bluuebunny/crossref_metadata_2025_split huggingface dataset:
Case Studies of Wetland Filtration of Mine Waste Water in Constructed and Naturally Occurring Systems in Northern Australia
Authors: Noller B. N. , Woods P. H. , Ross B. J. 
Published: May 2018

A problem common to mines operating in the tropics is the disposal of water, which may be alkaline, acidic, or contain toxic elements such as arsenic or cadmium. The availability of year-round water supply at many mine sites in Northern Australia, particularly from pit dewatering, together with the monsoonal climate, provide appropriate conditions for the formation of natural wetlands or establishment of artificial wetlands. Wetland species (particularly Typha spp.) flourish in the presence of flowing or shallow water from dewatering, and data collected from natural and experimental wetlands show reduction of metal concentrations by wetland filtration of mine waste water.
The following case studies are considered:Constructed wetlands, used to remove uranium from waste rock runoff before release to an adjacent creek provide a means of “polishing” runoff water prior to discharge to the creek.Creek-Billabong systems with existing wetlands adjacent to mine sites adventitiously “filter” waters discharged from mine sites. Trace elements in dewatering water from a gold mine discharged into an oxbow show reduction of elemental concentrations downstream, compared to discharge water.Naturally generated wetlands at several Northern Territory mines have developed along channels for discharge of pit water, with ingress of Typha domingensis. Such wetlands, associated with dewatering, have been examined at four mines, some with acid mine drainage. Water quality measured after wetland treatments shows reductions in concentrations of various heavy metals and sulfate. Volunteer Typha domingensis grows and spreads in shallow flowing channels, providing an inherent “filtration” of the water.Natural swamplands are incorporated in the waste rock runoff management design of a new gold mine, to reduce potentially high arsenic levels in the waste water.
Constructed and naturally occurring wetlands may be used in the treatment of most mine waste waters to achieve levels of constituents acceptable for discharge to the surrounding environment.
A comparison between ethanol and methanol as carbon sources for denitrification
Authors: Christensson Magnus , Lie Ewa , Welander Thomas 
Published: May 2018

Ethanol and methanol were compared for their performance as carbon sources for denitrification. The study was carried out in two chemostats, operated in parallel on synthetic media containing ethanol and methanol respectively as carbon sources. In addition, pure culture studies were performed on one ethanol- and one methanol-utilizing denitrifier.
Ethanol was found to be considerably more readily available as a carbon source for denitrification than was methanol. An efficient denitrification with ethanol was established in a short time, while denitrification with methanol required a substantial adaptation time and never showed the same stability as denitrification with ethanol. The growth rate of denitrifiers with ethanol as carbon source was 2–3 times higher than with methanol. The amount of COD required to denitrify a certain amount of nitrate was somewhat lower for ethanol (3.85 g/gN) than for methanol (4.45 g/gN) in the continuous experiments, while it was considerably higher for ethanol (6.1 g/gN) than for methanol (4.1 g/gN) in pure culture batch cultivations.
Electroosmotically enhanced sludge dewatering: pilot-plant study
Authors: Smollen Maryla , Kafaar Achmad 
Published: May 2018

Owing to the inherent inefficiency of dewatering equipment widely used today, the search for improved dewatering techniques has been pursued by the investigation of new innovative ideas. The main thrust of these investigations has been in electroosmotic dewatering which presents a novel approach in South Africa.
The separation of the sludge liquid phase is governed by the intensity of binding forces. There are different physical forms of water in sludge and these different forms play an important role in determining the ease or difficulty of phase separation. It seems that the inefficiency of dewatering applied to gelatinous and fine-particle sludges can be overcome by mechanical dewatering enhanced by electroosmosis. A prototype pilot-plant embodying these principles has been developed for commercial application to dewatering of troublesome sewage sludges.
Source Pollution Control Program at the Camaçari Petrochemical Complex: Overall and Individual Improvements
Authors: Freire P. A. , Neto D. B. , Carvalho D. M. 
Published: May 2018

Along with the technical progress experienced by the Camaçari Petochemical Complex in the last few years, new policies, following new worldwide trends, in pollution control and prevention became mandatory.
The knowledge acquired from recent development and research has helped CETREL-Empresa de Proteçao Ambiental S.A. and the State of Bahia EPA (CRA) to develop and implement new programs for the environmental protection of the entire Camaçari Petrochemical Complex area.
Among these strategies the Source Pollution Control Program (SPCP) has been playing a very important role in industrial pollution prevention.
In addition to other measures taken by CETREL to reduce pollutant emissions, the implementation of an incineration unit for organic chlorinated liquid residues has also proven to be a very efficient treatment. It not only avoids problems for CETREL's centralized activated sludge plant, but it also reduces dramatically the emission of volatile chlorinated hydrocarbons into the environment.
Combined Treatment of Olive Mill Effluent and Municipal Wastewater in a Small Tourist Community
Authors: Croce F. , Poulsom S. , Hendricks D. W. 
Published: May 2018

A technologically simple, cost-effective solution was provided to upgrade an existing municipal wastewater treatment plant in the tourist village of Casteldaccia, Italy, to support the seasonal loading of wastes from the olive oil industry. During the summer months, when the population of the village is about 15,000, the traditional activated sludge treatment plant will handle 100% of the municipal wastes.
During the eight months winter period, the municipal BOD loading is lower by a factor of two. During this time, the excess treatment capacity of the plant will accommodate the effluent from the local olive mills. The storage of this waste water, in a series of aeration tanks, permits its release as a steady flow to the activated sludge plant.
Spatial arrangement of the components of activated sludge flocs
Authors: Zartarian F. , Mustin C. , Bottero J. Y. , Villemin G. , Thomas F. , Aillères L. , Champenois M. , Grulois P. , Manem J. 
Published: May 2018

The purpose of this work was to observe the internal structure of activated sludge flocs and the relationship between the different components. Activated sludge flocs from the municipal sewage treatment plant at Nancy (France) were physically stabilized and solidified in an epoxy resin. The flocs were sliced into 0.1 μm thick sections and stained for characterisation of components and exopolymers by transmission electron microscopy. One small floc (10 μm × 20 μm), embedded in resin, was chosen and studied using a laser scanning confocal microscope. The focal plane was incremented in steps of 2 μm along the z axis of the microaggregate. In order to extract quantitative data (number of cells, floc size) a numerical treatment of the images was applied.
A typical floc exhibits an unhomogeneous distribution of the mass of the exocellular polymer matrix (mainly polysaccharides). This matrix maintains the integrity of the floc and connects most of the components. These components are isolated bacteria, waste and debris inherited from the effluent and microcolonies. The structure of the microflocs is fractal with a fractal dimension Df ≈ 3. This large value implies that the growth of the small aggregates is possibly generated by cellular division and polymer production.
Development of a land limited wastewater treatment plant for small and rural communities in the tropics
Authors: Yang P. Y. , Chen H. , Ma T. 
Published: May 2018

The treatment systems for strict and moderate land limited approaches were investigated. Both synthetic glucose and actual wastewater (domestic wastewater) were studied. For the strict land limited approach, a packed entrapped mixed microbial cell (PEMMC) process using cellulose triacetate as the polymer carrier was tested for synthetic wastewater. For the moderate land limited approach, a combined aquatic weed on the water surface and a bio-fixed film in the lower portion of the pond system was investigated for both the synthetic and actual wastewater. The actual domestic wastewater was examined in a single pond system with vertical flow under the BOD5 loading rate of 135 Kg/ha/day. BOD5 and nitrogen removal efficiencies of more than 85% and 70%, respectively, were received. The glucose synthetic wastewater was examined in a single pond system with horizontal flow at a BOD5 loading rate of 130 Kg/ha/day. BOD5 and nitrogen removal efficiencies of 92% and 60%, respectively, were received.
For the strict land limited treatment approach, it was found that more than 90% and 85% of soluble COD and total COD (including effluent suspended solid), respectively, could be removed at the loading rate of 1.6 g COD/L/day. The hydraulic retention time of 3.5 hours and the influent COD concentration of 200-250 mg/L were maintained and operated. This is comparable with the process performance of the conventional activated sludge for treating the domestic sewage under the same operational conditions. The PEMMC process also provides the advantages of maintaining a high SRT (Solid Retention Time) without external sludge recycling and a short starting period of less than 10 days.
Application of the present two systems will be dependent on the land and/or energy requirement. It is appropriate to use the treatment system of combining the aquatic plant with the bio-fixed film for moderately available land and in tropical areas. A strict land limited treatment system, of course, requires additional energy input.
Stirring and aeration system for the upgrading of small waste water treatment plants
Authors: Höfken Marcus , Zähringer Katharina , Bischof Franz 
Published: May 2018

A novel agitating system has been developed which allows for individual or combined operation of stirring and aeration processes. Basic fluid mechanical considerations led to the innovative hyperboloid design of the stirrer body, which ensures high efficiencies in the stirring and the aeration mode, gentle circulation with low shear forces, excellent controllability, and a wide range of applications.
This paper presents the basic considerations which led to the operating principle, the technical realization of the system and experimental results in a large-scale plant. The characteristics of the system and the differences to other stirring and aeration systems are illustrated. Details of the technical realization are shown, which conform to the specific demands of applications in the biological treatment of waste water. Special regard is given to applications in the upgrading of small compact waste water treatment plants.
Increase of efficiency of an activated sludge plant in paper manufacturing industry by application of a fluidized bed system
Authors: Schneeberg Emil 
Published: May 2018

In the past the paper mill Niefern GmbH had a yearly production of approximately 20 000 tons of high quality refined paper. For the purification of its wastewater in 1978 the paper mill put a mechanical/biological wastewater treatment plant into operation. Over years the conditions for the effluent concentration into the receiving water could be kept below requirements.
In the course of the years the production was switched over more and more to recycling products. Therefore the hydraulic load of the wastewater treatment plant increased by 140 %, the organic load by 295 %.
In order to keep the minimum requirements for the future the upgrading of the company's wastewater treatment plant became necessary. A conventional extension of the wastewater treatment plant was not possible because of the extremely restricted space. Therefore it was decided to employ a fluidized bed for the upgrading of the plant.
In spring 1991 the extended wastewater treatment plant was put into operation. The company's experience within approximately 1 1/2 years showed that upgrading of water purification plants by additional use of fluidized bed systems in paper producing factories offers an ecological and convenient possibility for extension.
Ultrafiltration membrane separation for anaerobic wastewater treatment
Authors: Fakhru'l-Razi Ahmadun 
Published: May 2018

Membrane technology has attracted a lot of attention from scientists and engineers in recent years as a new separation process. Various membrane technologies such as reverse osmosis (RO), ultrafiltration (UF) and microfiltration (MF) have been successfully used for a variety of water and wastewater treatment applications.
In this study UF membranes of 10 000 nominal molecular weight limit were used in conjunction with an anaerobic reactor to treat wastewater from a brewery. The UF membranes serve to retain active biomass in the reactor, which is essential for a good reactor performance and for the production of a clear final effluent. The reactor was operated over a range of hydraulic retention times and organic loading rates (OLR) in order to evaluate its treatment efficiency.
Six steady states were attained over a range of mixed liquor suspended solids (31 000-38 000 mg 1−1). The maximum organic loading rate applied was 19.7 kg COD m−3 d−1 resulting in a methane yield of 0.27 1 CH4 g−1 COD. The percentages of COD removal achieved were above 96%. The results indicated that the UF membranes were capable of efficient biomass-effluent separation thus preventing any biomass loss from the reactor and have potential for treating industrial wastewaters.
Treatment of wool scouring effluent by anaerobic bioflocculation
Authors: Lapsirikul Wipa , Cord-Ruwisch Ralf , Ho Goen 
Published: May 2018

Biological destabilisation of the wool grease/water emulsion in wool scouring effluent using anaerobic bacterial activity (biological flocculation) was investigated. The aim of biological flocculation is to remove the bulk of wool grease which is the major source of COD, therefore serving as a pretreatment step, prior to classical biological processes either aerobic or anaerobic.
In a semi-continuous system, a two-stage anaerobic bioflocculation process was employed to treat a high grease (&gt; 15 g l−1) wool scouring effluent (WSE). After 110 days of operation, the process showed removal of 70 to 90% grease at a combined hydraulic residence time (HRT) of 4 to 10 days. With low grease (&lt; 10 g l−1) WSE grease removal was lower. At an HRT of 3 days a single stage bioflocculation process removed 40% grease. The supernatant from the process was easily treated by activated sludge process reducing grease concentration from about 1.5 g l−1 to less than 0.1 g l−1 in the final effluent (HRT 3 days).
Methane production of the process was negligible. Most of the grease was removed by flocculation as a result of anaerobic bacterial activity. The mechanisms of the process were investigated by a series of batch experiments and found to be; (1) appropriate gentle mixing between WSE and anaerobic sludge results in the absorption of wool grease from the liquid to the sludge phase, (2) further destablisation of the wool grease emulsion is obtained when the mixed liquor is left undisturbed. The latter was due to bacterial activity and growth on organics contained in WSE.
Scenario Analysis of Pulp Manufacture in Finland to the Year 2010
Authors: Malinen Raimo , Wartiovaara Ilkka , Välttilä Olli , Anttila Suvi 
Published: May 2018

A scenario analysis was performed of alternative methods of pulp production in Finland up to the year 2010. The analysis included the effects of changing to totally chlorine-free bleaching of kraft pulp (TCF pulp), closure of the water cycles at kraft mill bleaching plants, and increased use of recycled fibre in papermaking. Scenarios for total figures in Finland were evaluated anticipating four different courses in the use of new technology and the increasing use of waste paper and TCF pulp.
The results revealed that the high investment rate in effluent management and air pollution control during the 80s and 90s will result in a very significant decline in pollution from the Finnish forest industry before the year 2000. The technology needed to eliminate AOX would be very costly and would have no significant effect on pollution parameters other than AOX. Closing the water cycles at kraft mill bleaching plants would cut discharges of dissolved substances and nutrients from the pulp and paper industry to at most half of those achievable with external methods.
Bioavailability of Pulp and Paper Mill Effluent Phosphorus
Authors: Priha Maarit 
Published: May 2018

The aim of this study was to examine the stability and bioavailability of different phosphorus fractions of pulp and paper mill effluents in order to assess the environmental benefits of reducing their phosphorus discharges. Two types of effluent were studied: activated sludge treated bleached kraft mill effluent and activated sludge treated paper mill effluent. Phosphorus was characterized on the basis of its solubility and chemical reactivity. The stability of particulate phosphorus was studied in long-term (6-8 weeks) degradation tests. The bioavailability of different phosphorus fractions was measured by algal growth potential tests.
In bleached kraft mill effluent (BKME) the proportion of dissolved phosphorus in relation to the total phosphorus was on an average 80%, and of this, approximately 80-90% was reactive phosphorus. During a 6-8 week incubation period some 60-70% of the particulate phosphorus in BKME was dissolved as soluble phosphorus, and most of it was of the reactive type. Approximately 90% of the dissolved phosphorus and 45% of the particulate phosphorus in BKME was biologically available phosphorus (BAP). Altogether some 80% of the total phosphorus in activated sludge treated BKME was available for algae either immediately or after inherent degradation.
The percentages of dissolved and particulate phosphorus of paper mill effluent (PME) total phosphorus were of the same order of magnitude as those of BKME, but less than 20% of the dissolved phosphorus was of the reactive type. Approximately 50-60% of the particulate phosphorus in PME was dissolved in degradation tests, and 90% of it was biologically available.
Overview of the Anaerobic Toxicity Caused by Organic Forest Industry Wastewater Pollutants
Authors: Sierra-Alvarez R. , Field J. A. , Kortekaas S. , Lettinga G. 
Published: May 2018

Numerous types of organic environmental pollutants are encountered in forest industry effluents which potentially could inhibit consortia of anaerobic bacteria. The purpose of this study was to collect anaerobic bioassay data from the literature to better estimate the impact of these pollutants on anaerobic wastewater treatment systems.
The most important methanogenic inhibitors in forest industry wastewaters are wood resin, chlorophenols and tannins. These compounds account for toxicity in alkaline pulping liquors, bleaching effluents and debarking wastewaters, respectively. Adaptation to chlorophenol toxicity can be expected since they are eventually degraded in anaerobic systems. Wood resin compounds, on the other hand, are not biodegraded anaerobically and therefore their toxicity is persistent. Toxicity in forest industry wastewaters does not necessarily preclude anaerobic treatment. A variety of techniques can be employed to diminish inhibition, such as dilution and detoxification treatments.
Oxygen reduces denitrification in biofilm reactors
Authors: Hagedorn-Olsen C. , Møller I. H. , Tøttrup H. , Harremoës P. 
Published: May 2018

The mechanism for the nitrate removal from wastewater in a submerged fixed film filter is reviewed and evaluated to demonstrate that the denitrification process is significantly reduced by the presence of oxygen.
The kinetics were developed for a fully nitrate penetrated biofilm, influenced by oxygen. It was demonstrated that there is a linear reduction of the denitrification rate with depth of oxygen penetration, proportional to the oxygen concentration to the half power. For a partly nitrate penetrated biofilm the influence of oxygen is a function of the ratio between the penetration of oxygen and the penetration of nitrate without the influence of oxygen.
The phenomenon was investigated in laboratory scale with biocarbone and biostyr as media and at a full scale biocarbone plant. The investigation was performed with organic matter in excess on a thin biofilm taken directly from a full scale plant. The results of the experiments with influence of oxygen fit the kinetic concepts well.
Transport and reaction of aromatics, O2 and CO2 within a membrane bound biofilm in competition with suspended biomass
Authors: Debus Oliver 
Published: May 2018

The biological removal of volatile o-, m-, p-xylene and ethylbenzene from the bulk fluid was investigated in a stirred laboratory reactor. The biofilm was grown on a gas-permeable silicone membrane tubing through which oxygen was supplied. A mathematical simulation could adequately reproduce the experimental values for the biofilm thickness and the concentrations for several species for both sides of the biofilm: in the bulk liquid and in the gas phase. A high xylene conversion plateau of more than 90% was determined by the chronologically occurrence of two sub-maxima: conversion by suspended biomass and by the biofilm. The two maxima can be explained by the spatial transport processes of oxygen and xylene in the biofilm. The first sub-maximum of the conversion by suspended biomass is determined by a maximum oxygen flux through the membrane-bound biofilm. Later oxygen becomes limiting in the bulk and less xylene is degraded by suspended biomass and a maximum transport of xylene into the biofilm occurred, which led to a maximum conversion of xylene within the biofilm. For biodegradable organic compounds, the biofilm can totally reduce the transfer of these compounds into the gas phase. If compounds are non-degradable a biofilm with a thickness of 2 mm reduces the transfer into the gas phase only by 35%. Therefore, the application of pure oxygen and low volumetric gas rates are necessary to reduce the transfer of compounds that are not biodegradable.
The transfer of CO2 into the gas phase of the membrane-bound biofilm is very important for the stabilization of the pH in the biofilm and the bulk. The transfer of CO2 from the biofilm into the gas phase is up to 6 times higher than the transfer of CO2 from the biofilm into the bulk. The pH-minimum in the biofilm is not more than 0.15 pH-units below the pH in the bulk.