Supervisory systems in waste water treatment plants: sistematise their implementation

La implantació de Sistemes de Suport a la presa de Decisions (SSD) en Estacions Depuradores d'Aigües Residuals Urbanes (EDAR) facilita l'aplicació de tècniques més eficients basades en el coneixement per a la gestió del procés, assegurant la qualitat de l'aigua de sortida tot minimitzant el cost ambiental de la seva explotació. Els sistemes basats en el coneixement es caracteritzen per la seva capacitat de treballar amb dominis molt poc estructurats, i gran part de la informació rellevant de tipus qualitatiu i/o incerta. Precisament aquests són els trets característics que es poden trobar en els sistemes biològics de depuració, i en conseqüència en una EDAR. No obstant, l'elevada complexitat dels SSD fa molt costós el seu disseny, desenvolupament i aplicació en planta real, pel que resulta determinant la generació d'un protocol que faciliti la seva exportació a EDARs de tecnologia similar. L'objectiu del present treball de Tesi és precisament el desenvolupament d'un protocol que faciliti l'exportació sistemàtica de SSD i l'aprofitament del coneixement del procés prèviament adquirit. El treball es desenvolupa en base al cas d'estudi resultant de l'exportació a l'EDAR Montornès del prototipus original de SSD implementat a l'EDAR Granollers. Aquest SSD integra dos tipus de sistemes basats en el coneixement, concretament els sistemes basats en regles (els quals són programes informàtics que emulen el raonament humà i la seva capacitat de solucionar problemes utilitzant les mateixes fonts d'informació) i els sistemes de raonament basats en casos (els quals són programes informàtics basats en el coneixement que volen solucionar les situacions anormals que pateix la planta en el moment actual mitjançant el record de l'acció efectuada en una situació passada similar). El treball està estructurat en diferents capítols, en el primer dels quals, el lector s'introdueix en el món dels sistemes de suport a la decisió i en el domini de la depuració d'aigües. Seguidament es fixen els objectius i es descriuen els materials i mètodes utilitzats. A continuació es presenta el prototipus de SSD desenvolupat per la EDAR Granollers. Una vegada el prototipus ha estat presentat es descriu el primer protocol plantejat pel mateix autor de la Tesi en el seu Treball de Recerca. A continuació es presenten els resultats obtinguts en l'aplicació pràctica del protocol per generar un nou SSD, per una planta depuradora diferent, partint del prototipus. L'aplicació pràctica del protocol permet l'evolució del mateix cap a un millor pla d'exportació. Finalment, es pot concloure que el nou protocol redueix el temps necessari per realitzar el procés d'exportació, tot i que el nombre de passos necessaris ha augmentat, la qual cosa significa que el nou protocol és més sistemàtic.

Androgenic activity of effluent from forty-five municipal waste water treatment plants in Victoria, Australia

It is well known that waste water treatment plant (WWTP) effluents are estrogenic. There has been much less consideration of the androgenic activity of WWTP effluents. To partly address the shortage of information on androgens in Australian WWTP effluents, in August 2006, and again in 2007, we collected discharges from up to 45 Victorian WWTPs (~25% of all WWTPs in Victoria), grouped by treatment process, i.e. activated sludge, extended aeration, and lagoon based treatment, and measured the total estrogenic, androgenic, retinoic acid, and aromatic hydrocarbon hydrogenase activity of the effluents using a hybrid yeast bioassay. This paper will concentrate on the androgenic activity and male hormone concentrations.

Computer cost models for potable water treatment plants /

Mode of access: Internet.

Ozone treatment of secondary effluents from waste-water treatment plants /

Mode of access: Internet.

Wastes from water treatment plants : literature review, results of an Illinois survey, and effects of alum sludge application to cropland /

"SWS Contract report 429." -- Cover.

Occurrence and elimination of cyanobacterial toxins in two Australian drinking water treatment plants

In Australian freshwaters, Anabaena circinalis, Microcystis spp. and Cylindrospermopsis raciborskii are the dominant toxic cyanobacteria. Many of these Surface waters are used as drinking water resources. Therefore, the National Health and Medical Research Council of Australia set a guideline for MC-LR toxicity equivalents of 1.3 mug/l drinking, water. However, due to lack of adequate data, no guideline values for paralytic shellfish poisons (PSPs) (e.g. saxitoxins) or cylindrospermopsin (CYN) have been set. In this spot check. the concentration of microcystins (MCs), PSPs and CYN were determined by ADDA-ELISA, cPPA, HPLC-DAD and/or HPLC-MS/MS, respectively, in two water treatment plants in Queensland/Australia and compared to phytoplankton data collected by Queensland Health, Brisbane. Depending on the predominant cyanobacterial species in a bloom, concentrations of up to 8.0, 17.0 and 1.3 mug/l were found for MCs, PSPs and CYN, respectively. However, only traces (< 1.0 mug/l) of these toxins were detected in final water (final product of the drinking water treatment plant) and tap water (household sample). Despite the low concentrations of toxins detected in drinking water, a further reduction of cyanobacterial toxins is recommended to guarantee public safety. (C) 2004 Elsevier Ltd. All rights reserved.

Utilisation of Glass Reinforced Plastics as Cost Effective Alternative to Traditional Materials in Access Panel Design for Waste Water Treatment Plants

Composites are fast becoming a cost effective option when considering the design of engineering structures in a broad range of applications. If the strength to weight benefits of these material systems can be exploited and challenges in developing lower cost manufacturing methods overcome, then the advanced composite systems will play a bigger role in the diverse range of sectors outside the aerospace industry where they have been used for decades.
This paper presents physical testing results that showcase the advantages of GRP (Glass Reinforced Plastics), such as the ability to endure loading with minimal deformation. The testing involved is a cross comparison of GRP grating vs. GRP encapsulated foam core. Resulting data gained within this paper will then be coupled with design optimization (utilising model simulation) to bring forward layup alterations to meet the specified load classifications involved.

Strength properties of composite clay balls containing additives from industry wastes as new filter media in water treatment

Pebble matrix filtration (PMF) is a water treatment technology that can remove suspended solids in highly turbid surface water during heavy storms. PMF typically uses sand and natural pebbles as filter media. Hand-made clay pebbles (balls) can be used as alternatives to natural pebbles in PMF treatment plants, where natural pebbles are not readily available. Since the high turbidity is a seasonal problem that occurs during heavy rains, the use of newly developed composite clay balls instead of pure clay balls have the advantage of removing other pollutants such as natural organic matter (NOM) during other times. Only the strength properties of composite clay balls are described here as the pollutant removal is beyond the scope of this paper. These new composite clay balls must be able to withstand dead and live loads under dry and saturated conditions in a filter assembly. Absence of a standard ball preparation process and expected strength properties of composite clay balls were the main reasons behind the present study. Five different raw materials from industry wastes: Red Mud (RM), Water Treatment Alum Sludge (S), Shredded Paper (SP), Saw Dust (SD), and Sugar Mulch (SM) were added to common clay brick mix (BM) in different proportions. In an effort to minimize costs, in this study clay balls were fired to 1100 0C at a local brick factory together with their bricks. A comprehensive experimental program was performed to evaluate crushing strength of composite hand-made clay balls, using uniaxial compression test to establish the best material combination on the basis of strength properties for designing sustainable filter media for water treatment plants. Performance at both construction and operating stages were considered by analyzing both strength properties under fully dry conditions and strength degradation after saturation in a water bath. The BM-75% as the main component produced optimum combination in terms of workability and strength. With the material combination of BM-75% and additives-25%, the use of Red Mud and water treatment sludge as additives produced the highest and lowest strength of composite clay balls, with a failure load of 5.4 kN and 1.4 kN respectively. However, this lower value of 1.4 kN is much higher than the effective load on each clay ball of 0.04 kN in a typical filter assembly (safety factor of 35), therefore, can still be used as a suitable filter material for enhanced pollutant removal.

Early warning sign attributes for the safety of drinking water treatment works

A proactive risk management strategy seeks to prevent accidents from taking place and maintain the safety of a system. In this context, the task of identifying and disseminating early warning signs and signals is among the most important. The problem is that warning signs that are present before an accident takes place are often being overlooked and not picked up or identified as warning signs. If these warning signs were responded to, then an accident may be averted. Accidents occuring in the critical domain of a drinking water treatments works can have serious implications for the public health of consumers of the water supplied. Realising and comprehending early warning signs is a major challenge for the domain of systems safety and especially in the domain of a water treatment works. The approaches that are typically used to enhance the realisation, comprehension and dissemination of early warning signs in the water treatment domain in Ireland mainly involves the creation of accident scenarios, the use of monitoring data and procedures for the dissemination of warnings. While all of these approaches are all useful to inform the mental or process models of possible accident scenarios, nevertheless, accidents are still occurring in this domain. Therefore, a new approach to enhance the comprehension of and effective dissemination of early warning signs is required in order to improve safety and proactive risk management strategies. The contributions of this thesis is the provision of a set of attributes associated with the early warning sign concept that provides meaningful data on the early warning signs and allows recipients to better comprehend them. The values of these attributes were customised for application in the water treatment domain. This research proves that early warning signs at a water treatment works received with information on their attributes are comprehended and communicated more effectively and efficiently than the usual pragmatic approach and thereby improves the safety and proactive risk management strategies.

Innovative reuse options for water treatment plant sludges

Reuse options were investigated for drinking water sludge. Research found sludges could be included with raw materials in brick and cement manufacturing with minimal impact. Poly-aluminium chloride sludge was found to an excellent adsorbent of phosphorus from wastewaters thus indirectly reducing potential algal blooms in our rivers.

Continuous-Flow Magnetic Separation with Permanent Magnets for Water Treatment

More efficient water treatment technologies would decrease the water bodies’ pollution and the actual intake of water resource. The aim of this thesis is an in-depth analysis of the magnetic separation of pollutants from water by means of a continuous-flow magnetic filter subjected to a field gradient produced by permanent magnets. This technique has the potential to improve times and efficiencies of both urban wastewater treatment plants and drinking water treatment plants. It might also substitute industrial wastewater treatments. This technique combines a physico-chemical phase of adsorption and a magnetic phase of filtration, having the potential to bond magnetite with any conventional adsorbent powder. The removal of both Magnetic Activated Carbons (MACs) and zeolite-magnetite mix with the addition of a coagulant was investigated. Adsorption tests of different pollutants (surfactants, endocrine disruptors, Fe(III), Mn(II), Ca(II)) on these adsorbents were also performed achieving good results. The numerical results concerning the adsorbent removals well reproduced the experimental ones obtained from two different experimental setups. In real situations the treatable flow rates are up to 90 m3/h (2000 m3/d).

Estimating costs for water treatment as a function of size and treatment efficiency /

Mode of access: Internet.

Biodetoxification of RCRA, Superfund, and other toxic wastes using resources of central wastewater treatment plants.

Mode of access: Internet.

Cost of landspreading and hauling sludge from municipal wastewater treatment plants : case studies.

Mode of access: Internet.