bluuebunny/crossref_metadata_2025 huggingface dataset:
Reliability of Sewage Systems as an Element of Environmental Protection in Urban Areas
Authors: Madryas C. , Kuliczkowski A.
Published: May 2018

This paper discusses some results of research into reliability engineering for urban sewerage networks, and the possibility of parameter estimation for particular reliability functions so as to establish a database which will enable operational control of the network and its renovation programme. A description and classification of the network failures is proposed for the sewers and the mechanism of their effects upon the soil-water environment will be presented. Very serious consequences are indicated for parametric failures of the networks operated without any program of regular technical state supervision, in the first place without network integrity inspection. The paper aims to underpin the theoretical background for optimal coordination of the renovation process, based upon typical technologies applied nowadays.
Practice of Automated Control in Urban Wastewater Transport System of Moscow
Authors: Ermolin Yuri A.
Published: May 2018

Control of the ramified head-and-gravity wastewater disposal system of Moscow is considered with respect to the possibility of redistributing flows of sewage between structural components through underground hydraulic connections (sewers). It is supposed that the sewerage pumping stations of a network are characterized by various consumptions of electric power for pumping a unit volume of sewage (specific consumption). Analysis is limited by the subsystem of transportation of the sewage (sewerage network). Controlling the network is reduced to the purposeful redistribution of the sewage flows between the sewers and pumping stations. The control criterion is the minimizing of total consumption of the electric power by all of the pumping stations of the network. Restrictions in control are the carrying capacities of the structural components. The control algorithm is adapted to the use of computer facilities.
Biological Filters for Post-Denitrification
Authors: Jepsen Svend-Erik , la Cour Jansen Jes
Published: May 2018

Nitrifying wastewater treatment plants exist in many European countries. These plants can be extended for Total-Nitrogen removal by a post-denitrification stage using an external carbon source. A compact solution for this process is submerged biological filters.

Two pilot plants have been used as post-denitrification reactors, a down-flow filter with expanded slate as carrier material (Biocarbone) and an up-flow filter with polystyrene pellets as carrier material (Biostyr). Nitrified wastewater was treated to a stable effluent quality from both pilot plants to below the Danish effluent standard which is 8 mg Tot-N/l.

The pilot plants have been operated at different loading rates with acetate as external carbon source. Stable removal with effluent nitrate less than 5 mg NO3-N/l was obtained for loading rates up to more than 4 kg NO3-N/m3 d at 10-17°C. The removal capacity of the pilot plants has been shown to be independent of time from last backwash. The removal rate over different sections of the filters does not change within one operation cycle. The backwash removes the excess biomass and particles which cause the head loss, but the removal capacity remains in the filter.

The head loss development in the two systems is quite different. In the Biostyr system, the head loss raises close to linear with time (load), while the Biocarbone shows slow increase in head loss with time until the surface is clogged by incoming particles and biomass growth. When this occurs, the nitrogen bubbles, which are produced in the lower part of the filter, are trapped just below the top layer. The void volume of the filter is occupied by nitrogen gas and the head loss increases very fast to the terminal head loss.

This investigation has shown that both kinds of submerged filters are capable to serve as post-denitrification reactors to remove nitrate to the most stringent effluent standards.
Membranes for Sewage Treatment: The Reality
Authors: Gosling P. , Brown D.
Published: May 2018

A crossflow microfiltration process using a dynamic membrane system has been developed for sewage treatment. The development has enabled a 1000m3/day plant to be designed and built. High quality permeates have been achieved with the pilot plant operating in a tertiary treatment position. The larger plant, which has just been commissioned, will operate on primary settled sewage.
Microfiltration Used as a Means of Disinfection Downstream: A Bacterial Treatment Stage on Fixed-Bed Bacteria
Authors: Langlais B. , Denis Ph. , Triballeau S. , Faivre M. , Bourbigot M. M.
Published: May 2018

Conventional methods of disinfecting sewage are all highly sensitive to variations in the effluent quality upstream of the disinfection stage. Microfiltration was tested as a tertiary treatment downstream of biofiltration, simulating very poor biofilter efficiency, to test the limits of the microfiltration process. Despite the poor quality of the secondary effluent (COD between 100 and 400 mgO2/l, BOD5 between 30 and 150 mgO2/l and suspended solid concentrations between 15 and 90 mg/l), the microfiltration process (filtration level : 0.2 µm) eliminated all faecal germs and tenia and ascaris eggs. The total elimination of free amoeba cysts still needs to be confirmed. With the COD and BOD5 reduced by an average of 60 and 70% respectively, the effluent quality is equivalent to level e after microfiltration (COD: 90 mgO2/l and BOD5 = 30 mgO2/l on samples averaged over 24 hours). Turbidity, measured instead of suspended solids at outlet from the microfilter, was 99 % eliminated. The colour remained between 50 and 150 mg Pt.Co/l. Under the operating conditions applied, the minimum filtration cycle was 72 hours for a minimum permeate flow of 80 1/h/m2 of membrane.

When microfiltration process was used to treat a secondary effluent of good quality (COD between 14 and 40 mg/l; turbidity between 1.4 and 5.1 NTU) the germ elimination remained the same; the COD removal (31 % average elimination) allowed us to get an effluent with an average COD concentration of 24 mgO2/l. The filtration cycle was much longer (300 hours).
Biological Nutrient Removal in a Single-Sludge Plant
Authors: Farchill D. , Goldstein M. , Kanarek A. , Aharoni A.
Published: May 2018

Single-sludge biological treatment systems for nitrification-denitrification and phosphorus removal have become widely accepted process options due to the increasingly greater demand for effluent nutrient control. The Soreq Biological Treatment Plant is a regional facility for municipal wastewater treatment and effluent reclamation for irrigation purposes, with a current average capacity of 220,000 m3/day. The performance data presented for one full year of operation (1989-1990) under automatic process control indicate consistently high rates of carbon oxidation, nitrification-denitrification and enhanced phosphorus removal.
Revision of Industrial Effluent Regulations in Israel
Authors: Weber B. , Schneider G.
Published: May 2018

Industrial effluent regulations in Israel can be promulgated pursuant to four statutory sources. No clear boundaries delineating the scope of these laws exist, and some of them are neither environmental nor water laws per se. The resulting legal situation is one of confusion, duality and even contradiction both institutionally and substantively.

A revision in the Israeli approach towards the regulation of industrial effluent is proposed, taking into consideration some elements of the U.S. Clean Water Act. Ideas are presented for setting up jurisdictional boundaries between the local and central government authorities to differentiate between organic loads and hazardous materials. In addition, the paper calls for criteria and discretionary limits on the setting up of permit conditions and enactment of regulations as well as the need for improvement of existing effluent criteria.
A Nylon Filter A-ELISA for Detecting Viruses in Water
Authors: Nasser Abidelfatah M. , Elkana Yehudit , Goldstein Leon
Published: May 2018

This study was designed to develop a modification of A-ELISA performed in microtitre plates. Nylon filters have been utilized successfully as a solid phase for the performance of A-ELISA. The use of nylon filters resulted in lower background than nitro-cellulose and paper filters, indicating their suitability as a solid phase for developing A-ELISA. With enteric viruses, human rotaviruses and MS-2 coliphage, negative results were obtained, suggesting high specificity of the developed technique for poliovirus 1. The sensitivity of the developed A-ELISA has been shown to be at least one order of magnitude greater than ordinary ELISA. A positive result with the nylon A-ELISA can be obtained with samples containing 100-1000 pfu/ml of poliovirus. Up to date methods used for detecting viruses in water are elaborate, time consuming and costly. Applying the nylon A-ELISA may overcome some of these disadvantages.
The Correlation between Soiling Index and Atmospheric Ozone Concentrations in Tel Aviv
Authors: Gabbay J. , Trachtman A.
Published: May 2018

The Research Institute for Environmental Health* operated monitoring stations for the measurement of air pollutants emitted by combustion in Tel-Aviv. Most of the soiling index (SI) data obtained for the years 1976-1985, showed a direct correlation with the other primary pollutants.

Days in the same month, which had approximately the same diurnal SI levels were grouped together. Half hour averages of SI and O3 were calculated for each group. These average values, obtained for the different groups of SI, were compared. The results showed that groups with high SI levels had low O3 values and vice versa. Also weekends, which had low SI levels, due to lower traffic, had higher O3 concentrations as compared to other days of the week.

SI values showed a clear negative correlation with O3 pattern. This phenomenon was most outstanding during winter, especially in January, due to lower dispersion. There may be a direct influence of soot on the O3 concentrations, or it may be that the SI is only an indicator of the total reducing pollutants levels.

It was also found that for high SI values, the slopes around the O3 peak were steeper than those obtained at low SI levels. O3 levels, except those at the peak were close to zero on days with high SI values.
Lead Pollution in Israel
Authors: Foner H. A.
Published: May 2018

The lead content of petrol used in Israel has been steadily decreasing over the past few years from 0.42 g/litre to 0.15 g/litre. Unleaded petrol has also been introduced. Blood lead levels measured in Israel suggest that some children may be above the 10 µg/dl threshold now considered to be hazardous. The lead contents of soils, food crops, water, and air in Israel are generally low compared with those in other developed countries, but measurements indicate that lead is still being added to surface soils. Further work in areas with heavy traffic shows that the reduced Pb level in petrol has so far not resulted in lower soil lead contents.
Carcinogenesis Risk Assessment Model for Environmental Chemicals
Authors: Helfand J. S. , Mancy K. H.
Published: May 2018

A Monte Carlo computer simulation model was created incorporating the pharmacokinetics of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and the stochastic pharmacodynamics of resulting carcinogenesis. The animal model was the female Sprague-Dawley rat. The model was calibrated to the observed tumor formation probabilities from a carcinogenesis bioassay. TCDD tissue distribution was modeled with a four-compartment physiologically based pharmacokinetic model, using compartments of liver, fat, muscle/skin, and richly perfused tissue. The model includes TCDD binding to two liver compartment sites, a cytosolic receptor and a microsomal binding protein. The concentration bound to the cytosolic receptor was used as the basis for dose-response in a stochastic pharmacodynamic model. Using a Monte Carlo approach, the stochastic model was calibrated to the bioassay controls, and then to the bioassay high and medium dose data using a two parameter fitting function. Fitting to low dose results was impossible because the bioassay had an anomalous decreased response relative to controls. The overall model is capable of predicting human carcinogenesis in response to environmental TCDD exposure through substitution of human biological parameters for those of Sprague-Dawley rats.
Viruses and Shellfish
Authors: Schwartzbrod L. , Boher S.
Published: May 2018

While studying the cycle of viral contamination of aqueous media, it appears that the human being is both the primary contaminator and the secondary receiver of the viruses transported in the aqueous medium. Human contamination takes place by drinking water of poor quality, by eating vegetables irrigated with waste water or shellfish. Shellfish consumption is clearly associated with the transmission of enteric infections and epidemics have been reported in many countries. The viruses responsible for the transmission of epidemics are mostly gastro-enteric viruses (Norwalk virus, Rotavirus and “small round viruses”) and the hepatitis A virus. The shellfish implicated are oysters, cockles, mussels and clams. Shellfish depuration techniques involve either closed loop circuits or semi-open circuits. They are very effective bacteriologically, but they do not totally eliminate the viral particles. Furthermore, sanitary controls are, usually, based on the sole research of fecal coliform although this bacterial type is a bad indicator of viral contamination. It is therefore necessary to include a virological criterion in the sanitary control of shellfish.
Long-Term Programme for Pollution Monitoring and Research in the Mediterranean (MED POL)
Authors: Jeftic L.
Published: May 2018

Long-term programme for pollution monitoring and research in the Mediterranean (MED POL) was adopted by the Mediterranean countries in 1981. Monitoring of the Mediterranean pollution in the framework of MED POL started in 1983 and at present 16 Mediterranean countries have on-going programmes and are submitting data. Through these programmes pollution is regularly monitored at hundreds of sampling stations. All national research centres involved in monitoring participate in the continuing programme of data quality control which includes intercalibration of sampling and analytical techniques.

By the end of 1991, over 400 research projects have been implemented in the framework of MED POL by 150 institutes from 15 Mediterranean countries. Results gathered through the research component of MED POL were presented at numerous scientific meetings and were published in a large number of scientific papers. Data generated through MED POL are used as the basis for the analysis of the present “state of the health” of the Mediterranean and of the trends in pollution levels. They also provide scientific information needed for the formulation of common measures to control pollution.

In-depth assessment studies, including concrete recommendations for measures to be taken by the Contracting Parties were completed for microbial pollution, mercury, cadmium, petroleum hydrocarbons, used lubricating oils, organotin compounds, organohalogen compounds, organophosphorus compounds, persistent synthetic materials, radioactive substances and pathogenic microorganisms. Similar assessment studies are being prepared on other subjects.
Distribution of Trace Elements in the Filterable and Acid Extractable Fractions of Waters of the Northern Jordan River
Authors: Sandier A. , Halicz L. , Brenner I. B.
Published: May 2018

Waters of the northern watershed of Lake Kinneret, sampled during the period 1985-1987, were analysed for their acid extractable and filterable major and trace element contents as part of an on-going research project. Water exploitation and reuse, mainly in the Hula Basin, resulted in an increase in concentration of trace elements in the different drainage canals. The distribution of high, exceptional values appears to be random, and cannot be clearly related to time-environmental processes. The highest concentrations of some major and trace elements were consistently recorded in the canal that drains peat soils. Nevertheless, the southern reaches of the Northern Jordan River were only slightly higher in concentration than the pristine sources. This implies that parts of the metal load were eliminated by poorly defined processes. The acid extractable concentrations were usually twice those of the filterable fraction, with the exception of interrelated Fe and AI, which were highly enriched in the suspended phase. The low levels of the element contents in the highly dynamic system prohibited the proposal of a model explaining the observed variations. The trace metal concentrations, generally below the regulation values, were similar to those reported for unpolluted world-wide streams.
Metal Pollution in the Golden Horn, Turkey: Contribution of Natural and Anthropogenic Components Since 1913
Authors: Tuncer G. T. , Tuncel S. G. , Tuncel G. , Balkas T. I.
Published: May 2018

Historical records of the Golden Horn, so named in antiquity because of its shape, were examined to construct the pollution history of the area and to find out the past and present-day entries of pollutants and hence the impact of man. The pollution level of the Golden Horn by metals is presented by comparison which the continental soil and two other polluted water bodies: Savannah River Estuary and Narragansett Bay. Metals are distinguished as crustal and anthropogenic according to their enrichment factors. Information on how pollution level changes in time was shown using the concentration profiles of the elements between years 1913 and 1988. Li, Na, K, Rb, Be, Mg, Ca, Sr, Ba, AI, La, Ti, V, Mn, Fe, Co and P in the Golden Horn sediments are in levels comparable with those in continental soil. Cd, Cr, Ni, Cu, Zn, Ag, Pb, Mo, Ca, Sr, on the other hand, displayed enrichment through the surface strata. Elements were further grouped using factor analysis. As a result, an anthropogenic component, whose origin is mainly domestic, two crustal components, and a sea-salt component were found to be the main constituents of the Golden Horn sediments.
Transformation of para-Substituted Benzonitriles in Sediment and in Sediment Extract
Authors: Masunaga S. , Wolfe N. L. , Carriera L.
Published: May 2018

Degradation mechanisms of chemicals in sediment must be known in order to permit more accurate assessment of aquatic pollutants. One possible degradation mechanism -- abiotic transformation -- has received little attention, however. In this study, the abiotic transformation of para- substituted benzonitriles in an extract prepared by protein extraction from sediment was compared with that in raw sediment and in water.

In water, the benzonitriles were hydrolyzed to benzoic acid through benzamides at elevated temperature. In anaerobic river sediment, the benzonitriles were transformed to the corresponding benzoic acids, except for iodo- and methoxy-derivatives. In the sediment extract, the benzonitriles, including iodo- and methoxy-derivatives, were transformed to benzoic acids. Benzonitrile transformation did not produce benzamides as intermediates in the latter two media. Transformation in sediment and in sediment extract must have been mediated by an enzyme whose activity is similar to that of nitrilase.

Analyses using quantitative structure activity relationships (QSAR) were carried out with the three sets of rate constants measured in the three media. The rate constants in sediment and sediment extract were correlated mainly with the hydrophobicity substituent parameter π. Rate constants for purely chemical hydrolysis in water were correlated with the electronic substituent parameter Hammett σp. These results showed that the reaction mechanisms in sediment and sediment extract resembled each other and indicate that the abiotic reaction mediated by the extracted sediment protein fraction was responsible for at least part of the reaction occurring in raw sediment.
Mass Transfer of TCDD/F from Suspended Sediment Particles
Authors: Hinton S. W. , Brunck R. , Walbridge L.
Published: May 2018

Experimentally determined mass transfer rates for the non-polar hydrophobic compounds known as tetra-chlorinated dibenzo-dioxin/furans (TCDD/F) were obtained by exposing contaminated sediment materials of two known size classes to a high grade distilled water in a completely mixed state for periods of up to 90 days. Water samples were removed at four time intervals, filtered through 1.2 µm and 0.7 µm glass fiber filters and subsequently analyzed for aqueous TCDD/F content using high resolution GC-MS methods. The results suggest that the mass transfer rates of highly hydrophobic compounds (log Kow>6) are affected primarily by the release of dissolved and colloidal size organic carbon materials and to a lesser degree by exposure time. The experimental data also suggest that the unquestioned use of equilibrium partitioning (EP) theory assumptions in water quality models may not be justified. An empirical model is presented that can predict water column TCDD/F concentrations due to chemical release from suspended solids.
Management of Dredged Material Capping Projects: An Example from New England
Authors: Kullberg P. G. , Fredette T. J.
Published: May 2018

Capping of contaminated sediments with cleaner sediments is a technique that has been used by the US Army Corps of Engineers, New England Division (NED) since 1979, to avoid or minimize the impacts of contaminated sediments disposed at open water sites. A case study of contaminated sediments from a project on the Thames River, capped at a disposal site offshore of New London, Connecticut, illustrates the application of this technique. Several steps, both regulatory and operational, must be accomplished to ensure proper employment of this technique.

First, once it is determined through the permit evaluation process that material to be dredged from a project is not suitable for unconfined open water disposal, the quantity of uncontaminated dredged material needed to achieve a desired cap thickness of 50 to 100 cm must be identified. This quantity may be determined by the use of a computer model - the DAMOS (Disposal Area Monitoring System) Capping Model - which simulates the disposal events and mound formation.

Next, the applicant/project proponent must submit a capping plan to NED, which includes provisions for obtaining the necessary quantity of cap material and a schedule for dredging and disposal of both contaminated and cap materials. Upon approval of this plan by NED, the contaminated material may be dredged and disposed at a taut-wire moored buoy located at a specified set of coordinates. The use of such a buoy is critical to the success of capping, since it aids in limiting the distribution of the contaminated material on the seafloor. Post-disposal bathymetric and sediment-profile camera surveys of the contaminated material are conducted to delineate the areal extent of the mound formed during disposal. Several sets of coordinates are then chosen by NED for disposal of the cap material, with the aim of covering all contaminated sediments.

The operational success of the capping technique is measured by adequate areal coverage and thickness of the cap over the contaminated material. Thus, following disposal (and sometimes during disposal) of cap material, additional surveys are conducted for this purpose.
The Fate of Hg Contaminated Sediments of the Ravenna Lagoon (Italy): Final Burial or Potential Remobilization
Authors: Miserocchi S. , Langone L. , Guerzoni S.
Published: May 2018

In the period 1957-77 a part of 100-200 tons of mercury as industrial waste was discharged into a 10 km2 lagoon (“Pialassa Baiona”) connected to the Ravenna harbor and the Northern Adriatic Sea (Italy). Extremely high levels of Hg (up to 160 µg/g) were found in surface sediments, but the maximum values (up to 1114 µg/g) were detected in subsurface layers, down to 80 cm, close to the industrial source, and values of 1-2 µg/g were recorded in the fore-harbor, outside the lagoon. The calculation of total Hg budget in sediments gave 38 tons of Hg being stored within a contaminated area of 15 km2. The redistribution of polluted sediments would seem to be due mainly to the tidal action; more than 80% of the total Hg discharged is confined in 10% of the area, i.e. in the southern ponds close to the input point. The time necessary for a restoration of the area was estimated by using different approaches of accumulation rate calculations (210Pb, Hg peak). It appears that 40-50 years would be needed to clean the surface sediments of the Ravenna lagoon from the mercury contamination. We suggest that remedial plans should be focused on the southern ponds.
Historical Loading Record of a Post-Depositionally Reactive Substance: A Model for Sulfur in an Adirondack Lake
Authors: Matisoff G. , Holdren G. R.
Published: May 2018

A model for the distribution of sulfur in the sediments of a lake in the Adirondack Mountains, New York State, is developed to gain insight into the timing and magnitude of anthropogenic increases in sulfur loading. Surficial sulfur concentrations are about 3500 µg/g, increase to 6000-7000 µg/g at a depth of about 6 cm, and then decrease downcore to background levels of about 2500 µg/g. Sulfate concentrations are about 60-80 µM in the overlying water and decrease rapidly below the sediment water interface. This reflects assimilation and/or dissimilatory reduction of sulfate into the solid phase fractions of the sediment. A mathematical model is constructed assuming sulfur is incorporated into sediments by burial of detrital organic matter and by diffusion with subsequent fixation of sulfate from the overlying water. Several historical scenarios of atmospheric sulfate loading rates were used as model boundary conditions. Model results are compared with observed sedimentary sulfur profiles. The observed sediment sulfur profiles are best described using model boundary conditions showing increases in lake water sulfate concentrations, and thus presumably in atmospheric deposition, within the last 50-60 years.
Critical Variables in System Success: Top Managements' Commitment is Key
Authors: Winter Mary H. , Manning Alan W.
Published: May 2018

Billions of dollars and vast amounts of human energy go into implementing advanced technology every year. Yet the success rate of automated systems is estimated as low as 25%. Even today's sophisticated technology cannot prevent expensive failure or non-use of automated systems. This suggests that a change in approach is needed to successfully plan and implement automated systems, which raises the following questions.

Are human factors or technical issues more significant to control systems success?

What are the most important non-technical contributors?

Is it possible to assure the success of a control systems project?

To answer these questions a survey was carried out of people who have experience working with computer systems at utilities.
Model Based On-Line Control of Sewer Systems
Authors: Bo Nielsen Jörgen , Lindberg Sten , Harremöes Poul
Published: May 2018

A new software package has been developed for use in real-time control of the flow in combined sewer systems (CSS). A central feature of the new package is forecast modelling of the flows and volumes in the sewer system. Based upon the forecast model predictions, an expert system or an optimisation module determines the set-points for all regulators in the system.

The new software package includes a comprehensive tool-set for use in the design of on-line control systems, including a model-based real-time simulator, which can be applied in the testing of control strategies.

The first practical application of the software package for a sewer system in the city of Aalborg is described.
Diagnosis Expert System for the Activated Sludge Process Using Biota Observed by Microscopic Examination
Authors: Ichikawa M. , Simizu K. , Iwahori K.
Published: May 2018

A diagnosis expert system for the activated sludge process was developed in conformity to our experience and reported studies. Using the biota observed by microscopic and data measurement easily obtained, i.e. pH or DO etc., the process treatability or the activated sludge condition was diagnosed and evaluated by this system. In this paper, the effectiveness of the diagnosis expert system was investigated using the microscopic and measurement results from both the actual sewage treatment plant and the bench-scale experiment. As a result, the low loading and the progress of nitrification were presumed in the case of the actual plant and the variations of treatment condition depending on DO set values were evaluated satisfactorily in the case of the bench-scale experiment. Therefore, it was shown that this system was applicable to the diagnosis of the activated sludge process.
Modelling, Control and On-Line Estimation of Activated Sludge Bulking
Authors: Chen J. , Beck M. B.
Published: May 2018

Sludge bulking is a problem widespread in the operation of activated sludge processes. Over the past fifteen years much research has been applied to identifying the nature of the microbial species responsible for bulking and to developing an understanding of their population dynamics. While some isolated attempts have been made at developing a unit process model capable of simulating the behaviour of bulking, none have been extensively evaluated against field data from full scale plants. This paper describes the development of a multiple-species model of the activated sludge process (for both the reactor and settler), its application to the assessment of various operational strategies for the control of bulking, and its simplification for incorporation into an on-line estimation scheme using a Kalman filter. Routine operating data from the Davyhulme Wastewater Treatment Works in Manchester are used for identification (calibration) of the model. Simulation studies of control strategies are based on the same Works. By using the Kalman filter to reconstruct real-time estimates of the “unmeasurable” states of the process model, the paper also explores the extent to which this filter-based control can bring improvements over similar control based entirely upon conventionally measured operating variables.
Experience with the Relay Procedure for Tuning Controllers in Automatic Control of Chlorination
Authors: Truett Garrett M. , Ahmad Zaki , Young Shelly
Published: May 2018

The recent requirements by U.S.E.P.A. for dechlorination and biomonitoring have increased the importance of automatic control of effluent chlorination in wastewater treatment plants. Difficulties with the Ziegler-Nichols controller tuning procedure were reported at the Kyoto Workshop, 1990. Problems are caused by the noise of incomplete mixing, a long time constant, and the disturbances of changing flow and chlorine demand. The Astrom-Hagglund relay feedback procedure provides acceptable control while data is logged to determine the controller constants. Experiences in using the procedure in existing facilities (not redesigning the mixing point) and the quality of control are presented.
Determining Influent Short-Term Biochemical Oxygen Demand by Combined Respirometry and Estimation
Authors: Spanjers Henri , Olsson Gustaf , Klapwijk Abraham
Published: May 2018

This paper describes a method for the continuous estimation of the influent short-term biochemical oxygen demand (BODst) of a wastewater treatment plant. The method uses the dissolved oxygen (DO) concentration in the inlet and outlet of a closed, completely mixed respiration chamber during the transients between two modes of respiration measurement which are alternately executed. In one mode, sludge having the endogenous respiration rate is directed through the respiration chamber. In the other mode, sludge from the aeration tank directly flows through the respiration chamber and, in addition, a sample of influent is continuously introduced in the chamber. The influent BODst is estimated for each cycle of both modes by integrating the mass balances of BODst and DO over the respiration chamber. Knowledge of the degradation kinetic of readily biodegradable matter is not required. The proposed procedure is verified using both simulated and experimental data from a pilot plant. It is concluded that the procedure enables the estimation of the influent BODst with a relative error ranging from 2 - 6%.
Instrument and System Maintenance: A Design and Operational Necessity
Authors: Watts J. B. , Garber W. F.
Published: May 2018

This paper will present a novel approach to the maintenance of instrumentation and systems. It will show that the true cost of ownership can be quantified by careful thought in the conception and design of systems and instrumentation. The authors will try to identify the true cost of inaccurate process information caused by poorly conceived instrumentation and maintenance.
Effect of Supplemental Carbon Source on Phosphate Removal in an Alternating Activated Sludge Process
Authors: Isaacs S. H. , Henze M. , Søeberg H. , Kümmel M.
Published: May 2018

Pilot plant studies indicate that the addition of COD in the form of acetate to an alternating nutrient removal activated sludge process as a means to improve denitrification rates is not detrimental to biological phosphate removal. This is in spite of the fact that the added acetate can cause a significant release of phosphate during the anoxic phases in the aeration tanks. The added COD also appears to result in increased rates of aerobic phosphate uptake, thus improving the phosphate removal ability of the process. These observations are presented and discussed in the paper.
URBAN IMPACTS ON MICROBIOLOGICAL POLLUTION OF THE ST. CLAIR RIVER IN SARNIA, ONTARIO
Authors: Marsalek J. , Dutka B. J. , Tsanis I. K.
Published: May 2018

Urban impacts on faecal bacterial pollution of the near-shore zone of the St. Clair River in Sarnia were studied by means of field observations and computer modelling. Towards this end, water samples were collected at various sources of faecal pollution and at nine sampling stations in the river, and analysed for faecal coliform, faecal streptococci, Escherichia coli, Pseudomonas aeruginosa and coliphage. Probabilistic distributions of the observed microorganism densities were used to assess the levels of faecal bacteria pollution, describe the impacts of urban sources on faecal bacteria concentrations in the river, and make inferences about compliance with the recreational water quality guidelines. Relatively high probabilities of guideline violations (p > 30%, at most sites, in dry weather) indicated the need for remedial measures. The screening of such measures was accomplished by preliminary modelling of indicator bacteria in the receiving waters, using a bacteria loading model interfaced with a receiving water model.
IN-SEWER OXYGENATION OF WASTEWATER USING VENTURI SIDE-STREAM DISSOLVERS
Authors: Holder G. A. , Leow J. M.
Published: May 2018

The objective of the studies was to improve the efficiencies of venturi-nozzle oxygen-injection facilities installed for in-situ sewer oxygenation as part of an odour control strategy. A procedure which can be utilised to estimate cost-effective operation for oxygen injection at a given site is outlined. The procedure requires the experimental determination of oxygen-adsorption efficiency / nozzle-pres sure-loss plots for the range of operating conditions. Results from both laboratory and field experiments, together with theoretical studies are reported. The total operating cost for an installation consists of the oxygen cost plus the pumping power cost. As could be anticipated, there is a trade-off between oxygen costs and mixing energy efficiency. The total operating cost can be minimised by operating at high mass transfer efficiency. In these situations oxygen wastage is low. However this can only be accomplished when the system is supplied with adequate mixing energy. The studies showed that the best way to reduce the existing oxygen wastage problems was to operate at maximum absorption efficiency with a relatively small diameter nozzle (provided that precautions are taken to avoid nozzle plugging problems) and adequate nozzle pressure loss.
URBAN DRAINAGE IN THE 21ST CENTURY: ASSESSMENT OF NEW TECHNOLOGY ON THE BASIS OF GLOBAL MATERIAL FLOWS
Authors: Beck M. B. , Chen J. , Saul A. J. , Butler D.
Published: May 2018

The process of innovation has been described as a function of the forces of technology ‘push’ and, in the present study, environmental ‘pull’. In order to assess what form of urban drainage system might be desirable by the middle of the next Century, speculation on the possible evolution of the associated technology, U1d the forms of the ‘ultimate’ standards of ‘environmental quality’ is necessary. Interwoven with these speculations is also the necessity to think through the implications of the scenarios for possible climate change and changes in the social fabric of cities in the future. The paper takes a first step in the direction of such speculation. It is noted that operational definitions of a ‘sustainable’ city, or of ‘environmental quality’ (beyond sustainability), are lacking. Cities, like organisms, are associated with !lows of material and energy. Within the broad context of the global cycles of certain principal materials, and in the absence of a good knowledge of the forces of environmental ‘pull’, the ways in which an urban drainage system of the future might introduce minimal distortion of these ‘natural’ material cycles are explored. Specifically, the cycles of C-, N-, P- and S-bearing materials, together with those of heavy metals, synthetic organic chemicals and pathogens, are examined. These represent the principal categories of pollution associated with the activities of a city. Much of the analysis points towards the desirability of returning the non-aqueous output fluxes of the urban drainage system to the land, as opposed to the aquatic environment This is hardly surprising given the history of social developments (in moving from a rural to urban society). The challenge is to combine the more specific insights from this study of a hypothetical ideal with the obvious practical constraints of existing infrastructures of sewer networks and wastewater treatment facilities.
WATER QUALITY SIMULATION OF TE-CHI RESERVOIR USING TWO-DIMENSIONAL MODELS
Authors: Kuo Jan-Tai , Wu Jiann-Homg , Chu Wen-sen
Published: May 2018

The application of a two-dimensional laterally averaged hydrodynamics model (LARM2) and a water quality model (WASP3) for the study of eutrophication problem in Te-Chi Reservoir in Taiwan is presented. The models were first calibrated and validated with field temperature and water quality data. The combined models were then used to characterize the temperature distribution, seasonal overturning phenomena, and the variations of chlorophyll-a, organic nitrogen, ammonia nitrogen, nitrate nitrogen, organic phosphorus, inorganic phosphorus, and dissolved oxygen in the reservoir. It was shown that the limiting factor for eutrophication in Te-Chi Reservoir is phosphorus, and that better control of phosphorus loading into the reservoir is the crucial step toward improving the water quality of Te-Chi Reservoir.
MODELLING CHEMICAL TRANSPORT IN TOPSOIL WITH A GAMMA DISTRIBUTION FUNCTION
Authors: Liu Clark C. K. , Lin Pengzhi , Firman Amalia
Published: May 2018

In applying the linear systems theory to the mathematical simulation of chemical transport in topsoil, the impulse response function is used to describe the overall effects of hydrodynamic and kinetic mechanisms of the system. The general nature of the impulse response function of a soil transport system can be represented by a gamma distribution function. The multiple regression equations derived in this study can be used to correlate parameters of a gamma distribution function with basic soil and chemical properties. Techniques developed in this study are most suitable for assessing spatial variation of groundwater contamination potential in a large area.
ALGORITHMS FOR PESTICIDES TRANSPORT DISTRIBUTED MODELLING
Authors: Settesoldi D. , Preti F. , Lubello C. , Becchi I.
Published: May 2018

In order to build up distributed models which require a proper evaluation of the different hydrological, sedimentological and chemical variables, various algorithms developed and based on results obtained in former experiences are here presented. A digital model which divides the catchment with a square grid to obtain a set of cells, called rasters, is adopted and all quantities playing a role in the model are represented according to this methodology. They are geographic (elevation, watersheds, channels network, exposure, flowing index, etc.), geological and pedological (gravitational and capillary water storage, erodibility, etc.), climatic (rainfalls. temperature, humidity. etc.) and anthropic (land use, agricultural nonpoint pollution, etc.). A limited set of parameters that regulates the dynamics of water. sediments and pollutants are common fop the whole basin. Grid dimensions and balance time-step are not fixed in advance, but they depend on information accuracy.
NEW TECHNOLOGIES AND PRACTICES FOR WASTE MINIMIZATION IN THE CHEMICAL AND PETROCHEMICAL INDUSTRIES : FINDINGS OF THE SALVADOR, BRAZIL, 1993 CONFERENCE
Authors: Lima Francisco Fontes , Alves Pereira Francisco
Published: May 2018

This paper describes the findings of the “Third International Conference on Waste Management in the Chemical and Petrochemical Industries,” held in Salvador, Brazil, October 20-23, 1993. A summary of the 74 technical papers, divided into six major categories, is presented together with comments on the more stringent legislation concerning source control programmes.

Case studies of two large chemical complexes that have been developing successful waste minimization programmes are described in detail: CETREL-Environmental Protection Company in Camaçari, Brazil, and BASF AG in Ludwigshafen, Germany.
Development of the Pollution of the River Morava Evaluated from Zoobenthic Communities
Authors: Bernardová I. , Mrázak K. , Škollová M.
Published: May 2018

To obtain a more detailed picture of the water quality changes in river longitudinal profiles, an original biological monitoring system has been developed by the Water Research Institute (WRI) in Brno. The system is based on the exact selection of representative macrozoobenthic sampling points. A precise taxonomic identification and statistical evaluation create the basis for documentation of the present water quality and consequently for a water quality simulation model. The biological monitoring system enables information from basic chemical monitoring to be enhanced, and constitutes an eco-engineering tool for the central and regional control of the water quality. A potential cost reduction, when compared to classical modelling techniques, is a benefit which cannot be ignored. The system described is applied in the watershed of the river Morava as given in this paper, as well as for the whole Czech Republic.
Present Status of the Salmonids Atlantic Salmon and Sea-Trout in the Dutch Part of the River Rhine
Authors: Cazemier W. G.
Published: May 2018

In the past, the anadromous salmonids, Atlantic salmon (Salmo salar) and sea-trout (Salmo trutta), have formed natural populations in the river Rhine. From the beginning of the nineteenth century onwards, the greater part of the drainage area of the river has been gradually altered from a more or less rural and agricultural area, into a highly industrialised one with subsequent industrialisation, river-engineering and heavy pollution. These developments are considered to be the major cause for the disappearance of the populations of anadromous salmonid fish in the 1950s. The water quality has recovered significantly during the past 25 years. From about 1975 onwards, this process gave rise to a recovery of the anadromous trout population. Results of recent studies of the sea-trout migration pattern are presented. They reveal that nowadays these salmonids can complete their up- and downstream migrations from the North Sea to places, situated at hundreds of kilometres upward the river and vica versa. The numbers of recorded Atlantic salmon and catch locations in inland waters are presented. They show a significant increase since 1989. These phenomena can be understood as promising signs of the recovery of the Rhine aquatic ecosystem.
OIL MIGRATION THROUGH UNSATURATED SOILS AND ITS EFFECT ON THE VADOSE ZONE INTERACTIVE PROCESSES (VIP) MODEL OUTPUT
Authors: Joseph Ajit T. , Grenney William J. , Stevens David K.
Published: May 2018

A mathematical model called the Vadose Zone Interactive Processes (VIP) model was developed and implemented at Utab State University (USU) for evaluating the fate of hazardous substances in the unsaturated zone of the soil during land treatment of oily wastes. The VIP model, which simulates the concentration profiles of the hazardous compounds in the soil, water, and the air phases, assumes a fixed oily phase. The purpose of this study was to measure oil migration in soil systems m1d to determine its effect on the VIP model output.

Experiments were conducted at USU to demonstrate the mobility of an oil through the unsaturated zone of the soil. The oil migration studies were conducted in laboratory scale glass columns. A light petroleum oil :md two types of soil were used for the experiments. The water flow rate through the columns was adjusted to maintain saturated and unsaturated soil conditions. A predetermined quantity of soil and oil mixture was applied to the top of the soil column. The concentration of oil in this mixture varied from 5% to 30% (on a mass basis). The oil present in the mixture migrated down through the column with the aid of the infiltrating water. After water had been flowing through the columns for the desired test times, the column was sectioned and the soil from the various depths was collected and analyzed for moisture and oil contents. The leachate produced was also collected ru1d analyzed for oil content.

The experiments demonstrated that oil migrates down significantly through the soil columns. The extent of migration depended on the volume of oil applied and the type of soil. However, the applied oil was completely immobilized in the columns. The VIP model was modified to incorporate oil migration. The modified VIP model can be expected to produce more realistic contaminant concentration profiles during land treatment of oily wastes when compared to that produced by the present version of the VIP model.
An Integrated Approach for Identifying Sources of Pollution: The Example of Cadmium Pollution in the Rhine River Basin
Authors: Anderberg S. , Stigliani W. M.
Published: May 2018

IIASA' s project, Sources of Chemical Pollution in the Rhine Basin, is a comprehensive analysis of the sources of toxic materials in the Basin 1950–2010. The study employs the concept of industrial metabolism. This approach provides a comprehensive view of production and consumption processes and their effects on the environment. It entails a systematic analysis of all sources of a given material, its pathways through the industrial economy, and the mechanisms by which it is transformed into outputs to be adsorbed and processed by the environment. Losses to air, water and soil are estimated. In this paper we present the results obtained for the historical development of cadmium pollution. The historical evolution of cadmium pollution is more or less representative of the overall trends for the other heavy metals. The results indicate that the Rhine river has experienced a significant decline in the load of cadmium over the last 20 years. Another observed trend is that while the absolute load to the river has decreased, the relative shares of the load contributed by point sources and diffuse sources have been reversed compared to 20 years ago. While point sources dominated emissions in the early 1970s, now diffuse sources are more important. These sources may be more difficult to control, however, since they are much more numerous than point sources, are related to dissipative consumptive uses which cannot be easily monitored or regulated, and in many cases the pathways and sources of emissions have not been identified.