bluuebunny/crossref_metadata_2025_split huggingface dataset:
Environmental Impact Assessment of the Discharge of the Effluent from the Faro Waste Stabilization Ponds into the Ria Formosa, Algarve, Portugal
Authors: Pereira Maria Amélia S. , Machado Luís 
Published: May 2018

This paper intends to present the main problems studied in the environmental impact assessment of the discharge of the tertiary effluent from a stabilisation pond system to be built for the city of Faro (Algarve) into Ria Formosa, a shallow coastal water body of high ecological, economic and touristic value.
The environmental assessment emphasized the analysis of the impacts that may affect the shellfish beds as well as the flora and fauna, which are mainly the decrease of salinity, the increase of nutrients content and the entry of pathogens.
Despite the impossibility of quantitative assessment, the study concluded that the effects of the variation of salinity and nutrients content will not be very significant. However, the pathogens are likely to contaminate the shellfish bads.
Recommendations are presented including construction and operation of a suitable treatment plant, tight sanitary control of the shellfish before human coneumption and monitoring of the future situation.
The Role of the Operation Regime in Wastewater Treatment with Duckweed
Authors: Oron Gideon , de-Vegt Andre , Porath Dan 
Published: May 2018

The results of outdoor experiments with Lemnaqibba (a duckweed species) grown in mini-ponds proved to be highly competitive in comparison with other existing secondary treatment methods. The treated wastewater is at an acceptable level and can be reused for agricultural irrigation. The duckweed biomass, with a crude protein content of over 30% of dry weight, may be used as a protein rich alternative fodder. The ease of duckweed harvesting makes the potential treatment system even more economically attractive.
Operational regime was controlled by the retention time and wastes depth. Retention time was in the range of 3 to 10 days, while the depths examined were 20 cm and 30 cm. The results indicate that shortening the retention time was associated with increase in protein content and did not affect the yield very much. The duckweed yield (dry basis) in the deep ponds (30 cm) was very similar to the 20 cm ponds, viz. around 14 g /m2 per day.
Biological Treatment for Low-Activity Nuclear Wastewaters
Authors: Ramadori R. , Fenoglio F. , Pozzi L. 
Published: May 2018

Safety problems loom so large for the nuclear industry that provision must always be made in treatment of liquid wastes for their recycling to the production process. In this regard, a wastewater treatment consisting mainly of ammonia stripping, biological denitrification and chemical precipitation, looks very promising.
With reference to the biological stage, this paper sets out the results of bench-scale tests performed to evaluate dimensioning parameters for the denitrification process.
The tetrahydrofurfury1 alcohol, the major organic compound in the wastewater, was used as electron-donor substance. The procedure adopted for full-scale plant design and the preliminary results obtained using it, are also presented.
Behaviour of Alkylphenol Polyethoxylate Surfactants and of Nitrilotriacetate in Sewage Treatment
Authors: Giger W. , Ahel M. , Koch M. , Laubscher H. U. , Schaffner C. , Schneider J. 
Published: May 2018

Effluents and sludges from several municipal sewage treatment plants in Switzerland were analyzed for nonylphenol polyethoxylates (NPnEO, n=3-20), nonylphenol mono- and diethoxylate (NPlEO, NP2EO), corresponding nonylphenoxy carboxylic acids (NP1EC, NP2EC) and nonylphenol (NP). These chemicals derive from nonionic surfactants of the NPnEO-type, and specific analitical techniques were used to study their behaviour during mechanical-biological sewage and subsequent sludge treatment. The parent NPnEO-surfactants, with concentrations in raw and mechanically treated sewage from 400-2200 mg/m3, were relatively efficiently removed by the activated sludge treatment. The abundances of the different metabolites varied depending on treatment conditions. The refractory nature of NPl/2EO, NP and NPl/2EC was recognized. Both biotransformations and physico-chemical processes determine the behaviour and fate of nonylphenolic substances in sewage treatment.
Nitrilotriacetate (NTA) was found in primary effluents at concentrations between 430 and 1390 mg/m3. The various treatment plants showed different removal efficiencies for NTA depending on the operating conditions. Activated sludge treatment with low sludge loading rates and nitrifying conditions removed NTA with efficiencies between 95 and 99%. High sludge loading caused a decrease in NTA removal efficiencies from 70% to 39%.
Dimensioning of Combined Sewer System Detention Basins by Long Term Simulation of Storm Water Runoff
Authors: Sieker F. , Durchschlag A. 
Published: May 2018

At present, dimensioning of combined sewer detention basins in Germany is based actually on the rational formula and on the idea of the existence of the so-called “first flush”. New measurements and recent investigations have led to the questioning of this dimensioning procedure.
An alternative developed in this paper is based on the application a storm-water-runoff-model (hydrological and/or hydrodynamic) in each special case. Input to the model is a period of at least one decade of continuous rainfall data (long term simulation). The sanitary waste water component is superimposed to the simulated runoff-hydrograph. The first flush-effect is neglected. The dimensioning of a detention basin is based on the determination of several quantities such as number, duration, peak discharge and volume of overflow events in relation to the total water detention volume of the system. The decision on final dimensioning has to be made with respect to the characteristics of the receiving water.
Study of a Non-Conventional Aeration System
Authors: Raschid-Sally L. , Roustan M. , Roques H. , Faup G. M. 
Published: May 2018

A non-conventional aeration system for oxidation ditches using jets has been developed. The principle of this system is based on the separation of the 2 actions: aeration and circulation.
It was concluded that the flow of the liquid in the channel can be successfully modelled using various theoretical approaches. The mean circulation velocity VC, the power dissipated P, and the Peclet number Pe are the 3 important parameters governing the circulation.
The oxygen transfer capacity of the system has been studied and compares favourably with that of conventional systems. The advantage of such systems over conventional ones has been discussed.
High Molar Mass Lignin in Bleached Kraft Pulp Mill Effluents
Authors: Sågfors P.-E. , Starck B. 
Published: May 2018

The proportion of high molar mass (M &gt; 1000D*) substances (HMM) in acid and alkaline bleaching effluents from kraft pulping has been studied by means of analytical gel permeation chromatography, GPC. The amount of HMM substances in alkaline effluents was found to be 65 - 75 % and in acid stage effluents 20 % of the UV-absorbing (A280 nm) components. Lignin is the precursor of the HMM substances in the alkaline stage, and lignin and carbohydrates are the precursors of the acid stage HMM substances.
For the purpose of characterization the HMM compounds were separated from low molar mass substances by preparative GPC. The IR spectra of both alkaline and acid stage substances in their neutral form had strong bands characteristic of carboxylic salts. There were no aromatic bands in the spectra of softwood HMM substances. In the spectra of hardwood substances a narrow aromatic band of low intensity was found in two alkaline stage HMM samples originating from mills using a high proportion of ClO2 to chlorine. Elemental analysis of the alkaline stage HMM substances showed that the chlorine content was as high as 9.8 % when the ClO2 charge had been small and less than 4 % with a large ClO2 charge. The low methoxyl group content and high oxygen content showed that the substances were largely oxidized. The LC50 test with water flea indicated no acute toxicity.
Biological Degradation of Volatile Chlorinated Hydrocarbons in Groundwater
Authors: Milde G. , Nerger M. , Mergler R. 
Published: May 2018

Chlorinated organic solvents - such as tetrachloroethene, trichloroethene and 1.1.1-trichloroethane - are the most frequently used compounds e.g. for degreasing in all branches of industries.
Due to their widespread use, their large consumption quantities (Fed.Rep.of Germ. 180 × 103 t/a) and their physical properties, these organic solvents are the most important point-source of groundwater contamination.
A serious case of soil, soil air and groundwater contamination by these organic solvents (maximum concentrations detected were 500 mg/kg, 7g/m3, 50 mg/l respectively) is reported, caused by the metal industry, rendering plant and paper production.
A special effect is the comparatively rapid degradation sequence of tetrachloroethene to trichloroethene to cis-1,2-dichloroethene and to vinyl chloride. Concentrations of cis-1,2-dichloroethene observed in groundwater were up to 1600 µg/l and of vinyl chloride up to 120 µg/l, respectively, although none of these substances were primary pollutants in the investigated area.
Results of laboratory tests give rise to the suggestion that degradation of chlorinated hydrocarbons in contaminated areas is mainly by microbiological means.
This effect is of special hygienic relevance, due to the fact that one of the metabolites, vinyl chloride, is known to be a human carcinogen and the polluted area (approx. 4 km2) is located in a catchment area of a waterworks.
Optimisation and Uprating of Activated Sludge Plants by Efficient Process Design
Authors: Chambers B. , Jones G. L. 
Published: May 2018

Requirements to improve effluent quality and reduce operating costs at existing activated sludge plants in the UK have led to the development of an accurate mathematical model of the process which can be used for full-scale design. The WRc Activated Sludge Model has been developed over a number of years and is based on the concept of describing the kinetics of BOD removal by including a Monod term for growth and a Michaelis-Menten term for enzymatic activity. Since the first formulation of the model, further equations have been added which describe the use of oxygen and nitrate as electron acceptors for the conversion of BOD.
The model equations can be used to predict the performance of most configurations of the activated sludge process by using the ‘tanks in series' concept to describe aeration tank mixing characteristics. Solutions to the equations are easily obtained by standard numerical integration techniques using a computer. The software has been written in such a way that the model can be used interactively by a plant designer.
Results obtained using the mathematical model have been used to redesign several full-scale activated sludge plants in the UK. In some cases, it has been possible to reduce the energy costs for aeration by 40% whilst maintaining effluent quality by accurately matching the supply of oxygen to the spatially-varying oxygen demand in plug-flow aeration tanks. Bulking sludge problems have also been solved by the conversion of completely-mixed aeration tanks to plug-flow aeration tanks with complementary redesign of the aeration system.
The Infuence of the Depth of the Secondary Sedimentation Tanks on the Sedimentation Efficiency at Bromma Sewage Treatment Plant
Authors: Tendaj-Xavier M. , Hultgren J. 
Published: May 2018

Bromma sewage treatment plant is the second largest plant in Stockholm with a design flow of 160,000 m3/d.
The wastewater is treated mechanically, chemically by pre-precipitation with ferrous sulphate, and biologically by the activated sludge process. The requirements for the plant are 8 mg BOD7/l, 0.4 mg P/l and 2 mg NH4+-N/l. The requirement for ammonia refers to the period July-October.
In order to meet those rather stringent requirements, the biological step was expanded 3 years ago with 6 new sedimentation tanks. The 6 new tanks have the same area as the 6 old ones but they have only a depth of 3.7 m compared with the depth of the old tanks, 5.7 m.
Experience from the first years of operation of the new tanks is that these tanks are more sensitive and less efficient than the older ones. It seems that the effluent suspended solids concentration from the old tanks is less influenced by rapid flow variations than the concentration in the effluent from the new secondary sedimentation tanks.
During the nitrification period denitrification takes place to some degree in the secondary sedimentation tanks. This may cause loss of solids and it has been observed that the deeper old tanks usually produce an effluent of better quality and seem to be less influenced by denitrification than the new ones.
Joint Sewage Treatment Plant I, Moenchengladbach-Neuwerk–A Review of the Past 50 Years and its Future Upgrading
Authors: Kugel G. , Zingler E. 
Published: May 2018

The paper describes the changes which have been made to the plant since it was built in the 1930s. It was initially designed to treat 50,000 m3/d by a 2-stage activated sludge process with integrated charcoal precipitation and was enlarged 25 years ago to treat 130,000 m3/d dry weather flow. It now treats a population equivalent of 650,000, half of which is industrial effluent mainly from textile and food processing factories.
Sludge treatment has always included digestion and this is to be upgraded to 2-stage thermophilic and mesophilic digestion with submerged combustion sludge heating. The sludge produced has always been disposed of to land, with or without drying, using digester gas, and some has been centrifuged. The gas has also been used for car fuelling but it is now purified and blended into the gas supply of a public utility.
The sewage treatment is also to be upgraded mainly to deal with increased storm water flows.
Resuspension of Sediments from Long Island Sound (U.S.A.)
Authors: Tsai Cheng-Han , Lick Wilbert 
Published: May 2018

Resuspension experiments were conducted in sea water in an annular flume on fine-grained sediments from Long Island Sound. From these experiments, the resuspension rates and the sediment concentrations at steady-state were quantitatively determined as a function of shear stress and bed compaction. In addition, net resuspension experiments were conducted. From these, the total amount of sediment that could be resuspended at a particular shear stress was determined. In these tests, the resuspension rate decreased with time and the total amount of sediment that could be resuspended at a constant shear stress approached a constant value as time increased. This demonstrates a major difference between the resuspension characteristics of fine-grained sediments and those of uniform-size, coarse-grained, non-cohesive sediments. For the latter case, the resuspension rate ideally would be constant with time.
Resuspension experiments were also conducted with deposit-feeding Nucula clams seeded into the sediment bed. In all cases, the steady-state concentrations as a function of shear stress were significantly greater than those in tests without Nucula. The tests also suggest that after sediments are seeded with Nucula for approximately 7 days, the sediment resuspension does not change with time of consolidation.
Effect of Salinity on Nitrification in a Tidal River
Authors: Furumai Hiroaki , Kawasaki Takashi , Futawatari Tohru , Kusuda Tetsuya 
Published: May 2018

Several field surveys were conducted to investigate changes of water quality with time in the tidal River Rokkaku, where a turbidity maximum exists. Suspended solids of the turbidity maximum reach more than 20 g/l in concentration. Based on the surveys, NH4-N, NO2-N, and NO3-N have peaks in concentration at certain salinities, located in order of NH4-N, NO2-N, and NO3-N toward the river mouth within 10 to 25 km from it. The salinities were 0.5, 1.7, and 3.0 %, respectively, and the maximum concentrations were about 3.0, 0.3, and 4.5 mg/l in winter time, respectively.
Laboratory batch experiments were conducted, using suspended solids and sediments taken from the river, to study the effect of salinity on nitrification and to estimate kinetics parameters of it in the river. Suspended solids and sediments were sampled at a point in the middle stream. The sediments were collected from the aerobic layer of mud, less than 1 cm thick from the surface. Experimental results indicated much more inhibition of NO2 oxidation by salinity than that of NH4 oxidation. Nitrifying bacteria in sediments were less sensitive to salinity than those in suspended solids. The change of nitrogen concentration with time was clearly explained with the Monod growth model and the two kinetics parameters were obtained by the curve fitting method. Maximum specific growth rates of NH, oxdizing bacteria ranged from 0.015 to 0.029 (hour−1), which decreased markedly with more than 15 %. salinity. Those of NO2 oxidizing bacteria ranged from 0.015 to 0.025 (hour). Saturation constants of NH4 and NO2 oxidation were also dependent on salinity. Changes in NH4-N and NO2-N concentrations in the River Rokkaku with time were simulated well using a newly developed river model and the parameter values obtained in the laboratory tests. The mechanism of nitrification by suspended solids and sediments in the river is shown to depend on tidal effects.
Strategies for Coastal Water Quality Management: A Case Study of Laem Chabang (Thailand) Deep-Sea Port Development
Authors: Muttamara Samorn , Baldisimo Julito M. 
Published: May 2018

An environmental study was conducted as a part of coastal water quality management for Laem Chabang Deep-Sea Port. It was revealed that the existing seawater quality at Laem Chabang area is generally well within standards for unpolluted seawater, making it suitable for fishing and recreation.
Environmental impact assessment of the different activities to be carried out in relation to the Laem Chabang port development indicated that the following significant impacts on the marine environment can be anticipated: (1) direct damage to biological organisms by resuspension of organics due to disturbance of marine habitat during dredging/reclamation and breakwater/pier construction; (2) creation of high turbidity by disposal of dredge spoil which disturbs and/or smothers marine flora and fauna and, more importantly, poses the greatest threat to the tourism industry in Pattaya located about 12 km from the project site; (3) modification of the tidal current direction and velocity in the Laem Chabang bay as a result of dredging in the entrance channel, fairway and basin; (4) deterioration of seawater quality due to discharge of tapioca powder losses, domestic wastewater from port area and sewage from ships (5) destruction of the aesthetic aspects of the port waters and surrounding areas as a consequence of solid waste generation from cargo handling from ships.
A number of strategies/measures for coastal water quality management to prevent or minimize the adverse impacts have been recommended. The proposed environmental protection program is necessarily justified considering the economic benefits to be gained by the country from port operations.
Mercury Fixation in Contaminated Sediments as a Management Option at Albany, Western Australia
Authors: Schulz R. S. 
Published: May 2018

Water overlying mercury contaminated sediments in Princess Royal Harbour, Albany, was found to contain up to 0.8 µg/L of mercury. Using contaminated sediments and water from Princess Royal Harbour experiments were carried out to remove the mercury from the waterbody and fix it to the sediment. Treatment with metallic iron reduced the mercury concentration of the water to less than 0.1 µg/L within 2 minutes and any potential visual pollution from the oxidation of iron was prevented by a sand overlay. The sand did not interfere with the lasting effectiveness of the iron.
A field trial was conducted to test the system under wind and tidal conditions in shallow waters of Princess Royal Harbour. It was established that due to the sedimental rework, the overlay thickness would have to be increased for the shallow waters. For deeper waters (&gt;2 m), the system is expected to give good results over sand bottoms. Seagrass covered areas are expected to yield staining problems due to ineffective sand overlay.
Impact of Catchment Urbanisation on Lake Macquarie (Australia)
Authors: Simmons B. L. , Trengove S. L. 
Published: May 2018

Increasing urbanisation of coastal areas is leading to impacts on coastal lakes which decrease their amenity for recreation and tourism. Runoff and wastewater discharge cause siltation, impact seagrass beds and change the characteristics of open waters, affecting boating, swimming, fishing and the aesthetic quality of the locale. Management of urban development and wastewater disposal is required to minimise sedimentation and nutrient enrichment. This could include development restrictions, runoff controls and a strategy for wastewater treatment and discharge.
The catchment of Lake Macquarie, a marine coastal lake, has been progressively urbanised since 1945. Urbanisation, through increased stormwater runoff and point source discharges, has caused a major impact on the lake in terms of sedimentation and nutrient enrichment. Losses of lake area and navigable waters have occurred. Accompanying problems include changes in the distribution of seagrass beds and nuisance growths of benthic algae. Since the 1950's, dry weather nutrient concentrations have increased and mean water clarity has decreased.
Severe problems, as observed in other New South Wales coastal lakes, for example benthic algae in Lake Illawarra and Tuggerah Lakes, have not yet developed. Because of the lead time taken to implement policies and controls, trends should be identified and policies developed now so as to avoid nutrient buildup and development of sustained problems.
Comparative Resistance of Bacteriophages Active against Bacteroides fragilis to Inactivation by Chlorination or Ultraviolet Radiation
Authors: Bosch A. , Tartera C. , Gajardo R. , Diez J. M. , Jofre J. 
Published: May 2018

In order to assess the potential usefullness of bacteriophages active against Bacteroides fragilis for the monitoring of viral disinfection in environmental samples, the sensitivity to chlorination and to UV irradiation of bacteriophage B40-8 was evaluated in comparison to that of poliovirus type 1 (LSc2ab), simian rotavirus SA11, coliphage f2, Escherichia coli and Streptococcus faecalis.
The inactivation of the different microorganisms by chlorine or UV treatment was monitored in tap water and sewage. The results indicated that viruses persisted significantly (p&lt;0.05) longer than bacteria in the presence of both disinfectants. Phage B40-8 was the most resistant microorganism to chlorination (p&lt;0.05) while coliphage f2 was the most resistant to UV irradiation. In the latter, phage B40-8 was nevertheless as resistant as poliovirus and rotavirus. As expected, all microorganisms were significantly (p&lt;0.05) more resistant to both disinfection procedures in sewage than in tap water. These studies lead to the suggestion of the use of bacteriophage B40-8, instead of indicator bacteria, for the monitoring of viral disinfection in sewage-polluted water.