Faculty of Engineering


Water pollution assessment

This project focuses on assessing the risk to the New Zealand environment from water pollutants by characterising their sources, degradability in treatment systems, pathways of transport and their impact on the receiving environment.

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Endocrine Disrupting Chemicals (EDCs) and Pharmaceuticals and Personal Care Products (PPCPs) are classes of emerging contaminants that occur ubiquitously in our environment and have been detected in all media (air, water and soil). A number of EDCs have been reported to interfere with human and animal hormone system, and have the potential to produce adverse developmental and reproductive outcomes at sub-nano gram levels of exposure.

EDCs and PPCPs have been grabbing media attention due to their documented effects (see related publications below) but little is known of their effect in the New Zealand environment. This study will address this lack of knowledge by characterising their sources, degradability in treatment systems, pathways of transport, and the impact on the receiving environment.

 

Key focus areas/issues


To study the fate and transport of EDCs and PPCPs in the New Zealand environment, a series of experiments have been conducted, with the following objectives:

  1. Develop analytical techniques for measuring concentration and toxicity of 11 EDCs/PPCPs, which includes estrogen (estrone, estradiol and estriol), synthetic estrogen (ethynylestradiol), androgen (testosterone), a plastics component (bisphenol A), surfactant (nonylphenol), anticonvulsant (carbamazepine), sun screen (oxybenzone), antibiotic (sulfamethoxazole) and an antibacterial agent (triclosan).
  2. Identify priority EDCs/PPCPs in the local region by measuring concentrations in selected source areas and receiving environment to assess their persistence in the environment by transport and fate properties.
  3. Assess the performance of biological treatment processes with and without incorporating an additional treatment step using a potential green catalyst, iron-tetraamido macrocyclic ligand (Fe-TAML).

 

Current major developments


The main facilities to undertake the experiments related to EDCs/PPCPs are set up. One postdoctoral fellow and three PhD students are involved in this project.

Analytical techniques development for measuring concentration, estrogenicity and toxicity of selected EDCs/PPCPs.
Jianlin Chen (postdoctoral fellow)

Study of the application of Fe-TAML on degradation of EDCs.
Emad Nazari (PhD student)

Investigation of the transport and fate of EDCs in soils.
Mohammed Alkali (PhD student)

Examination of EDCs degradation/removal in the wastewater treatment processes.
Mahshid Siami (PhD student)

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Key people


 

Contact


Naresh Singhal
Email: n.singhal@auckland.ac.nz
Phone: +64 9 373 7599 extn 84512

Related publications



Tamara Galloway, Riccardo Cipelli, Jack Guralnick, Luigi Ferrucci, Stefania Bandinelli, Anna Maria Corsi, Cathryn Money, Paul McCormack, David Melzer.
Daily Bisphenol A Excretion and Associations with Sex Hormone Concentrations: Results from the InCHIANTI Adult Population Study.
Environmental Health Perspectives, 2010; DOI: 10.1289/ehp.1002367

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Key achievements



Preliminary studies have been undertaken and baseline results have been obtained for future study.

1. The optimal derivatisation process for estrogens has been determined for the analysis by Gas Chromatography Mass Spectrometry (GC/MS).

2. The program to separate the mixture of EDCs/PPCPs by Liquid Chromatography Mass Spectrometry (LC/MS) has been developed. At the moment, the mixture of eight EDCs/PPCPs can be separated in 13 minutes. (refer to graph on right)

Experimental setup


1. Analytical techniques

The polar EDCs/PPCPs with hydroxyl group are analysed by GC/MS after being derivatised. The optimal derivatisation process is studied. Different GC temperature programs are conducted to optimise the separation of EDCs/PPCPs. At the moment, our focus is on developing an LC/MS program to analyse EDCs/PPCPs because by choosing an appropriate LC column, the polar compounds can be analysed directly without derivatisation.

 

 

2. Degradation of EDCs by addition of green catalysts of Fe-TAML

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The elegant Fe-TAML molecule features an iron atom in its centre, surrounded by four nitrogen atoms, which in turn are corralled by a ring of carbon atoms (right).

The treatment consists of adjusting parameters such as pH, the concentration of Fe-TAML and H2O2 in tertiary section of Waste Water Treatment Plant (WWTP) to remove the contaminant completely. In the laboratory, our experiment consists of adjusting H2O2, Fe-TAML and pH for a low concentration of EDC to optimise the amount of degradation in an acceptable timeframe for the WWTP.

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We have developed a pilot scale waste water treatment plant (above) that we can use to test the efficiency and performance of wastewater treatment processes in removing EDCs/PPCPs.

 
3. Fate and transport of EDCs/PPCPs in the soil/sediment

Different type of soil/sediment (at least three types) will be used to study the EDCs/PPCPs’ sorption and desorption behaviour and partition coefficient between the aqueous and soil phases.

4. Examination of toxicity and estrogenicity of selected compounds

cl-iande-sample-test-tubes1 If the sample has estrogenicity, the colour changes from yellow to red or pink (pictured above).

The yeast estrogen screen (YES assay) is conducted to assess the potential of environmental samples to activate the human estrogen receptor. The mechanism of YES is shown in the picture below.

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