Advanced Water Management Centre

AWMC Seminar Program: PhD Confirmation Seminar

Multiple use of iron in an urban water system (Mario)
Abstract: In the urban water system many of the processes involved makes use of chemicals. In drinking water treatment plant (DWTP), it uses a wide variety of chemical for its operation, one of the chemicals they use the most is for coagulation. Aluminum, iron, and other cationic polymers are commonly used. Although alum is by far the most widely used coagulant chemical, ferric-based coagulants form better flocs and more effecting in removing natural organic matter (NOM) compared to alum-based coagulants. Iron is also used in sewer networks for hydrogen sulphide control that cause corrosion and odour problems. In wastewater treatment plants (WWTP), many of its sub-systems use iron salts to improve operation. Iron salts are used to enhance primary settling, chemically remove phosphate in biological treatment, precipitate hydrogen sulphide in anaerobic digesters, and conditions sludge for better dewatering. The dosing of iron salts in sewers has beneficial effects to downstream processes just like as to direct application. The use of iron rich sludge from DWTP also showed promising results similar to the use of iron salts and has strong potentials to have similar benefits to the succeeding systems upon application.
This study will investigate the use of iron in drinking water production and the reuse of its sludge in the sewers and WWTPs on the physical, chemical and biological processes occurring in the sewer systems and in various sub-units of wastewater treatment. It will also look into the unintended effect that will identify how iron behaves in the process and its effect in the stages of the integrated urban water system. Lab-scale simulations will be performed similar to actual systems with a sewer reactor, primary settler, sequencing batch reactor (SBR), sludge thickener and the anaerobic digester (AD). This study will have a strong potential to significantly reduce cost for both water treatment and wastewater services and provide a more integrated approach to urban water system management.
 

Multiple reuse of iron-rich drinking water sludge in our urban water infrastructure: characterizing the fate, speciation, kinetics and reactivity of iron species (Sirajus)
Abstract: Reuse of iron-rich drinking water sludge could be a feasible option for utilities to look at cheaper disposal of the sludge as well as controlling sulfide and phosphate in sewer networks and downstream WWTPs. Therefore, a fundamental understanding of the fate, speciation, kinetics and reactivity of iron-species is necessary to understand the chemistry and mechanisms of various iron-bound complex formation such as Fe-O, Fe-NOM, Fe-S, and Fe-P species in our urban water infrastructure. Iron-rich drinking water sludge will be generated in the laboratory and subsequently in a pilot plant to investigate its dosing impacts on sulfide and phosphate removal in sewer networks and downstream WWTPs. Detailed laboratory studies as well as field studies at a full-scale WWTP will be conducted to monitor such impacts. Advanced analytical tools including X-ray diffraction, scanning electron microscopy, and infrared spectroscopy amongst others will be used in this thesis to find out the fate, speciation, kinetics and reactivity of iron-species.
 

Fate and impact of natural organic matter in sewers and wastewater treatment plants receiving drinking water treatment sludge (Jaga)
Abstract: Dosing of drinking water treatment sludge in to the sewer network, for its beneficial reuse is an innovative and paradigmatic approach to achieve integrated urban water management based on multiple iron use. Despite introducing the iron, the sludge also introduces some natural organic matters (NOM) derived from the drinking water treatment system, to the sewers and the wastewater treatment plants. To enable the wide acceptance and application of this approach, unintended effects related to the fate and impacts of NOM to the wastewater collection and treatment systems needs a thorough investigation. It was identified that NOM may be chemically oxidizing sulfide, complexing PPCPs and causing disinfection problems. This presentation gives an overall glimpse on the impacts that may arise because of the NOM in sewers and in downstream wastewater treatment processes in producing high quality recycle water.
 

Integrated modelling of urban wastewater system (UWWS) focusing on multiple uses of iron salts (Sohan)
Abstract: Urban water system (UWS) incorporates different sub-systems which have conventionally been modelled, designed and operated in isolation. With an advent of understanding in terms of complex physical, chemical and biological phenomena associated with wastewater treatment process, different sub-systems of UWS are no longer considered as separate entities. Accordingly, modelling of different components of UWS in an integrated manner is now receiving much attention as it appears to simulate the behaviour of the UWS more efficiently. Further, modelling an UWS as single entity may provide opportunities of studying the inherent dynamics of transformation and interactions between the different associated components. This sort of integrated modelling approach may be very useful in evaluating system-wide control strategies, optimal design and operating criteria including evaluation of benefits within integrated sub-systems. Accordingly, integrated modelling studies primarily focussing on investigating the multiple benefits of using iron salts in UWS and associated implications, are required to assess and validate the complex dynamic interactions of iron (Fe) occurring at different stages of UWS with other species, particularly sulphur (S) and phosphorus (P). The transformation of P is of particular interest during wastewater treatment and there exist close linkage of P transformation with Fe and S cycling. Hence, this study aims to develop ‘integrated system-wide sewer-WWTP model’ or ‘integrated system-wide multi-phase wastewater treatment process models’ focusing on multiple uses of iron salts, incorporating biochemical, physicochemical, and hydraulic modelling of sewers and WWTPs. In this notion, this study will be excellent example for integrated urban water management, as it would actually facilitate to gain in-depth insight in terms of dynamic interactions occurring across the UWS on dosing ferric salts.
 

Event Details
Date & Time: 
Friday, 27 January 2017
9am - 11am
Venue: AIBN Building 75, Level 1 Seminar Room
Speaker(s): 
  • Jagadeeshkumar Kulandaivelu
  • Mario Jr Robles Rebosura
  • Sirajus Salehin
  • Sohan Shrestha

Event Contact: awmcseminars@awmc.uq.edu.au