bluuebunny/crossref_metadata_2025_split huggingface dataset:
Public awareness and the environment: “How do we encourage environmentally responsible behaviour?”
Authors: Harvie M. , Jaques P. 
Published: May 2018

This paper examines:• the relationship between environmental action and knowledge of the environment;• political, social and economic factors influencing the ability of individuals and societies to act in an environmentally responsible manner;• the possible motivations and contexts for encouraging greater responsibility toward the environment in various communities.
The annual National Environmental Education and Training Foundation (NEETF) Survey reveals that many US residents subscribe to environmental myths which may interfere with their efforts to act or agitate for environmental responsibility. Conventional wisdom might suggest that people in developing nations such as China would have a lower environmental awareness. In fact, when Shanghai residents were recently asked comparable questions to those in the NEETF Survey (part of an Asian Development Bank project), they often outperformed their American counterparts in their knowledge of environmental issues and in willingness to participate in activities such as recycling. - However in countries like China, changes are also required at an institutional level to make serious inroads into the problem of environmental degradation. In these circumstances, public awareness is a powerful tool only if the public has the power to drive institutional change. In many countries political influence constrains implementation of environmental projects with insufficient short-term political accolades. Similarly there are short-term economic and social goals that can dominate over the environment in the decision making process for both communities and individuals. This paper draws on USA, Australia and China survey data and the international experience of its authors in public awareness campaigns. The paper will discuss how environmental communicators can possibly change environmental attitudes and behaviour by understanding the contexts and the motivations for this change.
Applying the IWA approach to water loss performance indicators in Australia
Authors: Carpenter T. , Lambert A. , McKenzie R. 
Published: May 2018

In 1999 and 2000, IWA Task Forces on Water Losses and Performance Indicators published their conclusions of over three years research, analysis and discussions. For the topics of Non-Revenue Water, Water Losses, Apparent Losses and Real Losses, these included:a recommended standard terminology, with definitions and procedures for assessing these components of the Annual Water Balance;recommended performance indicators for each of these components.
This work represents a major step forward in defining the “best practice” approach to assessing and presenting components of Non-Revenue Water, for more rational comparisons of performance in diverse systems within a single organisation, within the same country, and between countries. The 21 members of the Water Services Association of Australia (WSAA) provide water and wastewater services to 12.9 million Australians. WSAA seeks to promote “best practice”, and act as a national focus for all interested parties. In February 2000 WSAA organised a national Workshop in Melbourne to discuss the IWA methodology. Arising from this Workshop, WSAA commissioned the production of customised Software and an Associated User Manual known as “Benchloss”, to promote and facilitate the application of the IWA recommended methodology throughout Australia. The paper will describe the development and application of “Benchloss” to date, with a comparison of Australian performance data against an International Data Set used by the Water Losses Task Force.
Investigation of factors contributing to dirty water events in reticulation systems and evaluation of flushing methods to remove deposited particles
Authors: Polychronopolous M. , Dudley K. , Ryan G. , Hearn J. 
Published: May 2018

This investigation was to evaluate the factors contributing to dirty water customer complaints within the area supplied by South East Water Limited, a wholesale water company in Melbourne, Australia. It also evaluated the potential to derive a predictive method to facilitate proactive mains flushing. The study focused on a single reticulation network, within the suburb of Wantirna.
A desktop and field study were undertaken. The desktop study evaluated a range of parameters and their association with dirty water customer complaints over an 8-year period. Parameters evaluated included distance from the water source, street topography, population distribution, and variations in water velocity. The field investigation focused on evaluating the quantity of turbid material deposited in key locations, identified from the desktop investigations.
Several factors appeared to influence the likelihood of a dirty water complaint. These were: population density and the associated complexity of the reticulation network; the presence of an undulating topography in the street of concern; and the presence of a dead end.
Evaluation of hydrant flushing indicated there might be potential to reduce water usage and improve flushing efficiency by flushing at a reduced flow rate of 5L.s-1, down from the typical 10L.s-1 or higher currently used. Time to clear at a hydrant appeared to be the most effective measure of settled material in a water main, however more work is required to confirm a threshold value that could be used as a predictive measure for proactive mains cleaning.
Public or private “ownership” - what’s in a name?
Authors: Davis J. , Cashin G. 
Published: May 2018

This paper examines the similarities and differences between public and private ownership of water utilities, including variations such as corporatisation. In any utility where the asset owner and the asset operator are the same, there are pressures to reduce operations and maintenance costs and capital expenditure to maximise returns. The authors argue that this is the case irrespective of whether such returns are to private shareholders or dividends to government. On the other hand, where the asset owner and the asset operator are separate entities with a clearly defined contractual interface, it is not possible to increase returns by reducing operations and maintenance standards, presuming a properly constructed contract. This is because the performance standards are clearly stipulated in the contract with payment reductions applying for non-performance. Such a model can be put in place irrespective of whether the asset owner is a private company or a public utility. The paper examines the profit incentive applying to private and public sector organisations in models where:the asset owner and the asset operator are the same organisation;models where the asset owner and the asset operator are separate organisations, with the service delivery performance governed by a clearly defined contractual interface.
The paper shows why the drivers governing the behaviour of public sector and private sector owners are similar, and how the separation of asset owner and asset operator can be used to ensure that service delivery standards are achieved at the lowest cost, whilst providing full transparency to shareholders, regulators and customers alike. The paper also reviews actual comparative data on service quality and performance under a number of ownership and contractual models, and draws conclusions on the effectiveness of the various asset owner/operator models in terms of service delivery performance and costs.
Treatment of high sulfate and high strength wastewater in a single stage anaerobic reactor
Authors: Huang J.-C. , Kumar Khanal S. 
Published: May 2018

In this study, a preset oxidation-reduction potential (ORP) was employed to regulate oxygen dosing for online sulfide toxicity control during anaerobic treatment of high sulfate wastewater. The experiment was conducted in an upflow anaerobic reactor (UAF), which was operated at a constant influent total organic carbon (TOC) of 6740 mg/L (equivalent to a chemical oxygen demand (COD) of 18000 mg/L) but with different influent sulfates of 1000, 3000 and 6000 mg/L. The reactor was initially run without oxygen injection at a natural ORP of about −290 to −300 mV and then was followed by oxygenation to raise ORP by +25 mV above the natural level for each influent sulfate level. With 1000 and 3000 mg/L influent sulfates, the produced sulfide levels did not impose any appreciable toxicity to methanogens even without oxygen injection. However, with 6000 mg/L influent sulfate without oxygen injections, the dissolved sulfide level quickly went up to over 800 mg/L which imposed a significant suppression on methanogenesis. Upon oxygen injection to raise the ORP by +25 mV, the dissolved sulfide was quickly reduced to 160 mg/L. If more oxygen was injected to raise the ORP by +50 mV, then dissolved sulfide further decreased to 12.2 mg/L with a concomitant improvement in methane yield by 45.9%.
With a +25 mV preset ORP increase, it was found that at the 1000 mg/L influent sulfate the supplied oxygen was more than that needed for sulfide oxidation. The excess oxygen could be utilized readily by facultative heterotrophs for organic oxidation, which contributed 13.5% of the total COD removal in the UAF. At the higher sulfate levels of 3000 and 6000 mg/L, the facultative contributions to the total COD removal were only 4.7 and 4.1%, respectively. This study has clearly demonstrated that ORP is a workable and reliable means for regulating oxygen injection to achieve online sulfide toxicity control in a single-stage anaerobic system treating high sulfate wastewater.
Developing a strategy for leakage management in water distribution systems
Authors: Trow S. , Farley M. 
Published: May 2018

Much that has been written about leakage economics and strategy, has been aimed at either the leakage specialist or the economic regulator. This paper aims to make the practitioner aware of the key messages from the theory, and the issues which have to be taken into account, when developing appropriate policies and practices.
The most important aspect of any leakage strategy is the leakage target. What level of leakage should the water supplier aim for, and what level should be maintained in the longer term? In an ideal world, every water supplier would like to eliminate leakage from water distribution systems. However, there will always be a level of leakage which has to be tolerated, and which has to be managed. The paper gives an overview of the prime techniques for leakage management, which have been referred to as the four “pillars”. Each of these follows a similar law of diminishing returns on investment to make savings in leakage. The key issues for introducing these four elements are discussed, together with the steps required to calculate the economic level of leakage.
Influence of phosphorus on biofilm accumulation in drinking water distribution systems
Authors: Kasahara S. , Maeda K. , Ishikawa M. 
Published: May 2018

Continuous reactor tests using rotating reactors with polyvinyl chloride (PVC) coupons were conducted. Laboratory tap waters with and without 50 μg P/L KH2PO4 (phosphorus water and non-phosphorus water) were supplied to the reactors in the absence of residual chlorine. Numbers of cells attached on the surface of the coupons (biofilm cells) and numbers of cells suspended in the influent and effluent waters (planktonic cells) were enumerated, and then specific growth rates of biofilm cells and planktonic cells were estimated.
Concentrations of assimilable organic carbon (AOC) in both feed waters were comparable, whereas numbers of biofilm cells in phosphorus reactors were 1 order of magnitude larger than those in non-phosphorus reactors at the steady state of the continuous reactor test. Total planktonic cell concentrations in phosphorus reactors were also 1 order of magnitude higher than those in non-phosphorus reactors. Specific growth rate of biofilm cells estimated from heterotrophic plate count in non-phosphorus reactors was 1 order of magnitude higher than that in phosphorus reactors.
This study concluded that phosphorus would increase amounts of biofilm cells on distribution pipe walls because phosphorus lengthened the generation time of biofilm cells. The concentration of AOC could not represent the potential of biofilm accumulation sufficiently.
Bank filtration and groundwater recharge for treatment of polluted surface waters
Authors: Jekel M. , Gruenheid S. 
Published: May 2018

Investigations on the behavior of different bulk organics and trace organic compounds at a bank filtration site at Lake Tegel in Berlin, Germany, and in a long retention soil column system are reported. The objective of the research was to assess important factors of influence for the degradation of bulk and trace organics. More than two years of monitoring for the bulk parameter DOC proved that the redox conditions significantly influence the DOC-degradation rates but not necessarily the residual concentration. LC-OCD measurements confirmed that the change in character is comparable for aerobic and anoxic/anaerobic infiltration. Only the fraction of polysaccharides shows a better removal under aerobic conditions.
Furthermore, adsorbable organic iodine (AOI) measurements revealed a more efficient degradation of AOI and AOBr under anoxic/anaerobic conditions. The moznitoring of the single organic pollutants Iopromide, Sulfamethoxazole and naphthalenedisulfonic acids showed that the redox conditions have an influence on the degradation behavior of some of the monitored compounds. Iopromide was efficiently removed at all times, but no evidence for a dehalogenation under oxic conditions was found. Sulfamethoxazole showed a better removal under anoxic/anaerobic conditions. The very stable 1.5-naphthalenesulfonic acid was not removed under either redox condition.
New Trends in Water Quality Management
Authors: Benedek P 
Published: May 2018

In the present water quality management practice the ambient water quality is determined on the basis of classification of recipients. This system disregards, however, the fact that the majority of hazardous micropollutants is tending to accumulate in suspended solids and may contaminate the bottom sediment.
The proposed water quality management system is aiming at providing potable water of good quality without any regards to classification of surface waters. The tasks are outlined on the basis of morphological, hydrological, hydraulic and technological conditions of drinking water production. In this approach both the previous events i.e. deposition or scouring of polluted bottom silt and the transport of suspended solids with coupled micropollutants are involved.
The new system is focused on Danube river, since the water supply or rather the bank-filtered water resources along it is endangered at many locations by accumulated pollutants in bed load.
Electrochemical Processes for Wastewater Treatment
Authors: Mendia L 
Published: May 2018

Many electrochemical processes for watewater treatment have been developed over the years. In the field of sewage purification attention has focused on clarification, disinfection and phosphate removal with the aim of reducing costs compared to traditional processes. The on-site production of necessary chemicals is a step towards reducing operating costs. Electrochemical treatment is very efficient and reduces process detention times thereby allowing smaller plants.
Sea water or brine is mixed with the screened sewage in an appropriate ratio, then passed through an electrolysis cell rather similar to that used for hypochlorite production. Depending on the material of the electrodes, their arrangement (vertical or horizontal) and the applied potential difference, the reactions which occur produce the chemicals required for the purification processes.
Downstream the electrolysis, the mixture flows into a clarification basin which acts as a contact tank for disinfection. The detention time of this process depends on the type of basin used.
I report results of electrochemical treatment performed on a semiindustrial scale, using horizontal electrodes: anode of graphite or silicon-iron and stretch-iron cathodes; followed by a sludge recirculation clarification basin. The removal of suspended solids and the abatement of B.O.D. and phosphates were much better than those reached by traditional physical-chemical treatment. The energy consumption is approximately 0.5 kWh/m of raw sewage.
Fate of Heavy Metals and Potential for Clinker Formation during Pilot Scale Incineration of Municipal Sludge
Authors: Campbell H W , Crescuolo P J , Bridle T R 
Published: May 2018

This study describes multiple-hearth incineration investigations conducted at the Water Pollution Control Plant (WPCP) in Hamilton, Ontario. The objectives of the study were to determine, under controlled conditions, the fate of selected heavy metals present in the sludge and to determine optimal operating conditions to minimize clinker formation and residual organic content of the ash. A factorial experimental design which included four levels of temperature, three levels of throughput rate and three levels of centre shaft speed was conducted.
Within the constraints of the experiment, zinc, iron, magnesium, aluminum, nickel, copper, calcium, chromium, lead, silica and phosphorus proved to be conservative and remained in the ash. Varying proportions of cadmium, mercury and arsenic were classified to the gas stream. The destruction of total carbon was essentially complete under all test conditions, with the minimum level being 98.7%. Clinker formation was observed only under conditions of high temperature combined with a long furnace residence time.
The Use of Rheology for Sludge Characterization
Authors: Campbell H W , Crescuolo P J 
Published: May 2018

Rheological measurements were conducted on a variety of anaerobically digested sewage sludges to evaluate the potential use of rheology in describing the effects of chemical conditioning on the physical characteristics of sludges.
The objectives of the study were to evaluate the influence of the method of chemical conditioning on rheological measurements; to determine the response of the viscometer system to changes in the instrument variables; and to evaluate interrelationships between rheology and other physical properties. All rheological measurements were made using a coaxial rotational viscometer.
Evaluation of a variety of test procedures identified that both the method of adding chemical conditioners, and the acceleration rate of the rotational viscometer, could significantly alter the shape of the rheograms. A suggested methodology was identified and selected samples were analyzed in triplicate to test the reproducibility of the procedures.
Existing mathematical models do not adequately describe the variety of flow behaviour patterns observed with sewage sludge. The concepts of yield stress and apparent viscosity also have limited value due to problems of definition and calculation. A parameter termed the “instantaneous viscosity”, defined as the derivative of the flow curve, is suggested as being more suitable for describing sludge behaviour.
The relationships between chemical conditioning, particle size distribution and applied shear were explored. As polymer addition increased, the sludge particles became more susceptible to shear breakup. The extent of particle size reduction was a function of the rate of shear and the time during which the shear was maintained.
Continuous Countercurrent Ion Exchange for Desalination and Tertiary Treatment of Effluents and Other Brackish Waters
Authors: Hendry B A 
Published: May 2018

A continuous countercurrent ion exchange (CCIX) process has been developed for desalination of mineralized effluents and brackish water. The process utilizes macroporous resins in a strong cation/weak anion sequence. Removal of organic matter by the anion resin results in colour and odour removal and approximately 70% reduction of the COD of humus tank effluent.
No pretreatment is required and resin has been in use over the equivalent of more than two years of continuous operation without significant fouling or loss of capacity. Any required degree of desalination is attinable. The basic four-colunn system (cation load and regeneration pair and anion load and regeneration pair) of countercurrent fluidized bed multistage contactors attains greater than 80% water recovery using up to 1,0 N sulphuric acid and 0,2 N lime slurry as regenerants. Low solubility of CaSO4, in the cation waste liquid and column operating problems if high lime concentrations are used set limits on the water recovery. Calcium content of the feed water affects water recovery.
New techniques using five-column systems permit byproduct recovery and/or reuse of spent regenerants and result in over 90% water recovery. The capital cost estimate for a 10 000 kℓ/day plant is R5 million while unit costs of water are 30 to 40 c/kℓ. for removal of 500 mg/ℓ TDS. Present work involves lime contacting improvements and evaluation of carbon adsorption polishing of the ion exchange product to produce potable water.
German Experiences with Low and High Technology Methods for Disinfection of Municipal Sewage Sludges
Authors: Strauch D 
Published: May 2018

Municipal sewages contain considerable amounts of infectious agents like bacteria, viruses and parasites. It is known that primary, secondary and tertiary treatment of sewage do not destroy the infectious agents totally. Therefore the effluents of sewage treatment plants still carry infectious bacteria, viruses and parasites which are discharged into the receiving waters.
The sludges which are retained in the treatment plants (raw, surplus, and chemical) are enriched with pathogens. Even anaerobic digestion does not eliminate all of these pathogenic agents.
Because of the microbial hazards which these sludges pose for public health they must be disinfected prior to their agricultural use. Some available methods are: composting of liquid sludge in windrows with straw, pasteurization, aerobic-thermophilic stabilization, addition of lime as conditioner for dewatering in filter presses, irradiation with electron accelerators or radioactive sources, composting dewatered sludge in windrows or in aerated stationary/movable reactors with or without addition of matter like straw, sawdust, bark, refuse etc., solidifying with unslaked lime.
With these methods experiments using salmonellas, enteroviruses and eggs of ascaris suum as test agents were performed to evaluate their disinfecting effects. The results are described and discussed.