bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation model for real-time decision support in controlling the impacts of storm sewage discharges
Authors: Reda A. L. L. , Beck M. B.
Published: May 2018

The impacts of combined sewage discharges on river water quality are studied using the MCSTR (Multiple Continuously Stirred Tank Reactor) dynamic model. The potential for applying this model in a real-time context is demonstrated as a tool to support decisions regarding treatment plant operating during storm events, when it is often not possible to sustain full treatment of the incoming sewage flow. Discharges to the River Cam of treated and untreated urban wastewaters from Cambridge and the Cambridge Sewage Works are addressed as a hypothetical case study. Alternative treatment strategies are defined for improving receiving water quality and assessed through simulated water quality downstream of the discharge; the state variables of the model include the concentrations of biochemical oxygen demand, ammoniacal- and nitrate-nitrogen, and dissolved oxygen (chlorophyll-a concentrations are also calculated, but not considered herein). Strategies are assessed and ranked according to the reduction in maximum pollutant concentration (or the increase in minimum concentration, in the case of dissolved oxygen) promoted by each alternative, relative to conventional operation. The consequences of discharging overflows at an alternative position in the river, rather than together with the treatment-plant effluent, are also evaluated. Run times fr the MCSTR model are of the order of just a few minutes (at most), thus allowing the potential for its use in real time as a decision-support aid.
Danube River Basin: Progress with the Environmental Programme
Authors: Botterweg T. , Rodda D. W.
Published: May 2018

An Internationally funded Programme, involving the European Commission, the Global Environment Facility managed by UN Development Programme, the World Bank and the European Bank for Reconstruction and Development, is addressing river basin problems in a unique situation. The solution of these should lead to the prevention of pollution and better water quality, protected ecosystems, sustainable water resources and more efficient sewerage and waste water treatment facilities for the 90 million population living in the region and the reduction of pollution impact on the Black Sea into which the Danube River flows. The paper introduces current Programme activities, the challenges being met and progress. Work is described for implementing a monitoring strategy, an accident emergency warning system and implementation of the 1994 Strategic Action Plan. The applied research activity is explained. The Programme is a major activity with many elements addressing a wide range of environmental problems in the catchment of a major international waterway.
Water Quality Management Options for a Downstream Transboundary River Basin - The Sajó River Case Study
Authors: Fehér János , Galambos István , Lehoczki Zsuzsa
Published: May 2018

Water quality management has been a priority in Hungary in the past decades. Focus was especially upon improving water supply and stimulating economic development.

On 1st January 1996 new Law on General Regulations for Environmental Protection (No. 53/1995) and the Act on Water Management (No. 57/1995) came into force. These laws are framework laws providing objectives to the development of the legal instrumentation of environmental and water protection. These new regulations should reflect the transitional nature of Hungary and should stimulate and facilitate the use of the most cost-effective and efficient forms of water quality management. Furthermore the regulations should aim at harmonization with EC directives.

To support the elaboration of the new regulations case studies were carried out in the frame of a EU PHARE financed project to give answers to several water quality management and economic questions, such as (a) the way in which water quality objectives can be set when dealing with transboundary loads and vulnerable groundwater resources; (b) how to address industries in sanitation; (c) how to formulate collection and treatment requirements in the case of a very sensitive surface water originating in a river basin with predominantly non-vulnerable groundwater resources; (d) the cost effective sanitation strategy; (e) the determination of permissible loads by using water quality models; and (f) how to allocate this load among pollution sources. The paper is gives an overview of the case study with the discussion of the conclusions.
The Mersey Basin Campaign
Authors: Jones T.
Published: May 2018

The Mersey Basin Campaign is now at the mid-point of a 25 year government backed partnership, which brings together local authorities, businesses, voluntary organisations and government agencies to deliver water quality improvements and waterside regeneration throughout the Mersey Basin Campaign area. Whilst much has been achieved due to investment by North West Water, the Environment Agency, local authorities and businesses the strength of the Campaign lies in the formation and support of active partnerships with the voluntary sector.
The controversial role of tile drainage in phosphorus export from agricultural land
Authors: Dils R. M. , Heathwaite A. L.
Published: May 2018

Field drainage, in the form of permanently installed pipes or temporary mole drains, is extensively used in Britain to reduce the incidence of waterlogging, and increase the length of the grazing season. Whereas the installation of artificial drains significantly improves the structural stability of the soil, water quality in recipient streams may be adversely affected by the accelerated rate of nutrient transport, and the circumvention of critical storage areas such as buffer zones. This research investigates the importance of phosphorus (P) loss in tile drainage for a mixed agricultural catchment (120 ha) in the UK. Phosphorus concentrations in drain discharge were low (<100 μg Total P l−1) and stable during base-flow periods (<0.5 1 min−1), and generally lower than in the receiving stream. In contrast, temporary (hours) elevated P peaks exceeding 1 mg Total P l−1 were measured in drain-flow during high discharge periods (>10 1 min−1). Large sediment-associated particulate P losses were measured during the first major drain-flow events of the autumn. Field drains are evidently effective conduits for P export from agricultural catchments. Recommendations for controlling P loss from diffuse agricultural sources are therefore critically dependent on a better understanding of surface and subsurface transport pathways.
The effect of SO2 emission controls on critical load exceedances for lakes in Southeastern Canada
Authors: Jeffries D. S. , Lam D. C. L. , Moran M. D. , Wong I.
Published: May 2018

The UN ECE definition of critical load (CL) involving protection of aquatic ecosystem structure and function was adopted by using pH 6.0 as a damage threshold. Critical loads were determined for 4 lake clusters in SE Canada. An Integrated Assessment Model (IAM) was used to estimate steady-state lake pH distributions for each cluster for steps of wet sulphate (SO42−) deposition in the range 6 to 30 kg.ha−1.yr−1. The CLs were interpolated from the damage vs deposition relationships and are, if anything, over-estimated for a number of reasons. Critical load values were <6, 6.9, 8.0 and 13.2 kg wet SO42−.ha−1.yr−1 for the Kejimkujik (Nova Scotia), Montmorency (Québec), Algoma (Ontario), and Sudbury (Ontario) clusters, respectively. Wet SO2−4 deposition presently exceeds the CLs for all Canadian clusters by ∼7 to 12 kg.ha−1.yr−1. Moreover, it is also expected to exceed them by ∼6 to 10 kg wet SO2−4.ha−1.yr−1 even after all SO2 emission controls required by the Canada/US Air Quality Agreement are finally implemented. Further control of both Canadian and US SO2 emissions to achieve lower SO42− deposition will be needed to reduce the magnitude of the CL exceedances.
Wet weather control demonstration activities in southeast Michigan: some lessons learned
Authors: Murray J. E. , Cave K. A. , Bryson D. S.
Published: May 2018

Wayne County's Rouge River National Wet Weather Demonstration Project (Rouge Project) is a comprehensive program to restore the water quality of the Rouge River, a tributary to the Detroit River in southeast Michigan. The Rouge River Watershed is largely urbanized with over 1.5 million people in 48 communities and 3 countries. Sources of pollution to the river include industrial and municipal point sources, storm water runoff, combined sewer overflows (CSOs) and other minor sources.

While the Rouge Project first focused on controlling the 150 CSO discharges the focus shifted to other sources of pollution, such as storm water in order to restore the river. This paper describes the lessons learned in building institutional and regulatory frameworks necessary to accommodate a watershed approach to wet weather pollution management. Also described are the consensus building strategies which were used to engage numerous stakeholders, provide them opportunities to influence decisions, and participate in the Rouge River restoration.

The Rouge Project is demonstrating that a watershed-based pollution management program is achieving faster and more cost-effective restoration and protection of water resources.
Management of diffuse pollution in agricultural watersheds: lessons from the minnesota river basin
Authors: Brezonik Patrick L. , Easter K. W. , Hatch Lorin , Mulla David , Perry James
Published: May 2018

The Minnesota River (Minnesota, USA) receives large non-point source pollutant loads. Complex interactions between agricultural, state agency, environmental groups, and issues of scale make watershed management difficult. Subdividing the basin's 12 major watersheds into agro-ecoregions based on soil type, geology, steepness, and climate enhances predictability of stream water quality parameters. An eight-step framework for agricultural watershed management is presented.
Is public participation in the pipeline? A social impact assessment of marine waste disposal in southern kwazulu-natal
Authors: Scott Dianne
Published: May 2018

There is a growing pressure, both internationally and particularly in South Africa, to include people in a more democratic form of environmental management necessitating a more holistic and interdisciplinary approach. Within this context, the paper documents a case study of public participation in the regulation of marine waste disposal. This involves examining the social input, via a Social Impact Assessment, into the decision-making procedure for the issuing of permits for marine waste disposal via three marine pipelines along the south coast of KwaZulu-Natal in South Africa. The SIA was designed to elicit the substantive social issues and facilitate a process aimed at consensus-building among stakeholders. The SIA revealed that such processes, while lengthy and costly, can provide the basis for sustainable environmental management if institutionalised mechanisms are set up through which the partnerships can be fostered and informed contributions made towards the environmental decision-making process.
Removal of phenolic compounds from aqueous solution by activated carbon cloths
Authors: Brasquet C. , Subrenat E. , Le Cloirec P.
Published: May 2018

Granular activated carbon (GAC) is easily used in water or wastewater treatment in order to remove organic micropollutants. Recently, a new presentation of activated carbon has been developed: fibrous activated carbon in the form of cloth or felt. This work investigates the adsorption onto activated carbon cloths (ACC) of various phenolic compounds from aqueous solution. Experiments were carried out in batch reactors with two ACCs (called CS 1501 and RS 1301) and their performances were compared with those of GAC. Initial adsorption kinetic coefficients were higher with fibers than with granules due to the direct connection of micropores to the external surface of fibers. Adsorption isotherms were also performed and modelized by Langmuir and Freundlich equations. Adsorption capacities were similar or higher with ACCs than with GAC. The behaviour of the ACC CS 1501 was also studied in a dynamic reactor. The breakthrough curves allowed the determination of high maximum adsorption capacities, 117 mg.g−1 for phenol. Pressure drops in ACC beds were measured and the influence of various parameters was shown: the activation step, the number of fabric layers, the space between two layers.
The impact of physico-chemical water treatment on a novel flotation/filtration process
Authors: Scriven R. J. , Ouki S. K. , Doggart A. S. , Bauer M. J.
Published: May 2018

Recent research explored the application of mechanical flocculation ahead of a novel flotation/filtration process (Counter Current Dissolved Air Flotation/Filtration - COCO DAFFTM) and compared it to the process performance seen when hydraulic flocculation was used. The energy input to the system, expressed in terms of the mean velocity gradient, G (s−1), and retention time, t, were used as a guideline for comparison between the two types of flocculation. Generally, better COCO DAFFTM performance resulted from using mechanical flocculation as against that using hydraulic flocculation. High G values (in excess of 80 s−1) were found to give best results, as opposed to values of 30-60 s−1 utilised ahead of conventional treatment. The effect of flocculation contact time on the COCO DAFFTM process was also studied. Current design practice typically utilises 20-30 minutes flocculation contact time. It was found that process performance, in terms of water quality, did not deteriorate excessively if the contact time was reduced to as little as 2 minutes, but filter run times were found to be proportional to contact time.
Photocatalytic oxidation of chlorophenols in the presence of manganese ions
Authors: Chen Jong-Nan , Chan Yi-Chin , Lu Ming-Chun
Published: May 2018

The decomposition of chlorophenols in aqueous solution with UV-illuminated TiO2 suspensions in the presence of manganese ions was studied. It was found that the removal rate of chlorophenols would be the highest at pH 3 in the presence of 1.18×10−4 M manganese ion. The effect of ionic strength on the 2-CP decomposition can be ignored in the range from 0.1 to 0.005 M for NaClO4. This study is also to explore the relationship between the adsorption rate and reaction rate. Results showed that the more the adsorption rate the more the decomposition rate for the three chlorophenols. Manganese ions can increase the photocatalytic oxidation of 2-chlorophenol in terms of DOC. The relationship between temperature and reaction rate for 2-CP is k = 0.0043T - 1.2146.
Industrial effluent control and waste minimisation: case studies by UK regulators
Authors: D'Arcy B. J. , Todd R. B. , Wither A. W.
Published: May 2018

Most current discussion on the techniques for effluent control emphasise the sophisticated approach most appropriate to advanced industrial operations in prosperous environments. This paper aims to demonstrate that a more basic approach still has a valuable role to play. A series of case studies from the United Kingdom examine how the application of simple techniques were able to provide significant environmental benefits at minimal net cost to the discharger. The examples ranged from raw materials recovery and waste recycling, to lateral thinking and the development of non polluting processes. The consequent reductions in effluent load to receiving waters have been found to be highly significant for the environment.
Comparison of ozone and hydrogen peroxide/ozone for the treatment of eutrophic water
Authors: Freese S. D. , Nozaic D. , Pryor M. J. , Trollip D. L. , Smith R. A.
Published: May 2018

Tests carried out on eutrophic waters using ozone and peroxone (peroxide and ozone) indicated that an applied ozone concentration of between 1 and 1.5 mg/l (ozone:DOC ratio of 0.2 to 0.5) was generally required before significant removals of natural organic matter surrogate parameters and micropollutants were obtained. Peroxone produced the same effect as ozone used alone, but the maximum effect occurred at a lower ozone concentration when using peroxone. Peroxide to ozone ratios greater than 0.3 to 0.5 were not found to increase the benefit derived from the addition of peroxide.
The use of computational fluid dynamics (CFD). Technique for evaluating the efficiency of an activated sludge reactor
Authors: Karama A. B. , Onyejekwe O. O. , Brouckaert C. J. , Buckley C. A.
Published: May 2018

Adequate models for wastewater treatment are limited by the cost of constructing them. Many a time, studies carried out on wastewater treatment plants have not been very useful in enhancing their performance. As a result, numerous mathematical models presented by different researchers on sedimentation tanks and clarifiers have not been getting much attention. Recently, improvement in computers and computational techniques have led to the development of a new generation of highly efficient programs for simulating real fluid flow within any type of geometry including clarifiers and activated sludge reactors. Herein, a computational fluid dynamics code, PHOENICS, is used to determine the performance of an anaerobic zone in an activated sludge reactor. Plausible results were achieved when experimental data were compared with numerical results.
Sewage re-use for irrigation in Athi River town Kenya: its implications on public health
Authors: Ofosu-Asiedu Kingsley , Oteino Demas A. , Omolo John O. , Etiegni Lazare
Published: May 2018

Occupational environmental health associated with both industrial and domestic sewage reuse for food production in Athi River town Kenya has been studied. The levels of toxic heavy metals such as lead, cadmium, selenium and arsenic in the soil, roof crops, leaf crops and fruits (or seed) were determined using atomic absorption spectoscophy (AAS). In soils the average levels of lead and cadmium were 0.44mg/g and 0.13mg/g respectively. The crops analysed were selected as root crops, leaf crops and fruits (or seed) crops. The levels of lead found in these crops were 0.06 μg/g, 0.01 μg/g and fruit 0.05 μg/g for root, leaf and fruit crops respectively. Similarly, the cadmium in root, leaf and fruit crops was 0.016 μg/g, 0.03 μg/g and 0.02 μg/g respectively. Coliform counts were greater than 300 counts per 100ml in all samples, which gave a positive indication of the presence of Escherichia coli.
System Closure, Free Enterprise and the Environment
Authors: Reeve D.W.
Published: May 2018

In the manufacture of bleached kraft pulp, evolving restrictions for effluent discharges and evolving technology are taking us towards lower and lower discharges of effluent and dissolved pollutants. Conflicting interest between economy and the environment often arise. For successful pulp manufacturing enterprises, we must look to processes which are low cost: low capital cost, low chemical cost, high capacity and high yield; and which produce high quality pulp: high strength, clean, bright, stable and uniform. Economic pressure is currently exceedingly great, as chronic overcapacity has led to low prices, low return on investment and the flight of capital from the free markets in which investors operate. Certainly we must work to achieve minimum impact of pulp mills, but developments in processes and process equipment for pulp manufacture must be economically as well as environmentally sustainable.
Ozonation and Wet Oxidation in the Treatment of Thermomechanical Pulp (TMP) Circulation Waters
Authors: Laari A. , Korhonen S. , Tuhkanen T. , Verenich S. , Kallas J.
Published: May 2018

Ozonation and wet oxidation were studied as means of the treatment of thermomechanical pulp (TMP) processing waters. There were two objectives of the experimental research concerning circulation waters: to reduce concentration of lipophilic wood extractives (LWEs) and to treat the concentrated residues from evaporation and membrane filtration by low-pressure catalytic wet oxidation. Ozone was found to selectively react with LWEs. The selectivity of ozonation defined as the ratio of the rate coefficients of the reactions with LWEs and other organic matter was found to be from 3 to 20. The reaction was always found to be of fast or moderate rate and, therefore, no dissolved ozone could be detected in water during ozonation. However, the ozone dose necessary to remove 90% of the LWEs in TMP water was found to be rather high, from 500 to 800 mg O3/l. This was determined by high content of organic matter, COD ranged between 3 and 6 kg O2/m3. The implementation of ozone for LWEs removal is therefore problematic from economical point of view. Catalytic low pressure-wet oxidation of membrane and evaporation concentrates was found to be effective: 50% of COD were removed under 150°C with subsequent increase of the wastewater biodegradability.
Nutrients Within Integrated Bleached Kraft Mills: Sources and Behaviour in Aerated Stabilisation Basins
Authors: Slade A. H. , Nicol C. M. , Grigsby J.
Published: May 2018

As constraints on the discharge of nitrogen and phosphorus from the pulp and paper industry become tighter, a thorough knowledge of nutrient sources, and their behaviour through treatment systems, is required. Once nutrient behaviour has been characterised, strategies to minimise discharge can be formulated. A survey of nutrient sources around a modern ECF integrated bleached kraft mill showed that point sources of nitrogen and phosphorus could be identified. Approximately 40% of the nitrogen was contained in the foul condensate stream and 40% of the phosphorus contained in the acid stage of bleaching. Three Aerated Stabilisation Basin treatment systems were studied, two of which were nutrient limited in terms of theoretical nutrient requirements. All three systems achieved approximately 90% BOD removal without nutrient supplementation. For the wastewater with a high BOD:N ratio (100:0.8), nitrogen fixation was shown to be important. Benthic recycling was a more important mechanism when the BOD:N ratio was lower (100:2.1). For a severely phosphorus limited wastewater (BOD:P 100:0.04), treated in a system with a long retention time (85 d), benthic recycling was the predominant mechanism for nutrient supply. The relative roles of nitrogen fixation and benthic feed back to the nitrogen cycle in aerated stabilisation basins are discussed.
Nitrogen Fixation in the Treatment of Pulp and Paper Wastewaters
Authors: Gapes D. J. , Frost N. M. , Clark T. A. , Dare P. H. , Hunter R. G. , Slade A. H.
Published: May 2018

Pulp and paper wastewaters are generally low in the key nutrient, nitrogen. Nitrogen supplementation is often practised to ensure effective BOD removal. Maintaining consistently low effluent discharge concentrations of nitrogen from nitrogen supplemented biological treatment systems is very difficult. Matching nitrogen addition rates to load variations is effective, but requires accurate flow and organic load measurements. By manipulating treatment conditions to select for the growth of nitrogen fixing microorganisms, it is possible to achieve good BOD removals without the addition of nitrogen. As the organisms only fix the nitrogen required for growth, very low soluble nitrogen discharge concentrations are possible. This concept has been explored in the development of a new technology for the treatment of nitrogen deficient wastewaters.
Wastewater Biofilters Used for Advanced Treatment of Papermill Effluent
Authors: Möbius Christian H.
Published: May 2018

The application of tertiary biofilters -- submersed aerated upflow filmreactors -- can be classified as follows:

1. treatment of biologically treated wastewater with BOD below 25 mg/l;

2. treatment of biologically treated wastewater with BOD between 20 and 50 mg/l;

3. treatment of biologically treated wastewater with BOD below 30 mg/l followed by partial oxidation with ozone, resulting in BOD of up to 80 mg/l.

These three types have to be discussed seperately. Conditions in these plants are quite different from the well-known secondary biofilters following chemical-mechanical pretreatment. The differences have to be regarded in design and operation of the plants. Several questions still have to be evaluated. Based on operational experience about details of microbiota, biofilm growth and attachment, treatment efficiency and stability of elimination, virtual independence of COD elimination from BOD elimination, retention of suspended solids, criteria for design and operation of these plants are discussed. Biofilters following the ozonation plants after biological treatment are quite different to operate. Special points of view to be taken into account at this are: no entry of microorganisms, possible ozone influences, inert solids produced in ozonation (mainly oxalate). These items are discussed based on experimental results.
Comparing Biological Responses to Mill Process Changes: A Study of Steroid Concentrations in Goldfish Exposed to Effluent and Waste Streams from a Canadian Bleached Sulphite Mill
Authors: Parrott J. L. , Jardine J. J. , Blunt B. R. , McCarthy L. H. , McMaster M. E. , Wood C. S. , Roberts J. , Carey J. H.
Published: May 2018

During the cycle 1 environmental effects monitoring (EEM) studies, wild fish collected downstream of several Nexfor Canadian pulp mills indicated reduced gonad size or fecundity. A two-year collaborative study between Nexfor Inc. and the National Water Research Institute of Environment Canada was begun to investigate the reproductive responses. The purpose of the study was to assess final effluents from Nexfor Canadian mills for their ability to affect goldfish circulating sex steroids (testosterone, 11-ketotestosterone) or production of steroids in vitro by testes from exposed fish. Along with final effluent, individual waste streams from the mill processes were tested to investigate the potential source(s) of steroid-disrupting compounds from within the mill. The study also provided a chance to study effluent potencies over time as mill processes were changed and upgraded. Goldfish exposed for 16-21 days to final effluent (100%) from a bleached sulphite mill (BSM) showed reduced testosterone and 11-ketotestosterone production by testes. Testes of goldfish exposed to undiluted final effluent had steroid production one-tenth that of controls. Fish exposed to individual waste streams (2-40%) had steroid production similar to control fish. It was difficult to assess the waste streams, as fish-exposure concentrations were inconsistent among waste streams due to differences in the acute toxicity of streams. Final effluent from the same mill collected one year later, after numerous mill upgrades (such as changes in chip handling, digester operation and better control of spills), showed an improvement: Goldfish exposed to 100% effluent had normal steroid levels. The study demonstrates the use of the goldfish steroid bioassay for detecting changes in effluent quality. Changes in processes at the mill in the year following the fish tests resulted in final effluent that had no deleterious effects on fish testes production of steroids. The environmental consequences resulting from the improvement in BSM final effluent quality will be tested during the cycle 2 EEM.
Characteristics of Dissolved Organic Material in Total Chlorine Free Bleach Plant and Laboratory Effluents
Authors: Liukko S. , Poppius-Levlin K.
Published: May 2018

The dissolved organic material present in totally chlorine free (TCF) pulp mill bleaching effluents and in their laboratory made counterparts was characterized using chemical and chromatographic analysis. Special attention was given to analysis of material originating from lignin and carbohydrate. With the exception of the P2 laboratory effluent, the BOD7, COD and TOC loads and the content of aromatic lignin in the effluents, were higher in the mill effluents. After oxygen stages, the content of monomeric acidic phenols and aromatic acids in the effluents was very low. The highest amount of carbohydrates was found dissolved in the first P stage mill effluent. The average molar mass of UV-absorbing material was lowest in ozone effluents. Carbohydrates were determined as monosaccharides after acid hydrolysis. Xylan was the main carbohydrate component in most effluents, and after ultrafiltration more xylose was found in fractions over 10 000 NMM. Ozone effluents were rich in arabinose, which was mostly found in fractions below 10 000 NMM. Most of the mannose and galactose that dissolved in the first alkaline peroxide stage effluents was found in fractions over 10 000 NMM.
Effects of Chemical Spills on Activated Sludge Treatment Performance in Pulp and Paper Mills
Authors: Sarlin T. , Halttunen S. , Vuoriranta P. , Puhakka J.
Published: May 2018

The aim of this research was to study the effects of chemical spills on activated sludge metabolic activity and settleability. On-site, laboratory-scale tests were carried out at three pulp and paper mill activated sludge plants. Oxygen uptake rate (OUR) and dissolved organic carbon (DOC) removal were used for monitoring of metabolic inhibition. The effects of chemicals on 30-min settled sludge volume were studied. Accidental release reports from five pulp and paper mills were analysed.

Thirty-four chemicals were selected to the laboratory tests. Of the tested chemicals 2 biocides, monochloro acetic acid, soft soap and turpentine inhibited the OUR of the sludge and thus, had an acute toxic effect on the activated sludge. The biocides and disperging agent reduced DOC removal. Aluminium sulphate and optical brightener had a negative effect on sludge settleability and thus, they may cause losses of activated sludge from treatment plant. In conclusion, maximum possible spill of the five chemicals may reduce the performance of the activated sludge.
Advanced Effluent Treatment in the Pulp and Paper Industry with a Combined Process of Ozonation and Fixed Bed Biofilm Reactors
Authors: Helble Alfred , Schlayer Wolfgang , Liechti Pierre-André , Jenny Rudolf , Möbius Christian H.
Published: May 2018

An advanced treatment process was developed during the last five years to improve the treated effluent quality in view of stronger environmental regulations and the possibility for the reuse of treated effluent in the Pulp and Paper Industry.

The combination of ozone with fixed bed biofilm reactors is one of the most efficient tertiary effluent treatment processes to give maximum elimination of COD, colour and AOX with a minimum of ozone dosage. Several laboratory and pilot tests with effluent from a full biological treatment works confirmed the expected targets.

Ozone diffusion parameters, i. e. bubble size, and distribution, reaction time and hydrodynamic pattern are decisive for interface/film or bulk reaction. This is the key economic factor for the elimination of certain kinds of organic matter by transferring persistent “hard” COD into biodegradable compounds (BOD).

Two-stage ozonation with intermediate biodegradation proved to be a valuable tool for obtaining high COD elimination efficiencies in the tertiary treatment of effluent with high persistent COD concentrations.

A fully equipped bench scale plant using the ozonation - biofiltration process is in operation since the beginning of 1998. A separate batch ozonation system allows tests for optimisations which are difficult to perform in a continuous process. Results with papermill effluent are presented. This equipment gives results sufficient for determination of design parameters for an industrial size.
Control of nutrient removal based on simple measurement values
Authors: Rammacher J. , Hansen J.
Published: May 2018

For economical and process-technical reasons it can be useful for small waste water treatment plants (WWTP) to influence the essential manipulated variables of nitrogen and phosphorus removal processes by means of control. The precipitant dosage should be optimized within the framework of physico-chemical elimination of phosphorus in terms of control techniques. In the following, field tests at a municipal WWTP for the design and the step by step optimization of fuzzy control will be explained and problems occurring with it will be depicted. The presented examinations are dealing with the optimization of precipitant dosage, using mostly available and easy measurable parameters. Compared to conventional strategies a significant reduction of the precipitant amount could be reached with generally lower phosphorus effluent values.
Application of low pressure nanofiltration membranes for the recovery and reuse of dairy industry effluents
Authors: Koyuncu I. , Turan M. , Topacik D. , Ates A.
Published: May 2018

This paper outlines the requirements for water reuse of dairy industry treatment plant effluents. Two alternative membrane processes are described. Nanofiltration (NF) membranes were applied to the existing treatment plant effluents in the first part of the study. NF membranes were used in different operating conditions. Successive batch runs had shown that serious membrane fouling appeared not to be a problem with treatment plant effluents. Excellent rejections have been achieved. It will be possible to recover approximately 90% of the treatment plant effluent for reuse. Heavy metal removal was also very high. In the second part of the study, two pass reverse osmosis (RO) membranes were applied to the raw wastewater of the dairy industry. RO experiments demonstrated that two-pass RO produce permeate of very good quality. Almost complete COD removals were achieved and flux values decreased slightly during the each RO run.
Environmental engineering education in North America
Authors: Bishop P. L.
Published: May 2018

The field of environmental engineering is rapidly evolving, and environmental engineering education programmes have been forced to try to keep pace. Keeping up with all of these changes has been difficult for many university programmes, particularly those that do not have a separate environmental engineering curriculum. As a result, many universities are establishing separate environmental engineering degree programmes or even creating a separate Department of Environmental Engineering. This paper describes current curriculum development activities in North America and efforts to accredit these programmes. It also describes the structure and operation of the Association of Environmental Engineering and Science Professors (AEESP), an organization in North America that is dedicated to improving environmental engineering education.
Environmental science education at the Swiss Federal Institute of Technology (ETH)
Authors: Frischknecht P.M.
Published: May 2018

In 1987 ETHZ, the Swiss Federal Institute of Technology, first offered a degree course in environmental sciences. The curriculum is based upon a comprehensive view of the environment and its systems. The first two years of the programme cover a multidisciplinary basic education in mathematics, natural and social sciences. For their advanced education in the fifth to nineth semesters the students select one of four science disciplines (Chemistry/Microbiology, Physics, Biology or Environmental Hygiene) and one of four environmental systems (Aquatic Systems, Atmosphere, Terrestrial Systems or Anthroposphere). The education in natural sciences is accompanied by a compulsory case study, which is implemented as a didactic tool to teach ecological problem-solving, and courses in environmental social sciences and environmental technology. During the professional practical training of about four months, students gain insight into the constraints of a professional environment. In the tenth semester a diploma project - equivalent to a master's thesis - is carried out.
Environmental engineering education at the Swiss Federal Institute of Technology in Zürich
Authors: Gujer W.
Published: May 2018

A revised ten-semester curriculum in environmental engineering was introduced at the Swiss Federal Institute of Technology in 1998 which is based on 10 years of experience with a previous less focused curriculum. The scope of the new curriculum is rather broad and includes sanitary engineering, water resources management, soil pollution control and resource and waste management. Air pollution is not fully developed yet. Based on broad basic studies (first four semesters) the professional studies (semesters 5 to 9) require the students to choose two out of four possible areas of specialization. These studies are followed in credit groups which combine advanced courses and extensive project work designed to reach scientific depth in an exemplary fashion. There is an exchange of teaching units between Environmental Engineering and Environmental Natural Sciences but the two curricula are quite different and lead to significantly different professional profiles.
Integrated Urban Water Systems (IUWS) - an international postgraduate course
Authors: Rauch W. , Schilling W. , Vanrolleghem P. , Krebs P.
Published: May 2018

In this paper we describe the background, the concept and the current status of an international postgraduate course on the subject of integrated urban water systems. The course aims to overcome the typical fragmentation of the engineering curricula in that field. Hence, the objective is to give a comprehensive overview on the total urban water and pollutant cycle, thus hoping to provide the students with a wider perspective on the problem. The course is structured into 22 modules that can also be taught in certain combinations. Emphasis is given to engineering problem solving and modeling.
Evaluation of teaching in environmental engineering
Authors: Mikkelsen P.S. , Larsen B.S. , Bjerg P.L. , Henze M.
Published: May 2018

This paper describes the effect of changing course content and teaching methodology for an introductory course in Environmental Processes. Student evaluations were used both to monitor the effect of the changes, as well as to change the course structure and the didactics. The result of the change was a better average score at the examination, and higher student satisfaction. The paper illustrates the usefulness of course evaluations in course development.
Pilot-scale gasification of municipal solid wastes by high-rate and two-phase anaerobic digestion (TPAD)
Authors: Ghosh S. , Henry M.P. , Sajjad A. , Mensinger M.C. , Arora J.L.
Published: May 2018

Bioconversion of municipal solid waste-sludge blend by conventional high-rate and two-phase anaerobic digestion was studied. RDF (refused-derived fuel)-quality feed produced in a Madison, Wisconsin, USA, MRF (materials-recovery facility) was used. High-rate digestion experiments were conducted with bench-scale digesters under target operating conditions developed from an economic feasibility study. The effects of digestion temperature, RDF content of digester feed, HRT, loading rate, RDF particle size, and RDF pretreatment with cellulase or dilute solutions of NaOH or lime on digester performance were studied. A pilot-scale two-phase digestion plant was operated with 80:20 (weight ratio) RDF-sludge blends to show that this process exhibited a higher methane yield, and produced a higher methane-content digester gas than those obtained by single-stage, high-rate anaerobic digestion.
A conscious scheme for remediation of odour nuisance at sewage treatment plants
Authors: De heyder B. , Thoeye C.
Published: May 2018

A standard methodology is presented to remediate odour nuisance at sewage treatment plants. The basic procedure of this methodology is formed by a conscious scheme which integrates all relevant steps in the remediation process (investigative actions, migitating measures, communication, etc.). Theaim of this methodology is to obtain a realistic plan of action, keeping count with local boundary conditions (available resources, available knowledge, certainty about the causes, etc.). In this way, the methodology functions also as a backbone when a well defined odour regulation is lacking, as is the case in Flanders for the moment.
Sewage treatment works odour measurement
Authors: Gostelow P. , Parsons S. A.
Published: May 2018

Public concern over odours from sewage treatment works is increasing. More people are being exposed to odours, due to development around existing works or the construction of new works. Raised awareness of both the environment and individual rights has meant people are now more likely to complain. Odourabatement and control is a major issue for sewage works operators.

To control odours, they must first be measured. This is no easy task as response to odours is subjective and our understanding of the sense of smell is incomplete. In assessing an odour nuisance, odour formation, emission, dispersion and perception must be considered. There is no single measure that is suitable for this purpose. Odour measurements fall into two classes. Analytical measurements characterise odours in terms of their chemical composition and are more suited to formation, emission and dispersion models. Unfortunately, they tell us little about the perceived effect of the odour. Sensory measurements employ the human nose and characterise odours in terms of their perceived effect. A link between analytical and sensory measurements is clearly needed.

In this paper data collected from odour surveys at 17 different wastewater treatment sites are evaluated to explore possibilities for linking analytical and sensory measures. The relationship between hydrogen sulphide concentration and odour concentration as measured by threshold olfactometry is explored. Correlations suggest power-law relationships between hydrogen sulphide and odour concentration, with r2 values as high as 0.69. This paper will assess the use of hydrogen sulphide (H2S) and olfactometry measurements for a range of unit operations and abatement technologies.
Impact of purification procedures on the viability and infectivity of Cryptosporidium parvum oocysts
Authors: Slifko T. R. , Coulliette A. , Huffman D. E. , Rose J. B.
Published: May 2018

The development of new technologies for Cryptosporidium oocyst detection as well as inactivation and removal is at the forefront of research objectives for the drinking and wastewater industries. One of the major issues associated with testing new technology is determining oocyst viability and infectivity before and after treatment. Because oocysts must be isolated from feces, preparation and pretreatment procedures may affect oocyst infectivity and potentially confound results obtained during survival and disinfection studies. The principal objective of this study was to evaluate the effects of preparation and pretreatment on C. parvum oocyst (Ames, Iowa isolate) infectivity in an in vitro cell culture assay. In vitro excystation, sporozoite yield, and vital dye exclusion using DAPI and PI were used to test viability. A matrix of purification procedures using two defatting agents (ethyl acetate and ethyl ether), cesium chloride (CsCl) and Sheather's solution was evaluated. Effects of immuno-magnetic separation (IMS) and bleach treatment were also assessed. Oocysts purified using CsCl alone showed the most consistent infection from experiment to experiment, compared to preparations that were purified using a defatting agent. Defatting agents, IMS and bleach treatment had no detrimental effects on oocyst infectivity, however, considerable variability between oocyst lots was observed. This study determined that both purification processes and age affect oocyst infectivity.
Synergism in sequential disinfection of Cryptosporidium parvum
Authors: Rennecker J. L. , Corona-Vasquez B. , Driedger A. M. , Mariñas B. J.
Published: May 2018

Sequential treatment schemes using ozone or chlorine dioxide as primary disinfectant and free chlorine or monochloramine as secondary disinfectant were investigated for potential synergistic effects in the inactivation of C. parvum oocysts. Viability was determined by a modified in vitro technique based on sporozoite counts that was consistent with animal infectivity data. Primary disinfection with ozone resulted in the disappearance of a predominant shoulder in the secondary inactivation curve for both free and combined chlorine. The rate of secondary inactivation with monochloramine increased by approximately 250 percent compared to the post-shoulder rate with monochloramine alone.The level of synergy from using chlorine dioxide as the primary disinfectant was lower compared to that for ozone.
Ozonation of bromide-containing drinking waters:a delicate balance between disinfection and bromate formation
Authors: von Gunten U. , Pinkernell U.
Published: May 2018

The occurrence of Cryptosporidium in raw waters and bromate formation during ozonation of bromide-containing waters leads to a difficult optimisation of ozonation processes. On the one hand inactivation of Cryptosporidium requires high ozone exposures, on the other hand under these conditions bromate formation is favored. In order to overcome this problem we need information about (i) the oxidant concentrations (ozone and OH radicals) during an ozonation process, (ii) kinetics of the inactivation of Cryptosporidium, (iii) kinetics and mechanism of bromate formation, and (iv) the reactor hydraulics. The strong temperature dependence of the inactivation of Cryptosporidium which results in a higher ozone exposure (time-integrated action of ozone) at low temperatures makes it more difficult to fulfil disinfection and bromate standards at low temperatures. Underthese conditions control options for bromate formation can be applied. Depressionof pH and addition of ammonia have been selected to be the best options. For a given ozone exposure both measures lead to a reduction of bromate formation in the order of 50%.
Development of ATP assay as a surrogate indicator of viability of Cryptosporidium parvum oocysts
Authors: Somiya I. , Fujii S. , Kishimoto N. , Kim R-H.
Published: May 2018

Adenosine Triphosphate (ATP) determination was applied to evaluate viability of Cryptosporidium oocysts. Three pretreatment methods, such as incubation in acidified Hanks balanced salt solution (HBSS), excystation and sonication were investigated for ATP extraction from oocysts. Incubation in acidified HBSS was insufficient to extract ATP from oocysts, but a linear relationship between the number of oocysts and the concentration of ATP extracted was observed in the test of excystation and sonication treatments. Sonicationtreatment was able to extract ATP from oocysts more rapidly and precisely than excystation treatment. ATP amount per oocyst by sonication treatment (ATPs) was evaluated to be 2.9×10–8 μg on average, andits detection limit was 500 oocysts/100 μl. Ozone treatment experiments were conducted in batch condition to evaluate differences among ATP concentrations extracted, in vitro excystation and DAPI/PI permeability assays. ATPs assay was observed to have a linear relationship with DAPI/PI permeability assay (R2=0.98). As a result, ATP assay is applicable as a surrogate indicator of the viability of C. parvum, and is superior to in vitro excystation and DAPI/PI permeability assay, because of its rapid, accurate and simple procedure.
Metal speciation and leachability of heavy metals from Enersludge™ ash in concrete
Authors: Wong V. , Ho G.
Published: May 2018

The Oil From Sludge (Enersludge™) process converts sewage sludge into hydrocarbons, partially fixing heavy metals in the by-product ash. Research was carried out to investigate the speciation and leaching behaviour of heavy metals (cadmium, copper, chromium, nickel, lead and zinc) when using this ash product in concrete. This was achieved by conducting a sequential extraction procedure, a soluble fraction test and dynamic leach test. Sequentialextraction showed that heavy metals in the ash speciated mainly into a stable form. Leachable heavy metals were derived mainly from the concrete (control samples). The soluble fraction test and the dynamic leach test indicated that heavy metals from concrete with Oil From Sludge ash addition exhibited a low leachability.