摘要:

ABSTRACTNew UK regulations from June 1989 will enforce the provisions of an EC Directive on the use of sewage sludge in agriculture. Among the requirements is one that sludge should be treated before surface application to farmland. Treatment is needed to reduce ‘significantly’ both the fermentability of sludge and the health hazards resulting from its use on farms. In the UK, the health risks associated with sludge are principally beef tapeworm (Taenia saginataand cysticercosis) and Salmonellosis. Research on the effects of various treatment processes on pathogens has shown the conditions required to produce a 90% reduction ofT. saginataandSalmonellae.This information has been used as a basis for describing a list of ‘effective’ treatment processes and process conditions ‐ as given in a new UK National Code of Practice on the use of sludge in agriculture. The uprating of existing treatment plant, or provision of new plant, to meet the Code of Practice recommendations could involve significant costs. A comparison of the economics of each of the ‘effective’ treatment processes for different population sizes shows a fairly wide range of net present costs. In general, increased sludge quality means in

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1990.tb01551.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTFish farms are continuing to grow in numbers and in size. They cause concern because of their location in areas of high‐quality water, frequently in the headwaters where there is little dilution for large volumes of effluent. This jeopardizes the water quality, and may affect the ecology of the river ‐ migratory fish in particular.The use of chemicals for the treatment of disease is causing concern, particularly if the river is used for potable abstraction. Little information is available on the low‐level effects and the detection of chemicals such as antibiotics and hormones. The chemicals are not controlled nationally, the only control being through consents.With the continued growth of the fish‐farm industry, problems are likely to increase in the future unless a responsible attitude to their development is

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1990.tb01552.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTThis paper describes research in areas where the occasional failure to meet the EC standard for lead in drinking water is due to the presence of particulate lead. A method is described to disinguish between soluble, particulate and colloidal lead in tap water, and characteristics are given of water sources which are most likely to suffer from this form of lead problem. At least two types of particulate (insoluble) lead in tap water have been identified, and some factors are discussed which cause the occurrence of both types. Interim results of trials are presented, with remedial actions.

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1990.tb01553.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTThe paper reviews the pollutant emissions from the incineration of waste. The emissions to the atmosphere are discussed in detail in terms of odour, dust and litter, particulate metals and salts, and chlorine, fluorine, sulphur and nitrogen compounds. The products of incomplete combustion of waste are reviewed with particular emphasis on polycyclic aromatic compounds, dioxins and furans. The pollution arising from contaminated wastewater and ash is discussed. The sampling and analysis of the pollution emissions are also reviewed.

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1990.tb01554.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTTwelve methods of storage yield estimation available in the hydrological literature are identified. Eight of these are then selected for use in a comparative study where the objective is to select those methods with least bias and standard error. A time‐series model is used to generate a population of 3000 years of synthetic flow data for one set of Irish conditions. The true population storage volume for each level of yield and return period is obtained by counting, and the storage estimates obtained using the eight selected methods are compared with the population volume on the basis of bias and standard error. The Modified Gould and Behaviour Analysis Methods were found to have least bias and the lowest standard error. These methods are therefore recommended for use, in conjunction with simulation methods of investigating storage requirements, for Irish and similar climatic condition

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1990.tb01555.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTThe conference of Ministers representing North Sea littoral states, held in November 1987, agreed certain initiatives to reduce inputs of potentially dangerous substances to the North Sea from land‐based sources. The UK Government has responded by proposing reductions of substances on a ‘red list’, selected on the basis of ecotoxicity, persistence, potential for bio‐accumulation and estimated concentration in the environment.This paper describes the approaches which have been used in selecting candidate substances for the red list and other priority‐setting exercises, highlighting the difficulties presented by the lack of data for individual chemicals and the use of default values.The estimation of input loads via rivers and direct discharges is discussed, with particular reference to monitoring requirements and analytical performance

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1990.tb01556.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTThe performance of slow sand nitration can be; substantially improved by the application of a non‐woven synthetic fabric layer to the surface of the sand. By means of pilot‐scale experiments, using the i River Thames as the source water and pretreatment by sludge blanket clarifiers, the comparative performance of fabric‐protected slow sand filters has been evaluated over an eight‐month period. Under conditions designed to simulate poorly‐controlled pretreatment, a correctly‐specified fabric type, configuration and thickness can extend filter run times by a factor of 3–5 compared to a conventional slow sand filter. Furthermore, this can be achieved, together with the avoidance of any significant change in the hydraulic behaviour of the underlying sand, thereby avoiding the need to remove and clean sand. Fabric washing is relatively simple

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1990.tb01557.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTIn January 1988 the city of Truro experienced a severe flood from the River Kenwyn. The return period of this event was initially estimated at 350 years using the methodology recommended in the Flood Studies Report1. In October of the same year a second flood, of even greater magnitude, occurred. The subsequent investigations employed a variety of flood frequency estimation techniques including one which uses descriptive information on the history of flooding, obtained from local newspapers and journals, in addition to recent flow records. The return periods of the two events were reassessed to be 50 and 100 years respectively. This flood frequency behaviour was found to be markedly different from the regional average for the South West of England.

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1990.tb01558.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTRecords exist of the flooding of Venice from the days of the Republic. During the last century flooding incidents have become more severe due to subsidence of the city and rising water levels in the Adriatic. Calamitous flooding occurred in 1966, and two devastating floods were experienced during the last decade. The ‘Special Law for Venice’, enacted by the Italian Parliament in 1973, paved the way for a competition to devise a flood‐prevention scheme.A consortium of Italian contractors, who were commissioned to submit proposals for the implementation of the scheme, designated Technital Spa of Verona to carry out the design of the flood‐prevention works and improvements within the lagoon. This resulted in the design of three movable barrages to seal off the Venice lagoon in the event of a flood. The construction of a full‐size gate and caisson (the prototype of the eighty gates forming the barrages) was subsequently authorized.This paper describes the experimental module containing the buoyant gate and its caisson, its novel features as well as some of the events leading up to its design and con

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1990.tb01559.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTThe large accumulations of putrescible materials which comprise a modern landfill have potential to generate quantities of highly‐polluting leachate as they decompose anaerobically over many years. Operators must control and manage such leachates if severe environmental impacts are to be avoided.Progress has been made in the development of simple, automatic, robust and reliable treatment systems as full‐scale plants have been installed at UK landfills during the last decade, with the assistance of Department of the Environment funding to allow detailed monitoring of particular schemes.This paper describes the results from a site where such a plant was installed in 1985 to overcome a particularly difficult leachate problem, where high ammonia concentrations had posed a threat to local watercourses. More than two and a half years' results of detailed operational data are presented, and particular emphasis is given to the reduction of ammonia concentrations to low val

ISSN:1747-6585    

DOI:10.1111/j.1747-6593.1990.tb01560.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY