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An investigation of chloride Ion levels In coarse colliery discards was undertaken because modem British Coal practice is to restore discard tips and lagoon embankments at an early stage in construction, commonly before much leaching has taken place. High chloride ion concentrations result in physiological drought and the failure of vegetation cover. Sites at two collieries were studied using grid and traverse (depth) sampling procedures. Results Indicate downward leaching of chloride ions into the embankment during Winter months and an increase in chloride levels towards the surface of the discard during dry, summer months. Salt hotspots occur on embankment surfaces during Summer months. These high chloride/sulphate concentrations represent the desiccation of seepages, most of which are related to embankment construction inadequacies, rather than to lagoons incorporated into the structure. Chlorides within the discard originate from formation waters intimately associated with Coal Measures sequences. In the eastern coalfields in particular, high chloride ion concentrations in the coal and waste rock from deep underground excavations are not removed by the coal washing processes. Consequently, they are retained in fresh colliery discards. Seasonal movements of chloride ions are associated with an increase In (negative) suction pressures within the near-surface layers of a colliery embankment. Suction pressures were monitored experimentally in two experimental tips and in the field at a third colliery site (Bilsthorpe Colliery). On an annual basis, suction pressures become operative early in April, reversing to residual negative or small positive pore pressures in mid-September. The leaching of chlorides from discard embankments is a function of the drainage characteristics of the materials and in clayey discards leaching to low levels is shown to take 5 to 7 years. Hotspots do not decrease significantly. The results of the present investigation can be applied to current embankment restoration schemes. In particular, the sowing of an embankment during the Autumn window, when electrolytes move downwards into the structure, would enable young vegetation to become established before being subjected to the higher Summer chloride concentrations. Hotspots require individual field drainage treatment.

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Nuisance growths of Cladophora have been associated with eutrophication. A review of the literature, however, reveals a scarcity of relevant experimental growth studies. Sampling experimental streams reveals that the addition of sewage effluent to good quality water alters the flora from that dominated by Potamogetan crispus to one dominated by CLadophora. Spatial and temporal differences in biomass of taxa present are discussed in the context of accompanying physicochemical data. In laboratory batch culture, growth of unialgal C. glomerata was accompanied by elevation of medium pH - considered largely responsible for the poor growth in such culture. However, appropriate experimental conditions and indices of growth were selected and the effects of various herbicides assessed. Diquat and terbutryne were shown to possess algicidal activity towards Cladophora. A closed continuous culture apparatus was developed: growth proceeded through lag, logarithmic and linear phases. Inoculum size and medium flow rate had significant effects on growth, and were standardized. In continuous culture, specific growth rate increased linearly with increased duration of light per day, up to 24 hours, and increased light intensity, up to 6000 lux - the highest intensity tested. Comparison of field and laboratory results suggests that ammonia toxicity is attributable to the undissociated form. In the laboratory, 185 µg/1 undissociated ammoniacal nitrogen reduced specific growth rate to 50% of that at 10 µg/1 undissociated ammcniacal nitrogen. 0.077-1.057 mg/1 NO2-N had no significant effect on growth. 7.2-15.2 mg/1 NO3-N had no significant effect on specific growth rate. Neither was any nitrate/phosphate interaction significant. At 4.9 mg/1 PO4-1, specific growth rate was only 48% of that at 1.9 g/1 P04-P. The critical medium PO4-P concentration was < 0.1 mg/i. Specific growth rate was reduced to 50% of that in natural water by 0.036 mgCu/l, 0.070 mgzn/1 and 1.03 mgPb/l. Metal uptake was evaluated.

The research concerned the assessment of the pathways utilized by heavy metal pollutants in urban stormwater runoff. A separately sewered urban residential catchment of approximately 107 hectares in Chelmsley Wood, north-east Birmingham was the subject of the field investigation. The catchment area, almost entirely residential, had no immediate industrial heavy metal input, however, industry was situated to the north of the catchment. The perimeter of the catchment was bounded by the M6 motorway on the northern and eastern sides and was believed to contribute to aerial deposition. Metal inputs to the ground surface were assumed to be confined to normal suburban activities, namely, aerial deposition, vehicular activity and anthropological activities. A programme of field work was undertaken over a 12 month period, from July 1983 to July 1984. Monthly deposition rates were monitored using a network of deposit cannisters and roadside sediment and soil samples were taken. Stormwater samples were obtained for 19 separate events. All samples were analysed for iron, lead, zinc, copper, chromium, nickel and cadmium content. Rainfall was recorded on site with additional meteorological data obtained from local Meteorological Offices. Use was made of a simple conceptual model designed for the catchment to substantiate hypotheses derived from site investigations and literature, to investigate the pathways utilized for the transportation of heavy metals throughout the catchment.

The research examines the deposition of airborne particles which contain heavy metals and investigates the methods that can be used to identify their sources. The research focuses on lead and cadmium because these two metals are of growing public and scientific concern on environmental health grounds. The research consists of three distinct parts. The first is the development and evaluation of a new deposition measurement instrument - the deposit cannister - designed specifically for large-scale surveys in urban areas. The deposit cannister is specifically designed to be cheap, robust, and versatile and therefore to permit comprehensive high-density urban surveys. The siting policy reduces contamination from locally resuspended surface-dust. The second part of the research has involved detailed surveys of heavy metal deposition in Walsall, West Midlands, using the new high-density measurement method. The main survey, conducted over a six-week period in November - December 1982, provided 30-day samples of deposition at 250 different sites. The results have been used to examine the magnitude and spatial variability of deposition rates in the case-study area, and to evaluate the performance of the measurement method. The third part of the research has been to conduct a 'source-identification' exercise. The methods used have been Receptor Models - Factor Analysis and Cluster Analysis - and a predictive source-based deposition model. The results indicate that there are six main source processes contributing to deposition of metals in the Walsall area: coal combustion, vehicle emissions, ironfounding, copper refining and two general industrial/urban processes. |A source-based deposition model has been calibrated using facctorscores for one source factor as the dependent variable, rather than metal deposition rates, thus avoiding problems traditionally encountered in calibrating models in complex multi-source areas. Empirical evidence supports the hypothesised associatlon of this factor with emissions of metals from the ironfoundry industry.

The thesis is concerned with relationships between profit, technology and environmental change. Existing work has concentrated on only a few questions, treated at either micro or macro levels of analysis. And there has been something of an impasse since the neoclassical and neomarxist approaches are either in direct conflict (macro level), or hardly interact (micro level). The aim of the thesis was to bypass this impasse by starting to develop a meso level of analysis that focusses on issues largely ignored in the traditional approaches - on questions about distribution. The first questions looked at were descriptive - what were the patterns of distribution over time of the variability in types and rates of environmental change, and in particular, was there any evidence of periodization? Two case studies were used to examine these issues. The first looked at environmental change in the iron and steel industry since 1700, and the second studied pollution in five industries in the basic processing sector. It was established that environmental change has been markedly periodized, with an apparently fairly regular `cycle length' of about fifty years. The second questions considered were explanatory - whether and how this periodization could be accounted for by reference to variations in aspects of profitability and technical change. In the iron and steel industry, it was found that diffusion rates and the rate of nature of innovation were periodized on the same pattern as was environmental change. And the same sort of variation was also present in the realm of profits, as evidenced by cyclical changes in output growth. Simple theoretical accounts could be given for all the empirically demonstrable links, and it was suggested that the most useful models at this meso level of analysis are provided by structural change models of economic development.

(1) The major aim of this work was to provide a scientific basis for the management of St. Cyrus National Nature Reserve. The Nature Reserve itself consists of cliffs, sand-dunes and a salt-marsh. Most of the research was focussed on the latter two. The approach to the research was partly descriptive, partly experimental. (2) A description of the salt-marsh and sand-dune vegetation was obtained by means of classification and photointerpretation. The landform changes around the N. Esk estuary were mapped from aerial photographs (maps 1a and b). Six communities were described and mapped from the salt-marsh: a Festuca rubra-community, a Juncus gerardii-community, a Scirpus maritimus-community, a Relict Puccinellia or tall herb-grassland community and an open and closed Elymus-Ammophila -community on deposited sand (map 2). These communities were ranked into the Braun-Blanquet phytosociological classification system. The distribution of the surviving salt-marsh flora was mapped (map 3) and its distribution related to environmental conditions. The successional development since 1951 was related to the decrease in flooding frequency, a consequence of the landform changes in the area; most affected by the desalination and desiccation processes was the former Puccinelietum maritimae which developed into the tall herb-grassland or Relict Puccinellia-community, characterised by pasture and ruderal species. The future development of the salt-marsh vegetation largely depends on the dynamic processes around the N. Esk estuary. (3) A polythetic divisive classification method, TWINSPAN, led to the identification of the sand dune communities. The following sequence of communities was described (map 4): foreshore colonisation, mobile Ammophila-dune, Ammophila-dune in its stabilising and early stages of fixation, tall Arrhenatherum-grassland and grazed dune pasture. The last stage of the successional series is represented by dune scrub dominated by Ulex europaeus. The lichen-rich grey dune community, an anomaly in the present series, probably represents a deflection of the successional trends. The most important trends observed since 1951 were the stabilisation and fixation of the Ammophila-dunes, the development of tall Arrhenatherum-grassland and Ulex-scrub. The decrease in rabbit numbers after the advent of the myxomatosis in 1954 was partly responsible for these changes. (4) The effect of the removal of the rabbit grazing factor was assessed from rabbit-proof exclosures. Principal Components Analysis proved to be an effective means of detecting time-related trends in the vegetation. The exclusion of rabbits from the grazed dune pasture led to the development of taller vegetation, a significant increase in the cover of Festuca rubra and a small but significant decrease in species richness. Excluding rabbits from the grey dunes resulted in a decrease of annual species. A more detailed study of the grey dunes revealed that the variation in this community was related to the disturbance by man and/or rabbits. (5) About 18 km of paths, and tracks, were mapped from the Nature Reserve (map 5). This included 3 km of tractor tracks created by the fishermen. The remaining 15 km represented footpaths and old tracks. Nearly all of these paths and tracks were concentrated in the dunes which had a path, density of 739 m/ha. A general description of the vegetation and the amount of erosion revealed weak points in the dune system. Vegetation recovery on a footpath in the dunes took approximately two years. Camping on the dune pasture appears to favour a particular assemblage of species. Removal of camping pressures had initially little effect on the dune pasture vegetation. (6) Experimental burning of a part of the Arrhenatherum-grassland was followed by a rapid recovery of the dominants during the first season after the fire. Recolonisation by mosses started in the second season after the fire. Complete recovery of the vegetation is to be expected three or four years after the burning. Fire also appeared to have a rejuvenating effect on Ammophiia arenaria. (7) Bracken and gorse have been invading the dune pasture to the detriment of its attractive and rich flora. Experimental control of bracken with the herbicide asulam demonstrated that spraying with asulam was a safe method for controlling bracken on the Nature Reserve. Application of asulam at the recommended rate of 4.4kg active ingredient per ha resulted in an average reduction of bracken of 79% in the first year after treatment and 58% reduction in the second year after treatment. In the second year after treatment an increase in the cover of Arrhenatherum elatius and a decrease in the cover of bracken litter were observed. The rate of spread of gorse was estimated from maps made from aerial photographs and appeared to be exponential. Gorse-cleared sites in the Arrhenatherum-grassland and dune pasture were recolonised mainly by vigorous Holcus lanatus.