bluuebunny/crossref_metadata_2025 huggingface dataset:
The Rotterdam Initiative in Reducing Waste Discharges at Source
Authors: Vellinga T. , Nijssen J. P. J.
Published: May 2018

Much of the material dredged from the port of Rotterdam is contaminated to such a degree that it must be placed in specially constructed sites. The aim of Rotterdam is to ensure that the dredged material will once again be clean. This will entail the thorough cleansing of the sources of the contamination of the sediment in the harbours and in the River Rhine. The Rotterdam Rhine Research Project (RRP) is one of the means to achieve this based on: technical research, legal research, public relations and dialogues with dischargers.

The programme for five selected heavy metals is almost complete. For many heavy metal discharge points between Rotterdam and Rheinfelden, a specially devised independent load assessment has been carried out four times. Balance studies were used to determine the relative contributions of the point discharges to the total. Currently the results are being used in an attempt to negotiate agreements with a selected number of the major dischargers. At present, more detailed balance studies are being set up and exploratory measurements carried out for organic micropollutants.

It may be concluded that the research is progressing successfully and methods and techniques developed seem satisfactory and broadly applicable. The Rhine Action Programme encompasses an international effort to improve the quality of the Rhine water. Although the RRP plays a modest complementary role to the Rhine Action Plan, there is no doubt of the value of this Rotterdam initiative. The mode of work followed in the RRP contains elements that can be of use in combatting the contamination of the North Sea by rivers other than the Rhine.
Norwegian Strategies in the Treatment of Municipal Wastewater towards the Reduction of Nutrient Discharges to the North Sea
Authors: Ødegaard H. , Paulsrud B. , Bilstad T. , Pettersen J. E.
Published: May 2018

The paper deals with a research programme that the Norwegian environmental control authorities have established in order to be able to recommend how the municipal discharges of nutrients to the North Sea may be reduced by 50 % by 1995. The strategy is to ensure phosphorus removal by chemical treatment for all plants > 5000 pe, and nitrogen removal as well for all plants > 10 000 pe that discharge to the area of influence. One is aiming at compact plants. Pretreatment based on chemical coagulation and biological treatment based on high biomass reactors are investigated experimentally. An economic analysis of using physical/chemical treatment also for the N-removing step is presented. It shows that the physical/chemical methods for N-removal cannot compete economically with the biological methods.
Reduced Hydraulic Detention Time for Complete Nutrient Removal with Innovative Biological Reactors
Authors: Rogalla F. , Payraudeau M. , Sauvegrain P. , Sibony J.
Published: May 2018

To limit pollution discharges through wastewater into surface waters, increasingly stringent effluent standards particularly for nutrient removal require extensive upgrading of conventional wastewater treatment plants. Large sewage treatment plants in Western Europe are often located in densely urbanised areas where land is unavailable. To avoid additional unit processes for nitrogen and phosphorus removal, innovative solutions are demonstrated. A compact reactor is presented that achieves low pollutant residuals (carbonaceous matter, suspended solids, nitrogen and phosphorus) in reduced space and a few examples of full scale applications are given.

Through extensive pilots tests, the limiting parameters for nutrient removal are established on sewage after pretreatment and lamella settling. The biological treatment by two granular filters in series combines biodegradation and suspended solids retention without further particle separation. The anoxic reactor removal rates varied between 0.3 and 1.5 kg N-NO3/m3 d, depending on temperature and available carbon. Nitrification on the aerobic filter increases from 0.3 kg to 1 kg N-NH4/m3 d with temperature in a range between 5 to 20 °C. Total nitrogen residuals below 10 mg/l and effluent phosphorus below 1 mg/l can be achieved with hydraulic retention times of around 3 hours.
Limiting Factors for Phytoplankton in the North Sea
Authors: Peeters J. C. H. , Haas H. , Peperzak L. , Wetsteyn L. P. M. J.
Published: May 2018

Underwater light intensity and nutrients are important for the abundance and species composition of phytoplankton. In winter the development of phytoplankton in the North Sea is limited by light. In the central parts of the North Sea the spring bloom starts earlier than in coastal areas. This difference is caused by the higher light attenuation coefficients in the coastal zone. In summer the surface mixed layer (SML) of the stratified areas shows light saturation of phytoplankton photosynthesis. During the growing season the continental coastal waters of the North Sea are potentially phosphorus or silicon limited when tested with a bioassay of the diatom Skeletonemacostatum. The offshore waters are potentially nitrogen limited. There are indications that the spring diatom bloom in the coastal waters ends because of silicon depletion and that the nitrogen and phosphorus concentrations are still large enough to allow the development of a large bloom of Phaeocvstiscf. pouchetii. In summer diatoms disappear from the SML of the stratified areas, but they survive under the thermocline. Possible effects of a reduction of the nutrient loads to the North Sea are discussed in the context of experience in the Delta region (SW-Netherlands).
Soil Contamination, Contaminant Levels in Benthic Organisms and Intake by Oystercatchers on Tidal Flats in the Eastern Scheldt
Authors: Hidding H. , Bouwhuis J. S.
Published: May 2018

In the vicinity of former wrecking sites two tidal flats were investigated for the contents of heavy metals, PCBs and PAHs in both the sediment and in benthic organisms (cockle, mussel and lugworm). In the silt fraction PCB concentrations up to 140 µg/kg.dm were found. PAHs were detectable in all the soil fractions. Contaminant levels in organisms were enhanced. PCBs could only be observed in lugworms. Significant correlations were found between levels of lead, six individual PAHs and five individual PCBs in lugworm and in the silt fraction. The intake of contaminants is not expected to affect short-term hatching results of the oystercatcher feeding on the benthic organisms. Biomass and abundance of benthic species are not affected significantly.
Integral Risk Analysis as a Supporting Framework for Water Quality Management
Authors: Bos H. R. , Bowmer C. T. , Scholten M. C. T.
Published: May 2018

The prevention of pollution in a marine ecosystem such as the North Sea has traditionally been approached from two angles i.e. (1) by controlling the disturbance at source and (2) by monitoring the quality of the marine environment and act when deleterious effects occur. These approaches are loosely based on the precautionary principle and on the concept of assimilative capacity, respectively. Although in principle different approaches, they are similar in practice as they both accept, rightly or wrongly, a certain input of pollutants to the marine environment. There remains however, a stubborn lack of information as to what qualitative and quantitative relationship exists between the input(s)/sources and consequently the distrubance or effects in the marine environment.

Environmental stress in a marine ecosystem becomes visible when the dynamics of its elements deviate from their normal cycles or fluctuations. These observable end-effects are often the initial reason for concern, i.e. long after the process of disturbance is underway. It has always been difficult to interpret these mostly complex signals and relate the observations to primary causes. In order to handle the diversity of information and signals in the cause-effect chain between input(s)/sources and disturbance, the development of a comprehensive logic framework is needed.
Three-Fold Remedial Measures for Groundwater Protection: Case Study of the Khathkari Stream, Pune District, India
Authors: Kalantari Nasrollah , Thigale S. S.
Published: May 2018

A vast tract in Maharashtra State of India, constituted of horizontally disposed basaltic flows of Cretaceous-Eocene age, falls in the semi-arid climatic zone characterised by low precipitation and high temperature and evaporation. Such areas are marked by the variety of calcretes including massive, honeycomb, nodular, and powdery types. These calcretes which owe their origin to both pedogenic and nonpedogenic processes, are responsible for imparting the salinity to the groundwater.

An integrated approach, involving geological, hydrogeological and hydrochemical studies, has been employed for delineating the boundary of saline and fresh waters in the groundwater system and evaluating the variation in salinity in the area around the Khathkari stream (18 13’ to 18 18’ N latitudes, and 74 13’ to 74 22’E longitudes) in Pune district.

The paper briefly presents the data collected during the course of the work and incorporates the three-fold remedial measures such as i) protecting fresh water that occurs at deeper depth, ii) improving the present quality of water and iii) suggesting an appropriate crop-pattern that can stand for present and improved quality of water.
Water Quality Factor Identification by the “Principal Components” Statistical Method
Authors: Melloul A. , Collin M.
Published: May 2018

This paper proposes the means of using the “Principal Components” statistical method for identifying relevant groups of water and the factors that bring about a change in their quality. The major advantage of this method lies in its suitability for simultaneous analysis of a great number of variables and observations.It is here being applied for the investigation of Dan metropolitan region of Israel's Coastal Plain. The various parameters involved include major ions as well as the physical factors of depth to the water table, distance from the sea, and aquifer recharge.

Results include:–the identification of two major groups of water: low salinity, calcium bicarbonate water occurring in the phreatic portion of the Coastal aquifer; and more saline, sodium chloride water characterizing the neighboring Cenomanian aquifer and the confined portions of the Coastal aquifer;–influence by distance from the sea, depth to water table, and aquifer lithology on the major water input sources, such as rain, injection water, waste water, irrigation, etc.–affect by such lithological factors as clay lenses which contribute to water quality changes as indicated by disequilibrium in several ionic ratios upon water resource management; and–clear visualization on the same graph of evolutionary alteration in specific ion content with time.
Characterization of Hydrological and Hydrochemical Cycles as a Tool for Evaluation of Environmental Impact of Mining in Serra Dos Carajas, Amazonia, Brazil
Authors: Weissberg I.
Published: May 2018

The objective of this work is to show the importance of knowing, in detail, the hydrological and hydrochemical cycles so as to define the dynamic conditions for an ecosystem equilibrium and to detect the modifications introduced by open-cast mining, which is a potential cause of environmental impact.

Over four years research was carried out in the Carajas area to evaluate the elimate, soil and water characteristics. About the five hundred and fifty water samples from rivers, lakes and “igarapé” were collected and analysed from forty different points of the area. At nine different points, two hundred sixteen soil samples were collected and analysed. The analysed results were assembled with pluviometry, humidity, potential evaporation, insolation and temperature data for the area.

The data reveal that residence time of water is short in all “stages” of the cycles (convective rain); the pH is acidic (between 4.5 and 6.0) with high values of free CO2 (average 30 ppm) and saturated in dissolved O2 (average 8.O ppm) which produces a high degree of water reactivity when in contact with the surface. The Carajas ecosystem is in dynamic equilibrium with these conditions.

The water percolation through tailings from iron and manganese mining produces an agent that dissolves and removes mineral particles that in run off arrives in surface and groundwater, changing its physical-chemical equilibrium and disturbs the aquatic biota. At the start of exploration were detected Cr 0.14 ppm, Mn 0.43ppm, Pb 0.20 ppm and Ni 0.04ppm.

Salobo polymetals deposit has a very complex mineral paragenesis with Cu, pb, Ag, Mo, Co, Zn and other metals such as sulfide. This deposit has a high pollution potential since its tailings will will be exposed in the open.
Sensitivity Analysis of Clay Barriers
Authors: Nobre M. M. , Sykes J. F.
Published: May 2018

This paper illustrates the importance of sensitivity analysis in the design of clay barriers. Theoretical modelling simulations are performed using the finite element method in which realistic scenarios for unsaturated flow are conceived. Results show that the adjoint operator technique can be an efficient component to evaluate the impact of the thickness of the clay barriers as well as in the values of hydraulic conductivity values on pressure head distribution and integrated travel time.
Influence of Pumps on Salinity of a Coastal Aquifer with Legal Protection (A Zone in the North of Isla Cristina, Huelva, Spain)
Authors: González A. , Romero E.
Published: May 2018

In this article we show that the legal measures for protection of aquifers are not enough to lessen the pumping if the users are not associated and determined to have a rational distribution of water.

The expansive agriculture on the North side of Isla Cristina (Huelva, Spain), based on citrus and strawberry growing, uses high volumes of groundwater that comes from a tertiary age detritic coastal aquifer with a significant lack of resources. This causes a decrease of the residual flow to the sea, deep pumpcones, and an inversion of the hydraulic gradient, which initiates the progressive salinization of the aquifer northwards, in the sense that the fresh-salt water mixture zone is moving.

The problem is worsening because the number of uncontrolled pump-works in the areais increasing. This problem could be alleviated if a Users Community for the whole aquifer were created, itself to watch over the fulfilment of the legal requirements and to regulate the water extractions.
Handling and Processing of Hazardous Solid Wastes From Petrochemical Industries – Cetrel's Experience
Authors: Passos J. A. L. , Neves N. M. S. , Ferreira M. Q.
Published: May 2018

The increasing generation of hazardous solid wastes resulting from the recent rapid expansion of various industrial activities, within the region, requires a very conscious and careful assessment to establish an appropriate alternative of final disposal of these residuals, in order to avoid deleterious effects on the environment as well as on the population.

CETREL - Center of Treatment of Liquid Effluents and Special Industrial Wastes, located at Camaçari within the state of Bahia, is responsible for the operation of one of the most complete and complex systems which deals with hazardous solid wastes in Brazil, generated by approximately 50 chemical and petrochemical industries, comprising the largest Petrochemical Complex in Latin America.

The main purpose of this paper is to present an overview of the system's operation for treatment and disposal of solid wastes, from initial conditioning at its generating source, up to the handling, processing and final disposal, as well as operation, control and optimization.
State-of-the-Art of Landfill for Hazardous Wastes
Authors: Colombi Carlo
Published: May 2018

A landfill is a dynamic system. Its contents undergo chemical, physical and biological changes. Substances migrate on the water path or on the gas path out of the landfill. Barriers can slow down processes and migration, but they are never 100% effective. State-of-the-art techniques exist for design and operation of hazardous waste landfills. The landfill is the last link in a long chain of waste management techniques. Therefore it is important to control the waste, which must be conditioned by pretreatment. National differences exist, on whether investments should be concentrated on pretreatment or landfilling. It is likely however, that 20 years from now there will be a state-of-the-art in waste management which is accepted worldwide. The focus will be either on intensive pretreatment or avoidance of hazardous (and domestic) wastes, thus making landfilling simple and safe.
Recycling of Residues on Caraiba's Copper Smelter
Authors: da Conceição L. N. , Lima P. A.
Published: May 2018

This paper intends to summarize the steps of the process to produce primary copper from sulphides concentrates, relating to production and destination of industrial residues, making suggestions for research studies.
Evaluation of a Petroleum Refinery Land Treatment Unit Using Unsaturated-Zone Monitoring Data
Authors: Gomes D. C. , Cunha R. C. de A. , Gloeden E.
Published: May 2018

The difficulties in calculating degradation rates of the residues based on theoretical equations and parameters, together with the natural wide soil variability, make the “in situ” monitoring of land treatment units a fundamental management step to both ensure that the residues are being treated by the soil, and to guarantee no risk of groundwater deterioration.

Among the methods usually employed, monitoring the unsaturated zone is one of the most promising, since it is inexpensive, easy to use and to maintain, and can detect failures in the treatment system before the aquifer becomes polluted.

This paper reviews existing methods for unsaturated-zone monitoring, analysing recent monitoring results of a land treatment unit located at the recharge area of an important aquifer of the State of S8o Paulo, Brazil. Recommendations are made in terms of sampling, operational arrangements and management follow-up actions, so as to reduce pollution migration to the subsurface.
Education and Training Relating to Hazardous Wastes in Germany
Authors: Noeke Josef
Published: May 2018

The aim of a study undertaken in Germany was to provide a comprehensive picture and a comparative analysis of existing and planned education and training facilities in relation to hazardous wastes, and to identify educational and training needs of personnel working at hazardous waste facilities or involved in the transportation of hazardous wastes. The educational level of management and supervisory personnel is high. Most operatives have completed little more than basic schooling and have not received any prior training in the handling of hazardous wastes. Training provision varies considerably between works. A high proportion of training is undertaken in-house by training-on-the-job. The educational background of most drivers of hazardous wastes (road transport) is limited to basic school education. A special certificate is necessary for drivers. Most training relates to hazardous substances in general and there is only little training relating to the specific problems of hazardous wastes.
Perspective of Water Resources in Japan and in the World
Authors: Ishibashi Tamon
Published: May 2018

Recently, problems of water shortage are becoming global in both developed and developing countries. This is due to tremendous population increases and also urbanization and industrialization. In this paper, countermeasures for future water shortages are described.
Water Quality in the Priority Watercourses of Hong Kong in Respect of Various Environmental Control Measures
Authors: Kin-chung Ho
Published: May 2018

The water quality in the 12 priority watercourses of Hong Kong was appraised in respect of the various environmental control measures being undertaken. It was noted that water quality in Lam Tsuen River had been significantly improved since 1983. This is attributed to recent resumption of unsewered lands for town development, training of river basin to increase flow, and declaration of the catchment as a “Water Control Zone” under the Water Pollution Control Ordinance. In contrast with the other heavily polluted watercourses to which little abatement measures were implemented, the water qualities of Shing Mun River and Tuen Mun River were slightly upgraded because of the efforts to rectify unauthorized industrial discharges back to foul sewer and provision of interceptors and sewers to villages. The 10 year Livestock Waste Control Scheme enforced on 24 June 1989 was found in parallel with BOD and suspended solids decrease in watercourses. To assess its effectiveness, however, a longer term monitoring is required to get a conclusive result.
Environmental Studies of a Marine Wastewater Discharge from a Sulphite Pulp Mill – Example of a General Study Approach for Marine Industrial Discharges
Authors: Nyholm N. , Bach H. , Birklund J. , Jensen T. L. , Kusk K. O. , Schleicher O. , Schrøder H.
Published: May 2018

The results of comprehensive environmental studies of a marine discharge from a pulp mill is presented to illustrate a general strategy for environmental impact assessment and management of marine industrial wastewater discharges. The strategy includes the following elements: 1) a thorough chemical and ecotoxicological characterization of the wastewater which also involves degradability studies, 2) field monitoring, 3) cage studies with transplanted organisms, 4) hydrographical studies and subsequent dilution and fate modelling of wastewater and wastewater constituents, and 5) quantitative evaluation of the environmental impact as well as predictive evaluations of possible abatement measures by using the combined results of laboratory tests/chemical analyses and dilution/fate modelling to confine areas around the outfall, where adverse effects of various categories can be expected under various environmental settings. Results from field studies are used for comparison/verification. The present study deals with a discharge of unbleached semichemical sulphite pulp effluent which caused oxygen depletion and toxic effects, in particular towards phytoplankton algae. The usefulness of the general study approach was demonstrated and it was concluded in this case that biological field data alone gave limited clues to assessing nor to mitigating the pollution. This was due to the time and spacial variability of the data, and the limited possibilities of distinguishing effects of occasional oxygen depletion from toxic effects. Biological field studies were useful to assess the problem initially, however, and necessary to complement the calculated estimates both qualitatively and to give the study credibility.
Current Situation and Problems of Japanese International Cooperation in the Field of Water Supply and Waste Management
Authors: Yokoo Kazunobu
Published: May 2018

In order to improve public health in developing countries, the United Nations General Assembly decided to launch the International Drinking Water Supply and Sanitation Decade in 1980. But in the first half of the Decade, only 1/3 of the minimum funds required to achieve the Decade target was invested. Therefore, advanced countries, including Japan, are required to expand international cooperation more widely.

In Japan, international cooperation, such as Official Developing Assistance (0DA), is expanding rapidly, and a further interim target was set in the meeting of the ministers related to executing ODA in June 1988. In this target Japan will provide more than 50 billion dollars in total during five years from 1988 to 1992.

In addition to investment, in order to promote the Decade, it is necessary to find solution of problems, for example, raising funds for operation/management cost, development of human resources in developing countries, study of appropriate technology, and training of experts.
Water Quality and Health (Review of the Internationaal Drinking Water Supply and Sanitation Decade)
Authors: Benedek Pál
Published: May 2018

A review is presented of the development of the International Drinking Water Supply and Sanitation Decade (IDWSSD) launched in 1981 and terminated in 1990. Health aspects of drinking water quality in relation to chemical water contamination are investigated and an outlook to the future is presented as far as the tasks of water pollution control are concerned.
Bacteria and Virus Removal from Secondary Effluent in Sand and Red Mud Columns
Authors: Ho Goen E. , Gibbs Robyn A. , Mathew Kuruvilla
Published: May 2018

Column experiments were conducted to determine the improvement in the removal of Escherichia coli, Salmonella adelaide and poliovirus-1 through sands by amendment with bauxite refining residue. The residue (red mud) was neutralized using 5 % gypsum and incorporated to form 30% of the amended sands. In 65 cm long soil columns the removal of the three organisms in the amended sand columns was excellent with over seven orders of magnitude reduction in concentration. Removal in unamended sands was poor. From breakthrough curves in unamended sand columns filtration, die-off and adsorption all appear to play a role in organism removal. The results also show that E. coli can be used as an indicator for contamination, though S.adelaide was less efficiently removed than E. coli. Poliovirus was on the other hand better removed than E. coli.
Selection of Bacterial and Fungal Strains for Bioaccumulation of Heavy Metals from Aqueous Solutions
Authors: Wnorowski Aleksandra U.
Published: May 2018

Eighty strains of fungi and heterotrophic bacteria, isolated from natural water sources polluted with heavy metals, were tested for their bioaccumulation abilities. Metal-resistant strains were first selected in a preliminary step. Preselected cultures were then screened for gold, silver, nickel and cadmium uptake capabilities. A collection of bioaccumulating strains, consisting of 39 strains for the recovery of gold, 9 strains for silver, 28 for cadmium and 22 for nickel, has been established. All the strains selected were able to remove metals tested from diluted solutions (ca. 5 mg/l) to levels below 0.5 mg/l. The maximum uptake capacity of strains was determined in concentrated metal solutions (20 - 50 mg/l). Nine of the strains had saturation values of 100 mg/g dry weight or higher. The importance of pH in passive bioaccumulation process is discussed.
Future Perspectives for the Anaerobic Treatment of Forest Industry Wastewaters
Authors: Lettinga G. , Field J. A. , Sierra-Alvarez R. , van Lier J. B. , Rintala J.
Published: May 2018

Anaerobic treatment systems have been successfully applied over the last decade for combating wastewater pollution loads in the forest industry. However, anaerobic treatment of certain paper mill waste streams is limited by the presence of toxic and recalcitrant organic compounds, high concentrations of sulfur and in some cases high wastewater temperatures. Nonetheless, the future perspectives for the anaerobic treatment of difficult forest industry wastewaters are encouraging. This paper discusses a variety of measures available to anaerobic treatment technologies for dealing with the aforementioned limitations.
The Eutrophication of Pulp and Paper Wastewater Recipients
Authors: Wartiovaara J. , Heinonen P.
Published: May 2018

During recent years the BOD-loading of pulp and paper mill wastewaters has decreased dramatically, due to more effective circulation of water in the processes, and the new activated sludge biological treatment plants. This traditional threat to the environment has been forgotten by the scientists who nowadays are more interested in the role of chlorine compounds discharged from bleaching processes. However, eutrophication due to nutrient loading is still present in many recipients of pulp and paper industry. The BOD-reduction has often been carried out on the cost of adding nutrients, pnosphorus and nitrogen to the purification processes. The biological treatment has also decreased the inhibitive effect of wastewater on the biological production of the recipient water body. Therefore, the eutrophication arises immediatly. The authors worry about the research of nutrients; loadings, development trends and eutrophication effects.
The Concept of Phosphorus Storage Capability and its Implications for Design of Systems for Enhanced Biological Uptake of Phosphate
Authors: Reddy Movva
Published: May 2018

At steady state, the activated sludge process incorporating an anaerobic zone in the process train will have a fixed maximum phosphorus storage capabil ity. The maximum phosphorus storage capability can be related to the maximum phosphorus content the process sludge can incorporate. Data are presented showing that, as long as the sludge phosphorus content value does not exceed the maximum phosphorus content value, the phosphorus removal efficiency of the enhanced biological phosphorus removal process will be independent of the influent phosphorus loading and steady state net sludge yield or mean cell residence time.
A New Procedure for Screening Feasibility of Biological Phosphorus Removal for a Wastewater
Authors: Joh Kang Shin , Astfalk Timothy J. , Englert Christopher J. , Deline Royce R.
Published: May 2018

A batch procedure was developed to allow rapid assessment of applicability of biological phosphorus removal (BPR) to a specific location and its wastewater. This procedure requires anoxic (anaerobic) and then aerobic phases in sequence with enriched cultures and takes approximately 4 to 8 hours. Sodium acetate was used to verify adequacy of available carbon source. This procedure was verified with data from two full scale plants, one using the A/O, the other the PhoStrip processes. Cases for both favorable and unfavorable to BPR are presented.

Monitoring parameters found useful included D.O., orthophosphate, volatile acids, and COD. Volatile acid concentration in particular appeared to be a key element required for BPR. ORP and ATP was found useful to a lesser degree, due to their sensitivity to many environmental factors.

This procedure is also shown to be a useful tool in detecting toxic impacts of the waste water on the cultures responsible for BPR.

It is therefore recommended that this simplified procedure should be carried out in assessing the BPR feasibility in addition to evaluation of conventional parameters.
Purification of Waste Water from the Paris Conurbation: Biological Removal of Nitrogen at the Valenton Purification Plant
Authors: Gousailles Michel , Rovel Jean-Marie , Nicol Roger
Published: May 2018

Stage 1 A of the Valenton purification plant, located to the South West of the Paris conurbation, was designed to treat 15 0,00 0 m3/day, which represents pollution of 500,000 population-equivalents. Due to its situation upstream of Paris, the plant was designed primarily with nitrogen removal in mind. The nitrification-denitrification process with an anoxic zone at the plant inlet was selected.

This paper looks at results obtained over a three-year period. The results achieve expected levels of elimination of both carbonaceous and nitrogenous pollution.

The results achieved in terms of age of the aerated sludge and nitrification kinetics measurements clearly indicate that a nitrification over-capacity exists. However, the denitrification process varies as a function of the concentration levels of organic carbon in the settled water. During periods of rainfall with low BOD5 levels, denitrification is moderately efficient. When the nominal water concentration levels are observed, all the nitrates are reduced in the anoxic zone, and efficiency of the overall nitrogen elimination process reaches 60%.

In any case, and particularly in winter, high sludge concentration levels are required to maintain satisfactory kinetics in the nitrification and denitrification stages.
Extension of a Large Trickling Filter Plant for Combined Nitrogen and Phosphorus Removal (Ejby Mølle Wastewater Treatment Plant, Odense, Denmark)
Authors: Christensen Knud
Published: May 2018

Until 1985, one of the wastewater treatment plants in Odense, Denmark, was a traditional trickling filter plant designed for approx. 275,000 PE. To meet rigorous standards for N and P removal, the plant was extended in 1986-1988, and the extended plant was put into operation in April, 1989. Now, standards have been changed again and are : N < 8 mg/l and P < 0.5 mg/l. These standards must be complied, with before 1992.

The establishing of design criteria based on statistical methods is presented. On the basis thereof, one of various extension alternatives was chosen. This involved keeping the existing primary settling tanks and performing partial nitrification in the existing trickling filters succeeded by a new structure for N and P removal according to the BIO-DENIPHO method. The future extension for contact filtration is mentioned. Basic civil engineering data are described together with design and operating economy. Furthermore, mention is made of the commissioning procedure and the first results.
Energy Saving, High Biological Phosphorus Removal and Improvement of Sludge Settleability on Full-Scale Anaerobic–Aerobic Activated Sludge Process
Authors: Tanaka Toshihiro , Kitagawa Masayoshi , Ohkubo Eiichi
Published: May 2018

An anaerobic-aerobic process was modified from a conventional process used in municipal sewage works to enable phosphorus removal and improving sludge settleability. Research was conducted in three sewage works in comparison with the conventional process. The phosphorus removal efficiency by the anaerobic-aerobic process was higher. The T-P removal ratio ranged 80 - 90% and T-P concentration of the effluent was almost below 1 mg/l, when the average T-P/BOD ratio was 0.04. The removal efficiency of other water quality and excess sludge generation ratio were almost equal in both processes. The anaerobic-aerobic process is not only effective for improving the sludge settleability but also enables wastewater treatment with less quantity of air (approx. 20% reduction). Even including the power consumed for mixing, the anaerobic-aerobic process used up less power (approx. 12%).
Pre-Precipitation Facilitates Nitrogen Removal without Tank Expansion
Authors: Karlsson Ingemar , Smith Gunnar
Published: May 2018

Chemically coagulated sewage water gives an effluent low in both suspended matter and organics. To use chemical precipitation as the first step in waste water treatment improves nitrification in the following biological stage. The precipitated sludge contains 75% of the organic matter in the sewage and can by hydrolysis be converted to readily degradable organic matter, which presents a valuable carbon source for the denitrification process. This paper will review experiences from full scale applications as well as pilot plant- and laboratory studies.
Effect of Anaerobic Stabilization of Activated Sludge on its Production under Batch Conditions at Various So/Xo Ratios
Authors: Chudoba P. , Chevalier J. J. , Chang J. , Capdeville B.
Published: May 2018

The effect of anaerobic stabilization of returned activated sludge in a continuous system on biomass production under batch conditions at various So/Xo ratios was studied. A system without anaerobic sludge stabilization was also operated as a control unit. All experiments were carried out with Toulouse settled wastewater. Biomass growth, substrate removal, oxygen uptake and carbon dioxide production were measured using a quadrupole mass spectrometer (Inficon IQ 200) coupled to a 15-liter fermentor (Biolafitte). The results confirmed that one of the most important parameters in batch cultivation is the initial So/Xo ratio. It was found that anaerobic treatment of activated sludge changed its behaviour during batch cultivation. As a consequence, the observed biomass yield (Yobs) decreased with increasing So/Xo while it remained constant with the sludge from the control unit. In the anaerobic reactor, microorganisms are subject to a physiological shock due to lack of oxygen and food. Under the above conditions, they use ATP as a source of energy. After they are returned to aerobiosis and supplied with exogenous substrate, they rebuild energy reserves at the expense of growth.
Decomposition and Removal of Musty Odor Producing Phormidium tenue by Bacteria and Smaller Animals
Authors: Inamori Y. , Ouchiyama T. , Sugiura N. , Sudo R.
Published: May 2018

A bio-film process such as an aerobic submerged filter process has an effect on the removal of algae and the purification of polluted lake water. In this process, it is thought that smaller animals will play an important role by the way filamentous algae belonging to Phormidium sp., Anabaena sp, and Oscillatoria sp. appear in polluted lake water. Particularly Phormidiumtenue in these filamentous algae produce musty odor which is caused by 2-methylisoborneol 2M1B). Therefore, deodorization has to be conducted in a water treatment plant especially. This study was conducted for the purpose of clarifying the feeding and decompositional capacity of P.tenue by Protozoa Trithigmosotomacucullulus having a mouth structure fitted to the predation of the filamentous algae. The results obtained from this study are as follows. 1) Sludge extract was extremely effective as the growth factor in the growth of T.cucullulus. 2) The optimum growth temperature of T.cucullulus was about 20~25°C and it was necessary to keep an aerobic condition in existence and growth. 3) Filamentous P.tenue among some algae was the suitable food for T.cucullulus. 4) The predation speed of T.cucullulus in the case using filamentous algae as food was about 10~30µ m/sec. 5) The content of chlorophyll a was extremely low in its reduction rate in the system without T.cucullulus, but markedly reduced in the system with T.cucullulus. 6) The turbidity, TOC and DOC in culture medium were markedly reduced in the system with T.cucullulus as compared without T.cucullulus. 7) Investigating the effect of bacteria and T.cucullulus on the removal of the musty odor produced by P.tenue, the removal activity of the musty odor was markedly enhanced by the predation of P.tenue by T.cucullulus compared with bacteria only. 8) T.cucullulus had high capacity for reducing TON through the predation and decomposition of musty odor producing filamentous algae represented by P.tenue. Furthermore the reduction of 2MIB by T.cucullulus was made clear by the method of gas chromatography.
Effects of Heat Treatment on the High-Rate Anaerobic Digestion of Human Wastes Concentrates
Authors: Takashima M. , Sugawara Y. , Ohkawa T. , Ohkubo Y.
Published: May 2018

Effects of heat treatment (100-250 °C, 1 hour) on the solubilization of particulate organic matter and methane production were examined using human wastes concentrates with a view to applying an anaerobic digestion technology to human wastes. In batch studies, the heat treatments above 150 ° C were found to inhibit methane production to a severe degree as the temperature was raised. The addition of powdered activated carbon (PAC) or calcium to the heat-treated concentrates showed a complete reduction of the inhibition. This remedial effect of calcium and measurements on volatile fatty acids make long-chain fatty acids suspected as the inhibitory substances produced. The effectiveness of the heat treatment at 150 and 175 ° C was demonstrated in a continuous study which simulated a high-rate digestion process having a solids separation device, and was conducted at a HRT of 2.5 days and SRT of about 15 days and at a mesophilic operating temperature of 35 ° C : the fraction of particulate substrates solubilized increased about two-fold, and methane production increased 40% when combined with the PAC addition.
Sequencing Batch Anaerobic Reactors for Treatment of a High-Strength Organic Wastewater
Authors: Suthaker S. , Polprasert Chongrak , Droste R. L.
Published: May 2018

Laboratory-scale experiments were carried out to study the performance of sequencing batch anaerobic reactors (SBAR) with respect to substrate removal and biogas production using a synthetic high-strength organic wastewater. The fill:react ratios and the cycle periods of SBAR were varied to study their effects on SBAR performance. The settleability of SBAR microorganisms was tested. Maximum soluble substrate removal of 73% was observed in the SBAR operating with a cycle period of 16 days and a fill:react ratio of 1:3. For a particular cycle period, the fill period was observed to influence the SBAR performance more than the fill:react ratio. Quasi-second order substrate removal kinetics were developed which could describe the SBAR performance satisfactorily.
Sulfur Sources for Hydrogen Sulfide Production in Biofilms from Sewer Systems
Authors: Halkjær Nielsen Per
Published: May 2018

The relative significance of different inorganic and organic sulfur compounds on the sulfide production in anaerobic biofilms grown on domestic wastewater was investigated. The objective was to improve the understanding of microbial processes in dynamic systems and to evaluate the equations used to predict sulfide formation in pressure mains. Biofilms originally grown on domestic wastewater with sulfate as the only electron acceptor were also able to reduce sulfite and thiosulfate. The bacteria preferred thiosulfate to sulfate if both were present and the sulfide production rates increased with a factor of 1.5. Disproportionation of thiosulfate to equal amounts of sulfide and sulfate was demonstrated to take place in the biofilms but only at low concentrations of organic substrates. Some sulfide production from the organic sulfur compounds cysteine and methionine was observed. The rates were, however, insignificant compared to sulfide production from sulfate reduction in wastewater. Biofilm activity measured as the zero order volume constant (kof) was around 0.18 mg SO4-S cm−3 h−1 at 20 °C. If the biofilms were grown on domestic wastewater enriched with sulfite or thiosulfate, kof increased around two times. The sulfide production rate from both sulfite and thiosulfate was found to be considerably higher than the rate from sulfate in these biofilms. The results were modeled using biofilm kinetics which showed that the presence of sulfite or thiosulfate in the wastewater strongly affected the potential sulfide production and could in some cases be a limiting compound besides organic matter. Knowledge about the presence of sulfur compounds other than sulfate in wastewater, e.g. from industrial sources, may therefore be very important to forecast sulfide buildup in sewer systems.
Effects of Substrate Composition and Loading Rate on Methanogenic Process in Anaerobic Fluidized Bed Systems
Authors: Matsumoto Akito , Noike Tatsuya
Published: May 2018

The effects of substrate composition and high volumetric loading rate on the characteristics of substrate removal and biofilm formation in methanogenic phase of anaerobic two-phase digestion were investigated by using laboratory-scale anaerobic fluidized reactors.

First, the effects of substrate composition were studied using three kinds of substrate. The first one was composed of acetic acid, and second and third ones were composed of acetic acid, propionic acid and butyric acid. A small amount of yeast extract and glucose were added to the second and third ones, respectively. In the experiments in which yeast extract or glucose was added to the mixed acid substrate, the substrate removal efficiencies were higher than those in the experiment using acetic acid substrate. The biofilm formation was accelerated by using the mixed substrate to which yeast extract was added.

Secondly, the effects of high volumetric loading rate were studied using acetic acid substrate and mixed acid-glucose substrate, respectively. In both cases, substrate removal efficiencies of the reactors were remarkably high at a loading rate of 30kg COD·m−3·d−1. However, the effluent quality of that reactor to which acetic acid was added was unstable.
Sewage Sludge Composting Process by Static Pile Method
Authors: Ishii H. , Tanaka K. , Aoki M. , Murakami T. , Yamada M.
Published: May 2018

This paper reports the results of experiments on the static pile composting process undertaken in different conditions. The experiments have revealed the following:–In order to compost dewatered sludge with polymer without any bulking agents, we used recycled compost to adjust the moisture content of dewatered sludge.When the moisture content of feed mixture, which was dewatered sludges and recycled composts, was lowered to approximately 50%, the raw sludge could be composted by either natural ventilation or intermittent aeration.–When the BOD of feed mixture was lower than 50 g/kg-DS, the fermentation temperature did not reach 60°C and the moisture content of the mixture was not lowered during composting period.–The required composting time was approximately 50 days for natural ventilation (at an average temperature of 10°C or 24°C) and approximately 35 days for intermittent aeration (at an average temperature of 10°C to 24°C), when the moisture content and the BOD of finished compost was 40% or less and 30 g/kg-DS or less, respectively.–There was a highly positive correlation between the amount of water evaporated and the amount of BOD removed. This result suggested that the amount of water evaporation could be deduced from the amount of BOD removed.
Pilot Plant Test of Electron-Beam Disinfected Sludge Composting
Authors: Hashimoto S. , Nishimura K. , Iwabu H. , Shinabe K.
Published: May 2018

A pilot plant was built to get information on scale-up factors of composting plant of electron-beam disinfected sludge cake. The amount of sludge to be treated was about 500 kg/batch. A Cockcroft-Walton type of electron accelerator and a machine to make thin layer of sludge were used for sludge disinfection. The composting plant consisted of a mixer, a granulating machine, a fermenter with three screw-type mixing blades, and a conveyer system. Efficient composting could be realized also by the pilot plant, by controlling fermentation temperature in the optimum range, by controlling air flow rate and by frequent mixing in the fermenter. From an economic feasibility study based on the results of pilot plant test, capital cost and treatment cost for the process are expected to be lower than those for conventional one, when the treatment capacity of plant exceeds 50 ton/day.
Recent Advances in Water Reuse Research in South Africa
Authors: Odendaal Peter E.
Published: May 2018

Due to limited water resources, water reuse is pursued as a major component of an overall strategy to optimise water use in South Africa. Progress in South African water reuse research, mainly since 1985, is reviewed. In the field of potable reuse research, the topics addressed are epidemiological studies, activated carbon, the microbiology of reclaimed water, bioassaying, and reverse osmosis. Information is provided on the scale of direct agricultural and industrial reuse of purified sewage effluents. Indirect reuse is steadily increasing and research which traditionally addressed direct potable reuse is becoming of equal relevance to indirect reuse. In addition, research becomes necessary on problems which relate specifically to indirect reuse, such as : treatment of algal waters, variation of raw water quality, upgrading of sewage effluent quality, organohalogens, and salination problems. Recent advances in research on internal water reuse by industry focused in particular on membranes and salt removal technology. Cases mentioned are textile dyehouse, scouring, bleaching and mercerising processes; bottle washing; wool scouring; water works wash water; and power station cooling.