bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of the hydrology and flow of nitrogen in 17 Danish catchments
Authors: Andersen H. E. , Pedersen M. L. , Jorgensen O. , Kronvang B.
Published: May 2018

In the search for tools for evaluating the effects of national action plans combating diffuse nutrient pollution causing eutrophication of surface waters, a study of the nitrogen (N) flow in 17 Danish agricultural catchments was carried out. Data on N input and N harvest for the agricultural year of 1993/1994 was obtained from questionnaire surveys facilitating the set up of N balances. Net export of N from the catchments measured at the outlet was obtained from time-series of stream water chemistry and discharge from 1993-1997. N leaching from the root zone of each field was calculated using an empirical model. A physically based lumped rainfall-runoff model was used for separating the hydrograph time-series into three runoff components: baseflow, interflow and overland flow. Large regional variations in net N input were found ranging from 62 kg N ha−1 yr−1 in the loamy eastern part of the country dominated by cereal production to 137 kg N ha−1 yr−1 in the western part characterised by less fertile sandy soils and dominated by animal husbandry. N leaching from the root zone showed a corresponding variation with regional averages ranging from 34.5 kg N ha−1 yr−1 to 90.9 kg N ha−1 yr−1. No similar regional pattern could however be found regarding net N export, and no relationship could be established between net N export and root zone N leaching. This finding was ascribed to a varying and in some catchments very high (>80%) N retention during subsurface transport to the stream. The hydrological modelling revealed that loamy catchments had a high proportion of quick flow (overland flow + interflow), whereas baseflow dominated the sandy catchments. Further, a highly significant relationship between N retention and proportion of quick flow was found emphasising the importance of understanding the hydrological pathways. This should be taken into consideration when evaluating the N loading of surface waters resulting from a given agricultural practice and the effects of possible changes in this practice.
Estimation of environmental impact of some of the most often occurring pesticides in Slovenian surface and underground water
Authors: Z̆gajnar Gotvajn A. , Zagorc-Koncan J. , Tis˘ler T.
Published: May 2018

The use of environmental xenobiotics is increasing every day. We are now all dependent on synthetic substances in agriculture, pharmacy, petrochemical and food industries. Pesticides, when used correctly, have enormous benefits in increasing crop yield and improving the quality of agricultural produce. The problem is what happens to these chemicals in the environment. They can be widespread through various pathways. The aim of our work was to find out which pesticides occur most often in Slovenian surface and underground water and to assess some of their environmental characteristics. National monitoring on underground water includes analyses of 27 pesticides and their metabolites, which can be bought in the country. In spite of the fact that their use has not been allowed since 1994, the most often detected and widely spread pesticides in Slovenia appeared to be atrazine and alachlor. This is the reason why the toxicity of atrazine, alachlor and pentachlorophenol to different aquatic organisms was determined. Sensitivity of test organisms to pesticides was compared. The experimental results were compared with available literature data. Toxicity assessment shows their environmental impact and hazard on non-target aquatic organisms.
Numerical modeling of saline water transport in the lower Nam Kam Basin, Amphoe That Phanom, Changwat Nakhon Phanom, Thailand
Authors: Srisuk K. , Sribooniue V. , Buaphan C. , Archvichai L. , Youngme W. , Satarak P. , Jaruchaikul S.
Published: May 2018

The objective of the project is to establish a conceptual groundwater model over the lower Nam Kam Basin in order to apply a numerical technique for the prediction of the impact of saline water transport due to the proposed weir across the Nam Kam River. Hydrogeological investigations including mapping, drilling, piezometer installations and monitoring were systematically conducted during 1997 to 1998. Brackish groundwater is saturated under the area with a depth of 30-60 m. Groundwater regionally flows from the south (the Phu Phan Range) to the north and discharges to the Nam Kam River. Another direction is from the northern region to the southern region, discharging to the central region. A two-dimensional model was constructed along the principal gradient in the NW-SE direction. There are several local recharge and discharge areas across the Nam Kam floodplain. A local groundwater flow is active within the depth of 2 m to 30 m below the ground surface within the sand and gravel unit. Simulations were calibrated with hydraulic heads and salinity of groundwater in the piezometers. It is found that the recharge and evapotranspiration rates are 1% to 40% of the rainfall and 10% to 15% of a pan evaporation, respectively. The ranges of horizontal hydraulic conductivity to vertical hydraulic conductivity are 0.1 to 0.01. The possible longitudinal dispersivity values of the hydrostratigraphic units are 20 m to 500 m, but the transverse dispersivity is less than the longitude by one order of magnitude. The comparison of calculated heads and measured heads give a root mean square error of less than 1 m. The different salinity concentrations are still in a range of 2000 - 5000 mg/l. Ten year simulation of saline water transport indicates that the reservoir ponding with water level at +140.5 m above mean sea level may divert groundwater flow and discharging to the northern boundary of the reservoir at Ban Don Kao.
Monitoring coastal marine waters for spore-forming bacteria of faecal and soil origin to determine point from non-point source pollution
Authors: Fujioka R. S.
Published: May 2018

The US Environmental Protection Agency (USEPA) and the World Health Organization (WHO) have established recreational water quality standards limiting the concentrations of faecal indicator bacteria (faecal coliform, E. coli, enterococci) to ensure that these waters are safe for swimming. In the application of these hygienic water quality standards, it is assumed that there are no significant environmental sources of these faecal indicator bacteria which are unrelated to direct faecal contamination. However, we previously reported that these faecal indicator bacteria are able to grow in the soil environment of humid tropical island environments such as Hawaii and Guam and are transported at high concentrations into streams and storm drains by rain. Thus, streams and storm drains in Hawaii contain consistently high concentrations of faecal indicator bacteria which routinely exceed the EPA and WHO recreational water quality standards. Since, streams and storm drains eventually flow out to coastal marine waters, we hypothesize that all the coastal beaches which receive run-off from streams and storm drains will contain elevated concentrations of faecal indicator bacteria. To test this hypothesis, we monitored the coastal waters at four beaches known to receive water from stream or storm drains for salinity, turbidity, and used the two faecal indicator bacteria (E. coli, enterococci) to establish recreational water quality standards. To determine if these coastal waters are contaminated with non-point source pollution (streams) or with point source pollution (sewage effluent), these same water samples were also assayed for spore-forming bacteria of faecal origin (Cl. perfringens) and of soil origin (Bacillus species). Using this monitoring strategy it was possible to determine when coastal marine waters were contaminated with non-point source pollution and when coastal waters were contaminated with point source pollution. The results of this study are most likely applicable to all countries in the warm and humid region of the world.
Study of diffuse source pollution management for land use and drainage system planning
Authors: Yamada K. , Funaki T. , Honda S. , Sugihara M.
Published: May 2018

This study aims to clarify the mass balance of pollutants during both dry periods and storm events and to discuss the effects of some strategies such as pollutant removal, land use planning and new drainage systems by simulation. Three subjects are discussed in this paper. First, the amount of pollutants entering Lake Biwa from an urban area have been roughly estimated by using data collected by the local government. Second, many additional samples were collected from road surfaces, house roofs and parking lots to consider the role of land use in pollutant runoff. Third, some ongoing BMP projects in an urban area are introduced. As a result, some ideas on how to solve the problem of diffuse pollution in urban areas have been obtained.
Parameter estimation procedure for complex non-linear systems: calibration of ASM No.1 for N-removal in a full-scale oxidation ditch
Authors: Abusam A. , Keesman K. J. , van Straten G. , Spanjers H. , Meinema K.
Published: May 2018

When applied to large simulation models, the process of parameter estimation is also called calibration. Calibration of complex non-linear systems, such as activated sludge plants, is often not an easy task. On the one hand, manual calibration of such complex systems is usually time-consuming, and its results are often not reproducible. On the other hand, conventional automatic calibration methods are not always straightforward and often hampered by local minima problems. In this paper a new straightforward and automatic procedure, which is based on the response surface method (RSM) for selecting the best identifiable parameters, is proposed. In RSM, the process response (output) is related to the levels of the input variables in terms of a first- or second-order regression model. Usually, RSM is used to relate measured process output quantities to process conditions. However, in this paper RSM is used for selecting the dominant parameters, by evaluating parameters sensitivity in a predefined region. Good results obtained in calibration of ASM No.1 for N-removal in a full-scale oxidation ditch proved that the proposed procedure is successful and reliable.
Advances in high rate anaerobic treatment: staging of reactor systems
Authors: van Lier J.B. , van der Zee F.P. , Tan N.C.G. , Rebac S. , Kleerebezem R.
Published: May 2018

Anaerobic wastewater treatment (AnWT) is considered as the most cost-effective solution for organically polluted industrial waste streams. Particularly the development of high-rate systems, in which hydraulic retention times are uncoupled from solids retention times, has led to a world-wide acceptance of AnWT. In the last decade up to the present, the application potentials of AnWT are further explored. Research shows the feasibility of anaerobic reactors under extreme conditions, such as low and high temperatures. Also toxic and/or recalcitrant wastewaters, that were previously believed not to be suitable for anaerobic processes, are now effectively treated. The recent advances are made possible by adapting the conventional anaerobic high-rate concept to the more extreme conditions. Staged anaerobic reactor concepts show advantages under non-optimal temperature conditions as well as during the treatment of chemical wastewater. In other situations, a staged anaerobic - aerobic approach is required for biodegradation of specific pollutants, e.g. the removal of dyes from textile processing wastewaters. The current paper illustrates the benefits of reactor staging and the yet un-exploited potentials of high-rate AnWT.
An integrated approach to dissolved air flotation
Authors: Amato T. , Edzwald J. K. , Tobiason J. E. , Dahlquist J. , Hedberg T.
Published: May 2018

DAFRapide® techniques utilising reduced flocculation times, of the order of 5 minutes, together with flotation loading rates of up to 40 m/h, can be incorporated with conventional filtration systems operating at up to 20 m/h. Product quality of typically <1 NTU and <0.1 NTU after flotation and filtration respectively can be achieved.
Removal and fate of Cryptosporidium in dissolved air drinking water treatment plants
Authors: Edzwald J. K. , Tobiason J. E. , Dunn H. , Kaminski G. , Galant P.
Published: May 2018

In the first part of the paper, data from pilot plant studies are used to evaluate Cryptosporidium removal by dissolved air flotation (DAF) clarification and dual media filters under challenge conditions. Oocyst removals were investigated for design detention times and hydraulic loadings for winter and spring seasons. Coagulation was optimized for turbidity and removal of natural organic matter. DAF performance was better for spring water temperatures achieving 2.5 ± 0.3 log removal of oocysts compared to 1.7 ± 0.3 log removal in the winter. Cumulative log removal across DAF and filtration exceeded 5.4, and was not affected by water temperature. Low turbidities and particle counts are indicators of good treatment and good removals of Cryptosporidium. The second part of the paper uses a mathematical model to predict the fate of Cryptosporidium through a DAF plant and the impact of filter backwash recycle on oocyst build-up in the plant influent. Model predictions show that the fate of Cryptosporidium and the build-up of oocysts in the plant influent depend on: DAF performance, the percent of filtered water production used for backwashing, and the percent of filter backwash recycle flow. A DAF plant with 2.5% filtered water production for backwashing and that achieves 1.6 log removal or greater of oocysts by DAF clarification will not have a build-up of oocysts in the plant influent regardless of the recycle rate. This is because the oocysts are concentrated in the DAF floated sludge and not within granular filters.
The biological sulfur cycle: novel opportunities for environmental biotechnology
Authors: Lens P.N.L. , Kuenen J.G.
Published: May 2018

Although the study of sulfur cycle bacteria was already started around the 1890s by the famous microbiologists Winogradsky and Beijerinck, there are nowadays still many new discoveries to be made about the metabolic properties, phylogenetic position and ecological behaviour of bacteria that play a role in the biological sulfur cycle. The current interest of the scientific community in the biological sulfur cycle is very high, especially because of the many special organisms that have recently been discovered in the deep sea and other environments characterised by extreme conditions (such as high salt, low/high pH or temperature) and also in bioreactor environments. This paper highlights some of these new discoveries and relates them to environmental biotechnology. It is concluded that the micro-organisms from the sulfur cycle offer unique opportunities for sulfur pollution abatement and sulfur recovery.
Experiences and potential of anaerobic wastewater treatment in tropical regions
Authors: Wiegant W.M.
Published: May 2018

In this article an overview is given on the experience with anaerobic treatment of domestic wastewater in the tropics, with emphasis on the situation in India. Some design criteria and their impact on the costs of UASB reactors are discussed. The operational results of a number of full-scale reactors are presented. The applicability of the UASB, in combination with different post-treatment units to comply with a variety of effluent standards is compared with other systems. From the available data it is concluded that, if nitrogen removal is not required, a UASB system, followed by a polishing pond, is a relatively simple, affordable, and manageable wastewater treatment system. Trickling filters may follow UASB treatment if effluent standards require removal of TKN. The inclusion of UASB reactors in wastewater treatment schemes allowing for total nitrogen removal still needs further study.
Anaerobes, aerobes and phototrophs (A winning team for wastewater management)
Authors: Gijzen H.J.
Published: May 2018

Current mainstream technologies for wastewater treatment, such as activated sludge and tertiary nutrient removal, are too costly to provide a satisfactory solution for the increasing wastewater problems in developing regions. Besides, these technologies do not allow for re-use of valuable energy and nutrients contained in the wastewater. In light of these limitations, it is important to reconsider the technology and strategic approaches in wastewater management. This paper introduces the ‘Cleaner Production’ concept to sewage management, which combines two approaches: pollution prevention and re-use. Pollution prevention includes a shift towards low water use sanitation technology. The more concentrated wastewater, becomes more attractive for re-use oriented treatment schemes. A combination of anaerobic pre-treatment followed by macrophyte-covered stabilisation ponds is proposed for the effective recovery of energy and nutrients from sewage. By selecting optimal applications of the plant biomass and pond effluent, nutrients will end up as fish and crop protein. This contrasts favourably to tertiary nitrogen removal in activated sludge systems, which recycles ammonia through molecular nitrogen at the expense of energy and high costs. Macrophyte ponds are proposed as a key step in waste recycling, because these form the central unit of a recycling engine, driven by photosynthesis. The process is energy efficient, cost effective and applicable under a wide variety of rural and urban conditions.
Optimizing dissolved air flotation design and saturation
Authors: Féris L. A. , Gallina C. W. , Rodrigues R. T. , Rubio J.
Published: May 2018

Dissolved air flotation (DAF) of iron hydroxide precipitates at working pressures lower than 3 atm, using modified flotation units to improve the collection of fragile coagula, was studied. Conventional DAF flotation was studied as a function of saturation pressure in the absence and presence of surfactants in the saturator. Without surfactants, the minimum saturation pressure required for DAF to occur was found to be 3 atm. But, by lowering the air/water surface tension in the saturator, DAF was possible at a saturation pressure of 2 atm. This behavior was found to occur in both batch and pilot DAF operation tests and almost complete recovery of the precipitates was attained. Results are explained in terms of the minimum “energy” which has to be transferred to the liquid phase to form bubbles by a cavity phenomenon. Further, studies were conducted changing equipment design and feed bubbles size distribution (mixing micro and “mid-sized” bubbles). Thus, bubbles entrance position in the collision-adhesion zone (“capture” zone) was compared to bubble entrance position in the water flow inlet below the floating bed. A “mushroom” type diffuser was used for the “capture zone” experiment and better performance was obtained. Results are explained in terms of different mass transfer phenomena in the collection zone and in the separation zone. Finally, results obtained with the use of a column flotation cell working as normal DAF and with a wide bubble size range are presented. Results indicate good performance and some gains in process kinetics with middle size bubbles.
Small scale model for CFD validation in DAF application
Authors: Hague J. , Ta C. T. , Biggs M. J. , Sattary J. A.
Published: May 2018

A laboratory model is used to measure the generic flow patterns in dissolved air flotation (DAF). The Perspex model used in this study allows the use of laser Doppler velocimetry (LDV), a non-invasive, high-resolution (±2 mm s−1) laser technique of flow velocity measurement. Measurement of flow velocity in the single-phase situation was first carried out. Air-saturated water was then supplied to the tank and measurements of bubble velocity in the two-phase system were made. Vertical flow re-circulation was observed in the flotation zone. In the bottom of the flotation zone (near the riser) secondary flow re-circulation was observed, but only in the two-phase system. Another phenomenon was the apparent movement of flow across the tank width, which may be due to lateral dispersion of the bubble cloud. Data from preliminary computational fluid dynamics (CFD) models were compared against this measured data in the case of the single-phase system. The CFD model incorporating a k-e model of turbulence was found to give closer agreement with the measured data than the corresponding laminar flow model. The measured velocity data will be used to verify two-phase computational fluid dynamics (CFD) models of DAF.
From odorant formation to odour nuisance: new definitions for discussing a complex process
Authors: Van Harreveld A.P.
Published: May 2018

The process leading from odorant formation to individuals filing a complaint is complex, involving many steps and factors. A flow chart is proposed. The definitions that describe elements of this process, such as annoyance, nuisance, propensity of a population to experience nuisance, the “unpleasantness” of an odour, as used in odour literature, are often imprecise and confusing. A set of definitions is proposed to identify the issues involved and suggest a more precise use of terminology. A new definition for “annoyance potential” as an attribute of an odour is proposed. The concepts were developed for a study into the feasibility of developing a standardised method for measuring annoyance potential, funded by the programme “Improvement of the Quality of Environmental Measurements”, funded by the Ministry of Public Planning and the Environment in The Netherlands. The programme is expected to lead to a development programme, which will be outlined.
Meaendering: nature, culture and rivers
Authors: Clifford S.
Published: May 2018

Alongside science we need a parallel capability of exploring meaning so that intangible, uncountable aspects of our relationships with rivers, especially those understood by local communities, can be expressed. Common Ground has offered the concept of Local Distinctiveness and gives examples from England, including recent projects which they have initiated.
Challenges of the Blackwood Basin, Western Australia
Authors: Ecker S. , Karafilis A. , Taylor R.
Published: May 2018

Growing concern about the declining state of the catchment and river led to the formation of the Blackwood Basin Group in 1992. Funded primarily by the Natural Heritage Trust and using the river as the focus, the group aims to provide leadership and support to achieve sustainable management of natural resources in the catchment. Through an Integrated Catchment Management approach, the Blackwood Basin Group has managed a range of projects to improve the community's understanding and management of the Blackwood River and its catchment. A number of research, education, demonstration and on-ground action activities relating to river management have been undertaken in partnership with community and local, state and federal government organisations. Activities include demonstrations and evaluations of riparian restoration, funding riparian restoration activities, protection of high conservation value remnant vegetation, a flood risk study, zone action planning and monitoring the condition of the river and its tributaries.
Achievements of the Grand River Conservation Authority, Ontario, Canada
Authors: Krause P. , Smith A. , Veale B. , Murray M.
Published: May 2018

Winning the 2000 International Riverprize resulted from a significant investment by the community of Ontario over a long period of time in the Grand River Conservation Authority, GRCA. Innovative partnerships with the business community, government, universities, First Nations tribes, environment groups and the general community have been the hallmark of a broad-based river management program that has returned the Grand River to a healthy environment and usable resource. Recognising this, the Grand River received special recognition from the Canadian Heritage Rivers Board - as a designated Heritage River. Not content with the achievements of the past, the GRCA has turned its attention to the future needs of this river system and to increasing the depth and breadth of community partnerships.
Comparison of different approaches used to regulate odours around the world
Authors: Mahin T.D.
Published: May 2018

A number of different countries, and states and local regulatory agencies within countries, have struggled with developing effective odour regulations or guidelines. The challenge is to develop regulations or guidelines that both avoid odour annoyance conditions and are not excessively conservative. This paper will present highlights of odour regulations or guidelines in Europe, Asia, Australia, New Zealand and North America. A comparison between the different approaches will be presented. With a number of countries reporting an increase in complaints due to odours, the field of odour assessment is rapidly evolving. Complaints due to odours from livestock facilities are also significantly increasing in many countries. A comparison of approaches used to regulate livestock operations is also included in the paper. The potential impact of European olfactometry standardisation efforts to existing assumptions about odour annoyance or nuisance levels is analysed.
River loggers - a new tool to monitor riverine suspended particle fluxes
Authors: Mitchell A. W. , Furnas M. J.
Published: May 2018

The Australian Institute of Marine Science (AIMS) has developed an in situ digital turbidity logger (AIMS River Logger) to record time series of fine suspended sediment concentrations in North Queensland rivers. The loggers use dual LED transmissometers (15 and 85 mm pathlength) to measure in situ turbidity associated with the range of suspended sediment concentrations (0-5 g L-1) encountered in regional rivers. A system of wiper brushes clean the optical surfaces prior to instrument readings. Overlying water depth and temperature are concurrently recorded. Internal batteries provide sufficient power for unattended deployments of 6+ months with readings taken at 30 minute intervals. Records of suspended sediment concentrations in the lower Tully River over three wet seasons (1996, 1997, 2000) are shown in relation to concurrent river discharge. Peaks in suspended sediment concentration coincide with discharge events. During each event, peak sediment concentrations typically occur during the rising stage of the hydrograph, then decline rapidly prior to significant falls in water level. Derived suspended loads during discharge events are generally proportional to the size of the event, though higher responses are recorded during the initial flood event of each wet season.
The use of artificial oxygenation to reduce nutrient availability in the Canning River, Western Australia
Authors: Greenop B. , Lovatt K. , Robb M.
Published: May 2018

Artificial oxygenation has been used for two summer periods to improve the water quality of the Canning River in Perth, Western Australia. The project is part of the Swan Canning Cleanup Program, which aims to reduce the frequency and severity of nuisance and toxic algal blooms in the Swan-Canning estuary. The trials have proved that oxygenation has increased the dissolved oxygen concentrations in the water column, particularly in the bottom waters where dissolved oxygen concentrations are frequently below a critical level of three milligrams per litre. Oxygenation has had a positive impact on nutrient concentrations in the water column and nitrogen cycling processes. Reductions in nutrient concentrations were highlighted by drops in ammonium and total phosphorus concentrations of 97% and 64% following the recommencement of oxygenation after a plant shutdown. Results of a microbiological study combined with the data analysis indicate that the number of nitrifying microbes have increased due to oxygenation. However, comparisons between oxygenated and control areas were inconclusive about the ability of the oxygenation plant to reduce total nitrogen and phosphorus levels. This could be explained by factors such as spatial variability, water flow during the trials and measurement limitations in the monitoring program. Future work will concentrate on assessing the impact of the oxygenation plant on nutrient concentrations.
Effect of carvacrol and thymol on odor emissions from livestock wastes
Authors: Varel V.H. , Miller D.N.
Published: May 2018

A majority of the beef cattle and swine in the United States is produced in confined facilities. This generates significant environmental pollutants from the waste produced, including global warming gases, odor, and pathogens. The objectives of this study were to control the fermentation activity and pathogens in cattle and swine wastes with antimicrobial plant essential oils. Anaerobic one litre flasks with a working volume of 0.5 l were used to evaluate the effect of carvacrol and thymol on production of fermentation gas, short-chain volatile fatty acids, lactate, and bacterial populations. In cattle waste, 1 g l−1 each of carvacrol and thymol completely inhibited the production of volatile fatty acids and lactate over 23 days. In swine waste, 2.5 g l−1 carvacrol inhibited the production of all volatile fatty acids. We conclude that these essential oils are effective in controlling livestock waste odor emissions and field studies are warranted.
Combination of advanced oxidation processes and gas absorption for the treatment of chlorinated solvents in waste gases
Authors: Dewulf J. , Van Langenhove H. , De Smedt E. , Geuens S.
Published: May 2018

Treatment of chlorinated organic compounds in waste gases is difficult because of several reasons: these compounds are dioxin precursors when incinerated, and also biological treatment is difficult because of a limited number of suitable microbial degradation pathways. On the other hand, since the 1990s, a new generation of chemical oxidation techniques has been introduced in water treatment. Advanced Oxidation Processes (AOPs) are based on a combination of UV/H2O2, UV/O3 or H2O2/O3. The combinations result in the generation of OH-radicals, which subsequently attack the organic pollutants. In this work, the treatment of a gas stream (240 L/h) loaded with 20-40 ppmv trichloroethylene (TCE) is presented. Therefore, a combination of an absorption process in a bubble column with a liquid H2O2/O3 initiated oxidation, was investigated. Removal efficiencies, depending on the dosed H2O2 and O3, up to 94% were found. The production of chloride ions was investigated: the Cl-atoms from the removed TCE could be found back as chloride ions. Next to the experimental work, attention was paid to the mechanisms taking place in the proposed concept. Here, a simulation model was developed, considering gas/liquid mass transfer of TCE and ozone, axial liquid dispersion, advective gas and liquid transport and about 29 chemical reaction steps. The modelling allowed a better understanding of the technique and gives insight in its possibilities and limitations. Finally, it can be concluded that the proposed technique shows interesting perspectives: it is able to transform chlorine in chlorinated solvents into chloride ions effectively at ambient temperature conditions.
Indigenous property rights and river management
Authors: Sheehan J.
Published: May 2018

The presence of indigenous property rights and interests arising from the survival of native title in Australia presents unique issues in the management of rivers and riverine lands. Existing common law and statutory tidal and non-tidal rights are a complex overlay of public and private property rights which are themselves undergoing significant change through the commodification of many natural resources by Commonwealth and State governments, such as marine species stock and non-tidal water. The melding of indigenous values and management practices with existing management regimes for rivers and riverine lands offers considerable potential for both sustainability of resource utilisation, and respect and recognition of native title with resultant predicted benefits in the vexed area of compensation.
From here to accountability: securing healthy rivers
Authors: Crawford P. J.
Published: May 2018

While specifying “responsibilities” for river planning and management implies that outcomes are desired, defining “accountabilities” demands that results are achieved. This paper examines innovative ways of converting aspirations to results, with particular reference to the changes initiated in New South Wales in response to the establishment of the Healthy Rivers Commission of New South Wales and its first round of Inquiries.
Establishing river basin organisations in Vietnam: Red River, Dong Nai River and Lower Mekong Delta
Authors: Taylor P. , Wright G.
Published: May 2018

River basin management is receiving considerable attention at present. Part of the debate, now occurring worldwide, concerns the nature of the organisations that are required to manage river basins successfully, and whether special-purpose river basin organisations (RBOs) are always necessary and in what circumstance they are likely to (i) add to the management of the water resources and (ii) be successful. The development of river basin management requires a number of important elements to be developed to a point where the river basin can be managed successfully. These include the relevant laws, the public and non-government institutions, the technical capabilities of the people, the understanding and motivation of people, and the technical capacity and systems, including information.

A river basin organisation (or RBO) is taken to mean a special-purpose organisation charged with some part of the management of the water resources of a particular river basin. Generally speaking, such organisations are responsible for various functions related to the supply, distribution, protection and allocation of water, and their boundaries follow the watershed of the river in question. However, the same functions can be carried out by various organisations, which are not configured on the geographical boundaries of a river basin.

This paper outlines recent work on river basin organisation in Vietnam, and makes some comparisons with the situation in Australia.
A pilot-scale study on biofilters for controlling animal rendering process odours
Authors: Luo J.
Published: May 2018

Heating of animal tissue during the process of rendering liberates a variety of odorous compounds. The performance of biofiltration in removing these odours was investigated using pilot-scale biofilters containing different media (sand, finely and coarsely crushed wood bark, and bark/soil mixture). Odour-removal performance of the biofilters was determined using olfactometry. Biofilter odour removal efficiencies of between 29.7% and 99.9% were measured at influent odour concentrations of between 143,100 and 890,000 odour units m−3, and various air loading rates (0.074-0.592 m−3 air m−3 medium min−1). Biofilters with bark or bark/soil media and low air loading rates gave the best odour removal. The bark and sand biofilters generally maintained good odour reduction for about three years at an air loading rate of 0.148 m−3 air m−3 medium min−1. Drainage from the biofilters contained significant concentrations of nitrogenous and organic compounds, suggesting that controlled leaching has the potential to remove accumulated substances in biofilter media from rendering gas emissions and increase the longevity of a biofilter system. High pressure drop across biofilter media can adversely affect the odour removal performance. Sand and fine bark, due to their small particle size, caused high pressure drops. Coarse bark showed negligible pressure drop at several examined air loading rates. Pressure drop also increased with moisture content, particularly in sand and fine bark biofilters. Overall pressure drop characteristics of the biofilters described in this paper were maintained without significant change over the three year operation.
Water reuse in Japan
Authors: Ogoshi M. , Suzuki Y. , Asano T.
Published: May 2018

Even though Japan has mean annual precipitation of 1,714 mm and hundreds of dams and reservoirs constructed, frequent and severe droughts have occurred in wide regions of the country. Because of rapid economic growth and concentrations of population in urban areas, water demands in large cities have stressed reliability of water supply systems and necessitated the development of new water resources with considerable economic and environmental costs. To alleviate these situations, wastewater reclamation and reuse have been implemented widely in major cities. This paper summarizes the current status of water reuse in Japan and discusses dominant uses of reclaimed water, emphasizing non-potable urban applications such as toilet flushing, industrial reuse, and environmental water.
Wastewater reuse in Italy
Authors: Barbagallo S. , Cirelli G. L. , Indelicato S.
Published: May 2018

In many parts of Italy, particularly in the South, it has become ever more difficult to meet the water demand. The recent years of drought and the constant increase of water demand for the civil sector have made irrigation supply more problematic. Wastewater reuse could represent a viable solution to meet water demand. The focus of this paper is on the regulation problems, hampering the development of wastewater reuse for irrigation, and on the potentials for reuse, particularly in Southern Italy. Planned exploitation of municipal wastewater could help meeting the irrigation water demand particularly in Southern Italy, where farmers have been practising uncontrolled wastewater reuse for a long time. In Northern and Central Italy, where available water resources generally meet water needs for different purposes, wastewater reuse could play an important role in controlling the pollution of water bodies. Despite the fact that Italian legislation is extremely strict and outdated, for several years in some regions, such as Sicily, wastewater reuse systems have been in operation; furthermore, several projects of wastewater reuse are currently in progress.
Factors affecting the distribution of heavy metals in wastewater treatment processes: role of sludge particulate
Authors: Huang C. P. , Wang J. M.
Published: May 2018

The distribution of heavy metals, namely, Ag(I), Cd(II), Co(II), Cr(III,VI), Cu(II), Hg(II), Ni(II), Pb(II), and Zn(II) in 4 municipal wastewater treatment plants was evaluated as a function of several parameters including pH, COD, ionic strength and SS. Although there are variations in pH, alkalinity, COD and ionic strength, the results show that wastewater samples containing less than 5 g/L suspended solids concentration have similar characteristics. Correlations among heavy metal distribution (as the ratio between dissolved to total metals) and wastewater characteristics were attempted. Correlation between the parameters monitored and metal distribution is poor. In the case of pH, no apparent relationship could be seen. In general, increasing COD and ionic strength decreases the metal distribution. Metal distribution relies almost entirely on the concentration of solids in wastewater samples. Total metal removal in primary treatment process is lower than that reported in the literature. This could be attributed to the low average solids removal observed in the treatment plants investigated. Solids reduction at the effluent were larger than 80% and total metals removal was identical to that of the primary treatment process.
Reclaimed municipal wastewater - a potential water resource in China
Authors: Pinjing He , Phan L. , Guowei Gu , Hervouet G.
Published: May 2018

Due to water resource shortage and socio-economic development within twenty years, China faces serious problems of water supply and water pollution. Several criteria and suitable reclamation processes related to water reuse have been created in China, which are helpful to improve the situation of water scarcity. In the future, reclaimed municipal wastewater reuse will mainly be developed for urban and industrial use. Potential supply quantity of reclaimed water, quality of reclaimed water, and reclamation cost are favorable to potential reuses. Based on further public environmental education, on a relevant development of national and local standards for reclaimed water quality, and on an increase of sanitary rate, more and more planned reclaimed water reuse projects would be expected in China.
Technical-economic modelling of integrated water management: wastewater reuse in a French island
Authors: Xu P. , Valette F. , Brissaud F. , Fazio A. , Lazarova V.
Published: May 2018

An integrated technical-economic model is used to address water management issues in the French island of Noirmoutier. The model simulates potable water production and supply, potable and non potable water demand and consumption, wastewater collection, treatment and disposal, water storage, transportation and reuse. A variety of water management scenarios is assessed through technical, economic and environmental evaluation. The scenarios include wastewater reclamation and reuse for agricultural and landscape irrigation as well as domestic non potable application, desalination of seawater and brackish groundwater for potable water supply. The study shows that, in Noirmoutier, wastewater reclamation and reuse for crop irrigation is the most cost-effective solution to the lack of water resources and the protection of sensitive environment. Some water management projects which are regarded as having less economic benefit in the short-term may become competitive in the future, as a result of tightened environmental policy, changed public attitudes and advanced water treatment technologies. The model provides an appropriate tool for water resources planning and management.
Fractionation and characterization of sludge bacterial extracellular polymers by FT-IR, 13C-NMR, 1H-NMR
Authors: Zhou L.X. , Liang J.R. , Zhan X.H. , Wong J.W.C.
Published: May 2018

Sludge bacterial extracellular (BEP) polymers exhibit a strong affinity with metals in addition to their role in the bioflocculation of activated sludge. It is of utmost importance in elucidating the chemical characterization of sludge BEP prior to a better understanding of its environmental behavior. Sludge BEP extracted from activated sludge was characterized by FT-IR, 1H-NMR, and 13C-NMR and fractionated into 6 fractions (hydrophilic acid, base, and neutral; and hydrophobic acid, base, and neutral). The results indicated that sludge BEP contained more polysaccharides but fewer amino acids or proteinaceous materials compared to dissolved organic matter (DOM) derived from sludge. No aromatic substance was found in sludge BEP as indicated by NMR. Sludge BEP was dominated by hydrophilic fractions, accounting for 65% of total DOC of sludge BEP and hydrophilic neutral constituted about 58% of the hydrophilic fraction. The chemical fraction and characterization indicated that sludge BEP might exhibit a higher capability in enhancing the transport of the associated contaminants through porous media than that of sludge DOM.
Abiotic factors affecting inactivation of pathogens in sludge
Authors: Bujoczek G. , Reiners R.S. , Glaszkiewicz J.A.
Published: May 2018

Pathogen inactivation tests on anaerobically digested and dewatered sludge consisted of long-term incubation/storage of a mixture of sludge solids and lime at various doses in closed containers at several temperature levels. The containers simulated anoxic conditions that would exist in a landfill or a sludge monofill. After rapid initial increase of pH, and due to containment of the sludge, the alkaline conditions prevailed during the remainder of the storage. This led to inactivation of pathogen indicators at doses much below those traditionally recommended for alkaline disinfection and production of biosolids, i.e. properly treated sludge. Fecal coliform and Salmonella bacteria were inactivated to the US EPA's class A levels at quicklime doses as low as 20 g CaO/kg TS or about 6 g CaO/kg of wet solids. The pH 12 lasted for the entire storage time in containers with lime doses at or above 120 g/kg TS, regardless of the incubation temperature. Such high pH allowed elimination of the spores of pathogenic Cl. perfringens bacteria from the solute.
Characterisation of sewage sludge metals for classification purposes using the potentially leachable metal fraction
Authors: Snyman H.G.
Published: May 2018

The South African sludge guidelines were revised in 1997 with considerable amendments to the heavy metal loading and usage restrictions. The industry continued using the aqua regia extraction method to characterise and classify sewage sludge. This meant that a Class D sludge (most stable class and sellable product) could not be generated at any South African plant. This caused the industry to seek alternative non-beneficial disposal methods. It was then realised that the metal limits were in fact the TCLP (Toxicity Characteristic Leaching Procedure) extractable limit. This method was developed to determine the potential of a waste to contaminate ground and/or surface water. The agriculturists, however, use the NH4EDTA extractable fraction to establish metal concentration in soils. This paper specifically aims to establish the feasibility of using the available metals extraction methods such as NH4EDTA and TCLP to determine the fate and therefore the risk of sludge-borne metals (Cd, Pb, Zn, Cu). The results show that the TCLP extraction method could potentially underestimate the impact of sewage sludge-borne metals when amended to agricultural soils. The extraction efficiency of the NH4EDTA and TCLP methods relative to the aqua regia extraction method was presented for Cd, Pb, Zn and Cu. The NH4EDTA extraction method seems to be an alternative to the aqua regia method, especially since the NH4EDTA measures the fraction of the metal that may become available in the environment. It is recommended that the aqua regia and NH4EDTA be used to classify and characterise the metal content of South African sludges.
Secondary wastewater disposal for crop irrigation with minimal risks
Authors: Oron G. , Armon R. , Mandelbaum R. , Manor Y. , Campos C. , Gillerman L. , Saigot M. , Gerba C. , Klein I. , Enriquez C.
Published: May 2018

A critical objective for any wastewater reuse program is to close the gap between supply of and demand for water and to minimize health and environmental hazards. Thus, the effects of treated effluent on crops, soils and community health must be considered carefully. When applying wastewater to soil-plant systems, it is to be noted that the passage of water through the soil reduces considerably the number of microorganisms carried out by the reclaimed wastewater. Nevertheless, there is a need to study the real rate of organism decay subject to water quality, soil and vegetable characteristics, and irrigation method. The aim of this work is to determine the fate of the fecal coliforms, coliphages F+ and CN13, and helminth eggs survival during the application of reclaimed wastewater in a vineyard orchard near the City of Arad (Israel) via onsurface and subsurface drip irrigation systems. Wastewater obtained from a stabilization pond, and soil samples were tested and an important decrease of microorganisms was reached in both cases, with the better values obtained with the sub-surface drip irrigation system.