bluuebunny/crossref_metadata_2025_split huggingface dataset:
Understanding anaerobic decolourisation of textile dye wastewater: mechanism and kinetics
Authors: Willetts J.R.M. , Ashbolt N.J. 
Published: May 2018

Worldwide, some 280,000 tons of textile dyes are discharged per annum. Degradation of the predominant highly soluble reactive dyes is poor within activated sludge plants, and instead requires anaerobic pretreatment for reductive cleavage of the chromogenic azo bond to precede aerobic degradation. The mechanism for the anaerobic reductive cleavage, which results in decolourisation, is not well understood. Further, thermophilic anaerobic pre-treatment has not been reported, although the wastewater is produced at high temperature (50–80°C). This project therefore aimed to compare decolourisation kinetics under mesophilic (35°C) and thermophilic (55°C) conditions and elucidate biotic and abiotic factors in the decolourisation of the dye, Reactive Red 235.
Preliminary experiments indicated that acclimation of the up-flow anaerobic sludge blanket (UASB) biomass was unnecessary and there was no dye toxicity at expected wastewater concentrations (0.05–0.1g/L). Decolourisation of Reactive Red 235 was studied under batch conditions with intact and autoclaved biomass, and also using the pre-reduced supernatant from a spent culture (0.2 μm filtered). Based on HPLC identification of the dye and reaction products, first-order kinetics was observed and rate constants of –0.0096/min (thermophilic) and –0.0034/min (mesophilic) were estimated for intact, viable biomass. Abiotic decolourisation was 60–80% lower for the autoclaved samples, and under 12–35% lower for the filtered supernatant. Hence it may be concluded that active anaerobic cells give the most efficient and complete decolourisation, especially under thermophilic conditions. Nonetheless, abiotic reduction does occur and has implications for the design of a novel uncoupled reactor system.
Tertiary nitrification in an up flow biofilter on floating media: influence of temperature and COD load
Authors: Payraudeau M. , Paffoni C. , Gousailles M. 
Published: May 2018

The wastewater plant Seine Aval (located in Acheres, France) treats 6 million PE (25 m3/s average flow, 570 MGD) with activated sludge. Following a research program called “Azote Acheres” which demonstrated that biofilters are an economical solution, the Paris Metropolitan Area Sewage Service (SIAPP) has tested 3 industrial prototypes during a period of more than 4 years. One of these is an up-flow biofilter using a floating filter bed made of expanded polystyrene beads. This specific process is called BIOSTYR and is used here as a nitrifying tertiary biofilter.
The purpose of this paper is to show that the biofilter process achieves very low, steady state, effluent ammonia concentrations with different applied nitrogen loads (0.3 to 2.7 kg NTK/m3.d), even with low temperature and high applied carbonaceous load.
During this 4 years period, a model has been developed to explain the hydraulic behavior of the filter. By measuring the operating conditions (temperature, loads), the head loss of the filter can be predicted.
After this test period, the prototype has been operated by Seine Aval plant staff. The results obtained have confirmed the previous test results.
Performance of nitrogen removal and biofilm structure of porous gas permeable membrane reactor
Authors: Suzuki Y. , Hatano N. , Ito S. , Ikeda H. 
Published: May 2018

A porous gas permeable membrane can supply oxygen effectively, utilizing the high ability of oxygen uptake of nitrifying biofilm. If the membrane with the biofilm is applied to wastewater treatment, simultaneous denitrification occurs, but control of the biofilm thickness is necessary to maintain the high efficiency of the treatment.
In this research, small fluidized cylinders were tested as the media for slough off of excess biofilm, and the performance of nitrogen removal was investigated supplied with municipal wastewater. The results showed that the nitrogen removal efficiency was well kept for a long period with the method tested, especially the nitrification rate in the range of 1.1 to 3.1 gN/(m2 d), and that the biofilm formed a stable structure of double layers, that is, an inner firm nitrifying biofilm and an outer loose denitrifying biofilm.
Combined denitrification and phosphorus removal in a biofilter
Authors: Falkentoft C.M. , Harremoës P. , Mosbæk H. , Wilderer P. 
Published: May 2018

A lab-scale biofilter was run continuously for 1½ years for combined denitrification and phosphorus removal. lternation between anaerobic and anoxic (nitrate) conditions was used to obtain an enriched culture of denitrifying, phosphate accumulating organisms. Batch experiments were performed to test the importance of diffusion and zonation in the biofilm. Half- and zero-order anaerobic phosphate release and anoxic phosphate uptake rates were verified, which was taken as an indication of a zonated biofilm.
To investigate the practical applicability of the process, the development of a computer model is necessary due to the high complexity of the process. AQUASIM is suitable for this purpose. The model can provide insight into what goes on inside the biofilm and act as a tool when predicting required tank sizes, optimal phase lengths and biofilm thickness etc. for a large-scale system. For control of the process, on-line measurements and computer control of the system are essential.
Cleaner production in the chemical industry
Authors: Alzamora Rumazo C. , Pryor A. , Ocampo Mendoza F. , Campos Villareal J. , Robledo J.M. , Rodríguez Mercado E. 
Published: May 2018

A cleaner production demonstration study was developed in 1998 for the chemical industry by the Mexican Center for Cleaner Production with the support of the United States Agency for International Development (USAID). The project's objective was to develop cleaner production assessments for chemical plants by identifying and evaluating process and energy cleaner production opportunities for technical feasibility, economic benefit and environmental impact. Four plants in the chemical industry groups of inorganic and organic chemicals and plastic materials and synthetic resins were involved.
The main results are: (1) a reduction of solid toxic residues in the organic chemicals plant of 3,474 kg/year with after-tax savings of US$ 318,304/year; (2) an increase in plant capacity of 56%, and 10% reduction in VOCs emissions in the plasticizers and epoxidated soybean oil plant with after-tax savings of US$ 2,356,000/year; (3) a reduction of 31,150 kg/year of ethylene oxide emissions with after-tax savings of US$ 17,750/year in the polyethylene glycol plant and (4) a reduction of CO2 emissions of 9.21% with after-tax savings of US$ 44,281/year in the inorganic chemicals plant.
The principal areas for improvement in the chemical industry are process control and instrumentation, process design, maintenance programs and providing adequate utilities for the plants.
Upgrade of a petrochemical wastewater treatment plant by an upflow anaerobic pond
Authors: Noyola A. , Macarie H. , Varela F. , Landrieu S. , Marcelo R. , Rosas M.A. 
Published: May 2018

A petrochemical plant producing terephthalic acid faced a saturation of its wastewater treatment facilities due to an increase in production. In fact, the plant has been growing in recent years, and the effluents have been treated by reproducing the original activated sludge design. However, owing to lack of space, as well as energy consumption and sludge production reaching a certain level, the plant considered other options for coping with the new effluent flow and organic load.
Based on the authors' previous experience with this wastewater, the consultant designed a process consisting of modifying an existing pond, in order to add an anaerobic step before the aerobic tanks already in operation. The anaerobic pond is a three-stage process, all included in the same adapted basin, with a distribution system in the bottom of each stage that creates an upflow pattern. Terephthalic acid wastewater is a mixture of several organic acids, with different anaerobic degradation kinetics, acetic and benzoic acids being more rapidly removed; the staged design takes this into account. The first two stages have a plastic floating cover (5,813 m3 and 8,719 m3 volume, respectively), while the third one is a conventional UASB type reactor (6,276 m3 volume) with a gas-liquid-solid separation device on top.
The design wastewater flow is 230 m3/h, with 10,300 mg/l COD, a pH of 4.5 and a temperature of 40 °C. There is an effluent recycling pump (510 m3/h) to control upflow velocities and eventual acidification problems in the first two stages. The reactor, seeded with anaerobically adapted waste sludge from the aerobic plant, is now under start up, with the expected performance.
Global transport rates and future prediction of hazardous materials: Pu and Cs – from Nagasaki to Canadian Arctic
Authors: Kudo A. , Zheng J. , Yamada R. , Tao G. , Sasaki T. , Sugahara M. 
Published: May 2018

A historical man-made global pollution of hazardous materials occurred at Nagasaki, Japan on August 9, 1945 detonation of a plutonium (10–15 kg) atomic bomb. Recent advancements in analytical technology made it possible for artificial radionuclides released from the nuclear explosion to be detected in the Arctic ice core layer of 1945. The fission product, 137Cs (23.4 g or 7.44×1013 Bq), and unexpended fission material, 239+240Pu (8.8–13.8 kg or 2.22–3.49×1013 Bq), originating from the Nagasaki A-bomb were measured by collecting 10 ice cores on the Agassiz ice cap, Ellesmere Island, Canada.
The deposition rates were 20 mBq/cm2 for 137Cs and 0.16 mBq/cm2 for 239+240Pu, originating from Nagasaki. Assuming the radionuclides, excluding the amount deposited as local fallout, are deposited evenly throughout the northern hemisphere, a rate of 67% of the expected amount of 137Cs arrived at the Arctic while 1.1% of 239+240Pu reached the Arctic. The results suggest that different transport mechanisms exist for these two hazardous contaminants in the global transport system.
A non-reactive rare gas, such as neon and argon, can spread evenly throughout northern hemisphere, including Ellesmere island at the Canadian Arctic, while a reactive gas, sulfur dioxide (SO2) will not reach the ice cap. The measured global transport rates of 137Cs and 239+240Pu were 67% and 1.1%, respectively. These measured rates were for the historical man-made hazardous materials and probably obtained for the longest distance of global transport over 10,000 km. Assuming there was a consistency in climate for the next 10,000 years, the chronological anthropogenic deposits, mainly of 239+240Pu, could be detected in the ice layer between 97–98 m from the snow surface at 11,999 AD on the Agassiz ice cap. Even if there were no improvements in the radioactive analytical method used, the ice layers for the 1945–1980 period could still be easily identified with the present analytical technology. Hopefully this study will find a way to use our generation's artefacts for the benefit of our future descendants.
Floating geomembrane covers for odour control and biogas collection and utilization in municipal lagoons
Authors: DeGarie C. J. , Crapper T. , Howe B. M. , Burke B. F. , McCarthy P. J. 
Published: May 2018

The use of anaerobic lagoons as the first pond in waste stabilization pond systems in tropical and warm-temperature climates is considered a highly cost-effective and practical way to treat municipal wastewater. These anaerobic ponds, designed with hydraulic residence times of up to six days, can effect BOD5 removals of 60 to 80%. The subsequent aerobic stabilization pond surface area is greatly reduced over systems designed without anaerobic treatment up front due to the organic load reduction occurring anaerobically. In lagoon systems with mechanical aeration, operation costs can be greatly reduced.
While odour is a concern with anaerobic treatment, anaerobic ponds treating municipal wastewater can be designed to be relatively odour-free given sufficiently low wastewater sulfate concentrations. However, when sulfate concentrations are high, or when odour control or greenhouse gas emissions are significant issues, or when the wastewater is relatively high in organic strength resulting in commercial production of methane gas, anaerobic lagoons can be covered, and the biogas collected and burned both to produce energy and reduce emissions and odour.
The City of Melbourne treats approximately 50% of its municipal wastewater at the Western Treatment Plant in waste stabilization ponds designed with anaerobic ponds as the first pond in the system. Each of three pond systems at the Western Treatment Plant receives an average dry weather flow of 120,000 m3/d with an average strength of 400 mg/L BOD5. This paper describes the design, installation and commissioning of two 3.9 hectare floating, self draining, geomembrane covers on the anaerobic section of two of these lagoon systems. Biogas collection and utilization were an important part of the installation. A description of how the biogas is collected, the quantities generated and an overview of the control system used to operate the biogas handling facility is also included. Particular emphasis was placed on maximizing biogas utilization in design of the biogas control system.
Adequate model complexity for scenario analysis of VOC stripping in a trickling filter
Authors: Vanhooren H. , Verbrugge T. , Boeije G. , Demey D. , Vanrolleghem P. A. 
Published: May 2018

Two models describing the stripping of volatile organic contaminants (VOCs) in an industrial trickling filter system are developed. The aim of the models is to investigate the effect of different operating conditions (VOC loads and air flow rates) on the efficiency of VOC stripping and the resulting concentrations in the gas and liquid phases. The first model uses the same principles as the steady-state non-equilibrium activated sludge model SimpleTreat, in combination with an existing biofilm model. The second model is a simple mass balance based model only incorporating air and liquid and thus neglecting biofilm effects.
In a first approach, the first model was incorporated in a five-layer hydrodynamic model of the trickling filter, using the carrier material design specifications for porosity, water hold-up and specific surface area. A tracer test with lithium was used to validate this approach, and the gas mixing in the filters was studied using continuous CO2 and O2 measurements. With the tracer test results, the biodegradation model was adapted, and it became clear that biodegradation and adsorption to solids can be neglected. On this basis, a simple dynamic mass balance model was built. Simulations with this model reveal that changing the air flow rate in the trickling filter system has little effect on the VOC stripping efficiency at steady state. However, immediately after an air flow rate change, quite high flux and concentration peaks of VOCs can be expected. These phenomena are of major importance for the design of an off-gas treatment facility.
Model system for the management of nitrogen leaching at the scale of river basins and regions
Authors: Wendland F. , Kunkel R. , Grimvall A. , Kronvang B. , Müller-Wohlfeil D. I. 
Published: May 2018

In the framework of the EU-project RANR (Regional analysis of subsurface nitrogen retention and its impact on the nitrogen export from land to sea) a model system was developed to estimate groundwater-borne nitrogen inputs into river systems. The core of this model system is composed of a soil nitrogen leaching model (SOIL-N) and a groundwater residence time/denitrification model (WEKU). The application of the model system was carried out for the study catchment areas of the Uecker basin (ca. 2400 km2, Germany) and the Gjern basin (ca. 200 km2, Denmark). For both catchment areas, the modelled average nitrogen loads leached into the groundwater were about 40 kg N/ha a, while the remaining groundwater-borne nitrogen intake to rivers was quantified to an average of about
2 kg/ha a. The comparision with observed groundwaterborne riverine nitrogen loads showed a very good agreement, proofing the key role nitrogen retention in groundwater plays in the two catchment areas. With regard to the generalisationand transfer of the SOIL-N/WEKU model concept we assume that the model can be applicated in catchment areas in the European Pleistocene Lowland, which ranges from the Netherlands in the west to the Baltic States and the Ukraine in the east.
Assessment of changes to saltwater/freshwater habitat from reductions in flow to the Richmond River estuary, Australia
Authors: Pierson W. L. , Nittim R. , Chadwick M. J. , Bishop K. A. , Horton P. R. 
Published: May 2018

The Australian climate is highly variable and many Australian estuaries lack a seasonal pattern of freshwater flow. During periods of low freshwater inflow, saline waters enter from the ocean through the estuary mouth. These saline waters enter as density currents or as a result of tidal mixing. During periods of high freshwater inflow from the estuary catchment, salt water is flushed towards the estuary mouth. As a consequence, the saline structure of Australian estuaries can be highly variable, depending on the antecedent rainfall. The Richmond River in northern New South Wales is such an estuary.
The biota inhabiting estuaries have varying levels of freshwater and saltwater tolerance and reducing the freshwater flow into and along an estuary will favour saltwater species. However, if extractions of freshwater from an estuary are sufficiently high, freshwater habitat could be eliminated entirely for short periods (~one month) but with consequent, and perhaps long-standing, damage to the environment.
This contribution describes a new approach to quantify the impact of changes to freshwater flows to the Richmond River estuary. This approach includes a review of hydrological data gathered over the past century and includes a detailed assessment of: changes to the highly variable freshwater inflows and freshwater extraction below the tidal limit; consequent changes to the highly variable saline structure; and the risk to aquatic biota.
The crucial factors of magnitude, frequency and duration of short-term intrusions of saline water into freshwater habitat and their impact are quantified by the methods developed.
Establishing an Integrated Catchment Management (ICM) program in East Java, Indonesia
Authors: Booth C. A. , Warianti A. , Wrigley T. 
Published: May 2018

The Brantas is one of Indonesia's most important catchments. It is the “rice bowl” of Java and nationally important for its industrial activity. Surabaya, Indonesia's second largest city, is located at the mouth of the Brantas River which is pivotal to the city's water supply. The challenges associated with the institutional framework for natural resource management in East Java parallels that of many states and provinces around the globe. It is multi-layered and complex.
Integrated Catchment Management (ICM) may be defined as “the co-ordinated and sustainable management of land, water, soil vegetation, fauna and other natural resources on a water catchment basis”. Over a period of six months, an ICM Strategy was researched and facilitated for the Brantas River Catchment in East Java via a short term advisor attachment. The aim of the Strategy is to improve co-ordination, co-operation, communication and consistency of government and community efforts towards sustaining the catchment's environmental, economic and social values. The attachment was part of the Pollution Control Implementation (PCI) Project funded by AusAid and the Indonesian Government.
The ICM Strategy developed was broad based and addressed the priority natural resource management issues facing the Brantas Catchment. It was co-ordinated by BAPEDALDA, the Provincial Environmental Protection Agency, and developed by all agencies involved in natural resource management in the catchment. Various Universities and Non Government Organisations (NGOs) were also involved in the ICM process which developed the Strategy. At the conclusion of the attachment, a draft ICM Strategy and a proposed institutional framework had been developed. A working group of key agencies was also established to further enhance local “ownership”, finalise timescales and implementation responsibilities within the Strategy and bring the institutional arrangements into being through a Governor's Decree.
What makes catchment management groups “tick”?
Authors: Oliver P. 
Published: May 2018

The work of catchment management groups throughout Australia represents a significant economic and social investment in natural resource management. Institutional structures and policies, the role of on-ground coordinators, facilitation processes, citizen participation and social capital are critical factors influencing the success of catchment management groups. From a participant-researcher viewpoint, this paper signposts research directions and themes that are being pursued from the participant/coordinator, catchment group, and lead government/non-government agency perspective on the influence of these factors on the success of a catchment management group in the Pumicestone Region of Southeast Queensland, Australia.
Research directions, themes and discussion/reflection points for practitioners include - the importance of understanding milieu; motivation; success; having fun; "networking networks"; involvement of "non-traditional" stakeholders; development of stakeholder/participant partnerships; learning from other practitioners; methods of stakeholder/participant representation; evaluation; the need for guiding principles or philosophy; the equivalence of planning, implementation, evaluation, and resourcing; catchments as fundamental units of Nature; continuity of support for groups; recognising a new role for government; working with existing networks; and the need for an eclectic approach to natural resource management.
Transfer number in fine bubble diffused aeration systems
Authors: Capela S. , Roustan M. , Héduit A. 
Published: May 2018

On the basis of full-scale data from 58 clean water tests performed in 26 activated sludge tanks equipped with fine bubble diffusers and of a theoretical approach, it can be stated that fine bubble aeration systems with total floor coverage arrangement provide higher kLa values and the lowest spiral liquid circulation.
An efficiency criterion for oxygen transfer ( NT) was defined on the basis of the dimensional analysis. The transfer number NT allows us to take account of the impact of vertical liquid circulation movements on oxygen transfer. The values of NT calculated from the results of full scale nonsteady-state clean water tests vary from 5.3×10-5 to 9.1×10-5 and are directly dependent upon the arrangement of air diffusers. It has been shown that the highest transfer numbers corresponded to the total floor coverage arrangement and the average calculated NT values is 7.7×10-5, independently of the diffuser density and of the gas velocity, over the ranges studied. The lowest transfer numbers are obtained when the diffusers are located in separate grids, and the transfer number is reduced with increasing air flow rate.