bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization of Nutrient Removal in Stockholm
Authors: Brattberg G. , Reinius L.-G. , Tendaj M.
Published: May 2018

Stockholm was founded at the point where the waters of Lake Mälaren emerge into the Baltic Sea. Lake Mälaren is the water source of the water works of Stockholm. The Lake also receives water from one of the sewage treatment plants. The outlet from the two other sewage treatment plants are in the inner part of the archipelago. During 1968-73 the treatment was improved, after which the phosphorus load to the receiving water significantly decreased. The total P concentration in the surface water has decreased since 1970 and phosphorus has replaced nitrogen as the most limiting nutrient throughout the entire archipelago within 50 km from Stockholm. To further reduce the eutrophication a continued reduction of the phosphorus load is most effective. For the Baltic proper as a whole, where primary nitrogen limitation is present, it is important to reduce the supply of nitrogen to the greatest possible extent.

The treatment plants in Stockholm are located in subsurface rock-chambers. The treatment includes mechanical, biological and chemical treatment. In the mechanical stage the sewage is treated in screens, grit chambers and primary sedimentation. The biological stage is a conventional activated sludgeprocess. For the chemical precipitation ferroussulphateis added before the screens. The sludge is stabilized in anaerobic digesters and dewatered in centrifuges before disposal on farmland.

To meet more stringent requirements on nitrification and nitrogen removal several projects are going on to optimize the nutrient removal. The aim of these investigations is to improve the plants' performance within the existing plant.
Investigation of Nitrification under Storm Water Conditions in the Main Treatment Plant, Vienna
Authors: Schnell G.
Published: May 2018

The enlargement of the Main Treatment Plant of Vienna will be realized as a two-stage plant. The nitrification in the second stage has been studied under different conditions. Because of critical hydraulic conditions during storm flow, the change-over from two-stage operation to parallel operation will be necessary. The effect of different operating conditions in the 2nd stage was studied in a pilot treatment plant and was also simulated with a dynamical model for the activated sludge process. The IAWPRC Task Group Model as modified by W. Gujer (1985) was used here. With the information gained from several practical investigations of the pilot plant, that was operated for the enlargement of the Main Treatment Plant of Vienna, the simulation program could be adapted to the prevailing conditions of the process under investigation. The calibrated simulation program was afterwards used for the following applications:–simulation of dry weather conditions and comparison of experimental and simulated results of the effluent quality with given influent concentrations during the course of the day;–comparison of experimental and simulated results under wet weather conditions;–comparison of a storm event with and without sufficient oxygenation capacity;–effects of a storm event under extremely unfavorable conditions (melting snow increased nitrogen load due to nitrogen in thawing salts for streets).
The Development of Health Guidelines for Wastewater Reclamation
Authors: Shuval Hillel I.
Published: May 2018

Wastewater reclamation has multiple benefits including water conservation and supplementing available water resources, while providing valuable nutrients to the soil. It also contributes to the reduction of environmental pollution, by reducing wastewater discharges to surface and underground water sources. However, potential health problems associated with reuse of wastewater must be carefully assessed and health guidelines developed which effectively reduce health risks and allow for the full social and economic benefits of wastewater reuse to be achieved. This paper reviews the major findings of a World Bank/United Nations Development Program study aimed at evaluating health guidelines for wastewater reuse in agricultural irrigation. This study concludes that early guidelines were often unjustifiably conservative and recommends for unrestricted irrigation of all crops including edible vegetable crops, a microbial quality of the effluent of 1000 fecal coliforms/100 ml and l or less helminth eggs/litre. This microbial standard can be achieved in well designed multi-celled stabilization pond systems which are low cost, robust and simple to operate and are particularly suited to developing countries in warm climates. Alternative advanced treatment technologies can also meet these guidelines. The World Health Organization has recently provided a new impetus to wastewater reclamation in agriculture throughout the world with its official approval of these guidelines.
Removal of Ammonia Nitrogen by the Precipitation Method, on the Example of Some Selected Waste Waters
Authors: Zdybiewska M. W. , Kula B.
Published: May 2018

The topic of the paper was finding a possibility of ammonie nitrogen removal by the precipitation method, on the example of municipal wastes and two kinds of liquid industrial wastes, from a coking plant and Nitrogen Works. The concentrations of this component were of such a kind that they could inhibit both the processes of biological purification and the processes of self-purification, and cause far-reaching eutrophication. The initial concentration was:70 mg/dm3 NH4+ in municipal wastes, 3600 mg/dm3 NH4+ in coking plant wastes, and 16.142 mg/dm3 NH4+ in the liquid wastes from Nitrogen Works. The industrial wastes were diluted to about 156 mg/dm3 NH4+ in the case of coking plant wsates, and to about 170 mg/dm3 NH4+ in the case of wastes from Nitrogen Works.

The precipitants for the municipal wastes were magnesium chloride and 85% phosphoric aoid, and for the remaining wastes also magnesium oxide and phosphoric acid. The reaction time used was 5-30 minutes, the reaction -pH 8.0 : 9.5 and 10.5. The quantities of the precipitants - from 0-200% of the stoichiometric dose. The precipitation of ammonia nitrogen in municipal wastes was most effective with wastes reaction pH about 9.5 and precipitants doses 0.80 g/dm3 MgCl2 and 0.47 g/dm3 H3PO4, and the reaction time of 25 minutes.The effect of ammonia nitrogen removal was 36.0% which corresponded to 100% stoichiometric doses, Whereas an increase of the doses to 200% increased the effects by only 1%. The effects of ammonia nitrogen removal from the coke plant wastes were 470% with the precipitants doses of 4.54 g/dm3 MgCl2 and 1.28 g/dm3 H3PO4 which is 100% of the stoichimetric dose, and after increasing the dose to 200% they were increased by 35%. The degree of ammonia nitrogen removal from the liquid wastes from Nitrogen Works was 62.9% with 100% dose and increased to 81.2% at 200%. The use or magnesium oxide and phosphoric acid for the removal of ammonia nitrogen from industrial wastes in analogical conditions gave much worse results.
Kinetics of Anaerobic Treatment
Authors: Pavlostathis S. G. , Giraldo-Gomez E.
Published: May 2018

A review of the kinetics of anaerobic treatment and the reported values of such kinetic parameters as the maximum specific substrate utilization rate (k), the half-saturation constant (Ks), the microbial growth yield (Y), and the microorganism decay rate constant (b) are presented. The available kinetic information is presented for each subprocess: (a) hydrolysis of complex, paniculate organic materials; (b) fermentation of amino acids and sugars; (c) anaerobic oxidation of long-chain fatty acids and alcohols; (d) anaerobic oxidation of intermediary products (such as short-chain fatty acids); (e) homoacetogenesis; and (f) methanogenesis. The intrinsic rates of each step as well as mass transfer limitations and their effect on the intrinsic kinetics are discussed and areas requiring further research are also identified. Substantial variation exists in the reported values of the kinetic coefficients. This variation is due in part to the variability in mode of operation, environmental and operational conditions in the various studies as well as to the lack of a widely accepted standard procedure for measuring and expressing the biokinetic coefficients. The hydrolysis step is usually assumed to follow first-order kinetics. Whenever the kinetics of the hydrolysis step were studied, they were generally found to be the limiting-step in the overall conversion of complex substrates to methane. With the exception of the hydrolysis step, all other subprocesses of anaerobic treatment have been successfully modeled by following Monod kinetics. The Contois and Chen & Hashimoto model has also been used quite extensively to account for the effect of influent substrate concentration on effluent quality. Based on a brief overview of the observed phenomena related to the kinetics of mass transfer in methanogenesis, it is concluded that with but few exceptions, the evidence for the significance of mass transfer effects in the different reactor configurations is circumstantial and, in some cases, contradictory. Our understanding of the kinetics of paniculate substrate removal in biofilms is still incomplete for engineering applications, and more research is necessary.
UASB-Process Design for Various Types of Wastewaters
Authors: Lettinga G. , Hulshoff Pol L. W.
Published: May 2018

In this paper the design of UASB-reactors is discussed for different types of wastewater, viz. industrial soluble non-complex wastewaters, SS-rich complex wastewaters and domestic sewage. The paper not only deals with the UASB-reactor design, but also with other treatment steps, pre- as well as post-treatment, that are required for as complete as possible overall wastewater purification.
Discussion Report on Reactor Design of Anaerobic Filters and Sludge Bed Reactors
Authors: Tilche A. , Vieira S. M. M.
Published: May 2018

The discussion report of the session dedicated to reactor design is focused on sludge bed reactors and on upflow and downflow anaerobic filters.

The reactor hydrodynamics and their relationship with process efficiency and stability are particularly discussed.

The discussion ends with the formulation of some suggestions of design parameters for project engineers.
Significance and Current Status of Wastewater Reuse in Sicily
Authors: Croce F. , Dardanoni L.
Published: May 2018

In Sicily wastewater is being regarded as a supplemental source of water, especially for agricultural use, which represents the greatest demand at present and in the future. That is because water demand is already approaching total usable resources, and severe shortage is experienced almost everywhere and in every sector. To help overcome possible implementation problems due to high salinity and pollutant concentrations, lack in monitoring capabilities, and emotional public perception of possible health risks, major field research programs have been undertaken, including an experimental station with a pilot plant and a series of field plots.
Mechanisms for the Purification of Effluents with High Nitrogen Content by a Plant Cover of Water Hyacinths (Eichhornia Crassipes)
Authors: Basseres A. , Pietrasanta Y.
Published: May 2018

The mechanisms for the purification of three effluents containing a high level of ammoniacal nitrogen by water hyacinths (Eichhornia crassipes) have been studied. The pollutants (nitrogen, phosphorus, COD and suspended solids) were eliminated by means of the creation of a favourable ecosystem. The liberation of oxygen and the root support provided by the rhizosphere allow a nitrifying bacterial flora to develop. Denitrification can occur when there is no more available nitrogen, namely at the bottom of the pond or when a high BOD mobilises all the available oxygen in the pond. Ammoniacal nitrogen is eliminated by plants (<10%), by nitrification and denitrification (31-68%), sedimentation (2-28%). Phosphorus is eliminated by plant assimilation (3-38%) and precipitation; COD is eliminated by biodegradation and sedimentation (depending on the initial biodegradation of the effluent); the suspended solids (SS) are eliminated (30-90%) by sedimentation and trapping in the roots (26-36%).The purification of effluents containing a high level of ammoniacal nitrogen differs from that of urban effluents in that plants have a lesser role for the elimination of nitrogen.
Wastewater Reclamation and Water Resources Management
Authors: Shelef Gedaliah
Published: May 2018

Wastewater reclamation and reuse are becoming important components of the management of urban, regional and national water resources. Recently, not only countries with chronic water shortage, but also urban areas in temperate climates have considered and implemented wastewater reuse schemes expanding the scope of consumptive uses to include toilet flushing and landscape irrigation, using dual distribution systems and even the reuse as potable waters is being considered and evaluated. Israel is an example of intensive reuse in agricultural irrigation and much experience has been gained in treatment, seasonal reservoirs and establishing quality requirements. The economical justification of wastewater reuse schemes should take into account the overall treatment costs, the ‘environmental and health allowances', i.e. the cost of treatment required even when reuse is not practiced, the benefits of water and the savings in conveyance and pumping. The paper also briefly describes the two largest wastewater reclamation projects in Israel, namely: the Kishon Complex Scheme and the Dan Region Scheme, both aimed at unrestricted agricultural irrigation of all crops.
Reuse of Wastewater from Meat Processing Plants for Agricultural and Forestry Irrigation
Authors: Russell J. M. , Cooper R. N. , Lindsey S. B.
Published: May 2018

Meat-processing wastewaters contain high concentrations of nitrogen, phosphorus and potassium (in this study 40-230 g m−3, 6-35 g m−3 and 20-130 g m−3 respectively), but only low concentrations of heavy metals and other toxic compounds. The nutrients can be recovered by agricultural or forestry irrigation schemes. Application of these wastes to land in excess of plant requirements results in elevated concentrations of organic nitrogen, nitrate, phosphorus, potassium and sodium in the plant material, with nitrate approaching levels toxic to ruminant animals. Excess phosphorus that is applied to the land is precipitated as metal phosphates, and excess nitrogen is partially denitrified, thereby reducing nitrate contamination of ground water. At an experimental pasture site, receiving nitrogen loadings of 1200 kg N ha−1 y−1, denitrification losses averaged about 4% of that applied. Denitrification losses at an experimental forestry site receiving 715 kg N ha−1 y−1 averaged about 27%. Similar losses were observed at a full-scale pasture and forestry irrigation site. Sodium concentrations in meat processing wastewaters could, on occasions, detrimentally affect soil structure and sodium concentrations should be closely monitored.
Winning Support for Reclamation Projects through Pro-Active Communication Programs
Authors: Wegner-Gwidt Joyce
Published: May 2018

The importance of public attitudes in the adoption of reclamation projects has been recognized for some time. We know that people's perceptions and opinions are forces that can mean the difference between survival or extinction…success or failure. This is a reality that must be recognized in the way we plan and implement a reuse program.

While there is no “fool-proof” guarantee of success, a sound pro-active communication and education program is essential. This paper will give some guidelines that you can use to develop a planned communication program that can help you reach technical objectives, obtain public support, and win acceptance for your program.
A Decision Support System for Artificial Recharge Plant
Authors: Masciopinto C. , Palmisano V. , Tangorra F. , Vurro M.
Published: May 2018

The need for artificial recharge plants is the result of the qualitative and quantitative worsening of groundwater resources due to increased pumping and wastewater discharge. This paper described a system that uses artificial intelligence techniques for designing an artificial recharge plant. The system can be used as a training tool for new engineers, as well as an aid in the choices for expert engineers. The system is an application of an expert system shell running on a common p.c. machine. The model is made up of two knowledge bases, respectively denoted as Quantity artificial recharge and Quality artificial recharge. The former is related to the quantitative aspects, such as geology, climate and land availability, the latter to qualitative aspects, such as water use and treatment plant. Two case studies have been implemented in order to confirm the validity of this kind of systemic approach.
Alternative Strategies for the Disposal of UK Estuarine Dredgings
Authors: de Silva M. S. , Fleming G. , Smith P. G.
Published: May 2018

UK research into the beneficial uses of dredged material is being undertaken at Strathclyde University, and includes initiatives in research in the use of dredgings for soil in land restoration projects, and for brick manufacture.

Extensive research in the historically industrial River Clyde in Scotland has shown that pollutant levels do not preclude the use of selected materials for land restoration work. However, limitations are imposed on the use of the material for agricultural or grazing purposes at this time.

Brick manufacture from clay sediments has proved that an attractive, quality product can be provided to the industry although some further testing is required; particularly in the area of atmospheric emissions during firing.

The use of dredged clay for landfill capping and lining also remains a viable possibility.

Economic considerations for each application vary, and require further investigation, however, the options are technically feasible and if employed on a larger scale, can account for a significant proportion of dredged sediments which are currently disposed of at sea.
Towards Integrated Chemical and Biological Monitoring
Authors: Akkerman Ida , Cofino Wim , Colijn Franciscus
Published: May 2018

The monitoring programme of the Public Works Department of the Netherlands has recently been updated and now comprises measurements in water, suspended particulate matter, biota and sediments. Recently, a programme including biological parameters has been developed and implemented. Some examples of results of long-time monitoring series are given. The ‘amoeba' concept has been developed for presentation of biological monitoring results. In addition, biological effects techniques can be used.

Chemical monitoring in different compartments and biological monitoring should be complementary to make a proper assessment of the environmental quality possible. This integrated monitoring is reflected in the ecoplot concept. In the international monitoring programmes this approach of integrated chemical and biological monitoring is also incorporated. To achieve integrated monitoring on a large scale optimization of efforts is necessary, with special attention to quality assurance. Quality management covers the whole process from definition of the objectives for monitoring, optimization of the validity of the data to the reporting of the results.
Review of Offshore Chemical Selection, Use and Operating Procedure to Minimize Environmental Impact
Authors: Vik Eilen Arctander , Berg James D. , Bakke Siri , Lundh Tore
Published: May 2018

The only feasible strategy to minimize pollution from offshore installations is to control the chemicals used. Chemicals are normally only used in response to observed operational problems. They are used in a large number of application areas, and an extensive list of application areas exists. Only a small fraction of chemicals used will eventually reach the marine environment, mainly depending on the water solubility of the chemicals. Since the chemicals discharged are diluted in large quantities of water before and immediately after discharge, the acute toxic effects are considered as not very severe. However, chronic ecotoxicological effects and long-term problems may arise due to accumulation within the marine food chain. Unfortunately, very little information is available on environmental effects of offshore chemicals. However, the harmonizing work which has started within the EEC, requires that new environmental regulations include ecotoxicological data in the classification of chemicals. This important information can be a valuable tool so that operating companies can select alternative chemicals suitable to their operational needs.

There is, however, still a need to continue research to develop a suitable methodology to determine possible long-term environmental effects of low solubility chemicals. This paper introduces a research project initiated by Conoco Norway Inc. late 1989.
The Design and Construction of the “Houtrust” Waste Water Treatment Plant in the Hague
Authors: Sinke M. D.
Published: May 2018

Until a century ago, The Hague's waste water was discharged directly into the city's canals. However, the obnoxious smell and resultant pollution of local waters and beaches then necessitated the implementation of a policy of collecting and transferring waste water by means of a system of sewers. By 1937, it was being discharged, via a 400 metre-long sea outfall, directly into the North Sea. By 1967, however, the increasing volume of waste water being generated by The Hague and the surrounding conurbations called for the construction of a primary sedimentation plant. This had two sea outfalls, one 2.5 km long and the other 10 km long, the former for discharging pre-settled waste water and the latter for discharging sludge directly into the North Sea. This “separation plant” was enlarged during the period 1986-1990.

On account of the little available area - only 4.1 ha - the plant had to be enlarged in two stages by constructing a biological treatment section and a sludge treatment section with a capacity of 1,700,000 p.e. (at 136 gr O2/p.e./day). In order to gain additional space, a number of special measures were introduced, including aerating gas containing 90% oxygen and stacked final clarifiers. Following completion of the sludge treatment section, it has become possible, since 1st May 1990, to dump digested sludge into a large reservoir (“The Slufter”), specially constructed to accommodate polluted mud dredged from the Rotterdam harbours and waterways.

As a result of these measures, there has been a reduction of between 70% and 95% in North Sea pollution arising from the “Houtrust” waste water treatment plant. Related investment totalled Dfl. 200 million and annual operating and maintenance costs (including investment charges) will amount to Dfl. 30 million. Further measures will have to be taken in the future to reduce the discharge of phosphorus and nitrogen. So this enlargement is not the end. There will be continued extension of the purification operations of the “Houtrust” waste water treatment plant.
Exceptional Algal Blooms in Dutch North Sea Waters
Authors: Zevenboom W. , Rademaker M. , Colijn F.
Published: May 2018

During airborne and sea-going surveys, phytoplankton composition, and dynamics as well as relevant factors involved, were studied in Dutch North Sea waters.

The aim of the study is to increase our understanding of phytoplankton dynamics, the impacts of eutrophication and the measures that are taken to reduce the risk of adverse eutrophication effects. In the coastal zone during spring (April), the relative abundance of diatoms is small when compared with the dominant scum-forming species Phaeocystis pouchetii (71-96% of total). Some potentially toxic species, like Dinophysis acuminata. were present predominantly in late summer and autumn during calm weather conditions, in the coastal zone and northern offshore waters (Oyster grounds, Dogger Bank), but in lower concentrations in 1988 and 1989 when compared with 1976, 1979 and 1981. During these three years Dinophysisacuminata blooms gave rise to mussel infection (DSP) in the Dutch Wadden Sea. The potentially toxic species Gyrodinium aureolum showed higher abundance in somewhat deeper waterlayers than at the surface. The presence of the potentially toxic species Gonyaulax(Alexandrium)tamarensis was for the first time recorded in June 1989 in concentrations of ca. 2000 cells per litre. The results further indicate an increase in occurrence of the non-toxic species Noctiluca scintillans in Dutch North Sea waters. Airborne surveys from 1979 onwards demonstrated an annual occurrence of large-scale surface algal blooms with a total annual area coverage ranging from 30 km2 (in 1982) to 1860 km2 (in 1989). Surface algal blooms are predominantly occurring during May through August, and are likely to be promoted by calm sunny weather conditions, with windforce < 5 Bft over several days. Distinct “stratified” algal layers of some dominant species within an algal patch were observed, with Noctiluca in the top layer, and rather low oxygen concentrations below the large surface algal blooms.

Since nutrient availability in Dutch coastal waters has remained rather constant and high over the last 10-15 years, the risks of occurrence of nuisance algal blooms and their adverse effects have remained unchanged.
Modelling Transport Behaviour and Fate of Micropollutants in the North Sea
Authors: Nauta Tjitte A. , de Vries Mindert B.
Published: May 2018

In order to assess the rate and risk of North Sea pollution an integrated modelling framework of physical, chemical and biological models was developed, calibrated and applied to study environmental management strategies.
Groundwaters in Location of Chernobyl Atomic Station and Their Contamination with Radionuclides after the Accident
Authors: Ivanushkina N. I. , Ryabtseva G. P.
Published: May 2018

An evaluation of the influence of the Chernobyl Atomic Power Station (APS) accident upon ground waters of meliorative systems was carried out in a 30 km zone around the station. At the locations where elevation exceeds 5 m, the danger of contamination is minimum in the first 5 years, which is why emphasis was placed on flood plains of river valleys. In flood plains the ground water table (GWT) before the accident varied from 0.2 to 3.3 m with fluctuation from 0.5 to 3 m. Since the accident the systems haven't been in operation, the GWT fluctuation amplitude has decreased, the period of high water table has lengthened, and locations with secondary waterlogging have appeared. The ground waters chemical composition influencing the migration and sorption processes is typical for surplus soil water regions: mineralization is up to 1.0 g/l and pH from 6 to 7.5.

Ground waters are not naturally protected here against radionuclide migration because of the small thickness of aeration zone, the sandy and loamy composition of soils, and their low adsorption.

In 1989 contamination of ground waters with caesium-137 amounted from 2.26 × 102 to 2.413x 103 Bq/m3 and with strontium-90 it was from 37 Bq/m3 to 3.66 × 104 Bq/m3. Radionuclide migration towards ground waters depends not so much on surface contamination intensity as on soil physical and chemical characteristics in the aeration zone. It appeared that there were no direct dependencies between soil surface contamination intensity and that of ground waters contamination. It was noted that the amount of radionuclides depends upon the season.

Analysis of radionuclides concentration in ground waters at different depths, considering soil surface contamination, allows us to define a relatively safe level of GWT with initial contamination; this information contributes to working out the measures on GWT lowering to optimum levels.
Problems of Contamination and Protection of Underground Waters in the Veneto Alluvial Plain (Northern Italy)
Authors: Antonelli R. , Dal Prà A.
Published: May 2018

Rich water-bearing layers within alluvial gravels exist in the subsoil of the Venetian plain (North Italy). These aquifers are mainly fed by dispersion from the rivers crossing the plain. However, the northern belt of the plain, which is the recharge area for the hydrogeological network, is a high-risk area as regards pollution, due to the fact that the alluvial deposits are entirely composed of gravel. This work describes the space-time evolution of some cases of contamination of groundwater by 1,1,1-trichloroethane, 1,1,1-trichloroethylene, and tetrach-loroethylene.
Experimental Investigation of Soil and Ground Water Impacts Caused by Vinasse Disposal
Authors: Cruz R. L. , Righetto A. M. , Nogueira M. A.
Published: May 2018

The problems caused by the residual effluents of wine distilleries for alcohol production are well known. The effluent effects in soil and groundwater are being researched in an area with sugar cane culture which receives; yearly, vinasse by dispersion. Samples are being collected from the soil, the groundwater and the existing creeks in the area Four sub-areas are being monitored separately with a vinasse application of 300 m3/ha year. Experimentation periods in each area have been 0, 5, 10 and 15 years. In the unsaturated zone, samples are being collected at depths of 25, 75 and 150 cm. The chemical analyses include macro and micro nutrients, organic matter and pH. Physical analyses give the soil water retention, hydraulic conductivity and soil particle distribuition. These measurements permit the evatution of nitrogen absorption and fertility changes of the soil. A tendency for the maintenance of soil fertility can be observed but with an elevation of nitrate concentration in groundwater.
Fast Transmission of Nitrates into a Detritic Aquifer (Lepe, Huelva, Spain)
Authors: Gonzaléz A. , Romero E.
Published: May 2018

The nitrate ion has become in recent years extremely prevalent, particularly in the uncarbonated coastal aquifers. This is due to its almost exclusive origin in contamination from agricultural activities, which are especially intense in these aquifers.

This article describes a study of the causes of fast mobilization of nitrates and their almost instant (though very localized) transmission to a detritic coastal aquifer, increasing sharply their percentage in the groundwater and making it undrinkable.

The nitrates originate from solid and liquid nitrogenous fertilizers which are used as manure in the growing of strawberries and citrus fruits by the farmers of the region.

The high amount of fertilizers used, the proximity of many crops to the groundwater wells for urban supply the unsuitable construction of certain wells, and a period of very intense precipitation during November and December in 1989 can be considered among the principal causes of the high content of nitrates in the groundwater in some locations which has obliged the Town Hall of Lepe to declare the water undrinkable for 3½ months.
Chlorinated Hydrocarbons Liquid Wastes: Steam Extraction in Place of Incineration
Authors: Victorelli J. C. , de Andrade P. S. , Elkaim J.-C.
Published: May 2018

A process was devised to extract high levels (2000 ppm) of chlorinated and aromatic solvents from liquid wastes generated by our synthesis processes. It consists basically in introducing the wastes at the top of a column, appropriately filled, and injecting steam at the bottom. The resulting “cleaned” wastes get out of the system with less tham 0.5 ppm. The extracted solvents are absorbed on charcoal filters that can be regenerated.

The system consists in collecting liquid wastes in 3 m3 vessels. After the pH is adjusted, the incoming wastes are heated in two heat exchangers (12 m2 each), then they are injected at the top of a steel column (heights 4.8 m, diameter: 0.6 m ), with a flow of 1.5 m3/h. Steam is injected at the bottom of the column with a flow of 200 kg/h and a pressure of 4 kgf/cm2. The outcoming “cleaned” wastes get out at 100°C and are cooled on the two heat exchangers already mentioned. As can be seen the outcoming wastes are used to heat the incoming ones. Then this solution is collected in a 15 m3 vessel where it is neutralised and cooled to 40/50°C. The vapors of the extracted solvents that get out at 85°C are condensed in a heat exchanger of 12 m2 and the resulting mixture goes into a “F1orentino” vessel to separate the water phase from the solvents. The water phase goes back to the 3 m3 vessel to be mixed with the incoming wastes. The separated organic phase is put in drums. The heat exchangers and the “Florentino” vents are connected to a charcoal filter (0.1 m3 ) where the chlorinated vapors are trapped. This filter is reactivated every three days, and the solvents are again separated in the “Florentino” vessel.
Sanitation of Polluted Soil Areas and Hazardous Waste Management at DSM
Authors: Dijkstra F.
Published: May 2018

Hazardous waste management at DSM, a large chemical company in the Netherlands, relates to two types of activities:sanitation of areas polluted by waste or by operations in the past,management and control of waste, including hazardous waste, from existing operations.

Uncontrolled landfill and operations between 1925 and 1980 at the DSM site led to the creation of several polluted soil areas. In the period from 1987 to 1990 a large controlled landfill was constructed in order to sanitate a number of these places. The costs are about $ 25 million.

In order to deal in a proper way with all solid and liquid waste (except waste water) a central waste management department was established. Measures are being taken to prevent new cases of soil pollution. In accordance with the policy of the Dutch government DSM started a program to minimize waste production.
Industrial Solid Waste in the São Paulo Metropolitan Region – Situation and Perspectives
Authors: Bernardes C.
Published: May 2018

This paper compares and discusses the results of two solid waste surveys done by CETESB, the State of Sao Paulo environmental control agency, in the São Paulo Metropolitan Region. The objective is to get an idea of the accuracy of the results, as well as to establish points that can be considered in an industrial solid waste control policy for the region. The results of the two surveys were consistent with each other. The results were also checked against the amount of non-domestic waste that is disposed of in the sanitary landfills operated by the city of São Paulo, to verify the accuracy of the estimates. It was estimated that in the Region 3,250,000 t/year of industrial solid waste were generated in 1988, 376,000 t/year being hazardous. The recycling ratio is high, 27% for the hazardous waste, but the recycling industry is formed by small companies which are causing a lot of environmental problems. The municipal landfills receive relatively small amounts of hazardous wastes. There are large amounts of these wastes being disposed of in particularly dangerous forms: soil infiltration, impoundments and open dumps. Storage in drums is the second method used to dispose of hazardous wastes. Finally it is recommended that the State authorities take into account the above points in formulating the industrial waste control policy for the Region.
The Incineration of Hazardous Liquid Wastes Generated by the Petrochemical Complex at Camaçari, Brazil
Authors: Cain P. , Neiva M. R.
Published: May 2018

CETREL - Central de Tratamento de Efluentes Líquidos S/A, is responsible for the treatment of the majority of the industrial, wastes generated by more than fifty industries forming the Petrochemical Complex at Camaçari.

The hazardous wastes that cannot be handled by the central biological station have up to this year been stored in variuos types of “containers,” from large tanks, to barrels or disposal trenches.

To meet the requirements of an expanding Complex generating organic-chloride wastes, and to meet more rigorous environment standards, CETREL is implanting a unit for the incineration of hazardous liquid residuals. The plant, intended to start processing wastes in October of this year, will serve principally four companies; CPC, NITROCLOR, SILINOR and QUIMIFINA, which produce liquid chlorinated hydrocarbon residues mixed with nitrogen and silicon compounds.

The incinerator will have a nominal capacity of 10,000 t/year of residue and is designed to treat wastes such as PCBs, BHC, and other pesticides. Residence time in the afterburner is greater than two seconds at. 1450°C, which permits a destruction and removal efficiency of 99.9999%.

With respect to hazardous solid wastes CETREL is presently defining the requirements of the Petrochemical Complex and the surrounding industries to determine the capacity and type of incinerating unit that is most suitable.

This paper presents CETREL's experience which led to the definition and construction of a multipurpose liquid waste incinerator and why it is now planning to build a solid waste incinerator within the next three years.
Alternatives to Industrial Recycling of Phosphogypsum in Brazil
Authors: de Freitas B. J. , Albuquerque P. C. W.
Published: May 2018

Residual gypsum from phosphoric acid plants has been a world-wide problem, concerning the environment, disposal and handling.

In Brazil, till the end of 1989, the phosacid plants had accumulated 30.0 million tonnes of that by-product, corresponding to 5.5 million tonnes of recoverable sulphur, equivalent to US$ 625 million. This phosphogypsum storage increases at a rate of 3.4 million t/a which represents more than a half million t/a of sulphur.

Since 1984, Petrofertil has been coordinating a systematic alternatives evaluation for industrial recycling of phosphogypsum, of which the most viable seems to be sulphur recovery in the liquid form or as sulphur dioxide. These alternatives are briefly examined under technological, economic and calcium co-product diversification and market aspects.

The economic approach considers the investment per produced tonne, the value of co-product market and energy costs. The conclusion tries to define an objective strategic approach concerning to the problem of sulphur recovery from phosphogypsum.
A Study of the Planning of Water Pollution Control for Second Songhua River in China
Authors: Jun Yin
Published: May 2018

The paper takes the Second Songhua River as an object for research and selects Thomas's BOD-DO stable model as the initial structure on the basis of overall investigations and analyses on water pollution in every reach. In view of the characteristics of the river being located at the north, values k’1, k’2 and k’3 in dry season of winter were determined and calculated, and a series analyses have been made. The self-purification ability of the river and the total elimination amount of the main pollutants BOD5 were also calculated. In order to minimize the required cost, we distributed the cost to the main pollution sources, which are to be controlled. We firstly set a cost function of sewage treatment plant by series design and calculated the related cost parameters, then calculated two kinds of optimal distributing models of BOD5 elimination, which were a mathematical model of extreme value of conditions and a matrix mathematical model. Now they have been applied to the practical pollution control plan for the Second Songhua River.
Waste Allocation Models for Risk Assessment of Water Quality Management in a River Basin
Authors: Wen Ching-Gung , Fu Sing-Yih
Published: May 2018

This paper proposes a stochastic water quality management model which considers river flow as a random variable and optimizes waste allocation at point sources. The model is subjected to a chance constrain which can be converted into an equivalent deterministic constrain, and then can be solved by the use of the available deterministic programming algorithm. The allowable discharge loads and degree of required removal of each point source of a river basin are optimized under various degrees of reliability, and can be employed as information for decision making to decide the most suitable treatment degree of wastewater in a river basin.
Rain and Urban Stormwater Quality
Authors: de Luca S. J. , Milano L. B. , Ide C. N.
Published: May 2018

Aspects of the quality of rain and urban stormwater in the Metropolitan Area of Porto Alegre, Brazil, are presented. The results obtained in the survey show a significant occurrence of chemical and acid rain in the area. The data on urban drainage quality show that, besides contamined rain, other sources of pollution such as poor garbage collection, car exhaust, crankcase leakage, and badly done street cleaning, contribute to increase the pollution of the receiving body of water, the Guaiba river.
Water Quality and Health
Authors: Kreisel W.
Published: May 2018

Water quality can affect human health in various ways: through breeding of vectors, presence of pathogenic protozoa, helminths, bacteria and viruses, or through inorganic and organic chemicals. While traditional concern has been with pathogens and gastro-intestinal diseases, chemical pollutants in drinking-water supplies have in many instances reached proportions which affect human health, especially in cases of chronic exposure. Treatment of drinking-water, often grossly inadequate in developing countries, is the last barrier of health protection, but control at source is more effective for pollution control. Several WHO programmes of the International Drinking-Water Supply and Sanitation Decade have stimulated awareness of the importance of water quality in public water supplies. Three main streams have been followed during the eighties: guidelines for drinking-water quality, guidelines for wastewater reuse and the monitoring of freshwater quality. Following massive investments in the community water supply sector to provide people with adequate quantities of drinking-water, it becomes more and more important to also guarantee minimum quality standards. This has been recognized by many water and health authorities in developing countries and, as a result, WHO cooperates with many of them in establishing water quality laboratories and pollution control programmes.
Detection of Human Rotaviruses in Fresh and Estuarine Waters by Dot-blot Hybridization
Authors: Nasser Abidelfatah M. , Estes Mary K. , Metcalf Theodore G.
Published: May 2018

This study was conducted to evaluate the suitability of dot-blot hydridization for detecting rotavirus in fresh and estuarine water samples using cloned DNA of genome segment 6 of human strain Wa and simian SA-11 rotaviruses. Probes of Wa and SA-11 cross-hybridized with heterologous RNAs of SA-11 and Wa rotaviruses under low stringency conditions. However, cross-hybridization reactions were minimized or eliminated under high stringency conditions, while homologous reactions were not affected. Wa probe did not react with representatives of the major enterovirus groups or hepatitis A virus. Hybridization detection sensitivity was not affected by organic material present in waters or proteinaceous material of eluents. Hybridization using cDNA of Wa rotavirus was found to be more sensitive than either Rotazyme ELISA or electron microscopy for detecting rotavirus in stool specimens. Dot-blot hybridization using cDNA of genome segment 6 of Wa rotavirus was found to be more sensitive than SPRIA for detecting rotavirus in estuarine and fresh water samples. Only 9 out of 54 (18.5%) estuarine and fresh water samples were positive by SPRIA, whereas dot-blot hybridization with Wa probe resulted in 21 out of 54 (38.8%) positive samples. One out of 20 (5%) stool samples and 23 out of 54 (44.6%) estuarine and fresh water samples were found to be positive by a pBR-322 plasmid probe. These results indicate that pBR-322 and related plasmids are present in high frequency in fecally polluted waters. Although different numbers of positive results were found with Wa and pBR-322 probes, more research is required to ascertain that hybridization reactions with such plasmids do not occur when using cDNA rotavirus probes.
Supercritical Water Oxidation – Wastewaters and Sludges
Authors: Shanableh Abdullah , Gloyna Earnest F.
Published: May 2018

Environmental contaminants can be eliminated through the use of SCWO techniques. A comprehensive supercritical oxidation (SCWO) research laboratory, including bench and pilot-scale facilities has been developed. High temperature and pressure systems slightly less than and greater than supercritical water conditions can be used for the efficient destruction of waste biological treatment plant sludges, acetic acid, 2-nitro phenol, 2,4-dimethyl phenol, phenol, and 2,4-dinitro toluene. Above 400 °C, near complete destruction of sludge and transformation compounds such as acetic acid can be achieved with relatively short residence times. Ammonia and acetic acid are transformation products in the SCWO of biological treatment plant sludges. Acetic acid produced from the oxidation of sludge is oxidized rapidly at supercritical temperatures, 400 °C to 450 °C.
Methods to Set Soil Cleanup Goals to Protect Surface and Ground Water Quality at Hazardous Waste Sites
Authors: Huggins A. , LaGrega M. D.
Published: May 2018

Hazardous waste management programs in the U.S. have focused on the cleanup of sites so that environmental standards are met and environmental and human health risks will be mitigated. The programs involve the cleanup of abandoned sites as well as existing industrial facilities. In many cases the criteria for cleanup at these sites are based on the protection of ground or surface water resources. Criteria can be based on 1) background levels in the surrounding environment, 2) national or state standards set to protect surface and ground water uses, and/or 3) site-specific standards based on risk assessment techniques. Methodologies for the derivation of cleanup goals in the U.S. vary between regulatory programs. Media-protection standards or trigger levels are the simplest to manage, but their appeal can be diminished if they lead to unnecessary cleanup activities. Such simple systems also fail to deal with any unique site characteristics or exposure patterns. Partly in response to such concerns, some U.S. programs depend upon risk assessment to set site-specific cleanup goals. This paper provides several case studies where various approaches to developing cleanup goals have been applied, and discusses the advantages and disadvantages of the different approaches.
Factors Explaining Sediment Concentrations of 16 Elements in 28 Japanese Eutrophic Lakes
Authors: Fukushima T. , Amano K. , Muraoka K.
Published: May 2018

To understand lake sediment environments, the concentrations of 16 elements in sediments and suspended particulate matter (PM) from 28 Japanese eutrophic lakes were analyzed. Use of some statistical analysis permitted them to be grouped into a) alkali metals and alkaline earth metals (Na, Mg, Ca, Sr, K), b) elements originating from soil particles or rock (Ti, Fe), c) elements having significant anthropogenic inputs (P, Cr, Cu, Zn), d) organic carbon and nitrogen. The ratio of PM to sediments decreased in the order c), d), a) and b). With the aid of a simple conceptual model, some significant factors were successfully shown to explain the sediment concentrations of respective groups: a) salinity of the lake water, b) Ti concentration in PM, which reflects the arrival rate of soil particles at the mid-point, c) TP concentration in lake water representing the anthropogenic load, d) chlorophyll a concentration in lake water divided by the area ratio of drainage to lake surface.
Biological Bleaching of Wood Pulps – A Viable Chlorine-Free Bleaching Technology?
Authors: Kirkpatrick Neil
Published: May 2018

Biobleaching of wood pulp is bleaching caused by the activity of certain microorganisms. The term “biobleaching” is sometimes also used to describe enzymatic bleaching. In both cases, the aim is to effect bleaching without the use of chlorine, thus minimising the discharge of potentially toxic and mutagenic chlorinated organics in bleach plant effluents. In this paper, the current status of biobleaching research is reviewed and factors necessitating further investigation before biobleaching might be viable on a commercial basis are highlighted.