bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison between a Perforated Pipe and a Fixed Sprinkler System for Land Disposal of Treated Petrochemical Effluent
Authors: Simon Zeno , Baldasso Mario L. , Gazen Adejalmo F. , Aguirre Juan C.
Published: May 2018

At SITEL – the integrated effluent treatment system of Pólo Petroquímico do Sul (South Petrochemical Complex, Triunfo, Brazil) – the tertiary-treated effluent is disposed of on land at an average hydraulic application rate of 140 m3/ha.day. Two subsystems have been installed in order to minimize the devastation of indigenous vegetation during the construction phase, aiming also at investigating the cheaper processes to be adopted when expansions become necessary.

The first subsystem consists of a network of perforated PVC pipes which distribute the effluent over a forested area through an arrangement compatible with the local basin divides. It is fed by six submersible centrifugal pumps operating at moderate heads (ca. 30 m H2O). The second subsystem comprises high capacity rotating impact sprinklers fixed on hilltops covered predominantly by grasses. It is fed by two dry well centrifugal pumps operating at higher heads. The design criteria for both systems stem from a “zero runoff” legal requirement applicable within the limits of the 100 ha disposal site.

The two subsystems are compared as regards technical aspects and economics. Removal efficiencies are presented. Capital and running costs related to pumping stations, mains, distribution networks, ancillary equipment and appurtenances, power consumption, maintenance, operation, materials etc. are compared and discussed. Functions and indexes that may prove useful in feasibility studies for similar systems are presented.
Treatment of Liquid Effluents from a Hardboard Factory by a Spray-Irrigation System
Authors: Moura J. B.
Published: May 2018

Hardboard manufacturing by the wet process produces a liquid effluent difficult to dispose of due to its organic content and volume. This paper reports on a treatment system for the effluent of one of Duratex SA's hardboard plants. The effluent is sprayed over ground covered by grass. The hardboard mill effluent and its characteristics are discussed, as are the problems of trying to find a solution, the research already conducted and the system introduced with its results. After studying many treatment alternatives, effluent disposal by spray-irrigation in an area of 300 ha, was chosen. Besides the low operating and investment costs, this system has 100% efficiency in pollution control and also gives a significant income from the sale of grass as hay for animal feed.
The Upper James Estuary – A Study in Water Quality Management
Authors: Das K. C.
Published: May 2018

The James River has its head waters in the Allegheny Mountains and flows generally southeasterly to Hampton Roads, Chesapeake Bay and thence to the Atlantic Ocean. Below Richmond, Virginia, the river is tidal with the channel meandering through the coastal plains. Below Hopewell it widens to a broad estuary, with a deep navigable channel bordered by tide marshes. The upper estuary, between Richmond and Hopewell, is heavily used for water supply, recreation, and industrial development.

The water entering the estuary a few miles upstream of Richmond is of good quality. However, as one reaches Richmond, the quality of the water deteriorates. There are eleven major discharging municipalities and industries within a stretch of twenty two river miles between Richmond and Hopewell. The major factors contributing to water quality problems below the City of Richmond stem from the intermittent discharge from combined sewer overflows (CSOs) coupled with the continuous discharge from the City's sewage treatment plant. The CSOs contribute a large quantity of soluble BOD, suspended solids, settleable solids, and fecal coliforms to the estuary. The City's sewage treatment plant continuously discharges large quantities of ammonia-nitrogen and phosphorus, in addition to BOD and suspended solids.

Rational Management and use of the waters of the upper James estuary appear to be critical. The objectives of this paper, therefore, are the discussion of the present water quality and the wastewater discharge reductions required in order to meet certain water quality and water use objectives.
Sources of Heavy Metals and their Impacts on Wastewater Treatment and Receiving Water Bodies' Quality – Case Study of a Metropolitan Area
Authors: Yapijakis Constantine , Papamichael Fotios
Published: May 2018

In accordance with the USEPA General Pretreatment Regulations, New York City has conducted a comprehensive study to establish a local industrial pretreatment program. Heavy metals (Cu, Cr, Pb, Ni, Zn, Cd, and Hg) were the only priority pollutants found to be consistently present in the wastewater, and electroplating industry is the major contributor, as previously suspected. Heavy metals do not affect the performance of the treatment plants, as their levels at all plants are below the reported threshold limits. On the other hand, the existing levels of heavy metals found in NYC sludges limit its disposal options. Pretreatment can significantly decrease the amounts of Cr, Ni, and Cd discharged into the Harbor by NYC treatment plants.
Innovative Financing Techniques in a Volatile Market Require Cooperative Effort
Authors: Jack Davis L.
Published: May 2018

The key to any successful water related project is a successful financing project. This paper deals with the need to develop cooperation and understanding between administrative managers who must select and implement the necessary financing program and the project personnel who plan design and implement the physical program. The paper also examines the various financing vehicles that are available to the governmental managers in a volatile international money market and the need to mesh project implementation to favorable financing schemes. Several methods of financing are discussed with some references to bond rating criteria. The principal theme is the need for flexibility in all phases of project financing.
Use of Water Hyacinth in Tertiary Treatment of Domestic Sewage
Authors: Araújo H. , Clóris M.
Published: May 2018

The objective of the present paper is the verification and quantification of the reduction of phosphorus with the use of water hyacinths in tertiary treatment of domestic sewage.

Secondary effluents from a small treatment station were run through a series of four tanks containing water hyacinths. Measurements and analyses were conducted in order to verify reduction of nutrients in the final effluent.

Results showed removal up to 88% orthophosphates (leaving 0.21 mg/l) for an average detention time of 5.44 days. The average flow was 3.3 m3 per day.

These encouraging results suggest the practical value of the method when there is the need of tertiary treatment for the sewage of small communities.
The Hornsby Bend Hyacinth Facility in Austin, Texas
Authors: Dinges Ray , Doersam Jim
Published: May 2018

The Hornsby Bend Hyacinth Facility, the first such system built under the U. S. Environmental Protection Agency “Construction Grants Program”, represents the culmination of over a decade of experience at the City of Austin with hyacinth treatment.

The facility consists of three culture basins 265 m in length with an area of 1.6 ha. To permit year-round hyacinth culture, basins are covered with a 2.06 ha unitary greenhouse structure. Fenced exclusion areas at intervals along sides of basins serve as natural aerators and enhance fish production.

The system, operated in an aerobic mode, was designed to daily treat about three million liters of sludge lagoon supernatant. Exclusion of large vertebrate predators and stocking of basins with selected animal species will provide a unique ecosystem. Basins were planted with hyacinth in late October, 1985 and discharge commenced on February 3, 1986. Functional characteristics and ecological considerations of the facility are discussed and operational performance data are presented. Maintenance harvesting of hyacinth and disposition of plant material are described. Application of greenhoused hyacinth treatment systems are addressed.
Experimental Investigations into the Use of Emergent Plants to Treat Sewage in South Africa
Authors: Alexander W. V. , Wood A.
Published: May 2018

South Africa is a relatively water-short country which has many rural communities with water-borne sewage infrastructures requiring low technology treatment facilities. In order to protect the water resources of the country the authorities have set high standards for effluent quality (COD < 75 mg/l, NH3 < 10 mg/l, E. coli < 1000 and in some areas P < 1 mg/l).

Traditionally, oxidation ponds have been used in these applications but have not been able to consistently meet the required standards and recently interest has been shown in artificial wetlands as a low technology means of solving the problem. As a result several experimental projects are at present being initiated in South Africa, both as primary and secondary treatment for domestic sewage and also as a tertiary treatment to remove nitrogen, phosphorus and E. coli from conventional sewage plant effluents.

The designs of these experimental projects are described in the paper and it is hoped that data will be available for presentation at the seminar.
Purification of Pisciculture Waters through Cultivation and Harvesting of Aquatic Biomass
Authors: Simeon C. , Silhol M.
Published: May 2018

The study of thermal wastes from the nuclear plants around Pierrelatte for agricultural, piscicultural, energy and environmental protection purposes resulted in the establishment of a pilot facility as early as 1976.

An aquatic macrophyte pilot facility has been operational since 1983 to study the use of water hyacinths from the aspects of energy and ecology. The results obtained suggest that production yields for the 7 month growing period should exceed 60 metric tons (MT) (dry weight) per hectare in a European climate, and that such crops can feasibly be cultivated in temperate regions.

The pilot facility is supplied with pisciculture effluent water, making it possible to quantify the stabilization power of the plants. Without primary decantation, with a retention time of 4 days and stabilization with water hyacinths only, the organic matter waste pond surface area required is 3.5 m2/m2 of pisciculture pond. Any primary or secondary facilities will lead to a reduction of these areas. The final decision will depend on the economical optimization of all the wastewater.
Waste Stabilization Ponds in Europe: A State of the Art Review
Authors: Vuillot M. , Boutin C.
Published: May 2018

Waste stabilization ponds can be found in 16 countries in Europe. Information given at a consultation of WHO specialists to review the state of the art in lagooning, highlighted the varying development stages which have been achieved in this field in 10 different countries. Design criteria vary from one country to another, to suit local conditions and conform with the quality standards which effluents are expected to meet. Lagooning has found many different fields of application in Europe : small communities, tourist areas, tertiary treatment, where it is likely to be further developed.
A Simulation of Benthal Stabilization
Authors: Bryant C. W. , Bauer E. C.
Published: May 2018

An existing benthal model has been modified and calibrated for the description of the physical and biological processes in consolidating organic deposits of both municipal and papermill origin. Temperature sensitivities, phosphorus reactions, and flexibility as to solids identification were added to the model. Model predictions of organic stabilization, direct oxygen uptake, and soluble feedback of nitrogen, phosphorus, and chemical oxygen demand have been compared to data collected from both laboratory and field operations. Phosphorus distribution was controlled by advection and biological uptake in all cases. Nitrogen feedback varied in a complex manner and was difficult to simulate.
Design Equations for Bod Removal in Facultative Ponds
Authors: Joe Middlebrooks E.
Published: May 2018

Facultative pond performance data collected for the US Environmental Protection Agency (USEPA) at four locations throughout the USA and data collected by others were used to evaluate the most frequently used design equations and to develop non-linear design equations. Empirical models were evaluated as well as the classical plug flow and complete mix models. The first order plug flow model gave the best fit of all the rational models. The empirical non-linear models did not fit the data, nor did the other empirical models with the exception being the areal loading and removal model. Attempts to verify the models developed with the USEPA data using data collected by others were not successful with the exception of the areal loading and removal model.
The Hydraulic Performance of Waste Stabilization Ponds in Portugal
Authors: Marecos do Monte M. H. F. , Mara D. D.
Published: May 2018

The hydraulic regime in two Portuguese facultative waste stabilization ponds, a primary facultative pond receiving raw sewage (in Portimão) and a secondary pond receiving the effluent from an anaerobic pond (in Vidigueira) was studied by means of a fluorescent dye tracer technique. The resulting dispersion numbers, respectively for winter and summer, for each pond were as follows: 0.595 and 0.371 in Portimão, and 0.574 and 0.523 in Vidigueira. These results did not agree with those obtained from the available predictive equations in the recent literature.
A Study of the Performance of a High-Rate Photosynthetic Pond System
Authors: Pinheiro H. M. , Reis M. T. , Novais J. M.
Published: May 2018

Colour changes and other marked disturbances were observed at a high-rate photosynthetic pond system at Alcochete, Portugal. Previous chemical and microbiological tests made it possible to attribute these occurrences to the proliferation of purple sulfur bacteria, following the probable production of sulfide inside the ponds by sulfate-reducing bacteria. Results from more recent tests and observations are presented, which confirm the earlier conclusions, in addition to revealing a number of inadequacies in the ponds chosen operating conditions, which are in all probability at the origin of the observed disturbances. Corrective actions planned include a more efficient mixing of pond contents, the strict prevention of contamination with salty estuarine waters and the control of residence times and bottom sludge accumulation.
Harvesting of Algae from High-Rate Ponds by Flocculation-Flotation
Authors: Sandbank E. , Shelef G.
Published: May 2018

Microalgae grown in stabilization ponds and in high rate oxidation ponds (HROP) treating wastewater, were harvested by flocculation with aluminium sulfate and floated in a laboratory electro-flotation unit, where bubbles were produced electrolytically. It was shown that the higher the solids concentration, the lower is the air: solids ratio needed to achieve 90% algae removal. The simultaneous flocculation of suspended algae and release of bubbles while flocs grow, give equal suspended solids removal as the classical flush mixing flocculation followed by slow mixing-flotation stage. Air : solidsratios between 0.009 and 0.013 were sufficient for flocs flotation by dissolved air flotation (DAF) and electro flotation. Continuous flocculation-flotation in a DAF pilot plant unit showed that flush mixing can be replaced by injection of chemicals in-line provided a retention of 15 sec is given before the inflow to the flotation tank. Slow mixing could be eliminated altogether when bubbles were generated simultaneously with the flocculation stage. DAF was further simplified, replacing the air compressor used for pressuring air into water by a venturi suction at the under pressure side of the pump in the pressurised line. DAF in its simplified version is preferred for algae harvesting in fresh water algae cultures and in HROP systems, while it is recognized that electroflotation may be preferred in harvesting marine microalgae.
The Effect of pH on the Performance of High-Rate Oxidation Ponds
Authors: Azov Y. , Shelef G.
Published: May 2018

A common observation in high-rate oxidation ponds (HROP) is that pH riseswill usually be followed by decreases in algal production and in overall pond performance. It was found that pH has minor direct effects on algal production but has major indirect effects as it determines the ratios of the carbonate system species and the dissociation of ammonia in the pond. Thus, increased pH values may cause carbon limitation of algal production or free ammonia inhibition of algal photosynthesis in HROP.
Infiltration Rates for Separate Sewage Collection Systems
Authors: Murray J. B.
Published: May 2018

Factors that influence infiltration rates for separate sewage collection systems are reviewed.

Practical design and construction criteria that minimise infiltration and appropriate design infiltration rates adopted in 1960's are enunciated. Measured infiltration rates for typical catchments substantiate the design rates.
Reuse of Municipal Wastewater in Arid Countries
Authors: Neis U. , El-Gohary F. , Pinnow P.
Published: May 2018

Biological wastewater pretreatment with a rotating biological contactor was found to be an appropriate technology to be used in developing countries for the reuse of wastewater for irrigation. Criteria for the wastewater pretreatment prior to agricultural reuse were elaborated based on removal of put-rescible organic matter and on balancing the nutrient composition of the effluent. Experimental investigations performed in Cairo, Egypt, show that an organic surface loading of the RBC of 15 mg BOD5/l leads to optimum effluent quality in respect to irrigation reuse with high organic constituents and partial nitrogen removal. The biodegradation of municipal sewage and ammonia conversion in Cairo proceeds at higher rates compared to temperate conditions.
A Study on Reaeration in River Cascades
Authors: von Sperling Marcos
Published: May 2018

The reaeration caused by a series of natural cascades on the Arrudas River was studied. Experimental results were compared with theoretical ones given by formulae available in the literature and showed no positive agreement. An empirical formula was derived and further simplified for use in a more generalized way, giving very good correlation with observed dissolved oxygen values. This formula was tested in two other cascade systems, giving acceptable results. A sample calculation for a simulated situation is presented, showing the methodology to be employed in cascades of similar configuration.
The Role and Problems of Monitoring Bottom Sediment for Pollution Assessment in the Coastal Marine Environment
Authors: Literathy P. , Nasser Ali L. , Zarba M. A. , Ali M. A.
Published: May 2018

The role of bottom sediment in pollution assessment of surface water and the problems related to its characterization were reviewed and identified. The importance of data validation in monitoring bottom sediment was recognized. The effect of grain size distribution and of spatial variations in the bottom sediment justified a sound sampling and analytical protocol.

Analysing the clay-silt fraction to reduce the effect of grain size was shown to be reliable. Before monitoring, however, one should prove that bottom sediment characteristics are homogeneous horizontally around the sampling site. Due to vertical sediment stratification from temporal variation of pollution, identification of the sediment layer to be monitored is of the utmost importance. It was found that “double sampling”, i.e., simultaneous sampling of the surface and the top 1 cm of the sediment layer provided representative data when redistribution of the bottom sediment is within acceptable limits. When characterizing the release of carbonate-bound phosphates and heavy metals from sediments, the multistage extraction technique with carbon dioxide was found to be effective. It was concluded that pollutant dynamics and the impact of the intertidal zones on the coastal marine ecosystem could be evaluated by monitoring the sediment, interstitial water, tidal creek and tidal waters simultaneously.
Effect of Alternating Aerobic and Anaerobic Conditions on the Economics of the Activated Sludge System
Authors: Ip S. Y. , Bridger J. S. , Mills N. F.
Published: May 2018

Results of our trials demonstrate that the alternating aerobic/anaerobic activated sludge (AAA-CMAS) system is capable of producing effluent of high quality in either fully-loaded or under-loaded conditions. The aeration energy saving and the sludge reduction of the AAA-CMAS system was shown to be of the order of 30% and 15% respectively. Because denitrification process is taking place within the reactor under controlled conditions and not in the sedimentation tank where degree of denitrification cannot be controlled, effluent of the AAA-CMAS system was found to contain much less suspended solids and E. coli counts than that of the conventional system, resulting in further cost saving in chlorination and in back-washing of the filter.
Advantages of Dual-Media Dry Filters in Biological Wastewater Treatment
Authors: Richard Y. , Seyfried C. F.
Published: May 2018

SUMMARY

The main and original features of dry filtration are reviewed. Forced aeration increases the aeration capacity of the process. In addition, the dual layer of media results in a better control of the elimination of both dissolved pollution and that connected with suspended solids. The treatment of various waste water in which the ratio between soluble and insoluble pollution was varied, made it possible to differentiate the way in which each is removed. This study lasted for one and a half years with 10 month's actual testing on two separate pilot plants. The contact time was related to the water and air flow rates as well as the degree of cloqqinq. The effect of the type of support media and the rates of flow of the various fluids were studied and the result led to recommendations being set for application of the process on an industrial scale.
Control of Biological Scum in Activated Sludge Plants by Means of Selective Flotation
Authors: Pretorius W. A. , Laubscher C J. P.
Published: May 2018

The occasional occurrence of a biological scum of problematic proportions in activated sludge plants, is widespread. The causitive organisms have in Southern African plants been identified as members of the Nocardia and Microthrix species. When causing scum problems, these organisms have the property to be selectively separated from the settleable activated sludge floc by a process of selective flotation. By applying the process of selective flotation a quantitative method for the determination of biological scum has been developed. This method was used to compare the scum intensity of different activated sludge plants and to evaluate the efficiency of scum removal upon treatment. Pilot scale studies were undertaken to evaluate the process of selective flotation as a simple practical method for the control of scum forming micro-organisms in activated sludge plants.
Environmental Protection in the United States Pulp, Paper, and Paperboard Industry: An Overview of Regulation of Wastewater Under the U.S. Clean Water Act
Authors: Hanmer Rebecca W.
Published: May 2018

The pulp, paper, and paperboard industry in the United States is the larqest industrial user of water with half of the facilities discharging wastewater directly to our Nation's waters. The major pollutants of concern have historically been the conventional pollutants: biochemical oxygen demand (BOD5), total suspended solids (TSS), and pH. Biological treatment systems are currently employed to reduce these pollutants. Sludges generated by these treatment systems have been categorized as nonhazardous and are generally landfilled. Under the Clean Water Act, the Environmental Protection Agency (EPA) has promulgated all the reguired regulations for this industry. The national regulations are applied to individual pulp and paper mills through permits issued by EPA Regional or State staff. Permit limits can be written that are more restrictive than the national regulations to protect local water guality. In its current projects concerning the pulp and paper industry, EPA is focusing on the reduction of toxic pollutants. The Agency is conducting a joint EPA/industry program to study dioxin discharges at bleached kraft mills. The Agency will also undertake a comprehensive review of the pulp and paper regulations in 1988.
The Taman Process: Experiences of Full-Scale Operation at Anjala Paper Mill
Authors: Lehtomäki Matti
Published: May 2018

The first full-scale anaerobic waste water treatment plant in the Finnish wood processing industry has been completed at Anjala Paper Mill. This TAMAN process together with the extensive renewal of the water circulation systems as well as solids recovery have made it possible to meet the new environmental requirements coming into force in June 1987. The total BOD7 reduction due to this investment program is nearly 90 %. The waste water flow through the TAMAN process is 11000 m3/d. The specific water consumption of the debarking plant has been minimized and circulation water is clarified in a separate settler. TAMDEC gravity thickeners make solids retention more effective and the TASSTER screw press ensures that all the mill's sludge is dewatered before fluidized bed incineration.
An Anaerobic Process for Treatment of CTMP Effluent
Authors: Welander T.
Published: May 2018

A multi-stage process for treatment of CTMP effluent has been developed. It comprises primary settling and four biological stages. The concentration of hydrogen peroxide, a compound which is toxic to anaerobic bacteria, is reduced in the first biological stage by means of the biocatalytic action of biomass that is recycled from the following acidogenic and/or aerobic stages. The second stage is an acidogenic stage, in which volatile fatty acids are formed and remaining peroxide is decomposed. A mixture of aluminum, iron and calcium salts is added to the effluent in order to detoxify compounds which are toxic to methanogenic bacteria. The main part of the COD and BOD removal takes place in the third stage, the methanogenic stage, after which follows an aerobic stage for polishing and removal of bad-smelling compounds. The COD and BOD7 removals in the anaerobic part of the process are 60 and 90 %, respectively, and the methane yield is 0.20-0.25 Nm3/kg COD removed.
Process Alternatives for Enhanced Biological Treatment Efficiency of Forest Industry Effluents
Authors: Mehner A. , Morange H. , Rintala J. , Silvo R. , Viitasaari M. , Vuoriranta P.
Published: May 2018

Biological wastewater treatment methods are being used at an ever increasing extent for the treatment of wastewaters from the Finnish forest industry. Conventional activated sludge processes treating the composite wastewaters from the mill are most commonly used.

Present plants may turn out to be inadequate in some cases, or they may not serve the purpose. This can happen for example when 1) the process fails or the running costs become extremely high, 2) the legal regulations concerning the quality of the treated wastewater change or 3) production of the mill expands or is diversified. These situations can be handled by expanding the existing treatment capacity. An alternative is to develop specific additional treatment units more appropriate for the wastewaters in question.

In this paper the advantages and disadvantages of some biological process units completing activated sludge treatment plants are studied. In experimental studies a, b and c, a two-stage activated sludge process, a modified activated sludge process and an anaerobic pretreatment, respectively, are examined. The results of these studies show that a selective, highly loaded first stage of a two-stage activated sludge process can efficiently equalize and improve effluent quality, especially when the suspended solids concentration in the influent is high (Study a), that an anoxic/anaerobic unit together with a small aerated contact unit combined with a conventional activated sludge process can reduce phosphorus levels in the effluent (Study b), and that anaerobic pretreatment of concentrated wastewaters efficiently reduces the organic loading, improves sludge settling properties, and reduces sludge yield and phosphorus demand (Study c).
Improving the Settling of Activated Sludge by Chemical Additives
Authors: Demel I. , Möbius C. H.
Published: May 2018

One of the main problems encountered in biological waste water treatment plant of papermills is poor settling of activated sludge in secondary sedimentation tanks. In many cases, activated sludge volume indices stay above 150 ml/g. Moreover, bulking of sludges in activated sludge plants of papermills is more frequent than usual. Bulking sludge is characterized by excessive growth of filamentous microorganisms.

In a lab-scale activated sludge plant, tests were made to improve the settling of activated sludge by adding the following chemicals: Lime, alkaline activated bentonite, powdered lignite coke, polyelectrolytes used as flocculants.

The findings reveal that dosage of the above additives actually gives improved sedimentation. Moreover, biochemical degradation becomes more effective if bentonite and powdered lignite coke are added. Test results are evaluated to determine the extent to which settling of the activated sludge and plant efficiency are improved, taking into account operational and waste water parameters. Using lime, bentonite, lignite coke or polyelectrolytes is an economic method of fighting or preventing acute or permanent problems caused by bulking sludge and high sludge volume indices.
Control of Activated Sludge Circulation and of Secondary Settling Tank Hydraulics
Authors: Huster R. , Möbius C. H.
Published: May 2018

The directives issued by the German Waste Water Association (ABWASSERTECHNISCHE VEREINIGUNG (ATV)) and by the British WATER RESEARCH CENTRE (WRC) in respect of the rating and control of activated sludge circuits and of the loading of secondary settling tanks of biological waste water treatment plants were studied for their applicability to papermill effluents. To this end, several years' testing was carried out on an activated sludge pilot plant and on various industrial plants. These tests revealed that secondary settling tanks of papermill effluent treatment plants may safely be rated in accordance with ATV up to a sludge volume index (SVI) of 300 ml/g and a sludge return rate of 3. If SVI values are low, the WRC process permits excessive surface loadings and is thus only practicable for high SVI levels. If sedimentation properties of the activated sludge are poor, load capacity limits are indicated more correctly by the WRC method. A simplified settling velocity method derived from the WRC process gives reliable information on the load capacity of secondary settling tanks and may readily be used for sludge circulation control.
Methods for Determination of Sum Parameters and Characterization of Organochlorine Compounds in Spent Bleach Liquors from Pulp Mills and Water, Sediment and Biological Samples from Receiving Waters
Authors: Martinsen Kari , Kringstad Alfhild , Carlberg Georg E.
Published: May 2018

Methods suitable for determination of extractable organic chlorine in water, sediment and fish have been optimized. Cyclohexane was found to be the best nonpolar extraction solvent. For sediment and fish samples a cyclohexane/isopropanol solvent mixture was used. The organic chlorine in the extracts was determined by neutron activation analysis. The precision of the methods varied between 1 and 11 percent over a large concentration interval. Two methods for determination of adsorbable organic halogen using carbon and XAD-4 as adsorbents were compared. The carbon adsorption method had a lower detection limit (3 µg/l) and gave higher concentrations for effluents,and fresh and brackish water samples. The XAD-4 method gave higher concentrations for sea water samples. Examples of treatment with sulphuric acid containing different amounts of water and the use of thin layer and gel permeation chromatography to separate and characterize extractable organic chlorine are shown.
Atmospheric, Geological, Marine and Anthropogenic Effects on Groundwater Quality in Finland
Authors: Lahermo Pertti W.
Published: May 2018

The atmospheric, geological, marine and anthropogenic factors affecting the chemical quality of groundwater are evaluated. Sulphates and nitrates derive mainly from the atmosphere as wet or dry deposition in weakly mineralized shallow groundwater in natural uncontaminated surficial aquifers. The texture, structure and lithologic composition of aquifer material have an impact on water chemistry although marine influence and anthropogenic pollution generally outweigh the geological influence. Relict seawater trapped in deeper parts of confined aquifers and in bedrock covered by clay deposits has a marked effect on the quality of groundwater drawn from wells drilled into bedrock in the broad coastal belt. Brackish or saline groundwater is encountered all over the country in holes drilled in crystalline bedrock to a depth of more than 500 to 1000 metres. The lithologic environment affects the quality of deep bedrock groundwater which tends to change from Na-Cl type towards Ca-Na-Cl type with increasing salinity and depth of occurrence. Anthropogenic pollution is reflected in elevated amounts of all major dissolved components, although the most sensitive indicators of contamination are nitrates, chlorides and potassium. Nation-wide hydrogeochemical mapping of rural water sources revealed that shallow wells dug into glacial till deposits had the highest median NO3 contents, and that spring water discharging from glaciofluvial sand deposits had the lowest. The quality of groundwater distributed by public waterworks is generally good.
Movement and Survival of Bacteria in Porous Media
Authors: Kott Yehuda
Published: May 2018

Floodwater and flowing rivers contain bacteria and viruses from sewage and manure which may percolate to aquifers and contaminate groundwater. This study investigated the behaviour of bacteria and viruses introduced with tap and other waters in sand columns. The adsorption and desorption from sand of Escherichiacoli, Enterobacteraerogenes, Staphylococcusaureus, Streptococcusfecalis and Bacillusmegaterium were examined. The capability of Salmonellatyphimurium, Salmonellatyphi and Shigellaflexneri of surviving in natural organic matter accumulated in sand was examined, as was the survival of poliovirus 1 and colibacteriophage in sand columns. Size and morphology of the bacteria had no influence on the filtration efficiency. No difference was found between Gram positive and Gram negative bacteria. Survival of the enteropathogenic bacteria in the rich organic matter in the column ranged up to not more than about twenty days. However, Salmonellatyphimurium survived much longer. Poliovirus 1 was less resistant to the adverse conditions of the sand column as compared with f2 bacteriophage. However, both viruses behaved in the sand column like the bacteria, but survived for over 100 days.
Ground Water–A Living Ecosystem
Authors: Seppänen Harri
Published: May 2018

Many living organisms affect the quality of the ground water. Precipitation and/or solubility of many inorganic compounds depends in some way or other on biological activity of living organisms. The role of bacteria and other organisms in these processes may be either direct or indirect.

The oxygen consumption as a result of the decomposition of organic compounds is one of the most important processes affecting the quality of the ground water. In anoxic environments both iron and manganese are reduced becoming soluble in the ground water.

In weakly buffered ground water the release of the carbon dioxide during decomposition of organic substances decreases the pH of the water promoting the solubility of iron and manganese.

Most of the bacteria living in the ground water are psychrophilic and are attached on soil particles. Only few types of bacteria are free living.
Biotechnology for Manganese Removal from Groundwaters
Authors: Peitchev T. , Semov V.
Published: May 2018

This paper presents the results of investigations into the purification of river terrace groundwaters containing manganese (Mn2+) up to 3 mg/l. It has been found that if manganese is present in terrace waters, it is always accompanied by manganese oxidizing bacteria. Based on this, a process has been developed for the biological removal of manganese without the use of chemical reagents. The technology was implemented under operational conditions in 1982, and has given stable treatment to date.
Groundwater Investigations in the Lavia Deep Drilling Hole-Sampling Techniques and Results
Authors: Lampén Paula H. , Nikula Anneli
Published: May 2018

The Industrial Power Co. Ltd (TVO) studied the final disposal of spent nuclear fuel in Finnish crystalline bedrock. During the years 1984-85 preparative work for the execution of site investigation was carried out. The tests of investigation methods and equipment have been carried out in a 1000 m deep test borehole at Lavia, Western Finland. Geophysical and hydrological borehole investigations have been carried out and groundwater samples taken.

As a part of TVO's R & D work Imatran Voima Oy (IVO) has planned and built new equipment for groundwater sampling and chemical field measurements in deep boreholes with a minimum diameter of 56 mm and a maximum depth of 1000 m.

The borehole assembly of the groundwater sampling equipment comprises an inflatable double packer system and a membrane pump. It is connected via hoses to a mobile unit consisting of a flow-through-cell system with electrodes and a micro-computer for automatic control and data processing (Fig. 1). Nitrogen gas is used to inflate the packers and to drive the membrane pump. The specific conductivity, amount of dissolved oxygen, pS, pH and Eh of the groundwater sample are measured in a system of four flow-through-cells before the sampled water gets into contact with air.

Using this instrument groundwater samples were taken from the test borehole in three stages, at five depths in the borehole. The concentration of iodide, the tracer of the drilling fluid, was frequently controlled during sampling. Several different physico-chemical analyses was performed comprising e.g. the main cations and anions and trace elements. Also samples for isotopic and gas analyses were taken.

According to field measurements and laboratory analyses, the groundwater seems to have a low ionic strength with no considerable variation in depth. Rather reducing conditions (minimum Eh about −450 mV) were observed below the depth of 400 m. Especially data from isotopic analyses gives evidence of mixing with drilling fluid. In spite of the disturbances in groundwater caused by drilling fluid and vertical flow in the open borehole the samples can be considered representative enough in evaluation of the general ionic composition of the groundwater.

The experience gained from the groundwater sampling at Lavia has had a significant influence on planning the future groundwater sampling during field investigation for the years 1987–92.
Chemical, Mineralogical and Microbiological Factors Affecting the Precipitation of Fe and Mn from Groundwater
Authors: Vuorinen A. , Carlson L. , Seppänen H. , Hatva T.
Published: May 2018

Precipitation of hydrous Fe and Mn oxides was investigated in 12 plants, constructed for purification of groundwater from excess Fe and Mn. The re-infiltration method was applied in 7 plants and the slow sand filtration in 5 plants (Hatva et al., 1985; Hatva 1987, this symposium)

Water was analysed for aquatic chemistry and for the speciation of Fe, Mn, Zn and Cu. The distribution and mode of occurrence of the elements in the precipitates were studied by successive extraction and dissolution kinetics techniques. The mineralogy of the oxidic Fe and Mn precipitates was studied using XRD techniques.

The results suggest the presence of Fe(II), Mn and Zn in groundwater mainly in cationic form. Cu was in colloidal and organically bound forms.

The precipitation of hydrous Fe and Mn oxides from groundwater is affected by chemical and microbiological factors. The oxidation of Fe(II) took place mainly chemically with increasing O2 content, pH and Eh of the water. Ferrihydrite, a poorly ordered oxidic Fe mineral was the dominant product. Environmentally controlled colloidal and surface chemical properties of the precipitating species enhanced the precipitation causing sorption and scavenging of Si and cations. Owing to the relatively high Si content (over 4 mg Si/l) of groundwater in Finland and the interaction of Si and Fe the crystallization of lepidocrocite that is formed in Si-free systems was inhibited and ferrihydrate was formed instead.

15-20% of total Fe and above 50% of total Mn were in sorbed form in the precipitates. Only 15-20% of Mn was in sorbed form in the precipitates that contained MnO2 minerals, vernadite and birnessite (in two plants).

The oxidation of Mn(II) appeared to involve microbial catalysis because it was adversely influenced by high pH and copper sulphate.

The freshly precipitated MnO4 strongly sorbed and scavenged heavy metals (e.g., Ag, Sn, Ni, Co, Zn and Cu). Cations (Ca2+, Mg2+, K+ and Na+) were sorbed by the hydrous Fe oxides at high pH (above 7) whereas Cu tended to be sorbed at low pH levels.

Gallionella was the dominant type of bacteria in the raw water and the bacterial density was low. In the filtration basins Leptothrix, Siderocapsa and Ochrobium were the typical microorganisms. The bacterial density was highest in the upper part of the sand in the infiltration basins and the bacteria were covered by Fe (and Mn) precipitate encrustations.
The Use of Carbon Dioxide in the Neutralization of Alkaline Water
Authors: Simas L. E. D. , Pessoa A. A.
Published: May 2018

This paper discusses the use of carbon dioxide in the neutralization of alkaline industrial effluents. The process advantages of the use of carbon dioxide, in comparison with the use of acids, are emphasized and details of the process are presented.
Ammonia Controlled Activated Sludge Process for Nitrification-Denitrification
Authors: Spies P. J. , Seyfried C. F.
Published: May 2018

The standards for discharge of sewage of a waste water treatment plant with an organic load of 110,000 FE require an ammonia nitrogen value of max. 5 mg/l. Since the design capacity of the plant is subject to important load variations, a process configuration guaranteeing full nitrification efficiency at each load is required. The described treatment system is equipped with an aeration control regulating the ammonia concentration in the effluent. The reactor configuration combined with the controlling equipment allows to fully utilize the simultaneous nitrification/denitrification capabilities of this plant. Finally the operation experiences and results obtained with this treatment process will be reported.
Oxygen Transfer Measurements and Air Distribution for an Aeration Basin with Fine Bubble Diffusers
Authors: Warriner Read
Published: May 2018

The off-gas method was used to study oxygen transfer efficiency in a long, narrow activated sludge basin. The basin was equipped with square, ceramic, fine pore diffuser plates arranged in a uniform longitudinal pattern at a depth of 4.3 m. Oxygen transfer efficiency, at 20°C and zero dissolved oxygen concentration, during the second and third years following diffuser cleaning, was between 15 and 17%. A uniform distribution of air to the tank was compared with a tapered air supply (more air at the inlet end and less at the outlet). The tapered air supply gave lower dissolved oxygen at the outlet and did not increase overall oxygen transfer. With a 3 to 5-fold variation in air flow, at either the inlet or outlet zone of the basin, the oxygen transfer efficiency, adjusted for zero dissolved oxygen, stayed constant.
Evaluation of the Efficiency of a New Aeration System at Henriksdal Sewage Treatment Plant
Authors: Reinius L.-G. , Hultgren J.
Published: May 2018

Henriksdal sewage treatment plant is the largest plant in Stockholm with a design flow of 370 000 m3/d. In one aeration tank of eleven a new fine-bubble aeration system has been in operation since August 1985. The tank is divided into 6 equal parts. The first part is an anoxic zone and the other five are aeration zones with tapered diffusers. Several instruments are installed in the block including separate air flow monitors in each of the five zones and D.O.-probes in the inlet and outlet of the zones. Equipment for flow measurement of settled sewage and return sludge is also installed. Every instrument is connected to a computer for data acquisition.

To evaluate the efficiency of the aeration system the oxygenation transfer capacity has been calculated from the oxygen massbalance equation for each zone as a function of air flow. To solve this equation the respiration has to be known and this is done by a simple respirometer for samples of the MLSS in each zone.

When the KLa-values are known as functions of the air flow the mass balance equation can be used to calculate the respiration rate in each zone. The computer has been logging data for 2 2 months, and it is possible to calculate the respiration rates in the different zones every hour during this period.

It is very important to know the respiration along the tank and how it varies to get the optimal tapering of the diffusers when it is time to change the aeration system in the other 10 tanks. The calculations show a different pattern in the respiration over the year depending on the rate of nitrification. Another use of the calculation of the oxygenation transfer efficiency is to recognize if any long-term change occurs due to clogging of the diffusers.
Performance Analysis of the Aeration Tanks in the Activated Sludge System
Authors: Iida Yukio
Published: May 2018

The performance of large scale aeration tanks was evaluated from the mutual relationship between the flow characteristics snd the substrate removal patterns. The results of the tracer studies indicated that the flow conditions in the aeration tanks were too complicated to describe satisfactorily with the mathematical models. In the light of the transient nature of physical, chemical, and biological factors controlling the mechanism of the activated sludge process, it would seem most unlikely to provide a unified kinetics model. As regards the load distribution, the empirical equation C/C0 = u/(u + Kx) well described the BOD distribution in the aeration tanks whatever the flow characteristics and tank geometry. The equation of C/C0 = u/(u + Kx) or C/C0 = 1/(1 + Kt) is definitely valid in field installations operating under conventional conditions.
Anaerobic-Aerobic Treatment of Industrial Wastewater
Authors: Bode H.
Published: May 2018

The paper evaluates the question of whether a combined anaerobic-aerobic or a solely aerobic treatment of some particular industrial wastewaters leads to better results. Therefore three different industrial wastewaters were treated in two different process lines: one line consisted of anaerobic treatment prior to aerobic treatment and in the other, only aerobic treatment was applied. The experiments were run with wastewater from:–the pectin industry–the sugar industry (beet sugar)–the animal pulp industry.

The data presented in this paper were gained from experimental work which was conducted over a period of two years. Different scales of treatment plants were used. The anaerobic treatment was done in full- and semitechnical scale reactors, while the aerobic treatment took place in labscale and semitechnical scale plants.

Surprisingly in all three cases the solely aerobic treatment led to slightly better results in terms of residual pollution.

Finally the paper presents data gained from a recently built, full-scale anaerobic-aerobic process which treats pectin waste. The aerobic stage of the process was designed on the basis of the results from the experimental work which was mentioned above. The results from the former experimental work and from the full-scale operation are compared.