The environmental estrogens have been well known as a risk for ecosystem and human health. Many natural and man-made estrogens are found in the water environment. However, some unknown estrogenic disinfection byproducts (DBPs) form during the water treatment process, which could escape the water quality monitoring due to the unawareness of their existence. This study developed an estrogen receptor based affinity chromatography to screening unknown estrogenic DBPs from environmental estrogens, 17β-estradiol (E2) and diethylstilbestrol (DES). A strong estrogenic compound (stronger than estrone), Δ9(11)-dehydro-estradiol, was found as a DBP of E2 after chlorine or UV or chlorine-UV combined disinfection. For DES, UV disinfection could cause photochromism, and further dehydrogenation, and generate a strong estrogenic DBP, 9,10-diethylphenanthrene-3,6-diol, which is stronger than E2. This result explains why DES still can persist for a long time in the surface water. While under the oxidative disinfection, like chlorination and ozonation, DES generated a relatively weak estrogen, Z,Z-dienestrol (DE), but it is still stronger than bisphenol A (BPA). In summary, this study proposed a novel way to study the unknown estrogenic DBPs, which might be the potential micropollutants in the water environment.

Membrane technology has played a vital role in the treatment of water and wastewater in Singapore. Fouling is a commonly encountered problem that can dramatically diminish the treatment process efficiency and cost effectiveness of membrane related treatment. Traditionally, flux or TMP change were used to determine the timing and frequency for cleaning foulant. However, our preliminary results had showed these two parameters may mislead the cleaning programme settings. Thickness and strength, which are two direct properties of the foulant, provide more representative and complementary information for optimization of operating protocols, cleaning regimes and module design. The fluid dynamic gauging (FDG) is able to provide additional valuable information which is the foulant strength. In addition, FDG is also able to uncover the removal behaviour of biofilm through local biofilm strength. Our findings suggest that FDG is able to provide valuable additional information related to biofilm property that has not been disclosed by other monitoring methods.

 The oxidation of arsenite (As^III) to arsenate (As^V) as an effective pre-treatment step was usually considered in order to ultimatly remove arsenic (As) from reducing aquatic environment such as groundwater. The present work selected quartz sand and pozzolan as two support materials filled into the parallel up-flow fixed-bed reactors. Concentrated As^III was completly oxidized with two support materials after inoculation of acclimatized arsenite-oxidzing bacteria (AsOB) with various HRT of 6 h, 3 h and 1 h. Moreover, pozzolan was more efficient than quartz sand for As^III oxidation even at a HRT of 40 min. Batch tests demonstrated that As^III oxidation rate was negatively correlated with the axial length of reactors, which was closely related with the AsOB distribution in the fixed-bed reactor. Finally, high efficient removal of As realized through the microbial As^III oxidation followed with the fixed-bed reactors filled with zero valent iron (ZVI) or negative ion-exhange resin.

The increasing pollution of water bodies, the global climate change accelerating toxic algae blooming problems, the growing demand of drinking water to be treated from lakes, rivers and groundwater as well as the one still coming from the residual natural water sources require the real time control of a large number of water quality parameters.

Most of them are measured in laboratory by well-known and long term established analytical methods, but it is not easy to apply the same methods for continuous on-line monitoring in different field applications.  

The current state of the art on the application of optical based analytical methods to measure chemical parameters for automated water quality measurement using different instrumental technologies (LFA, µLFR, CFA and Discrete one) for on-line and field applications will be presented, as well as the basics of early warning systems using optical methods and biosensors for detection of acute toxicity in water samples.

The field automation for unattended use on floating platforms and coastal buoys of Enzyme Linked Immuno-Magnetic Optical assays to measure specific toxic algae species from the genera Alexandrium, Pseudo-nitzschia and Dinophysis, their associated toxins (Saxitoxin, Okadaic acid, Domoic acid), flame retardants (PBDE) and pesticides (Glyphosate) in coastal water, developed in the frame of the SMS European research project (http://www.project-sms.eu) will be finally shown.

The inflow and infiltration, exfiltration and overflow are dynamic processes in the sewer. The status of a sewer may change from one to another status in a rainfall event. However, the methods mentioned above can’t diagnose and identify the transition between status, which is important in early warning of the sewer system.

This study was conducted in a sewerage system in a city in southern China. Through constructing online wastewater quantity and quality monitoring systems, the variation characteristics of flow and water quality under different operating status of the sewerage system was investigated and a database was established. At last, a diagnosis method based on conventional index such as water level and conductivity was developed to evaluate the different sewerage status through the established database.

An online monitoring system was constructed and a data-driven diagnosis diagram was proposed. The conductivity was chosen as a sensitive index to support the diagnosis. The variation pattern of flow, level, conductivity wastewater was analysed. For the wet weather flow, the variation pattern of water indexes was different from that in dry weather flow. The water level will increase, and the conductivity will decrease because of inflow and infiltration. Based on the variation pattern of water indexes at different status such as blockage, inflow, overflow, the database corresponding to different operation status was constructed. At last a diagnosis diagram was proposed and successfully applied in a sewerage system.

Thousands of organic micropollutants and their transformation products can be found in water. Although most of them are present at low concentrations, individual compounds contribute to mixture effects and this overall effect is a still a significant public concern. Traditional chemical identification and monitoring of those micropollutants or their products is pain staking and full of challenges. More recently, a battery of cell-based bioassays that target health-relevant biological endpoints are used to assess the water quality to complement chemical analysis. However, the bioassay methods are not cost-effective and lack of significance of systems biology. The objective of this study is to evaluate the suitability of metabolomics technology to benchmark water quality and to assess efficacy of water treatment processes. In details, cell-based (MCF7) metabolomics method is used to assess a set of 8 water samples collected in Australia, including wastewater treatment plant effluent, two types of recycled water (reverse osmosis and ozonation/activated carbon filtration), stormwater, surface water, and drinking water. The result showed that many of critical metabolic pathways has been altered in the water samples and there is great difference between treatments. Among them, filtration has the most effective removal of the toxicity. This study has preliminarily demonstrated that cell-based metabolomics method are sensitive to benchmark water quality and could be potentially used in the risk assessment in the future.

Anode modification with MnO2, Pd and Fe3O4 nanoparticles was evaluated for pharmaceutically active compounds (PhACs) removal and power generation in microbial fuel cells (MFCs). The MFCs with Pd, MnO2 and Fe3O4 anodes achieved a maximum power density of 824, 782 and 728 mW m-2, respectively, which were higher than that with carbon black (CB) modified anode (680 mW m-2) and nonwoven cloth (NW) anode (309 mW m-2). The removal percentages of carbamazepine and diclofenac in MFCs with MnO2, Pd and Fe3O4 anodes were more than 80% and 50%, respectively, while ibuprofen and iohexol showed limited biodegradation. Moreover, anode modification with MnO2, Pd and Fe3O4 could reduce the total anode internal resistances and thus result in the enhanced power generation of MFCs. The study for the first time reported anode modification with MnO2, Pd and Fe3O4 nanoparticles to enhance the PhACs removal and power production, which may help to understand the role of metal and metal oxides nanoparticles in the degradation of PhACs and power generation in a bioelectrochemical system.

This paper reports a bioaugmentation process which is applicable to intensify the removal of co-contaminated pollutants in electroplating wastewater. Microbial consortia which constructed with organic degradation and heavy metals resistant strains could promote COD and Cu²⁺ removal efficiencies in a laboratory-scale hydrolytic-anoxic-oxic membrane bioreactor. In surface processing industrial parks, co-contaminated pollutants of low concentration of heavy metals and refractory organics, which were generally more difficult to remove than individual, will put an adverse impact on the biological treatment system in the long term operation. Although many screened strains and acclimated microbial consortia had shown strong heavy metal biosorption capacity in various wastewater [1, 2]. Few researches focused on the strains which had both strong organic degradation capacity and heavy metals resistance to the bioaugmentation of co-contaminated water.

In this study, five isolates were screened and identified as Burkholderia sp., Enterobacteria sp., Meyerozyma guilliermondii, Meyerozyma guilliermondii and Enterobacteria sp. Marking them as L1-L5. Evaluating their Cu²⁺ biosorption performance and organic degradation capacity under diverse pH values, temperatures, growth phases and Cu²⁺ concentrations. The bioaugmentation process was divided into four periods: period 1 (75 days, 3 mg/L CuO NPs), period 2 (75 days, 10 mg/L CuO NPs), period 3 (60 days, 10 mg/L CuO NPs + one-time bioaugmentation) and period 4 (60 days, 10 mg/L CuO NPs + repeated batch bioaugmentation). Using T-RFLP technology, the survival and persistence of the added strains in the reactor were further analyzed.

Results in LB broth of the isolates presented higher minimum inhibitory concentration (MIC) to Cu²⁺ than other reported microorganisms [3]. The MIC of Cu²⁺ were 200.0, 200.0, 450.0, 300.0 and 200.0 mg/L. The maximum Cu²⁺ removal of L1-L5 was achieved at pH 5, 6, 6, 6 and 6, respectively (Fig. 1). The biosorption of Cu²⁺ due primarily to cell-surface binding and their adsorption courses met pseudo-second-order kinetic (Fig. 2). Their adsorption equilibriums of Cu²⁺ fitted the Langmuir model better than the Freundlich model (Table 1). L2, L3 and L4 had better Cu²⁺ adsorption and tolerance capacity than others. Maximal COD removal rates for L2 (77.9%), L3 (68.0%) and L4 (79.0%) were observed at pH 6, 7 and 7, respectively. Obvious COD removal rates decrease happened when the Cu²⁺ concentration reached to 3.0, 5.0 and 10.0 mg/L. L2, L3 and L4 were selected to construct the microbial consortia with the volume ratio was 1:1:1. The dosage was 400.0 mg dry cell/L.

After one-time and repeated batch bioaugmentation, the average COD removal rates reached to 69.0±2.0% and 76.2±2.6% (Fig. 3). Repeated-batch bioaugmentation was more suitable for the bioremediation of seriously deteriorated biological treatment system. The addition of microbial consortia altered the microbial community structure by changing the species evenness and diversity of microorganisms, and establishing a new microbial community balance in situ (Fig. 4). L2 can survive and proliferate to a high and stable quantity, but fungi L3 and L4 cannot become dominant communities and live in the reactor for a long time.

REFERENCES:

[1] J. Fan, T. O. Okyay and D. F. Rodrigues, “The synergism of temperature, pH and growth phases on heavy metal biosorption by two environmental isolates,” J. Hazard. Mater. 2014, 279, 236-243.

[2] E. Mejias Carpio, G. Machado-Santelli, S. Kazumi Sakata, S. S. Ferreira Filho and D. F. Rodrigues, “Copper removal using a heavy-metal resistant microbial consortium in a fixed-bed reactor,” Water Res. 2014, 62, 156-166.

[3] Monchy, M. A. Benotmane, P. Janssen, T. Vallaeys, S. Taghavi, D. Van der lelie, and M. Mergeay, “Plasmids pMOL28 and pMOL30 of Cupriavidus metallidurans are specialized in the maximal viable response to heavy metals,” J. Bacteriol. 2007, 189, 7417-7425.

Reverse osmosis (RO) process is widely used for water desalination and reclamation. However, the process is challenged by membrane fouling; the formation of a deposit layer on the RO membrane surface due to the accumulation of rejected particles/bio-materials/organic matters/solutes. Membrane fouling is inevitable, thus effective control and cleaning strategies are critical for the sustainability of the process. To implement the control or cleaning process, it is important to monitor the state of the process which typically involves measurement of pressures and flows. These are crude measurements and fail to detect incipient fouling. Here, we present fouling monitors that are based on a side-stream RO cell simulating the flows in the plant, where the incipient foulants will be detected by non-invasive methods of Electrical Impedance Spectroscopy (EIS) and Ultrasonic Time Domain Reflectometry (UTDR). The EIS involves measuring the electrical properties across the device via small electrodes either side of the membrane while the UTDR applies an acoustic signal that reflects from interfaces i.e. membrane, fouling layer etc.

Photonic technologies are set to revolutionise acquisition of chemical and biochemical information, driven by the demand for fast, low-cost, automated chemical analysis in a multiplicity of applications from point-of-care diagnostics to water quality monitoring. The integration, low cost and robustness of the microfabrication approaches which have made consumer electronics possible are enabling mass-produced chemical and bioanalytical microsystems. Optical techniques play a major role in quantitative chemical analysis and remain the mainstay of detection in “lab-on-chip” systems, but the degree of optical functionality integrated within these systems remains limited, and they have yet to benefit fully from the massive growth in optical telecommunications technologies in recent decades. Biosensor and lab-on-chip research and commercialisation have also been hampered by the lack of integrated photonic platforms which can operate over the mid-infrared (MIR) region from 2μm to 15μm, which would enable new opportunities for sensitive, selective, label-free biochemical analysis. Progress on new materials and approaches for high-sensitivity integrated photonic sensors for application in water and other aqueous media will be described.