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This research involved survey, laboratory and field studies. First, an evaluation of the present status of intestinal parasitic infections was made in the Jordanian population. Second, laboratory investigations were conducted on the development of a new technique to detect the viability of Ascaris eggs. Third, field studies were carried out to investigate the survival and occurrence of indigenous parasite eggs and indicator pathogens in domestic waste sludges in Jordan. Field investigations were also conducted on the effect of open natural drying beds on the inactivation of parasite eggs and bacterial pathogens. The results of this study and a survey of available literature indicated a need for a universally accepted definition of a "viable" Ascaris egg. A staining technique for detecting Ascaris egg viability was developed in conjunction with research studies of Ascaris eggs in sludge. The vital stain Crystal violet showed high correlation with the incubation method, and was more precise than the other stains tested. Crystal violet showed the best spontaneous detection of changes in egg viability and, within certain limits, it was found to be a strong indicator of the state of egg viability; furthermore it did not show any evidence of toxicity. In the staining method, Crystal violet stain is added directly to an egg preparation and observations are then made immediately using a light microscope. The results are available in only 10 minutes, compared to the 30 days required for the Incubation method. Since only stained or unstained eggs were observed, the method is less subjective than the Incubation method. In order to evaluate the versatility of the staining method, the effect of UV light and temperature was also investigated. The ultimate disposal of domestic wastewater treatment plant sludges has been recognised recently as a problem in Jordan, and has never previously been investigated from the point of view of pathogen survival and transmission. This study showed that a huge volume of sludge (36,600 m3 dry weight basis) accumulated from 1985-1993 in six anaerobic ponds, now requires desludging, treatment and disposal. Anaerobic pond sludges displayed some physico-chemical similarities to digested primary sludge. This research concludes that sludge drying beds can be an effective method for inactivating parasite eggs, particularly in warmer geographic locations, and thus the treated sludge can be considered safe in terms of parasite transmission for application to agricultural land. Ascaris eggs had degenerated when the percentage of total solids was recorded as more than 88%; this took a shorter time in sand than in gravel drying beds. The inactivation of Ascaris eggs in drying beds is probably due to more factors than desiccation alone. Temperature, oxygen content, solar radiation, exposure time, mould activity, type of sludge, type of media etc., may also affect survival of the eggs. Anaerobic pond sludge bacterial counts showed higher resistance to desiccation and treatment conditions in drying beds compared with oxidation ditch sludge.

Acidogenic activities, as part of anaerobic digestion, have been discovered since the beginning of the century. Still it was mid '60's when it was initially stated in the literature that engineered phase separation would increase stability in anaerobic reactors and possibly increase substrate digestion rates. Pioneering research in the early '70's, with the first report on two-phase digestion of sludges, came as practical proof of those past assumptions. Today phase separation is a proposed option to single-stage digestion, due to the many advantages over conventional operation. Such an application utilises the different steady-state kinetic rates in the two main bacterial groups in anaerobic digestion. Furthermore, the process benefits through differences of these two groups, in relation to changing conditions. The overall result of two-phase applications is lower operational costs, with higher treatment efficiency and energy recovery. In recent decades much research work has created a positive image for two-phase applications, compared to single-stage digestion. Still until today, many consultants in the field of anaerobic processes, are not provided with sufficient knowledge to utilise fully the potential of the twophase process. It seems often the case that leading companies in the design and construction of anaerobic plants, will design pre-acidification tanks without understanding the uncontrolled acidogenic activities taking place in them. Therefore, design is based on an empirical approach or lack of knowledge of the effects of reactor design parameters on acidogenesis. Although data on acidification of industrial wastewaters is in high demand, few studies have been carried out previously to assess the effects of the whole range of engineered reactor design parameters on acidification of industrial wastewater. Out of these few studies none has examined the whole range of design parameters on freshly collected agro-industrial wastewater. Apparently, most studies have been made on synthetic versions of wastewaters or simple compounds. Additionally since the '80's anaerobic processes have been extensively applied for the treatment of agro-industrial wastewaters. Obviously the extent of information provided from this study, was particularly required to clarify many issues related to the role of acidification in the pre-treatment of agro-industrial wastewaters. The research project presented in this thesis is based on a 3-year laboratory study. Some early conclusions of this study have been presented previously in a number of papers on preacidification discussing design guidelines, advantages of two-phase applications and methods to assess acidogenesis. This thesis is focused on the complete range of findings related to the effects of various reactor design parameters, namely: temperature (from ambient to thermophilic); pH (from 4.5 to 7.0); HRT (from 6 to 12 hrs, with and without variations in the organic loading rate); addition of commercial micro-nutrients; and mixing the reactor contents. The two wastewaters studied are slaughterhouse, collected fresh each week; and synthetic instant coffee production. They are both considered as high strength wastewaters. Slaughterhouse wastewaters are found everywhere, as they are connected with daily human activities, while they are easily biodegradable wastewaters for high-rate digestion. On the other hand instant coffee production wastewaters, although not a common global industrial activity, involves more complexity for high-rate digestion, due to various recalcitrant and inhibitory compounds present in the composition of coffee. Results are based on analyses for: VFA concentration and composition (Acetic to Caproic acid). Tot. and Filt.COD, Tot.BOD, TS, VS, SS, VSS, TKN, NH 3-N, PO4-P, gas composition and for slaughterhouse wastewaters protein concentrations. In particular, results on VFA are presented as concentration, COD of the acids, composition and in relation to the influent and effluent COD. Assessment of the effects of design parameters on the performance of acidogenic biomass are based on: VFA production and composition; acidified COD; and overall effluent quality in relation to methanogenic treatment requirements. This study provides information on all design requirements needed to use acidogenic phenomena to convert organic matter into simple carbon source (i.e. VFA). Such a conversion appears to benefit biological wastewater treatment when used as pre-treatment for anaerobic digestion, but also for its potential in aerobic processes and nutrient removal processes. The process proves to have great low-cost pre-treatment potential, but can also be used for advanced wastewater treatment. Finally, the extensive data collected is used to present various guidelines for process engineers. which should be considered in order to design anaerobic plants. Also, they should be even further used for the overall assessment of the treatment or pre-treatment potential of pre-acidification for agro-industrial wastewaters.

As environmental awareness increases, it will become increasingly difficult to discharge pollutants to the environment without treatment. New and improved technologies can only be based on a knowledge of a large number of factors for each situation. These can be divided into: legislative requirements, environmental impacts, economics, and technical feasibility. Meeting all these criteria will often mean that no single technology will be sufficient to completely alleviate the problem. Hence, a combination of technologies can often be employed. Industrial wastewater, which is often very difficult to treat by conventional treatment, and the large volumes of sludge produced by the wastewater industry have opened up the potential for wet oxidation, which could be very effective in destroying many hazardous organic wastes, and also very effective in reducing the volume of sludge to be disposed of. The decant liquor from WO is often very concentrated and contains low molecular weight organic compounds, mostly acetic acid, but which could be treated to some degree by a biological treatment process. The Wet Oxidation (WO) process is recommended for the oxidation of organic effluent with a solids concentration of between 1% to 25% but which are too toxic to be biologically treated or too diluted to be incinerated. This research project was a continuation of a previous study by Luduvice (1992) and, when possible, most of his recommendations were investigated, including the use of pure oxygen instead of air in the reactor, the biotreatability of the heat liquor and an evaluation of the chemical characteristics of the liquor. It was not, however, possible to develop a continuous Wet Oxidation process capable of operating at both subcritical and supercritical conditions. This thesis describes the ability of wet oxidation to treat different organic wastewaters and sludges under conditions which included the stoichiometric requirement of oxygen being provided and with further biological treatment being given to the decant liquor. The organic wastewater and sludges tested were from different origins and characteristics, including paracetamol wastewater, detergent wastewater, from industries plus raw primary sludge and activated sludge from a biological wastewater treatment plant. Tests were carried out at temperatures varying between 1600 C and 3000 C at retention times of 10, 15, 30 and 60 minutes in a 3.78 1 stainless steel reactor. Temperature proved to be the most significant parameter, followed by retention time and oxygen overpressure. A considerable reduction in sludge volume and organic content was obtained in most runs, which in general produced an effluent liquor with a high oxygen demand and relatively stable residual solids. The residual WO solids, when dried were found to be capable of removing colour from a textile-dye wastewater, implying that dried WO sludge may have adsorption properties similar to that of activated carbon. Simplified empirical equations were developed from the experimental data. The equations adequately described the transformation pattern of the organic and inorganic components of the activated sludge in a WO environment. The empirical equations further demonstrate a direct relationship between the influent VTS and the transformed organic and inorganic components in the liquor after WO. The purpose of this study was also to demonstrate the feasibility of reducing the strength of heat treatment liquors to that approximating domestic wastewater. A range of aerobic and anaerobic biological treatment systems was investigated. Aerobic biological processes proved to be very effective and robust in COD and BCOD removal compared to the anaerobic biological processes.

The changes that have taken place in the British Coal Industry over the last five years have meant that in many coalfileds the last deep mines have closed. When a coalfield is abandoned and dewatering ceases, groundwater levels rebound, threatening surface waters with polluting discharges. However, the sparse data sets available limit modelling with existing techniques. A lumped parameter model GRAM (Groundater Rebound in Abandoned Mineworkings) has been developed. This model conceptualises a coalfield as a group of 'ponds'. Each pond is an area of the coalfield that has been extensively worked and can be considered as a single hydraulic unit. The ponds are connected by pipes which represent major inter-connecting roadways along which flow is assumed to be turbulent. Discharge to the surface is also represented using pipes. Flow through the pipes can be calculated using the Prandtl and Nikuradse of the Colebrook-White pipeflow equations. The storage coefficient can vary vertically to represent both worked Coal Measures and the intervening unworked strata. GRAM is able to predict the timing and volume of discahrges. An iron component gives an indication of the water quality evolution of the discahrges. Monte Carlo simulation allows the variables that have most error in their estimation to be represented by probability distributions. The Dysart-Leven Coalfield in eastern Fife, Scotland has not been mined since 1985. However, dewatering has continued to protect the workings in the Frances Colliery. In 1994 British Coal decided the Frances would never reopen, there is therfore no longer a need to continue dewatering. GRAM has been used to produce estimates of the quantity, timing and location of dischargges from the Dysart-Leven Coalfield should pumping cease. MODFLOW has also been applied to the coalfield with less success. Water quality modelling was also attempted using GRAM's iron component, however, conclusive results will not be obtained until the three variables over which ther is most uncertainty have been calibrated against existing discharges.

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