bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anaerobic treatment of partly acidified wastewater in a two-stage expanded granular sludge bed (EGSB) system at 8°C
Authors: van Lier Jules B. , Rebac Salih , Lens Piet , van Bijnen Friso , Elferink Stefanie J. W. H. Oude , Stams Alfons J. M. , Lettinga Gatze 
Published: May 2018

Psychrophilic (8 °C) anaerobic treatment of partly acidified waste water was investigated using a two stage EGSB system with a total volume of 8.6 dm3. The reactor system was operated at an up-flow velocity of 10 m·h−1 and was fed with a sucrose-VFA mixture of 550–1100 mg COD dm−3. The average CODsol and VFA-COD removal efficiencies were 97 and 90 %, respectively, at total organic loading rates (OLR) ranging between 5.1–6.7 g COD dm−3·day−1, sucrose loading rates up to 1 g COD dm−3 day−1 and a hydraulic retention time (HRT) of 4 h. An increase in the sucrose loading rates resulted in a significant wash-out of biomass from the first stage. The second stage satisfactory served as a scavenger of non-degraded VFA from the first stage.
Specific activity assays showed an increase of 15 % in the specific methanogenic activity of the sludge present in the second stage and a decrease of 9 % in the first stage. Apparently, an enrichment of methanogens and acetogens in the anaerobic sludge in the second stage took place at temperatures as low as 8°C. The acidogenic population became much more dominant in the first stage, resulting in a higher acidifying activity and a decreased methanogenic activity. 16S rRNA probe-techniques (dot blot hybridization) showed that the acetate consuming Methanosaeta (formerly Methanothrix) and the hydrogenotrophic Methanobrevibacter species (or relatives) were the most abundant methanogens present in the psychrophilic sludge. The ratio between bacterial and methanobacterial hybridization signal of the first stage was 3 times higher than that of the second stage. By using NMR techniques, a higher effective diffusion coefficient was found for the smaller sized granules in both reactors, which is in congruent with the higher maximum specific acetate degrading activity of the smaller granules.
Simpol: a simplified urban pollution modelling tool
Authors: Dempsey Paul , Eadon Andy , Morris Gerard 
Published: May 2018

In the UK, the standards which protect river aquatic life against the effect of short term intermittent pollution events are expressed in terms of river concentration/duration thresholds for return periods ranging from 1 month to 1 year. To demonstrate compliance with these standards, it is necessary to simulate the performance of a drainage system and the river impact for a number of wet weather events, chosen such that the return periods of critical concentrations/durations can be estimated with confidence. Many events must be simulated leading to long computer runs and large result files when using detailed simulation models.
This paper describes how this problem has been addressed within the UK Urban Pollution Management procedure by developing a simplified urban pollution model called SIMPOL. This model is designed to represent the key urban processes in a relatively simple way. Accuracy is preserved by calibrating the model against a small number of detailed model results. As multiple runs can be carried out easily, SIMPOL modelling allows greater account to be taken of the variability in rainfall, river conditions and foul flow quality. Potential solutions can be rapidly tested against both environmental and emission standards. A case study is used to illustrate the application of SIMPOL.
Predicting the risk to permit compliance of new sewage treatment works
Authors: Dunn A. J. , Frodsham D. A. , Kilroy R. V. 
Published: May 2018

The privatised water industry in England and Wales has the requirement to construct a substantial number of new assets to meet new national and European legislation. In order to do so economically, the risk of performance of new assets has to be matched to the cost of construction. To undertake such risk management, a risk technique has been developed that allows the performance against permit compliance of new processes to be established. The technique is based on statistical analysis of data effectively creating a pure black box model to determine performance.
The technique has been further developed to take into account the dependency between influent quality and process performance. The dependency factor selected is the Spearman's Rank Coefficient which is a convenient way to define complex relationships. It can be used to define many dependent variables referring to the same independent variable and as such removes the need for complex mechanistic equations. This technique has been calibrated using two years, existing data and then validated for the next 6 months data of a wastewater treatment works in the North West of England. The results of the validation illustrate the ability of the technique to be used as a predictive tool.
The output from the model allows the direct comparison of different process options and permits executive management to make informed decisions about investment against risk to permit compliance.
Characterization of the municipal wastewaterpart human urine and a preliminary comparison with liquid cattle excretion
Authors: Fittschen Imke , Hahn Hermann H. 
Published: May 2018

In separation toilets, human urine and faeces are separated at source in order to keep them away from the aquatic environment and to enable recycling. 24-hour urine samples of 19 individuals were analysed for several wastewater parameters. The daily loads and their mean variation are presented, and the contribution of human urine to the total daily load in municipal wastewater is calculated.
The concentration of plant nutrients in human urine was compared with those of liquid cattle excretion as traditional organic fertilizer. Nearly all investigated chemical parameters showed great differences. Cations and anions could not be balanced. During storage, the urea in both human urine and cattle urine was quickly converted to ammonium. During 41 days, storage of human urine with passive gas transfer did not lead to significantly higher nitrogen losses than closed storage. Cattle urine reached highly significantly better results than human urine in a germination test with summer barley and in most of the cases highly significantly or significantly worse results in a germination test with cress. The results indicate that the effects of liquid cattle excretion on plant growth are not the same as those of human urine.
Influence of ageing on the catalytic activity of ferric sludge for oxidation of fe(II)
Authors: Tufekci Nese , Sarikaya Hasan Z. 
Published: May 2018

The catalytic effect of freshly formed or added ferric iron on the Fe(II) oxidation has been demonstrated by previous studies. High Fe(III) concentrations significantly accelerate the oxygenation rate. High Fe(III) concentrations can be maintained only by sludge recycle which eventually leads to sludge ages as high as 10 days. Therefore, the aim of this study was to determine whether ageing of ferric hydroxide sludge affects its catalytic effect on the oxidation of ferrous iron by aeration.
In order to reach this aim four different groups of experiments were carried out using ferric hydroxide sludge aged for a period of 0 to 10 days. Initial Fe(III) concentrations were varied within the range of 50 mg/l to 200 mg/l. It has been demonstrated that the catalytic effect of ferric hydroxide sludge on the oxidation of ferrous iron by aeration increases with increasing sludge age contrary to what is commonly expected. It has been concluded that, catalytic oxidation rate constant kcat obtained from the batch systems can safely be used in design of continuous flow iron oxidation reactors with sludge recycle.
Anaerobic/aerobic biodegradation of pentachlorophenol using GAC fluidized bed reactors: optimization of the empty bed contact time
Authors: Wilson Gregory J. , Khodadoust Amid P. , Suidan Makram T. , Brenner Richard C. , Acheson Carolyn M. 
Published: May 2018

An integrated reactor system has been developed to remediate pentachlorophenol (PCP) containing wastes using sequential anaerobic and aerobic biodegradation. Anaerobically, PCP was degraded to approximately equimolar concentrations (&gt;99%) of chlorophenol (CP) in a granular activated carbon (GAC) fluidized bed reactor (FBR) at empty bed contact times (EBCTs) ranging from 18.6 to 2.3 hr. However, at lower EBCTs, chlorophenol concentrations decreased to less than 10% of the influent PCP concentration. The optimal EBCT was determined to be 2.3 hr based on PCP conversion to CPs and stable reactor operation. Decreasing the EBCT fourfold did not inhibit degradation of PCP and its intermediates, and thus, removal of PCP is possible at lower detention times providing a significant cost advantage.
Analytical grade PCP was fed via syringe pumps into a GAC FBR at an influent concentration of 200 mg/L. Acting as the primary substrate, ethanol was also fed at a concentration of 1388 mg/L. Effluent PCP and chlorinated phenolic compounds were analyzed weekly to evaluate reactor performance. Biodegradation pathways were also identified. 3-chlorophenol (3-CP) was the predominant CP. Concentrations of 3-CP follow the same trends as 3,5-dichlorophenol (DCP) concentrations. In a similar manner, 4-chlorophenol concentrations correlate with 3,4-DCP concentrations.
A second stage aerobic GAC FBR was added after the anaerobic bioreactor which removed the remaining CP and phenols. No phenol or CP has been observed in the effluent or on the GAC. Overall, the influent chemical oxygen demand (COD) loading was reduced from 34 g/L*d to less than 1.36 g/L*d.
Metal toxicity on the dechlorination of monochlorophenols in fresh and acclimated anaerobic sediment slurries
Authors: Kong I.-C. 
Published: May 2018

The biotransformation of 2- and 3-chlorophenol(CP) was examined in anaerobic fresh and acclimated sediments in the presence and absence of CuCl2, CdCl2 and K2Cr2O7 ranging from 10 to 200 mg/l. Differing inhibitory effects of specific metals were observed on dechlorination of CPs in sediment slurries. In case of fresh unacclimated slurry, addition of 20 mgCu/l resulted in no appreciable inhibition of dechlorination for tested CPs. In contrast, 20 mg/l of Cd and Cr moderately affected lag periods prior to dechlorination. In this case, Cd was more inhibitory than either Cu or Cr (Cd &gt; Cr ≥ Cu), which illustrated nearly similar effect.
In case of acclimated slurry, the dechlorination activity of 2- and 3-CP was inhibited in the presence of 20 mg/l of three tested metals. Metals amended to 2- and 3-CP acclimated sediments exhibited inhibition degree in the order of Cd &gt; Cu &gt; Cr, which are different patterns compare to fresh slurry.
Possibilities of reduction of recipient loading of tannery wastewater in Slovenia
Authors: Roš Milenko , Gantar Anton 
Published: May 2018

The leather industry is well known as a high consumer of water (30 to 80 m3 for 1 ton of processed raw skins). At the same time this industry is known for the high specific pollution of wastewater. The main characteristics of tannery wastewater are: high salinity, high organic loading (COD, BOD5), high content of ammonia and organic nitrogen, and presence of specific pollutants (sulphide, chromium).
The largest Slovenian tannery (IUV Vrhnika) processing 40 to 50 t of pig skins daily has a good system of physico-chemical pre-treatment of their wastewater (coagulation and flocculation with Al-sulfate and anionic polyelectrolyte). In pre-treatment, about 60% of organic substances are removed (COD and BOD5) and above 95% of sulfide and chromium. Concerning Slovenian regulations and taking into consideration the fact that this tannery is located on the relatively small and slowly running river Ljubljanica such pre-treatment is not sufficient. The company would like to supplement pre-treatment with biological treatment.
Laboratory and pilot scale feasibility experiments including conventional biological treatment with activated sludge and combined anaerobic-anoxic-aerobic treatment with fixed biomass using mechanical pretreated wastewater and pretreated wastewater with flotation were performed. It became clear that effective biological treatment requires long retention times (several days) for applicable effluent.
Environmental monitoring initiatives to sustain growth in Ontario, Canada
Authors: Palmer R. M. , Jones C. , Walters M. 
Published: May 2018

Sustainability, which attempts to balance environmental preservation and economic growth, includes puzzling problems such as better managing the world's water resources and enhancing the quality of life.
Municipalities within the Nottawasaga Valley and Lake Simcoe Watersheds, north of Toronto, are now considered to have a high potential for significant growth. Both watersheds form part of the Georgian Bay ecosystem, within the Great Lakes Basin. Integrated watershed management planning by the Nottawasaga Valley and Lake Simcoe Region Conservation Authorities is protecting water resources and ensuring the availability of water servicing for controlled development. This includes the maintenance of streamflows for the assimilation of treated sewage effluent from headwater basins and protection of unimpaired aquatic habitat at the same time.
Monitoring the performance and success of the watershed plans is a vital component to sustain a healthy ecosystem pulse while accommodating growth. The comprehensive GIS based, multi-partnered monitoring program being used is unique. This low-cost, transferable approach for watershed monitoring includes a biological method known as BioMAP. The monitoring program has a proven track record for pre-design and post-construction stages of new development. Various case studies are presented.
Selection of operational strategies in activated sludge processes based on optimization algorithms
Authors: Ayesa E. , Goya B. , Larrea A. , Larrea L. , Rivas A. 
Published: May 2018

This paper presents a new optimization algorithm for the selection of design and operation parameters in complex Activated Sludge (AS) processes. The algorithm estimates automatically the dimensions and operating point of the plant that minimize a global penalty function combining effluent requirements and costs. The mathematical optimization is based on a direct search algorithm integrated in a previously developed simulation package.
Some illustrative examples concerning the design and operation of the Alpha process have been included to show the potential of this kind of mathematical tool when the complexity of plant configuration increases. The results obtained by the optimization procedure generate useful guidelines for the design and operation and suggest a great potential in the application for solving more complex problems when additional objectives and costs are included.
Hydrophobic/hydrophilic properties of activated sludge exopolymeric substances
Authors: Jorand F. , Boué-Bigne F. , Block J. C. , Urbain V. 
Published: May 2018

Hydrophobic interactions may be fundamental in the cohesiveness and other properties of bacterial aggregates called flocs. Exopolymeric substances (EPS) form a matrix in which bacteria and other particles are embedded. However, knowledge about EPS hydrophobic properties is rather scanty.
In this study, EPS extracted from activated sludges from different origins were fractionated, exploiting their property of sorbability by non-ionic resins and the formation of precipitates under-acidic environment. In the light of the results obtained with the XAD-8 resin, at least 7% of the dissolved carbon and 12% of the proteins may be considered as hydrophobic. No carbohydrates were found in the hydrophobic fraction. The precipitable fraction at pH 2 on the other hand contained 64% carbohydrates and 76% proteins. This suggests that EPS are heteropolymers principally made up of carbohydrates and proteins.
Detection of filamentous and nitrifying bacteria in activated sludge with 16S rRNA probes
Authors: van der Waarde Jaap J. , Geurkink Bert , Henssen Maurice , Heijnen Guido 
Published: May 2018

Activated sludge samples from wastewater treatment plants from potato starch and starch derivatives factory and from a municipal sewage treatment plant were analyzed with DNA probes specific for several filamentous bacteria. It was found that Haliscomenobacter hydrossis, Sphaerotilus natans, Thiothrix sp. and Eikelboom Type 021N were common in the activated sludges. Fluorescent in situ Hybridization (FISH) analysis could detect more types of sheathed bacteria and yielded a more accurate quantification of bacteria than conventional microscopy.
In a pilot and a full scale wastewater treatment plant (WWTP) clear correlations were found between the SVI and growth of a Sphaerotilus natans and a Thiothrix sp. Addition of chlorine to the bulking sludge resulted in an improved SVI of the sludge but only damaged filamentous cells outside the floc. Nitrification was measured with substrate depletion and FISH analysis. Signal interpretation of FISH analysis was demonstrated both manually and with automated image analysis.
New technology of mechanical treatment of dredged material from Hamburg Harbour
Authors: Detzner Heinz D. , Schramm Wolfgang , Döring Ulrich , Bode Wolfgang 
Published: May 2018

Harbours and water ways can only fulfil their commercial task if there is always sufficient water depth for navigation. Environmental problems have started to influence dredging methods in recent decades. As a logical consequence of a policy giving high priority to environmental protection, Hamburg built the METHA plant (Mechanical Treatment of Harbour Sediments). METHA produces a clean sand product (grain size &gt; 63 μm) which is reused and a contaminated silt fraction (grain size &lt; 150 μm) which is disposed presently. Previous investigations showed that the content of heavy metals and organic contaminants are primarily governed by the grain size. In 1995 Strom- und Hafenbau started a new investigation to produce a further fraction from the METHA silt which can be reused.
The result of laboratory- and pilot-scale research showed the possibility of a further separation at 20 μm grain size. The best result was reached through a two-step separation made by hydrocyclons and spirals. The produced fraction (20–150 μm) is mainly quartz material with a low level of contamination. In February 1996 Strom- und Hafenbau decided to built a test plant in a technical scale. The capacity of the test-plant is 50 t/h based on dry substance The technical concept is integrated into the METHA concept. All aspects of technical feasibility, economy, environment and product reuse will be investigated in the test plant. The results of the early test phase will be presented.
Field monitoring of ripening of dredged material at three sites in the Netherlands (preliminary results)
Authors: de Haan W. , Otten K. J. , Heynen J. J. M. , Folkerts H. , Elsman M. 
Published: May 2018

Ripening of dredged material in a deposit is a natural ‘drying’ process by which raw dredged material transforms into soil. The aim of ripening is to obtain soil which complies with environmental legislations and geotechnical specifications for application in earthworks (e.g. dikes, noise reduction banks, landfill covers).
The paper deals with the background and contents of a monitoring programme on the ripening behaviour of clayey, peaty, and sandy dredged material, and changes in chemical composition, especially of organic compouds, and leaching characteristics during ripening. The main objectives of the monitoring programme are (1) to develop a management system for the ripening process, (2) to quantify the input and output volumes of dredged material, and (3) to develop guidelines for the design of (transit) deposits. The results of the monitoring programme will also be used for calibration and validation of a computer model on ripening. Prelimanary results on ripening of clayey material and biodegration of PAH and mineral oil are presented. On the basis of these results it is expected that large volumes of slightly to moderately contaminated dredged material are suitable for beneficial use after ripening.
Treatment of simulated aquaculture water using biofilters subjected to aeration/non-aeration cycles
Authors: Shanableh A. , Hijazi A. 
Published: May 2018

The overall objective of this research activity is the development of a fixed-film biological nutrient removal (BNR) biofilter system for the reuse and discharge of a selected aquaculture water. The three stage biofilter system used in the study provided alternating aeration/non-aeration cycles for phosphorus removal in two of the three biofilters. The removal of TOC and ammonia improved as the cycle duration (CD) increased as a result of the reduction in the frequency of the transition periods between the cycles. The system achieved limited net phosphorus removal due to the limited sludge wasting and lack of external organic carbon supplies during phosphorus uptake. However, the phosphorus activity in the system was significant and was modified by the CD. The denitrification activity was coupled with phosphorus uptake and both activities appeared to have been supplied by an internal organic carbon source.
The major challenges of achieving phosphorus removal in the system include: (1) overcoming the deterioration in the performance of the system during the transition period following the start of each new cycle; and (2) wasting the excess biomass following the aeration cycle. Without active sludge wasting, the system behaves as a phosphorus reservoir with a limited storage capacity. On the other hand, frequent sludge wasting may disrupt the performance of the system.
Characterization and treatment of effluent from opium alkaloid processing wastewater
Authors: Sevimli M. F. , Aydın A. F. , Sarikaya H. Z. , Öztürk İ 
Published: May 2018

Opium is a traditional produce of Turkey planted and harvested under the control of the Government. This study was undertaken to characterize the wastewater from opium alkaloid processing. Thus, the laboratory records of the two stage aerobic biological treatment plant of the Opium Alkaloid factory were evaluated. Following the statistical analysis of the results for the last three years, it was found that the median values of influent COD and BOD5 concentrations were 29,300 mg/l and 15,000 mg/l respectively. Two stage aerobic biological treatment could reduce these values down to 1,132 mg/l and 100 mg/l. Specific wastewater generation was 6.7 m3 per ton of the opium capsule processed.
Experiments conducted at an upflow anaerobic sludge blanket reactor type pilot plant have demonstrated that 70 percent of the incoming COD can be removed anaerobically, and can be considered as a cost effective substitute for the 1st stage of the aerobic treatment.
Post treatment of the effluents of the existing two stage aerobic treatment with ozone resulted in significant color removal and COD reduction.
Effects of integrated stormwater management strategies on the combined sewer system and the wastewater treatment plant-river system
Authors: Welker A. , Leinweber U. , Klepiszewski K. , Schmitt T. G. 
Published: May 2018

This is an investigation into possible changes to quantity and composition of sewage in the combined sewer system and the waste water treatment plant (WWTP) caused by new stormwater management strategies (mainly by disconnecting areas from the sewer system). Various scenarios were developed and the consequences on the water systems were calculated by using the simulation model KOSMO, in a fictional catchment.
The results of the combined sewer overflow-calculation show an enormous decrease of the overflow annual load for different parameters (COD, ammonia) by the reduction of impervious surfaces. Thus, the overflow concentrations of some parameters increase dramatically under these conditions, in particular the ammonia concentration might cause critical situations (e.g. sensitive receiving water).