ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1992.tb00700.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ABSTRACTThe upgrading of the Ivry‐sur‐Seine water‐treatment plant, which produces potable water for consumption in Paris, is described. This upgrading is based on the slow biological filtration stage. The pretreatment comprises a primary filtration stage through biolite, and a secondary filtration stage through sand, with the possibility of coagulation. The polishing treatment includes ozonation and biological filtration through granular activated carbon. Ozone is produced from pure oxygen, with two ozone generators operating at medium frequency and producing a total of 52 kg/h. A description of pilot tests of the upgraded plant is given, together with the first re

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1992.tb00701.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ABSTRACTThe Environment White Paper entitled ‘This Common Inheritance’, published in September 1990, set out for the first time a comprehensive statement of the Government's environmental policies and its strategy for their implementation. It established a number of principles on which that strategy is based, the key one being that we have a duty to hand on our world in good order to future generations.Another principle is that we must only act on the best available scientific evidence, but if that evidence is inconclusive we must take precautionary action. In applying this principle, the Government is aware of the need to promote scientific research to ensure that the results are given wide and clear dissemination.Everyone is involved in protecting and improving the environment. Many businesses are already investigating ways of reducing damage to the environment that, in fact, make good commercial sense. Local authorities, voluntary groups and individuals can and do h

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1992.tb00702.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ABSTRACTThe sewage from the Greater Athens area is discharged without treatment to the nearby Saronicos Gulf. Recently the Greek government decided to implement an appropriate treatment and disposal scheme, on the basis of a study of the hydrodynamic behaviour of the Gulf and the fate of the discharged pollutants. The study was conducted with the aid of suitable hydrodynamic and water quality models for a number of alternative treatment schemes, ranging from primary treatment to biological treatment with seasonal nitrogen removal, combined with outfalls of different lengths. The results indicate that, although none of the examined schemes will lead to an immediate substantial impact, the scheme that includes biological treatment with seasonal nitrogen removal can eliminate the danger of serious ecological disturbances at a reasonable cost.

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1992.tb00703.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ABSTRACTThe Federal German Water Law of 1976 postulated for the first time that a licence for the discharge of wastewater into public watercourses might only be granted when the wastewater, prior to discharge, is treated according to laid‐down standards. In 1976 it was also decided that for the residual pollution load in sewage‐treatment plant effluents a pollution fee has to be paid.At present three pollution units have to be paidper capitaand annually for untreated domestic wastewater. One pollution unit is assessed at 17/annum, but the price will be increased to 30/annum in future.Since the pollution units encompass COD, nitrogen, phosphorus, heavy metals, and chlorinated hydrocarbon compounds, the pollution unit is a good tool to compare the effectiveness of treatment. For different drainage systems the residual pollution units (per litre and second) can also be calculated for low‐flow condi

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1992.tb00704.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ABSTRACTThe quality of the North Sea has become a topic high on the political agenda. Various claims have been made about quality deterioration but hard evidence has been less available. The paper reviews these concerns, summarizes the scientific evidence and considers the specific contaminants involved, together with estimates of inputs and the available controls. The new initiatives stemming from the Ministerial conferences and the evolving legislation should go a long way towards producing reassurance on the one hand and solutions to real problems on the other.

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1992.tb00705.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ABSTRACTThe design parameters for the City of Copenhagen sewage‐treatment works were established on an experimental basis, and parallel studies of six pilot plants were made over a two‐year period. The key parameters are (a) the rate of nitrification and denitrification, (b) temperature, and (c) BOD: N ratio in the influent. The data obtained from different methods had to be normalized with respect to the fraction of nitrifiers, temperature, and concentrations of substrates in order to achieve consistent results. The results indicated a substantial inhibition of the nitrifiers, i.e. a 20–30% reduction of the reaction rate. Significant savings were made possible by a comprehensive analysis of the temperature condi

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1992.tb00706.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ABSTRACTThe Venice lagoon has been the subject of many studies during recent years directed towards the assessment of its ecosystem and to its environmental restoration, as well as to finding a solution to the problem of the high water condition which affects the historical city centre. This paper presents input and output data of the ecosystem and the present situation concering eutrophication and the pollution of the environment.The analysis of nutrients shows that the biological processes do not occur at the same rate. In fact the variation of phosphate concentrations is wider than that of nitrogen because of the greater biological reactivity of phosphate. The analyses show that it is impossible to determine the dominant eutrophication element in the lagoon, therefore its environmental protection needs action to reduce both nitrogen and phosphorus input.

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1992.tb00707.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ABSTRACTThe European countries where sewage treatment in waste stabilization ponds is largely developed and commonly used are West Germany (more than 2000 operational systems) and France (about 2500 plants). Portugal has over 50 systems at present and will have about 100 by the year 1993. Spain has more than 10 operational plants and in Denmark there are 50 ponds for tertiary treatment. A survey on the present practice in the countries where the process is largely applied, including size of plants, type of ponds, type of influent and design criteria, is presented. It is found that waste stabilization ponds are particularly appropriate for full treatment of effluents from small communities (less than 5000 population equivalent) and for tertiary treatment following conventional larger plants.

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1992.tb00708.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ABSTRACTThe specific problems of the Mediterranean, leading to progressive deterioration of the marine environment as a result of an interplay of climatic, oceanographic and socio‐economic factors requiring cooperative in addition to individual intervention, are briefly described, and areas of concern are identified. Events leading to the adoption of the Mediterranean Action Plan in 1975 by governments of the region, to control the situation, are outlined.The main components of the Action Plan (legal, environmental assessment and environmental management) and institutional and financial framework, together with its gradual evolution from a mainly marine pollution orientated programme into a comprehensive environmental one for the whole of the Mediterranean basin, are described.The Plan's achievements in (i) the progressive reduction of marine pollution at source, (ii) the establishment and enhancement of national pollution monitoring programmes, (iii) the formulation and adoption of common environmental quality criteria and standards, (iv) the creation of alternative scenarios for Mediterranean development, and (v) orientation towards integrated coastal zone planning and management programmes, are discussed, together with technical and political problems in implementation.The role of the Mediterranean Action Plan as a potential model for other regions is appraise

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1992.tb00709.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY