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The removal of mono-dispersed suspensions of 0.46 μm and 0.816 μm particles in the early stages of deep bed filtration was found be higher at a certain range of influent mass concentration. For both equal number concentrations and equal surface area concentrations of mono-dispersed suspensions of 0.46 μm and 0.816 μm particles, the removal of particles of 0.816 μm size was higher during the early stages of filtration than 0.460 μm particles, at lower concentrations. Specific surface coverage was higher for 0.816 μm particles compared to 0.460 μm particles, for influents of these mono-dispersed particles having same number concentrations. However, it was similar for influents of these mono-dispersed particle suspensions, having equal surface area concentration.

This study investigates the interaction between the fulvic acid and sub-micron latex particles of different types and sizes and the effect on the removal of sub-micron particles in deep bed filtration.

A laboratory scale membrane bioreactor (MBR) consisting of worms was operated for 214days. The objective was to evaluate the treatment and operating performance of the MBR with and without the addition of Ametryn which is a toxic and persistent herbicide. Removal of Ametryn was doubled (up to 80%) in the MBR when the worms were present. Increased rate (2.5kPa/day) of trans-membrane pressure (TMP) and low concentration of MLSS (5.5g/L) were recorded when the worm population was high (80-100 worms per 70μL). Short-term critical flux values were increased from 7.5 to 15 and then to 30L/m(2)/h when the worm numbers decreased from 90 to 35 and then to 18 per 70μL of mixed liquor respectively. Further, high levels of carbohydrate concentration of soluble microbial products (SMP) and smaller sludge floc-sizes were found when the worm numbers were high.

In this chapter, advanced characterization of membrane fouling as a diagnostic tool has been summarized to prevent membrane fouling. Physical, chemical and biological analyses as membrane autopsies are mainly utilized to better understand membrane foulant. The physical characterization gives structure, roughness, charge effect, strength and hydrophobicity of membrane fouling. The chemical methods provide qualitative and quantitative measurements of different inorganic and organic matter. The biological properties present the spatial biofilm distribution, structure of dominant microorganisms and isolation and identification of microorganisms. In addition, detailed membrane foulant types are reviewed in terms of structure, roughness, hydrophobicity, charge effect, strength, calcium, magnesium, aluminum, iron, silicate, particle, functional group, biopolymer, humic acid, polysaccharide, structural composition, biofilm structure, microorganism and foulant interaction.

Hybrid TiO(2)/microcrystalline cellulose (MC) nanophotocatalyst was prepared in situ by a facile and simple synthesis utilizing benign precursors such as MC and TiCl(4). The as-prepared nanocomposite was characterized by XRD, XPS, BET surface area analyzer, UV-vis DRS and TGA. Surface morphology was assessed by the means of SEM and HR-TEM. Statistics-based factorial design (FD) was adopted to investigate the effect of precursors concentrations and therefore to optimize the nanocomposite synthesis through catalytic adsorption of methylene blue (MB) from aqueous solutions. The results indicated that TiO(2)/MC nanocomposites were photocatalytically active in diminishing 40-90% of MB in 4h.

Ametryn, which is a second generation herbicide, was introduced to a lab-scale MBR at a concentration of 1 mg/L and a 20–40% removal was observed at HRT ranging from 7.8 to 15.6 h for an average influent Ametryn concentration of 0.8 mg/L. Components of EPS (protein and carbohydrates) increased in the bioreactor and the observed biomass production reduced after the addition of Ametryn. In a batch study, GAC was added to MBR mixed liquor and removal of Ametryn via biodegradation and adsorption were measured. Five common bacterial colony types (Gram negative and positive bacilli and Gram negative cocci) were identified and three of these were resistant to Ametryn up to 5 mg/L. GAC was found to be a very effective Ametryn adsorption medium and in some occasions Ametryn may have acted as a nutrient source for bacteria.

Knowledge in the field of environmental health is growing rapidly. Within the context of external factors that define its boundaries, environmental health has evolved over time into a complex, multidisciplinary and ill-defined field with uncertain solutions. Many of the key determinants and solutions to environmental health lie outside the direct realm of health and are strongly dependent on environmental changes, water and sanitation, industrial development, education, employment, trade, tourism, agriculture, urbanization, energy, housing and national security. Environmental risks, vulnerability and variability manifest themselves in different ways and at different time scales. While there are shared global and transnational problems, each community, country or region faces its own unique environmental health problems, the solution of which depends on circumstances surrounding the resources, customs, institutions, values and environmental vulnerability. This work will contain critical reviews and assessments of environmental health practices and research that have worked in places and thus can guide programs and economic development in other countries or regions.

The effect of electrodialytic treatment in terms of a current density, pH and Na(2)H(2)EDTA addition on the methanogenic activity of copper-amended anaerobic granular sludge taken from the UASB reactor from paper mill was evaluated. Moreover, the specific energy consumption and simplified operational and treatment costs were calculated. Addition of Na(2)H(2)EDTA (at pH7.7) to copper-amended sludge resulted in the highest microbial activity (62 mg CH(4)-COD g VSS(-1)day(-1)) suggesting that Na(2)H(2)EDTA decreased the toxic effects of copper on the methanogenic activity of the anaerobic granular sludge. The highest methane production (159 %) was also observed upon Na(2)H(2)EDTA addition and simultaneous electricity application (pH7.7). The energy consumption during the treatment was 560, 840, 1400 and 1680 kW h m(-3) at current densities of 0.23, 0.34, 0.57 and 0.69 mA cm(-2), respectively. This corresponded to a treatment costs in terms of electricity expenditure from 39.2 to 117.6 € per cubic meter of sludge.

The second conference on the “Challenges in Environmental Science & Engineering” series CESE-2009 was held at Jupiters Hotel, Townsville, Australia from the 14th to the 17th of July 2009. The conference brought together internationally renowned engineers, scientists and researchers in the fields such as sustainability, water reuse, renewable energy, public health and biotechnology to discuss the environmental challenges the world is facing today and into the future. The conference had parallel presentation sessions for two full days that dealt with coastal processes and the Great Barrier Reef, catchment management, water quality, membranes, wastewater treatment, storm water management, reuse, sustainability and bioprocess technology. The guest editors of this special issue are thankful to the Chief Editor of Desalination and Water Treatment, Professor Miriam Balaban for providing an opportunity to publish selected papers that were presented at CESE-2009 after peer review.

‘‘Challenges in Environmental Science & Engineering’’, CESE International Conference Series is an annual event initiated by Associate Professor Jega V. Jegatheesan and Dr. Li Shu both of whom are currently attached to Deakin University, Australia. Researchers, policy-makers, academics, students and the broader community active in contributing solutions to the myriad of environmental questions posed by the challenges facing environmental sustainability are the consistent participants of CESE series. ‘‘Challenges in Environmental Science & Engineering’’, CESE International Conference Series is an annual event initiated by Associate Professor Jega V. Jegatheesan and Dr. Li Shu both of whom are currently attached to Deakin University, Australia. Researchers, policy-makers, academics, students and the broader community active in contributing solutions to the myriad of environmental questions posed by the challenges facing environmental sustainability are the consistent participants of CESE series. The CESE Series aims at making significant contribution to ‘‘Sustainable Growth’’ and this could only be possible if scientists and engineers were worked together. This will pave way for further interactions with other stakeholders who are as important as the previous two to find ways for complete solutions. Sustainable growth could only be achieved if the complex interactions among many processes were understood and the sustainability is considered simultaneously in all those processes. Sustainability of fresh water and other resources as well as energy should be emphasized for sustainable growth. Better management of catchments and cleaner production are important criteria for the sustainability of fresh water and other resources. Sustainability of energy depends on innovative applications of renewable energy sources. In this special issue, two advanced technologies namely membranes and nano-particles are highlighted through some of their specific applications. Membranes are used for separations of solid–liquid, liquid– liquid, liquid–gas and gas–gas phases. Membranes are mainly characterized by their pore sizes and applied pressures. Type of material will also play a significant role in their applications. For example, separation at high temperatures will need membrane materials that V. Jegatheesan (&) L. Shu School of Engineering, Deakin University, Geelong, Australia e-mail: jega.j@deakin.edu.au

Natural organic matter (NOM) in water contains organic compounds that are both hydrophobic and hydrophilic with a wide range of molecular weights. It is composed of non-homogeneous organic compounds such as humic substances, amino acids, sugars, aliphatic and aromatic acids, and other chemical synthetic organic matters. NOM in water is a major concern not only because of its contribution to the formation of disinfection by-products (DBPs) and taste and odor, but also its influence on the demand for coagulants and disinfectants, the removal efficiency of water treatment processes, etc. This research aims at identifying the influence of NOM in coagulation and flocculation processes in order to optimize the coagulation and flocculation conditions. In this study, pretreated pond water was used as the source water. It was observed from the experimental results that:The optimum pH for coagulation to remove NOM is around 7.The optimum alum dose at this pH can vary from 125-1,225 mgl-1 when the TOC is increased from 4 to 25 mgl-1.The presence of secondary compounds such as Ca2+, Mg2+ divalent cations had no significant effect on the removal of organic matter.The presence of clay increased the organic removal by 15%.The organic compound with higher molecular weight has higher removal affinity in coagulation process.Floc size and settling velocity of floc and sludge production all increased with the increase in NOM concentration. From the results of Capillary Suction Time (CST) tests, the floc formed with lower TOC readily released the water to make the dewatering process easier.The organic removal efficiency was significantly different for natural water containing non-homogeneous organic compounds compared to the synthetic water containing humic acid only (homogeneous organic matter). For example, the NOM removal efficiency was 80% for the synthetic water containing humic acid with TOC of 7 mgl-1 at pH 7; but the NOM removal for the pretreated pond water was 60%.

A laboratory-scale set-up consisting of rapid mixing device and floating medium filter was used to study the use of a downflow floating medium filter (DFF) with an in-line flocculation arrangement as a static flocculator and a prefilter. The semi-empirical mathematical model formulated incorporates flocculation within the filter, particle/floc attachment onto the filter and the detachment of flocs from the medium. The mathematical model for filtration takes into account the expansion of the filter bed. The removal efficiency of DFF and headloss development were successfully simulated for different conditions of filtration velocity, filter depth and influent suspended solids (SS). The values of attachment coefficient apβ and headloss coefficient β′ were found to be independent of filtration velocity, filter depth and influent SS concentration.

(2009). Special Issue on the Challenges in Environmental Science & Engineering, CESE-2009 14–17 July, 2009—Jupiters Hotel, Townsville, Queensland, Australia. Desalination and Water Treatment: Vol. 11, No. 1-3, pp. 1-1.

We commend Jonkergouw et al. (1) for adopting the goal of developing a chlorine decay model that is practical for “...day-to-day water distribution network modelling purposes and chlorine dosing optimisation studies” in the sense that the model coefficients are independent of loading conditions (initial and rechlorination doses).

Two laboratory-scale membrane bioreactor systems were investigated to treat high saline wastewater containing 1,000 mg/L COD and 32 g/L NaCl, namely: the yeast membrane bioreactor (YMBR) and the bacterial membrane bioreactor (BMBR). COD removal of both processes was above 90% at a hydraulic retention time (HRT) of 5 hours (volumetric loading of 5 kg COD/m³.d), sludge retention time (SRT) of 50 days (the MLSS of above 14 g/L and the F/M of 0.4 d-1). Under these operating conditions, the YMBR could run at a ten-fold lower transmembrane pressure with significantly reduced membrane fouling rate compared to BMBR. This may be because of low production of adhesive extracellular polymers (ECP) and the secondary filtration layer formed from large yeast cells. ECP production of bacterial sludge was increased considerably at high salt concentrations (32 g/L and 45 g/L) and long SRTs. For the bacterial sludge, the increased salinity led to increase in ECP, whereas the ECP content of the yeast sludge was relatively small.