Particulate forms of radium and barium in uranium mine waste waters and receiving river waters

A method of selective dissolution was used for analysis of particulate forms of radium and barium in a system consisting of uranium mine waste waters purified by coprecipitation with barium sulphate and of adjacent river waters. Four particulate forms of both the elements were distinguished: “loosely bound”, “acid soluble”, Ba(Ra)SO₄ and “in crystalline detritus”. It was found that the distribution of radium and barium between dissolved and particulate forms in waste waters depended on the time interval elapsing between the sampling and membrane filtration of the waters. No such dependence occurred in river water. The main particulate form of radium and barium in the system was Ba(Ra)SO₄. River water upstream of the mine water discharge contained radium mainly in “acid soluble” form or “in crystalline detritus” and barium as BaSO₄ or “crystalline detritus”. In unpurified mine effluents, a large part of radium and barium was present as “crystalline detritus”. Abundance of the “loosely bound” form was very low in all the samples analyzed. The bond of radium in bottom sediments was approximately the same as that in the solids suspended in waste waters. Suitability and accuracy of the selective dissolution method for analysis of surface and waste waters has been demonstrated by the analysis of the results and by radiotracer experiments.     

Treatment in municipal plants: Innovations for removal of phosphorus

The paper provides a background of a variety of different phosphorus removal techniques which have been reported in the literature. Forty-nine different references which may be described under the general headings of “biological”, “chemical”, “chemical-biological”, and “chemical-physical”, have been abstracted and described under a series of salient headings. The manner in which they are described considers the point of application of the process, the percentage removal of phosphorus which was experienced, the cost of the process where this was given, and whether or not the process is related to a concentrated sub-stream within the waste water treatment plant.The main emphasis of the paper deals with the concept of removing phosphorus from waste water by using a sub-stream within the plant which naturally has phosphorus concentrated considerably above the ambient (influent) concentration.A continuous laboratory-scale plant was studied, operating under contact stabilization conditions, and using an anaerobic holding technique on the return activated sludge, phosphorus was removed from the supernatant of the return sludge stream. The plant was operated with and without the anaerobic holding modification, and the results of the operation are reported in the paper. Both before and after the modification, the organic carbon as measured by COD removal was of the order of 90 per cent; and after modification of the plant to release the phosphorus from the return sludge stream, phosphorus removals jumped from 10 to 30 per cent up to a high of 75 to 90 per cent removal. A very slight decrease in sludge activity could be observed due to the anaerobic holding, but the very slight reduction in COD removal was more than offset by the increased removal of soluble phosphorus through the supernatant of the return sludge line.Development of this process onto a full-scale basis is considered as the next stage of this research programme.     

Pollution of the river rhine with halogenated organic compounds an investigation during a “Fliessende Welle”

In August 1982 and between 13 September–1 October 1982, during two “Fliessende Welle” surveys, about 400 R. Rhine water sample were taken. The total organic halogen contents of about 200 samples were analyzed by different methods. In waste water samples, as well as in river water samples, there were considerable differences in the analytical data depending on the method used. Some discharge points for organic halogens into the Rhine are identified.     

Design and operational charts for complete mixing activated sludge systems

This paper provides charts enabling the derivation of design and operational procedures for an activated sludge waste water treatment system including the final settler. These charts are based on a mathematical model including Monod relationships describing the microbial growth and the substrate removal in the aerator, while sedimentation in the final settler is assumed to follow the limiting flux theory. Charts represent the minimum required settler area, insuring that given effluent standards will be met, as a function of either the hydraulic retention time or the recycle rate. Most design and operational characteristics of the activated sludge system can be read directly on the charts, while a simple equation is provided for the sludge wasting rate.Operational procedures under constant or variable inflow conditions are first derived from the charts. It is concluded that operational policies including a constant recycle sludge concentration are especially attractive in response to various types of influent variations. Such policies allow one to maintain either the effluent substrate concentration or the recycle flow rate at the same level in most situations. Furthermore, the required settler area remains reasonably small. Large aerators provide considerable operational flexibility and appear to be required when hydraulic overloads are expected.The charts allow one to design the activated sludge system in such a way that expected overload conditions can be overcome. Least-cost design is briefly studied through simplified cost functions. This allows derivation of the best compromise between sufficient operational flexibility and least-cost design, leading to the “optimal overdesign” of the system.Parameter variability has a significant influence on the charts. Hence, correct determination of the model parameters is required before calibrating and using the charts.     

Nitrogen elimination by rapid alternation of aerobic/“anoxic” conditions in “orbal” activated sludge plants

Methods of operation for obtaining maximum nitrogen elimination in the “Orbal” endless channel extended aeration plant are compared. The most efficient method required balancing of sludge concentration, organic load and oxygen input against one another in such a way that a rapid alternation of aerobic/anoxic conditions was brought about between aeration points in each channel. This resulted in minimal amounts of ammonia and nitrate remaining in the effluent. Automated control of oxygen input and of sludge concentration is considered necessary for consistent maximum nitrogen removal.     

Distribution and balance of volatile halogenated hydrocarbons in the water and air of covered swimming pools using chlorine for water disinfection

A survey of the “chlorination practice” of swimming-pool waters is presented taking the case of covered pools in Bremen. Chlorination of water may result in specific health hazards by various halogenated chemicals. Trihalomethanes (THMs), among others, are determined in water and air samples. We succeeded in identifying one organic “precursor” of the synthesis of THMs in swimming pools. An estimate of the average and maximum burden of the user/swimmer is given. Short and long range alternative measures are proposed to diminish the health hazards. We conclude from this work that the application of chlorine for disinfection should be minimized.     

Self-cleaning in an estuarine area formerly affected by 226Ra anthropogenic enhancements

The estuary of the Odiel River has been affected by both direct discharges of phosphogypsum (radium enriched industrial waste) and dissolution and weathering of the exposed piles where this radium enriched waste was stored. In 1998 the waste management policy for industries changed. The direct discharges stopped and the new phosphogypsum piles were well protected against dissolution processes, avoiding any transference of radium into the environment. This work presents a study of the evolution with time (1999-2002) of the levels of 226Ra in river water and sediment samples with the new waste management policy. A liquid scintillation technique was used to measure the 226Ra activity concentration in sediment samples. A gas-proportional counter was also used to measure the 226Ra activity concentration in river water samples. The main conclusion is that a systematic and continuous decrease of the activity concentration of 226Ra with time in the Odiel River estuary is occurring. Thus, a possible self-cleaning in the estuary, once the direct waste discharges were avoided, can be inferred.     

Monitoring anionic surfactants at a sea outfall, Halifax Harbour, Canada

Anionic surfactants enter the coastal water via untreated sea outfall discharges. A concentration range between 1.0 and 200 μg l⁻¹ can be found in polluted areas. The highest concentration being detected near the point source. In Halifax Harbour, high concentrations of surfactants are associated with the presence of rising plumes. Wind and tidal currents can affect both the spreading of these compounds and the waste field. Under certain circumstances, anionic surfactants may be used as waste effluent tracers but in combination with other parameters.     

Organic contaminants in the aquatic environment I. Sources and occurrence

Literature pertaining to the sources and occurrence of organic compounds in raw, potable and waste waters is reviewed. The introduction of organic micropollutants into the hydrological cycle is considered in terms of both point and non-point source discharges and the individual industrial and domestic sources of particular classes of organic chemicals are assessed. The occurrence in waters and waste waters of a wide variety of organic contaminants has been evaluated with regard to their concentrations in particular aqueous samples and frequency of occurrence. Although specific sources are known to be responsible for the addition of certain organic compounds to water and waste water, the occurrence of particular compounds cannot always be related to a particular source. In addition, it is evident that the reported occurrence of many organic contaminants has been limited by the capabilities of presently available analytical techniques.With the number of organic chemicals in use increasing, the potential for continued contamination of water resources exists. The implications for water quality and the possible effects generated by the introduction of organic compounds into the hydrological cycle on water re-use operations are discussed.     

Measurements of the dispersion of liquid industrial waste discharged into the wake of a dumping vessel

100,000 t yr⁻¹ of acidic effluent with an organic content of 3–7% are dumped 15 km off the mouth of the River Tees in water 50 m deep. In order to achieve adequate dilution, the rate of discharge of this effluent has been restricted on the basis of calculations made using a formula adopted by the International Maritime Organisation (IMO, formerly IMCO). To ensure that these calculated minimum conditions were achieved in practice, field measurements of waste concentration in the wake of the dumping vessel were made on 3 days under different climatic conditions. The measurements were made by a number of methods, both in-situ and involving analysis in a laboratory onshore. The dilutions calculated from the “IMCO formula” were compared with those found in practice and the formula was found to underestimate dilution in this case. The results obtained are compared with other theoretical and practical studies.     

Distribution of species of Cu, Pb, Zn and Cd in a water profile of the Yarra river estuary

The behaviour of Cu, Pb, Zn and Cd in a highly stratified estuary was examined. The distribution of ionic and ‘organically bound” forms of the metals was determined by differential pulse anodic stripping voltammetry (dpasv) before and after u.v. irradiation. The two forms of the metals were compared with the water characteristics of salinity, temperature, turbidity, flow, and inorganic and organic carbon.Irradiation increased the concentration of all four elements detectable by dpasv. The greatest increase was for Cu in the 1 m depth river water which yielded 7.5 μg l⁻¹ before irradiation and 29 μg l⁻¹ after irradiation. Cu and Cd showed minimum concentrations in the seawater layer at 4 m depth, corresponding to the fresh seawater flowing upstream below the halocline. The concentrations of Cu and Cd were higher in the river water than in the underlying seawater. Zn concentration in the river water was lower than in the seawater. Relationships between the trace metal concentrations and the characteristics of the water column are not clear, but the direction of water movement is a major influence.     

Mecanismes de l'epuration biologique sur charbon actif

Activated carbon was used for the treatment of waste water, and a study made of the fixing-properties of the adsorbent and the part played by micro-organisms. The process of “fixing” remains to be demonstrated because it has not yet been proved that bacteria are fixed on carbon. Study of the biological mechanism of activated carbon was carried out in three stages. The first was a survey of the adsorption on this material of various products present in waste water [amino-acids, enzymes, total organic matter (COD)]. In the course of these tests, the part played by the micro-porosity of activated carbon in regard to such molecules was observed. In the second stage, by using various techniques (electron microscope, scanning and transmission, X-ray fluorescence, Castaing micro-gauge), we determined the part played by fixation-spots initially present on carbon (surface functions, heavy metals) during bacterial development. In the third stage, we correlated the eliminated organic pollution with the bacterial mass present on the adsorbing material.The conclusions drawn were that the micro-porosity of carbon does not play a fundamental part in the adsorption of organic matter in sewage, but it does come into play in the adsorption of certain molecules taken separately (amino-acids, enzymes), and that the presence of fixation-spots (metals, surface functions) can have some influence during bacterial development. Experiments are in progress to determine the part played by the specific surface in regard to the adsorbable molecules and its correlation with the bacterial mass and also, to observe the part played the adsorbing material and the bacteria in regard to the non-adsorbable molecules (ethanol, methanol).     

Aspects of water quality and the toxicity of copper to rainbow trout

Studies were made of the effects of additions of a sewage effluent, an amino acid, humic substances, and suspended organic matter on the acute lethal toxicity of water containing copper sulphate to rainbow trout. In all cases the toxicity of a given total concentration of copper was quantitatively reduced. It was concluded that neither the total concentration of copper nor that of “soluble” copper in a water could be used to determine the toxicity to fish which was attributable to copper. It was also concluded that data from toxicity tests with copper in which natural surface waters are used for dilution purposes cannot define the true toxicity of copper or have application to other natural waters except when the concentrations of the toxic chemical species are known.     

Rationale for a water pollution code

A water pollution code must quantitatively express the amount and locations of allowable waste discharges. To do this, each of the steps leading to the decision on allowable waste discharge must be defined and quantified.

Six of these steps were discussed in Part I of this analysis. The seventh step, which will be discussed here, concerns the assessment of the costs and benefits associated with different levels of water quality, and the selection of a water quality standard with reference to prevailing community attitudes. The procedure for making this assessment is discussed. The development of a social welfare function using the cost benefit approach and also the relative preferences approach, is described, and the selection of the appropriate water quality standard, using the social welfare function, is discussed.

The final step in deciding allowable waste discharges, which concerns the selection and application of the most acceptable and efficient waste control strategy, will be considered in Part III of this analysis.     

Comparison of low-cost and engineered materials for phosphorus removal from organic-rich surface water

Excess phosphorus (P) in lakes and rivers remains a major water quality problem on a global scale. As a result, new materials and innovative approaches to P remediation are required. Natural materials and waste byproduct materials from industrial processes have the potential to be effective materials for P removal from surface water. Advantages of natural and waste byproduct materials include their low-cost, abundant supply, and minimal preparation, especially compared with engineered materials, such as ion exchange resins and polymeric adsorbents. As a result, natural and waste byproduct materials are commonly referred to as low-cost materials. Despite the potential advantages of low-cost materials, there are critical gaps in knowledge that are preventing their effective use. In particular, there are limited data on the performance of low-cost materials in surface waters that have high concentrations of natural organic matter (NOM), and there are no systematic studies that track the changes in water chemistry following treatment with low-cost materials or compare their performance with engineered materials. Accordingly, the goal of this work was to evaluate and compare the effectiveness of low-cost and engineered materials for P removal from NOM-rich surface water. Seven low-cost materials and three engineered materials were evaluated using jar tests and mini-column experiments. The test water was a surface water that had a total P concentration of 132-250 μg P/L and a total organic carbon concentration of 15-32 mg C/L. Alum sludge, a byproduct of drinking water treatment, and a hybrid anion exchange resin loaded with nanosize iron oxide were the best performing materials in terms of selective P removal in the presence of NOM and minimum undesirable secondary changes to the water chemistry.     

Automated determination of carbon in natural waters

An automated method for determining inorganic carbon and organic carbon in water is described. The sample is acidified and the CO₂ from inorganic carbonate is removed in a packed column and measured with an i.r. analyzer. The stripped liquid is pumped to a furnace containing cobalt oxide catalyst at 950°C where the organic carbon is oxidized; the resulting CO₂ is measured with an i.r. analyzer. Operating as a “two-channel” system, inorganic carbon and organic carbon are measured simultaneously at 20 samples per hour. If used in a “single-channel” mode, inorganic and organic carbon are measured separately, inorganic carbon at 60 samples per hour, organic carbon at 20 samples per hour. The coefficients of variation at 1 and 5 mg l⁻¹ organic carbon are 5.1 and 2.8% respectively. The detection limit is 200 μg l⁻¹C.     

Compaction of flocculated material

The device used in the experiment consists of a flat-bottomed graduated cylinder and a coaxial plunger. A suspension flocculated with chemicals is sedimented after being mechanically worked within the graduate, and the supernatant water is removed with a pipette. The plunger is thrust into the sludge at a constant speed. The sludge is not only compressed but also flows into the annular gap between the plunger and the graduate, resulting in liberation of water. The liberated water is accumulated on the sludge in the annular gap. The “sludge bulkiness” β is used to describe the volumetric proportion of sludge and solids in it. The sludge bulkiness values before and after the “plunger test” are denoted as β_i and β_f, respectively. The values of β_i and β_j have been explored as a function of the time of the mechanical working. As a result, there is a definite time lag between the maximum value of β_i and the minimum value of β_f. The minimum value of β_j is obtained when the sludge consists of “pelleted flocs”.     

Etude de l'evolution de la qualite des eaux de riviere

In France, the creation of a “Ministère de l'Environnement et du Cadre de Vie” and “Agences Financieres de Bassin” has made it possible to obtain information on the water quality of rivers and on the measures necessary to improve water quality. Particularly in the Adour-Garonne Basin, much information is now available. The methodology needed to draw conclusions concerning the quality of the rivers and to show the effectiveness of control measures has been developed.This method has been tested in two catchments (Fig. 1): L'Adour (15,000 km²) and La Dordogne (24,000 km²). The steps that were necessary before this method could be used were: critical assessment of the available data; identification and measurements of pollution sources. This called for the collection of information, annual statistics for each sampling station and information concerning the value and importance of measured parameters.Detailed information is available from 1971 and 1976 and this is shown by maps and graphical representations of the variations in the value of different parameters (Fig. 2).Statistical analysis has also been carried out on the information available for the period 1971–1976.Two methods were used: analysis of the principal components, the method most used being shown by Figs 3 and 4 and the “STATIS” method developed recently which treats the whole data “At 3 indices” (Fig. 5).Research has been carried out on the causal relations between the water quality and the sources of pollution.A simple graphical method is proposed to explain the effect of a strongly preponderant pollutant source. It allows easy visualisation of the change in the relationship between two series of variables (Fig. 8).In general cases of several sources of pollution a simplified method using BOD exclusively has been developed. It consists in comparing the values measured in the river and the estimates obtained from inflows of various sources and those from upstream basins (Fig. 9).The application of this method has made it possible to distinguish local or general tendencies in reference to the intervention realised by the “Agence Financiere de Bassin”.Attention has been given to the variations obtained between laboratories and research information and the necessity to extend application of the statistical method to parameters other than BOD₅.Comparable action is being taken for the whole basin of the Rhone (French). The information obtained for “L'Adour and La Dordogne” has led to a study not only of the concentration of pollutants but two types of flow, with flow measurements and concentration being taken into account in order to eliminate hydraulic effects.     

Modeling antimicrobial contaminant removal in slow sand filtration

Slow sand filters are used in rural regions where source water may be subjected to antimicrobial contaminant loads from waste discharges and diffuse pollution. A numerical model (LETA) was derived to calculate aqueous antimicrobial concentrations through time and depth of a slow sand filter and estimate accumulating contaminant mass in the schmutzdecke. Input parameters include water quality variables easily quantified by water system personnel and published adsorption, partitioning, and degradation coefficients. Simulation results for the tetracycline, quinolone, and macrolide classes of antimicrobials suggested greater than 3-log removal from 1 microg/L influent concentrations within the top 40 cm of the sand column, with schmutzdecke antimicrobial concentrations comparable to other land-applied waste biosolids. A 60-day challenge experiment injecting 1 microg/L tylosin to a pilot slow sand filter showed an average 0.1mg/kg of the antimicrobial remaining in the schmutzdecke layer normally removed during filter maintenance, and this value was the same order of magnitude as the sorbed concentration predicted by the LETA model.     

Sorption of zinc by Lake Michigan sediments: Implications for zinc water quality criteria standards

A series of sorption and leaching tests were performed to investigate the uptake and release of zinc from Lake Michigan sediments. In general it was found that these sediments had a moderate affinity for zinc in the neutral to slightly alkaline pH range. If the pH of the sediment slurry was decreased to 6 or less, zinc release was found. Increasing the pH to 7 or greater did not result in the zinc being readsorbed. The sorption of zinc by the sediments was rapid, usually complete in 1–2 h. These results are in accord with the results of the other studies conducted with other waters and sediments. Field observations in Lake Michigan have shown that high concentrations of zinc in tributary waters rapidly decrease within a few kilometers of the tributary mouth to an essentially constant lake-wide concentration. This concentration ranged from 2 to 4 times the typical tributary concentrations. These results may be explained by the uptake of zinc by the suspended sediment in the river and nearshore waters, with settling to the quiescent sediment-water interfaces of the deeper areas of Lake Michigan, often far removed from the tributary input.The rapid, essentially irreversible sorption of zinc by aquatic sediments raises important questions concerning the appropriateness of using the US EPA water quality criterion for zinc as a state water quality standard. The US EPA criterion is based on the total zinc concentration. In many aquatic systems most of the zinc would be adsorbed by suspended sediment, and therefore unavailable to aquatic organisms. It is recommended that the US EPA criteria be used to indicate potential zinc water quality problems where “excessive” concentrations of zinc are investigated on a site-specific basis, using a hazard assessment approach designed to evaluate the actual impact of the zinc in impairing beneficial uses of the water.