance comfort. Such a process would be a welcome alternative to extra secondary storage where an existing works does not have sufficient capacity, particularly if the differences in costs between the options are small.
Enzymic hydrolysis was found to be up to ten-fold more effective in E coli reduction than conventional secondary digestion. A two-stage digestion process based on this technique has been developed by United Utilities and Montgomery Watson Harza (termed the enzymic hydrolyser, patent pending). Studies showed that the mean numbers of E coli were significantly lower in the enzymic hydrolyser systems (P&gt;0.05; t=13.19) compared to conventional digesters. Increased stability was a secondary benefit of the system (foam was eliminated or greatly reduced in the enzymic hydrolyser units). Another benefit of the system for retrofit to existing assets is the decreased tankage volumes required compared to secondary digestion to achieve more than twice the log kill of pathogens.
Two years of full-scale storm operation experience
Authors: Bixio D. , Carrette R. , Thoeye C. 
Published: May 2018

Current practice in Flanders is to limit the hydraulic capacity of the wastewater treatment plant to 6Q14 (Q14=1.7 dry weather flow QDWF). A maximum of 3Q14 is treated in the biological system, the excess flow undergoing only physical treatment in the stormtank. This practice has been challenged by a new concept, consisting of the treatment of the full storm sewage flow in the biological train and of the use of the stormtank(s) as additional secondary clarifier(s).
This paper reports on the long-term experience gained on a total of 12 full-scale plants. The analysis focused on the parameters subject to regulatory discharge (BOD, COD, suspended solids, total nitrogen and total phosphorus) plus ammonia. Special attention is paid to the performance of the clarification and of the nitrification processes. The significance of the proposed way of operation in attenuating the overall pollution impact on the receiving water body is shown.
Suitability of macrophytes for nutrient removal from surface flow constructed wetlands receiving secondary treated sewage effluent in Queensland, Australia
Authors: Greenway M. 
Published: May 2018

From a botanical perspective the major difference between waste stabilisation ponds and wetlands is the dominance of algae or floating plants in the former and emergent plants in the latter. Algae, floating and submerged plants remove nutrients directly from the water column whereas emergent species remove nutrients from the sediment. Water depth is a crucial factor in determining which plant types will become established. Surface flow constructed wetlands offer the greatest potential to grow a wide variety of different types of macrophytes. In assessing the suitability of plant species for nutrient removal, consideration must be given not only to nutrient uptake for growth but also storage of nutrients as plant biomass.
A survey of macrophytes in 15 surface flow constructed wetlands treating secondary effluent was conducted in Queensland; 63 native species and 14 introduced species were found. Emergent species have been able to tolerate deeper water than in their natural environment and permanent waterlogging. All species grew well in the higher nutrient enriched wastewater. Submerged, floating leaved-attached and free floating species had the highest tissue nutrient content, followed by aquatic creepers. All these species remove nutrients from the water column. Emergent species had lower nutrient content but a greater biomass and were therefore able to store more nutrients per unit area of wetland. In order to maximise the efficiency of constructed wetlands for nutrient removal, a range of species should be used. Native species should be selected in preference to introduced/exotic species.
An introduction of co-management approach into Babon River management in Semarang, Central Java, Indonesia
Authors: Susilowati I. , Budiati L. 
Published: May 2018

The Babon River lies over three regions, i.e. Semarang District where the upstream is located while downstream it passes through Semarang Municipality and Demak District. This river has been used for many purposes by the neighbouring communities (e.g. water source, canal disposal, mining, etc). Thereafter many transboundary environmental problems have arisen here. The environmental management strategy (using a top-down approach) such as Program Kali Bersih (Clean River Program) on Babon River, which had been implemented by the Bapedalda of Semarang Municipality, is not successfully achieving the targets. In the past, most policies were formulated based on top-down orientation. Hence, the communitiesÕ participation was not paid enough attention. Co-management is a participative-management approach to empower the stakeholders (related parties) to achieve a certain goal. This study seeks answers to the research questions: (1) whether the co-management approach has good prospects for managing the Babon River; and (2) what kinds of strategy should be formulated to empower the stakeholders to manage the Babon River in the study area.
The study employed a multistage sampling method to select the location of the study areas and key-persons sample. Rowosari, Penggaron Kidul and Karangtoro were selected to represent the upstream, middle stream and downstream areas, respectively. The descriptive statistics method had been used to describe the significance of river resource attributesÕ characters. Institutional analysis approach, introduced by Pomeroy and Williams, was adopted with necessary modification in this study.
The results showed that the level of participation of the community in the three segments of the Babon River is different. The prospects for the co-management approach to manage the river resource in the study area are fairly good and in the upstream area are better than in the other two segments. The level of participation is far from complete; nevertheless the response from society towards development is quite good. There are five significant attributes in Babon River, which affect the community participation in river management, namely: (1) intensity of resource commercialisation; formal education of the community; and dependency of the community toward the resources, resource products distribution and resource damage. These variables could influence the pattern of participation of the community in the study area. The other stakeholders such as industrial or plant owners, academics, and the related institutions have not been explored in detail in this study.
The co-management model that has been developed in this study has the prospect of encouraging the community and other stakeholdersÕ empowerment in economic activities, natural resource conservation, and environmental law enforcement, as part of achieving the ultimate goal of sustainable environmental management.
Groundwater pollution risk assessment methodology
Authors: Lytton L. , Howe S. , Sage R. , Greenaway P. 
Published: May 2018

A generic groundwater pollution risk assessment methodology has been developed to enable the evaluation and ranking of the potential risk of pollution to groundwater abstractions. The ranking can then be used to prioritise risk management or mitigation procedures in a robust and quantifiable framework and thus inform business investment decisions. The risk assessment considers the three components of the pollution transport model: source - pathway - receptor. For groundwater abstractions these correspond to land use (with associated pollutants and shallow subsurface characteristics), aquifer and the abstraction borehole. An hierarchical approach was chosen to allow the risk assessment to be successfully carried out with different quality data for different parts of the model.
The 400-day groundwater protection zone defines the catchment boundary that forms the spatial limit of the land use audit for each receptor. A risk score is obtained for each land use (potential pollution source) within the catchment. These scores are derived by considering the characteristics (such as load, persistence and toxicity) of all pollutants pertaining to each land use, their on-site management and the potential for the unsaturated subsurface to attenuate their effects in the event of a release. Risk scores are also applied to the aquifer characteristics (as pollutant pathway) and to the abstraction borehole (as pollutant receptor). Each risk score is accompanied by an uncertainty score which provides a guide to the confidence in the data used to compile the risk assessment.
The application of the methodology has highlighted a number of problems in this type of work and results of initial case studies are being used to trial alternative scoring methods and a more simplified approach to accelerate the process of pollution risk assessment.
Investigation of potential surrogate organisms and public health risk in UV irradiated secondary effluent
Authors: Simpson D. , Jacangelo J. , Loughran P. , McIlroy C. 
Published: May 2018

Watercare's Mangere Wastewater Treatment Plant in Auckland, New Zealand treats sewage from a population equivalent of approximately 1,000,000. The treatment plant is currently undergoing a major upgrade, and as a part of this upgrade the largest UV disinfection plant in the world (at the time of award of the contract) is being constructed.
Pilot scale investigations were undertaken at a purpose built facility. The pilot plant employed secondary treatment, sand filtration, UV disinfection and a number of low pressure membrane systems. Investigations at the facility focussed on attempting to identify relationships between potential surrogate indicator organisms (including enterococci, faecal coliforms, Clostridium perfringens spores and F-specific bacteriophage) and pathogenic organisms (including culturable human enteric viruses, bacterial pathogens and parasites).
The aim of the study was to identify a suitable indicator organism and an associated effluent concentration that would ensure that an acceptable level of public health risk was maintained in the environment.
The results showed that no suitable surrogate indicator organism could be found. However the results did indicate that a two tiered operating strategy, based on the concentration of enteroviruses present in raw sewage and an appropriate UV dose, would ensure that an acceptable level of public health risk was maintained in the environment.
The River Rhine as a source of micropollutants in the canal sediments of the city of Delft (The Netherlands)
Authors: Kelderman P. , Xuedong Y. , Wenchuan Q. , Drossaert W.M.E. 
Published: May 2018

This paper presents a statistical analysis of the pollution levels for heavy metals and organic micropollutants at 182 sediment stations in the city canals of Delft. High pollution levels were especially observed in the inner city canal sediments, probably related to the import of polluted river Rhine water. In contrast, the more-or-less isolated outer city sites were generally much less polluted.
Regression analysis on the database generally showed highly significant correlations between individual heavy metal contents. The heavy metal contents were usually significantly correlated with polycyclic aromatic hydrocarbons (PAHs) as well. This points to one or more common sources for these micropollutants.
Factor analysis and the K-means cluster analysis technique were applied on the above database; it showed a large cluster of stations, nearly all located in the outer city of Delft, characterized by relatively low heavy metal and organic micropollutants’ contents. Another cluster of 18 stations, mostly located in the inner city of Delft, possessed intermediate pollution levels, directly related with the supply of river Rhine water. Finally, the stations of a third cluster, situated in the inner city as well, were highly polluted, especially by local pollution sources. The above hypotheses were further supported by a more detailed statistical analysis for a number of inner city stations, together with 10-year river Rhine pollution data.
An intelligent controller for automated operation of sequencing batch reactors
Authors: Cohen A. , Hegg D. , de Michele M. , Song Q. , Kasabov N. 
Published: May 2018

In this paper the results are presented of original research into the automatic and “intelligent” detection of breakpoints in Dissolved Oxygen (DO) profiles. The research has been based on a large body of data collected from laboratory SBRs operating on synthetic wastewater. Two different approaches were followed to identify the endpoints. The paper analyses and evaluates the results of automatic breakpoint detection on the basis of geometric features in the DO profiles. This was followed by classification of the detected breakpoints using different soft computing techniques based on Neural Network (NN), Fuzzy Neural Network (FuNN) and Evolving Fuzzy Neural Network (EfuNN) software systems for breakpoint classification. A high rate of successful detection and classification was obtained with up to 96% of the decisions made correctly.
In order to overcome the limitations of this system to adapt to dynamically changing process conditions, an intelligent control model was developed by a combination between an Evolving Fuzzy Neural Net (EfuNN) combined with a logic decision unit. This system has the ability to “learn on-the-fly” and adjust its response pattern in order to maintain a high rate of successful breakpoint detection under varying changing process conditions.
This software system has been successfully embedded on a small programmable controller for integration into larger process control systems for the operation of SBR plants.
Water and wastewater related issues in Sri Lanka
Authors: Bandara N.J.G.J. 
Published: May 2018

The primary problems concerning water resources in Sri Lanka are the depletion and degradation of the resource caused by various anthropogenic activities. Surface inland waters in urban areas are polluted heavily with domestic sewage and industrial effluents, and in rural areas with agricultural runoff. With regard to ground water in certain areas of the dry zone, there is a high fluoride content and in hard, rocky, alluvial areas, there is a high concentration of iron. In urban over-crowded cities, there is biological contamination of ground water. Over-utilization, particularly through tube wells, is another major problem affecting ground water resources in Sri Lanka. Oil spills, dumping of waste from ships, coral and sand mining, and industrial activities are the main causes of marine pollution in the country. Except for pipe-borne water supply, irrigation and hydropower schemes, in general water resources in Sri Lanka are managed very poorly. Regulations are available to control most water related problems but enforcement of these regulations is lacking.
The ultimate result of degradation and depletion of water resources is the increasing health hazards. Water-borne and vector-borne diseases are prevalent, particularly amongst urban low-income communities with poor sanitary facilities and drainage. Despite government initiatives and legislation, very slow progress has been made towards combating water pollution. This paper examines the most significant water and wastewater related issues in Sri Lanka and their controlling mechanisms.
Modelling to assist in wastewater collection system odour and corrosion potential evaluations
Authors: Witherspoon J. , Allen E. , Quigley C. 
Published: May 2018

Odour emissions and corrosion concerns can be a constant focus for many wastewater treatment and collection system owners, usually from the first day that their collection systems begin operation. Many sewer systems are reaching the end of their useful life, or have experienced either odour or corrosion issues. This paper shows a link between odour generation and corrosion potential, and how modelling can be used to assist in odour/corrosion assessments of existing wastewater collection systems.
A model has been developed that is capable of predicting liquid-phase sulphide generation and subsequent release to overlying sewer headspace as hydrogen sulphide (H2S), where it can be the source of either odour or corrosion problems. This paper presents an overview of the model, and uses a case study involving both odour and corrosion issues to demonstrate the utility in modelling. The model was used to identify potential locations within the system where odour/corrosion may be problematic, as well as assisting in the evaluation of potential odour control alternatives.
Development of automated high-throughput ecotoxicity and genotoxicity test systems and fields of application
Authors: Eisentraeger A. , Brinkmann C. , Michel K. , Hahn S. , Huettner M. , Weber G. 
Published: May 2018

Bioassays like growth inhibition and genotoxicity assays are frequently used for the characterization of chemicals and contaminated environmental samples. In this work two standardized bioassays are automated completely using newly developed liquid handling stations and robotics.
A high-throughput algal growth inhibition assay prototype is set up and optimized in cooperation with Hoelle & Huettner AG (Tuebingen, Germany) and Polygen GmbH (Langen, Germany). A software package for both the control of the test system and for data evaluation has been developed (Biolane(tm) Supervisor, BioLaneTM Manager HTT). The applicability of the prototype is demonstrated by testing reference compounds with the automated assay in parallel with the Erlenmeyer flask assay. It is shown that EC50-values of chemicals do not differ significantly when incubation parameters like homogeneity of light intensity, temperature and evaporation during 72 hours of incubation are optimized.
The umu-genotoxicity test is automated completely using a “RoboSeq® 4204 SE” pipetting station (MWG AG, Ebersberg, Germany) equipped with two shakers, microplate photometer, four pipettes, stacker for ten microplates and incubation cabin with temperature regulation. As a result of miniaturization and automation large numbers of toxicants and far more treatments and parallels can be tested and, additionally, only low sample volumes are needed.
Behaviour of biofilm systems under varying hydrodynamic conditions
Authors: León Ohl A. , Horn H. , Hempel D.C. 
Published: May 2018

Heterotrophic biofilms were cultivated in long-term experiments in biofilm tube reactors. During the biofilm cultivation the substrate loading of glucose was kept constant while the hydrodynamic conditions were changed stepwise. To describe the behaviour of the biofilm structure under these varying flow conditions the mass transfer and transport at the bulk/biofilm interface and inside the biofilm was investigated with oxygen microelectrodes. Furthermore, the biofilm density was used to describe the biofilm compactness before and after the change of the hydrodynamic condition.
The obtained results show that the biofilm density and also the substrate flux decreased with decreasing flow velocity in the bulk phase. Additionally the slope of the oxygen concentration profiles decreased and the thickness of the concentration boundary layer increased. On the other hand, increasing the flow velocity in the bulk phase led both to a higher biofilm density and a higher maximum substrate flux. The biofilm surface became more homogenous and the thickness of the concentration boundary layer decreased. The time for adaptation of the biofilm structure after changing the hydrodynamic conditions ranged between 1 and 3 weeks.