bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anaerobic treatment of Municipal Solid Waste
Authors: Plaza G. , Robredo P. , Pacheco O. , Saravia Toledo A. 
Published: May 2018

This paper discusses the present state of Municipal Solid Waste (MSW) disposal in Argentina, focusing on the particular situation of the city of Salta, and suggests the future trend of the anaerobic treatment of this residue.
Source-sorted household solid waste was determined by means of a statistical design. Municipal solid waste produced 147,103 kg per day +/- 6.7%, the major portion corresponds to the biodegradable organic fraction (55.4%). The plastic, metal, paper, glass, and other material production was also evaluated.
The organic municipal waste was chemically and biologically characterized, in order to study its behaviour during anaerobic digestion. The ratio normally found in organic fractions from MSW in Salta, Argentina, was in the optimum range which is 126:7:1 (C:N:P, w/w). The stability of the anaerobic process was analized in a 18 liter batch reactor. Its pH, biogas production, alkalinity, and volatile fatty acid production was determined.
Although the work has been carried out at a small scale it appears to be sufficiently promising to encourage further work at a larger scale.
Environmentally friendly method in reactive dyeing of cotton
Authors: Knudsen Hans Henrik , Wenzel Henrik 
Published: May 2018

The recipe for reactive dyeing of cotton can be divided into three steps: the pretreatment, the dyebath and the final rinse. The consumption of chemicals and water in the rinse has been found to be considerable: three quarters of the total COD discharge of the recipe have relations to auxiliary chemicals used and three quarters of the total water consumption have relation to the rinse. The improvement potential in the rinsing procedure were found to be considerable, and the newly developed recipe focuses on improvements in the rinse.
Tests with the new recipe have documented that neutralization, detergents and complexing agents can be left out completely with no adverse effect on product quality. All recognized tests of fastness and shade have been performed and evaluated in cooperation with the dyehouses.
More than 50 full-scale dyeing experiments have been carried out in jets, overflow and drum batch machines. The experiments include 25 different reactive dyestuffs, among these azo, anthrachinon, phtalocyanin and formazan dyestuffs, including both monoreactive and bireactive dyestuffs of which 15 had the vinyl sulfone as reactive group. The dyestuffs have been combined in 20 different recipes covering very light to very dark shades.
Hot membrane filtration of the hot rinsing water has been investigated in parallel projects and it is documented that membrane filtration saves chemicals, water and production time, and also gives large energy savings in one new recipe.
Remediation of PCB-containing sediments using surface water diversion “dry excavation”: a case study
Authors: Praeger Thomas H. , Messur Stuart D. , DiFiore Richard P. 
Published: May 2018

Remediation of contaminated sediments presents an on-going challenge in the efforts toward improved water quality and environmental restoration. Faced with this challenge, Mercury Marine recently selected a remedial alternative that included diverting creek flow and removing approximately 5,900 in-situ cubic meters of sediments containing PCBs from an impoundment in Cedar Creek. The regulatory objective was to remove all sediment containing PCBs “to the extent practicable” from an 180-meter stretch of the impoundment.
A remedial investigation was conducted to collect the data necessary to characterize the site and prepare a remedial design. Technical issues involved with dry excavation that were critical to implementing this alternative included: channel diversion, sediment characterization, pond dewatering, wastewater treatment, groundwater infiltration, surface water run-off, and sediment removal, handling and disposal.
Mercury Marine and its engineering staff found sediment removal by dry excavation to be a labor intensive and costly means of remediating the PCB-affected sediments at this site. Before implementing dry excavation at any site, owners, consultants, and regulatory agencies must realize the many limitations of this alternative and give special consideration to site conditions, engineering, and planning.
Hepatic enzymatic activities of the european eel Anguilla anguilla as a tool for biomonitoring freshwater streams: laboratory and field caging studies
Authors: Fenet H. , Casellas C. , Bontoux J. 
Published: May 2018

Hepatic monooxygenase activity and conjugation enzyme activity were studied in young european eel (Anguilla anguilla). Laboratories studies were performed by treatment with β-naphtoflavone (β-NF). Two sources of eels, wild and reared eels were compared during a time-course study. MO activities measured as 7-ethoxyresorufin O-deethylase (EROD) were induced by β-NF, peak values were reached 2 and 4 days after treatment. The time-course induction of EROD activity was similar for wild and reared eels. In contrast, the conjugation reaction enzymes measured as glutathione-S-transferase (GST) didn't respond to this treatment.
During field studies, EROD and GST activities were studied in wild and reared eels held in cages upstream and downstream of a PAH polluted area. Similar induction of EROD activity was observed in the polluted site after 14 days of caging. The period of caging was studied and EROD activities were significantly induced in wild eels caged in the polluted site after 7 and 14 days. GST activities were not affected by the caging in the polluted site. The results indicate the usefulness of EROD activity as a biomarker of PAH contamination in the model of wild eels caging in the field.
Microbial technology for management of phenol bearing dyestuff wastewater
Authors: Kanekar Pradnya , Sarnaik Seema , Kelkar Anita 
Published: May 2018

Environmental pollution caused by dyestuff industry wastewater is two-fold since it contains toxic chemicals like phenol, aniline etc. and also imparts the colour of the dye manufactured. For management of dyestuff wastewater, microbial technology becomes a novel approach since microorganisms have the characteristic ability to break down aromatic compounds and decolourize the dyes.
Microbial treatment of a dyestuff wastewater containing phenol and methyl violet was studied at the site of a dye factory near Pune in a fixed film bioreactor. The bioreactor consisted of a rectangular cement concrete tank of dimensions 9.5 m length × 7.3 m breadth × 1.5 m height and brick pieces of size 10 cm × 8 cm × 6.5 cm used as supporting media for formation of microbial film. A mixed culture of Pseudomonas alcaligenes (phenol degrader) and Pseudomonas mendocina (decolourizing methyl violet) grown in the dyestuff wastewater was spread on brick media. After formation of a microbial film on brick media, the dyestuff wastewater was recycled in form of a shower through the brick bed for 24, 48 and 72h. The influent loading rate was 1.44 m3/m2 brick bed area per day. The phenol and Chemical Oxygen Demand (COD) loading rates were on average 0.9 kg phenol/m2/day and 5.67 kg COD/m2/day respectively.
The performance of the microbial degradation evaluated for a period of 68 days showed 97.5%, 63%, 54.4% and 51% removal in phenol, methyl violet (MV) content, COD and Total Organic Carbon (TOC) respectively in 24 hours of recycling and marginally enhanced in 48 and 72 hours.
The microbial technology was thus effective in removal of phenol and the dye from dyestuff wastewater.
Evaporation phenomenon as a waste management technology
Authors: Duarte E. A. , Neto I. 
Published: May 2018

The problems concerned with waste management abound in most regions of the world, and so, efforts must be made to assess the global level of pollution and to understand the major factors involved in order to propose efficient waste treatment technologies. This must be compatible with environmental and economic conditions and appropriate to semi-urban settlements, isolated communities and a variety of industrial situations.
The main purpose of this paper is to present recent waste management technology as an alternative solution to traditional treatment systems in regions where those systems are not economically or technically feasible, using for this purpose the advantages of climatic conditions (air temperature, relative humidity and wind speed).
This integrated technology combines two different processes: optimization of the solid/liquid separation, using a decanter, followed by the utilization of evaporation panels to eliminate the liquid fraction of the effluent, optimizing by this way the evaporation phenomenon, which is so important and resolute in certain cases, that it is absurd not to exploit it intensely.
The technology presented was followed by a research programme developed in the last three years, implemented in an agro-industrial unit located in a high polluted area of Portugal, with the aim to evaluate its efficiency and optimize the performance parameters. The conclusions of this research programme emphasized the importance of the evaporation phenomenon as a simple solution to deal with complex environmental problems.
Process selection, design and operation of the EDE WWTP
Authors: Leeuw E. J. , van't Oever E. 
Published: May 2018

According to European agreements, many WWTPs (waste water treatment plants) have to be modified and extended to reach stricter effluent standards with regard to phosphorus and nitrogen. This paper presents the modification of a 300,000 p.e. WWTP. The following steps are distinguished: location/centralization study, process pre-selection, pilot tests and process control.
Most important aspects in the location study are costs and ecological importance of the receiving water. In the process pre-selection study two nitrogen and phosphorus removal processes were selected: a high cost/low risk process and a low cost/high risk process. Final selection of the Bio-Denipho process was based on comparison of both processes in pilot tests. During the six months operation period the process control programs for weekdays/weekends, day hours/night hours, dry weather flows/storm weather flows resulted in low nitrogen concentrations in the effluent.
Application of experimental research methodology to the study of nitrification in mixed culture
Authors: Mauret M. , Paul E. , Puech-Costes E. , Maurette M. T. , Baptiste P. 
Published: May 2018

Nitrification is an aerobic process formed by two consecutive reactions: nitritation and nitratation. Using an experimental research methodology, we have studied the specific effects and the possible interactions between initial ammonia concentration, pH and temperature on these two reactions as well as on the experimental conditions leading to a nitrite build-up.
In the experimental field studied (35 &lt; [N-NH4+]O mg.l−1 &lt; 90, 15 &lt; T°C &lt; 25 and 7 &lt; pH &lt; 8.5), the statistic interpretation of the results shows that only temperature and pH have a significant positive effect on ammonia removal. Moreover, the effect of these two parameters is linear. As for nitrite accumulation, the temperature effect is negligible and a strong interaction between [N-NH4]O and pH is revealed. When the values of these two variables are high, nitratation is inhibited and 50% of the nitrogen introduced at the beginning accumulates temporarily in the form of nitrites.
The results clearly show that a high NH3 concentration inhibits Nitrobacter, starting from between 6.6 and 8.9 mg N-NH3.l−1.
This research enables a better understanding of the nitrite build-up phenomena which can be thus minimized or maximized in the case of new process of nitrogen treatment.
Qualitative mode of action of sewer tanks with surplus flow
Authors: Pecher K. H. , Haußmann R. 
Published: May 2018

The sewer tank is a specific type of overflow tank. While sewer tanks with a surplus flow at the beginning of the sewer are regarded as uncritical, in sewer tanks with a surplus flow at the end of the sewer, sedimentation may be remobilised and transported into the receiving waters. For this reason, in Germany, additional capacity over and above the minimum requirements is demanded for these sewers.
In order to ensure the qualitative mode of action of sewer tanks with a surplus flow at the end of the sewer, pilot-scale investigations into a model sewer, with artificial combined water, as well as large-scale investigations under real life conditions, were carried out.
The findings of these investigations illustrated that a sedimentation of solids takes place in the majority of flow circumstances, including times of overflow. Thus, even at times of high stormwater flow, the outflow to the receiving waters contains only a low level of pollution. As well as storing the stormwater, the sewer tank with a surplus flow at the end of the sewer has the additional environmentally friendly effect of improving the quality of the outflow and reducing its pollution content.
Combined control of sewer and treatment plant during rainstorm
Authors: Nielsen Marinus K. , Carstensen Jacob , Harremoës Poul 
Published: May 2018

The use of flow predictions and on-line nutrient sensors in BNR plants has given the basis for introduction of radical operational changes. Because of the detailed monitoring, the control actions are allowed to go closer to critical process limits while balancing between hydraulic and biological capacities.
One of the new modes of operation, settling in the aeration tanks as an active control, is documented below. This new operation, Aeration Tank Settling (ATS) has been tested at full scale and shows a great potential for storm water control. With ATS control the hydraulic capacity is increased 25–75% on existing plants without reducing the organic capacity in periods ranging from 2 hours to 2 weeks.
ATS control can be initiated directly by raising the inlet flow to the treatment plant, but even better by 1/2 - 1 hour prediction of the inlet flow. These predictions of flow are achieved from statistical grey-box handling of data from on-line rain gauges and measured inlet flow pattern during normal and stormwater conditions.
Hourly predictions of concentrations in the inlet to the plant and selected points in the sewer system during dry weather and storm situations will improve the combined system control efficiency radically.
Membrane aerators and stirring systems for the operation in large and small wastewater treatment plants
Authors: Höfken Marcus W. A. , Huber Peter , Schäfer Marcus , Steiner Ralf 
Published: May 2018

Stirring and aeration processes are the major operations needed for effective wastewater treatment. Especially in activated sludge processes and the variants of this process stirring and aeration systems need to be chosen carefully since both operations are crucial for the purification power and the energy demand of wwtp's. The aim of the present work is to define the demands on stirring and aeration systems for activated sludge treatment plants, to give an overview about suitable systems currently available on the market including latest developments and to give advice how to choose the optimum system.
A brief review of the literature and the market of stirring and aeration systems leads to a simple classification of the existing numerous systems. In order to choose the optimum system, first one has to decide, about the demands in each process step. In anaerobic and anoxic reactors the use of hyperboloid stirring systems or combined hyperboloid stirring and aeration systems which distribute small air bubbles throughout the entire reactor in the aeration mode (for intermittent aeration) and gently circulate bacteria flocks in the stirring mode is recommended. For aerobic processes like BOD-removal and nitrification highly efficient membrane aerating systems using silicone membranes are recommended.
Mechanical pre-thickening of excess sludge: influence on the process technology of anaerobic sludge treatment and operating experiences
Authors: Buer Thomas R. , Roos Hermann-Josef , Pecher Klaus 
Published: May 2018

A volume reduction of the sludges with relatively low solid matter contents encountered during water treatment is a requirement for the economical treatment and disposal of sludges. Therefore, during expansion of anaerobic sludge stabilisation plants, new methods are increasingly being applied that provide for mechanical pre-thickening of the excess sludge. At present, there is no safe database describing the influence of the higher solid matter concentration and the resulting increased raw sludge viscosity on the sludge treatment. This paper introduces various results of a targeted survey regarding this subject characterising differences in the methodology and operation during sewage sludge treatment between plants with and without separate mechanical excess sludge thickening. It turns out that plants that have a mechanical excess sludge pre-thickening unit are more frequently subjected to mechanical and apparatus-related operation problems, although in practice the increase of the solid matter concentration in the raw sludge is only 20–25% compared to conventionally operated plants.
The maximum achievable solid matter content in the thickened excess sludge - and therefore that in the raw sludge - is especially dependent on the choice of the mechanical pre-thickening unit and the application of a flocculant. At the same time, plants with mechanical pre-thickening of excess sludges achieve a higher gas yield and degree of stabilisation. On the whole the results of the survey lead to the conclusion that mechanical pre-thickening of the excess sludges is better applied for the training of sludge treatment plants, which show sludge solid matter contents of less than 4% DSM (dried solid matter) under normal operating conditions.
Upgrading performance of an activated sludge process through addition of talqueous powder
Authors: Cantet J. , Paul E. , Clauss F. 
Published: May 2018

This study is intended to induce better performance of existing activated sludge wastewater plants without modifying the physical structure of the plant.
The process consists in injecting a specific mineral powder into the aeration stage with two precise purposes: firstly to improve floc structure and thus facilitate solid/liquid separation in the clarifier, and secondly to reduce nitrogenous pollution.
By means of two experimental models the indisputable and rapid effect of talc/chlorite blend on the solid/liquid separation was established (with a sludge volume index improvement by a factor of 2 to 3 within a few days) compared with a control unit.
The increase in nitrification capacity of the system is also clearly shown with nitrification yields being increased by 30%. These results lead us to believe that it is possible to use this process of enhanced nitrification for running a plant reliably without dysfunctioning.
Problems linked to hydraulic or biological excess loading can be solved this way. Moreover, the addition of talqueous powder improves sludge dewaterability.
Nutrient content of wetland plants in constructed wetlands receiving municipal effluent in tropical Australia
Authors: Greenway Margaret 
Published: May 2018

Several pilot wetlands have been constructed in Queensland to treat municipal wastewater. The wetlands are in tropical, subtropical and arid geographical locations. Most wetlands are free water surface and contain a variety of macrophyte types and species. A total of 49 native and 11 exotic species of wetland plants have been identified. This paper examines tissue nutrient content in different species and plant components from 7 wetlands.
Most species translocated to the constructed wetlands flourished indicating their ability to tolerate nutrient enriched waters, and tended to have higher tissue nutrient concentrations than their controls in natural wetlands. Submerged and free floating species exhibited higher nutrient concentrations than floating leaved and emergent species. Maximum dry weight nutrient concentrations (mg.g−1) were recorded in duckweed 18 mgP.g−1; 58 mgN.g−1; Ceratophyllum 14 mgP.g−1, 35 mgN.g−1; Monochoria cyanea (a native relative of the water hyacinth) 13 mgP.g−1, 30 mgN.g−1; waterlilies: Nymphoides indica 16 mgP.g−1, 40 mgN.g−1; aquatic vines Ipomoea diamantinensis 10 mgP.g−1, 53 mgN.g−1, I. aquatica 9.5 mgP.g−1, 53 mgN.g−1; Ludwigia peploides 10 mgP.g−1, 52 mgN.g−1; and the water ferns Ceratopteris thalictroides 10 mgP.g−1, 31 mgN.g−1,Marsilea 10 mgP.g−1, 43 mgN.g−1. Emergent species with the highest nutrients (P or N) were Eleocharis sphacelata 9.4 mgP.g−1, 31.7 mgN.g−1, Baumea articulata 8.7 mgP.g−1, 24 mgN.g−1,Typha domingensis 7.2 mgP.g−1, 51.8 mgN.g−1 and Cyperus involucratus 7 mgP.g−1, 44.6 mgN.g−1.
Pooled data showed no significant difference between tissue nutrient content in plant components, though nitrogen was highest in the leaves and phosphorus highest in the roots of most species. There was some evidence of spatial variation in tissue nutrient content between different wetlands but it has not been possible to correlate this with nutrient loadings or removal efficiencies.
Evaluation of pollution reduction scenarios in a river basin: application of long term water quality simulations
Authors: Demuynck C. , Bauwens W. , De Pauw N. , Dobbelaere I. , Poelman E. 
Published: May 2018

Because of stricter environmental regulations for surface water quality in Flanders, large efforts are made for the construction of sewers and water treatment plants. The present methodology to determine the necessary pollutant load reductions is based on the combination of simple mass balances, the 90-percentile discharge and neglects the self-purification capacity of the surface water. This method is very easy to apply but offers little guarantee that the goals set will be met. A sustainable river basin management requires a methodology to evaluate different options in pollution abatement strategies. Only by this, the available resources can be applied in the most advantageous, sustainable way.
In this paper, a methodology is proposed to evaluate water quality based on dynamic modelling. This methodology is illustrated by means of a case study on the river Dender. Continuous and simultaneous measurements uin 3 places along the river were used to calibrate and validate the model. Continuous simulations over a period of four years guarantee that, in contrast with traditional event type simulations, most discharge and hydrometeorologic conditions are taken into account. Attention was given to the occurrence of extreme events. These events will determine the global ecological condition of the river. CDF-curves (Concentrated-Duration-Frequency) make it possible to gain insight in the duration and the frequency of occurrence of events with inadmissible concentrations of dissolved oxygen and ammonia.
Besides simulations taking into account the present loads, different pollutant abatement strategies were analysed and compared. The applied methodology offers the possibility to evaluate the impact of different strategies and to locate present and future problems.