decolourisation of cotton bleaching effluent with wood rotting fungus

The decolourisation of cotton bleaching effluent by a wood rotting fungus was studied. It was found that fungus No. 7 could remove more than 70% of the colour (initial A₄₀₀=2.0–2.4) from the effluent within 4 days under agitated conditions. The fungal mycelia could be reused for a prolonged time and the decolourisation activity of mycelial pellets was quite stable during a long period of cool storage. Many factors affecting the decolourisation process were studied, including: concentration of glucose, effluent, NH₄⁺ and Mn(II); initial pH; temperature. The activity of manganese peroxidase (MnP) appeared to correlate well with the decolourisation rate. After the fungal treatment, an improvement in the treatability of the effluent by other microorganisms was observed.     

Characterization and pro‐inflammatory responses of spore and hyphae samples from various mold species

Mold particles from Aspergillus fumigatus, Penicillium chrysogenum, Aspergillus versicolor, and Stachybotrys chartarum have been linked to respiratory‐related diseases. We characterized X‐ray‐inactivated spores and hyphae fragments from these species by number of particles, morphology, and mycotoxin, β‐glucan and protease content/activity. The pro‐inflammatory properties of mold particles were examined in human bronchial epithelial cells (BEAS‐2B) and THP‐1 monocytes and phorbol 12‐myristate 13‐acetate (PMA)‐differentiated THP‐1. Spores from P. chrysogenum and S. chartarum contained some hyphae fragments, whereas the other preparations contained either spores or hyphae. Each mold species produced mainly one gelatin‐degrading protease that was either of the metallo‐ or serine type, while one remains unclassified. Mycotoxin levels were generally low. Detectable levels of β‐glucans were found mainly in hyphae particle preparations. PMA‐differentiated THP‐1 macrophages were by far the most sensitive model with effects in the order of 10 ng/cm². Hyphae preparations of A. fumigatus and P. chrysogenum were more potent than respective spore preparations, whereas the opposite seems to be true for A. versicolor and S. chartarum. Hyphae fragments of A. fumigatus, P. chrysogenum, and A. versicolor enhanced the release of metalloprotease (proMMP‐9) most markedly. In conclusion, species, growth stage, and characteristics are all important factors for pro‐inflammatory potential.     

Application of bacteriophages to selectively remove Pseudomonas aeruginosa in water and wastewater filtration systems

Water and wastewater filtration systems often house pathogenic bacteria, which must be removed to ensure clean, safe water. Here, we determine the persistence of the model bacterium Pseudomonas aeruginosa in two types of filtration systems, and use P. aeruginosa bacteriophages to determine their ability to selectively remove P. aeruginosa. These systems used beds of either anthracite or granular activated carbon (GAC), which were operated at an empty bed contact time (EBCT) of 45 min. The clean bed filtration systems were loaded with an instantaneous dose of P. aeruginosa at a total cell number of 2.3 (±0.1 [standard deviation]) × 10⁷ cells. An immediate dose of P. aeruginosa phages (1 mL of phage stock at the concentration of 2.7 × 10⁷ PFU (Plaque Forming Units)/mL) resulted in a reduction of 50% (±9%) and >99.9% in the effluent P. aeruginosa concentrations in the clean anthracite and GAC filters, respectively. To further evaluate the effects of P. aeruginosa phages, synthetic stormwater was run through anthracite and GAC biofilters where mixed-culture biofilms were present. Eighty five days after an instantaneous dose of P. aeruginosa (2.3 × 10⁷ cells per filter) on day 1, 7.5 (±2.8) × 10⁷ and 1.1 (±0.5) × 10⁷ P. aeruginosa cells/g filter media were detected in the top layer (close to the influent port) of the anthracite and GAC biofilters, respectively, demonstrating the growth and persistence of pathogenic bacteria in the biofilters. A subsequent 1-h dose of phages, at the concentration of 5.1 × 10⁶ PFU/mL and flow rate of 1.6 mL/min, removed the P. aeruginosa inside the GAC biofilters and the anthracite biofilters by 70% (±5%) and 56% (±1%), respectively, with no P. aeruginosa detected in the effluent, while not affecting ammonia oxidation or the ammonia-oxidizing bacterial community inside the biofilters. These results suggest that phage treatment can selectively remove pathogenic bacteria with minimal impact on beneficial organisms from attached growth systems for effluent quality improvement.     

Survey of 1012 moldy dwellings by culture fungal analysis: Threshold proposal for asthmatic patient management

Different countries have tried to define guidelines to quantify what levels of fungi are considered as inappropriate for housing. This retrospective study analyzes indoor fungi by cultures of airborne samples from 1012 dwellings. Altogether, 908 patients suffering from rhinitis, conjunctivitis, and asthma were compared to 104 controls free of allergies. Portuguese decree law no 118/2013 (PDL118), ANSES (a French environmental and health agency) recommendations, and health regulations of Besançon University Hospital were applied to determine the rates of non‐conforming dwellings, which were respectively 55.2%, 5.2%, and 19%. Environmental microbiological results and medical data were compared. The whole number of colonies per cubic meter of air was correlated with asthma (P < 0.001) and rhinitis (P = 0.002). Sixty‐seven genera and species were detected in bedrooms. Asthma was correlated to Aspergillus versicolor (P = 0.004) and Cladosporium spp. (P = 0.02). Thresholds of 300 cfu/m³ for A. versicolor or 495 cfu/m³ for Cladosporium spp. are able to discriminate 90% of the asthmatic dwellings. We propose a new protocol to obtain an optimal cost for indoor fungi surveys, excluding surface analyses, and a new guideline to interpret the results based on >1000 cfu/m³ of whole colonies and/or above threshold levels for A. versicolor or Cladosporium spp.     

The effectiveness of a biological treatment with Rhizopus oryzae and of a photo-Fenton oxidation in the mitigation of toxicity of a bleached kraft pulp mill effluent

Huge efforts have been made both in adopting more environmental-friendly bleaching processes, and in developing advanced oxidation processes and more effective biological treatments for the reduction of deleterious impacts of paper mill effluents. Even so, the success of such treatments is frequently reported in terms of chemical parameters without a proper evaluation of the effluent's toxicity mitigation. This is the first study reporting an exhaustive evaluation of the toxicity of a secondary bleached kraft pulp mill effluent, after either tertiary treatment with the soft-rot fungi Rhizopus oryzae or with a photo-Fenton oxidation, using a battery of freshwater species. As it has been reported the photo-Fenton/UV treatment has proved to be the most effective in reducing the colour and the COD (chemical oxygen demand) of the effluent. Nevertheless, extremely low EC₅₀ values were reported for almost all species, after this tertiary treatment. The treatment with R. oryzae was less effective in terms of colour removal and COD reduction, but proved to be the most promising in reducing toxicity.     

Medically-derived (131)I in municipal sewage effluent

This work presents ¹³¹I (t_½ = 8.04 d) concentrations in sewage effluent from the Stony Brook Water Pollution Control Plant (WPCP), a small plant serving a regional thyroid cancer treatment facility in Stony Brook, NY, USA. The concentrations detected in sewage effluent ranged from 1.8 ± 0.3 to 227 ± 2 Bq L⁻¹. The primary source of ¹³¹I is excreta from thyroid cancer inpatients treated at the Stony Brook University Medical Center. Based on several time series measurements following known inpatient treatments, the mean sewage half-life (T_s) of iodine is 3 d in this plant. The T_s, analogous to a radioactive half-life, describes the time it takes for half of a wastewater component to be removed from a WPCP. Flow recycling, or activated sludge, used to maintain bacterial populations necessary for sewage treatment causes iodine to remain in this plant far longer than its hydraulic retention time. The experimental results suggest that most ¹³¹I entering the Stony Brook WPCP leaves in sewage effluent, not in sewage sludge. Patient treatments can result in continuous discharges of ¹³¹I to surface waters where it can be used as a tracer of sewage-derived material and to understand the behavior of ¹³¹I in aquatic environments.     

Size-fractionated (1 → 3)-β-D-glucan concentrations aerosolized from different moldy building materials

Release of submicrometer-sized fungal fragments (< 1.0 μm) was discovered in earlier studies, which investigated the aerosolization of spores from moldy surfaces. However, the contribution of fungal fragments to total mold exposure is poorly characterized. The purpose of this study was to investigate the size-fractionated concentrations of particulate (1 → 3)-β-D-glucan and numbers of particles aerosolized from the surface of artificially mold-contaminated materials using a novel sampling methodology. Aspergillus versicolor and Stachybotrys chartarum were grown on malt extract agar and building materials (ceiling tiles and gypsum board) for one to six months. Fungal particles released from these materials were collected size-selectively by a newly developed Fragment Sampling System, and (1 → 3)-β-D-glucan in air samples was analyzed by Limulus Amebocyte lysate (LAL) assay. The concentrations of (1 → 3)-β-D-glucan varied from 0.4 × 10⁰ to 9.8 × 10² ng m^− 3 in the fragment size and from 1.0 × 10¹ to 4.7 × 10⁴ ng m^− 3 in the spore size range. Numbers of submicrometer-sized particles aerosolized from 6-month old cultures were always significantly higher that those from 1-month old (P < 0.001). This can be attributed to increased dryness on the surface of material samples and an increase in fungal biomass over time. The average fragment to spore ratios both in particle numbers and (1 → 3)-β-D-glucan mass were higher for S. chartarum than for A. versicolor. The results indicate that long-term mold damage in buildings may lead to increased contribution of fragments to the total mold exposure. Therefore, the health impact of these particles may be even greater than that of spores, considering the strong association between numbers of fine particles and adverse health effects reported in other studies. Furthermore, the contribution of fragments may vary between species and appears to be higher for S. chartarum than for A. versicolor.     

Fire extinguishing properties of novel ferrocene/surfynol 465 dispersions

This paper reports a novel fire-extinguishing agent: an aqueous dispersion of fine ferrocene particles. In this study, the ferrocene–water–surfactant dispersions were prepared to optimize the gas-phase concentration of ferrocene, and their ability to extinguish heptane fires was examined. The fire-extinguishing efficiency was characterized by three parameters: the ferrocene concentration in the dispersion (0–175 ppm), the surfactant used, and the ferrocene particle size (d₅₀=10.4, 11.4, 21.5, and 68.8 μm). The results indicated that (1) the ferrocene (d₅₀=10.4 mm)–water–surfynol 465 dispersion is the most stable among the dispersions tested, (2) the ferrocene–water–surfynol 465 dispersions have an optimal value of ferrocene concentration regarding the extinguishing time, and (3) in the ferrocene particle size range of 10.4–21.5 μm, the minimum extinguishing time of the ferrocene–water–surfynol 465 dispersions is remarkably shorter (1.2 s) than those observed when using a conventional wet chemical agent (45 wt% aqueous solution of potassium carbonate, 12.9 s).     

Investigation of inflammatory and allergic responses to common mold species: Results from in vitro experiments,from a mouse model of asthma,and from a group of asthmatic patients

Most studies on molds focus on Alternaria alternata and Aspergillus fumigatus. Here, we report on inflammatory and allergenic properties of more typical indoor species Aspergillus versicolor, P. chrysogenum, C. cladosporioïdes, and C. sphaerospermum that were compared to A. alternata and A. fumigatus. In a mouse model, after intranasal instillation, A. alternaria, A. versicolor, and C. sphaerospermum induced the early recruitment of neutrophils and the strong expression of inflammatory markers in the bronchoalveolar lavages fluids. A. fumigatus also induced the early accumulation of neutrophils but with lower levels of inflammatory markers. Chronic treatment induced variable response according to species: P. chrysogenum and A. fumigatus appeared strong pro‐allergenic inducers compared to A. alternata and C. sphaerospermum while A. versicolor and C. cladosporioides induced a mixed pro‐allergenic/pro‐inflammatory response. In mold‐sensitized asthmatics, mold‐specific Immunoglobulin E (IgE) were detected with an in‐house dot‐blot assay. A. fumigatus and A. alternata were the most frequent sensitizers. Altogether, P. chrysogenum, P. brevicompactum, C. sphaerospermum, and C. cladosporïoides were the “major sensitizer” (defined as the strongest response against a single mold species) for almost 30% of the asthmatics. These results show that, not only A. alternata and A. fumigatus, but also indoor species have strong inflammatory and allergic properties and a harmful potency.     

Pilot treatment of olive pomace leachate by vertical-flow constructed wetland and electrochemical oxidation: An efficient hybrid process

A hybrid process comprising biological degradation in a vertical-flow constructed wetland (CW) and electrochemical oxidation over boron-doped diamond electrodes to decolorize, mineralize and detoxify a leachate from olive pomace processing (OPL) was investigated. Two alternative treatment schemes were compared: According to the first treatment scheme, OPL was treated by electrochemical oxidation followed by treatment in a constructed wetland pilot unit (CW-A). The second scheme comprised of treatment in a constructed wetland followed by electrochemical treatment (CW-B). The constructed wetlands units were planted with Phragmites australis (reeds) and were fed intermittently at organic loadings between 5 and 15 g COD m⁻² d⁻¹ and a residence time of 3 d. Electrochemical oxidation (EO) was performed for 360 min at 20 A.Treatment of OPL in the wetland at 15 g COD m⁻² d⁻¹ led to mean COD and color reduction of 86% and 77%, respectively; the wetland effluent with a COD of about 800 mg L⁻¹ was polished electrochemically for 360 min after which the overall COD and color removal of the combined process (i.e. CW-B/EO) was around 95%, while the final effluent was not toxic against the marine bacteria Vibrio fischeri.Electrochemical oxidation of the original OPL at COD values between 6250 and 14 100 mg L⁻¹ led to moderate COD and color reduction (i.e. less than 40%) through zero order kinetics. When this was coupled to constructed wetland post-treatment (i.e. EO/CW-A), the overall COD and color removal was 81% and 58%, respectively. The decreased efficiency may be assigned to the increased toxicity of the electrochemically treated effluent which was only partially removed in the natural treatment system.     

Release of antibiotic resistant bacteria and genes in the effluent and biosolids of five wastewater utilities in Michigan

The purpose of this study was to quantify the occurrence and release of antibiotic resistant genes (ARGs) and antibiotic resistant bacteria (ARB) into the environment through the effluent and biosolids of different wastewater treatment utilities including an MBR (Membrane Biological Reactor) utility, conventional utilities (Activated Sludge, Oxidative Ditch and Rotatory Biological Contactors-RBCs) and multiple sludge treatment processes (Dewatering, Gravity Thickening, Anaerobic Digestion and Lime Stabilization). Samples of raw wastewater, pre- and post-disinfected effluents, and biosolids were monitored for tetracycline resistant genes (tetW and tetO) and sulfonamide resistant gene (Sul-I) and tetracycline and sulfonamide resistant bacteria. ARGs and ARB concentrations in the final effluent were found to be in the range of ND(non-detectable)-2.33 × 10⁶ copies/100 mL and 5.00 × 10²-6.10 × 10⁵ CFU/100 mL respectively. Concentrations of ARGs (tetW and tetO) and 16s rRNA gene in the MBR effluent were observed to be 1-3 log less, compared to conventional treatment utilities. Significantly higher removals of ARGs and ARB were observed in the MBR facility (range of removal: 2.57-7.06 logs) compared to that in conventional treatment plants (range of removal: 2.37-4.56 logs) (p < 0.05). Disinfection (Chlorination and UV) processes did not contribute in significant reduction of ARGs and ARB (p > 0.05). In biosolids, ARGs and ARB concentrations were found to be in the range of 5.61 × 10⁶-4.32 × 10⁹ copies/g and 3.17 × 10⁴-1.85 × 10⁹ CFU/g, respectively. Significant differences (p < 0.05) were observed in concentrations of ARGs (except tetW) and ARB between the advanced biosolid treatment methods (i.e., anaerobic digestion and lime stabilization) and the conventional dewatering and gravity thickening methods.     

River phosphorus cycling: Separating biotic and abiotic uptake during short-term changes in sewage effluent loading

Medium to small scale point sources continue to threaten river ecosystems through P loadings. The capacity and timescales of within-river processing and P retention are a major factor in how rivers respond to, and protect downstream ecosystems from, elevated concentrations of soluble reactive P (SRP). In this study, the bio-geochemical response of a small river (∼40 km² catchment area) was determined before, during and after exposure to a fourteen day pulse of treated sewage effluent using an upstream reach as a control. A wide array of approaches (batch and column simulations to in-situ whole stream metabolism) allowed independent comparison and quantification, of the relative contribution of abiotic and biotic processes in-river P cycling. This enabled, for the first time, separating the relative contributions of algae, bacteria and abiotic sorption without the use of labelled P (radioisotope). An SRP mass balance showed that the ecosystem switched from a P sink (during effluent inputs) to a P source (when effluent flow ceased). However, 65-70% of SRP was retained during the exposure time and remained sequestered two-weeks after-effluent flow ceased. Batch studies treated with biocide gave unrealistic results, but P uptake rates derived by other methods were highly comparable. Downstream of the effluent input, net P uptake by algae, bacteria and sediment (including the biofilm polysaccharide matrix) were 0.2 (±0.1), 0.4 (±0.3), and 1.0 (±0.9) mmol m⁻² day⁻¹ during effluent exposure. While autotrophic production did not respond to the effluent exposure, heterotrophic production increased by 67% relative to the control and this translated into a 50% increase in biological P uptake rate. Therefore, both biological and abiotic components of stream ecosystems uptake P during exposure to treated sewage effluent P inputs, and maintain a long ‘memory’ of this input in terms of P storage for considerable timescales after loading.     

Bacterial community characteristics under long-term antibiotic selection pressures

To investigate bacterial community characteristics under long-term antibiotic selection pressures, water samples from the upstream and the downstream sections of two rivers individually receiving the treated penicillin G and oxytetracycline production wastewater, as well as the anaerobic and the aerobic effluent of the penicillin G production wastewater treatment plant, were taken and analyzed. Antibiotic resistance ratios of bacterial communities in water samples were estimated by culture-based analysis. The majority of bacterial colonies (approximately 55%-70%) in both downstream rivers and the aerobic effluent showed resistance to 80 μg/ml of antibiotics tested, while the resistance ratios were less than 10% and 5% respectively for both upstream rivers. Six 16S rRNA gene clone libraries were constructed with 355 sequences and 215 OTUs totally obtained representing 465 clones. The antibiotic stresses seemed not reduce the diversities of bacterial communities in antibiotic containing water samples compared to those in the two reference upstream rivers. Bacterial groups present in the two reference upstream rivers were common residents in freshwater ecosystems, with the dominant groups as the phyla Proteobacteria including Alphaproteobacteria, Betaproteobacteria and Gammaproteobacteria, as well as Actinobacteria and Bacteroidetes. The phyla Proteobacteria and Firmicutes were dominant in all antibiotic containing water samples, with the clones belonged to Deltaproteobacteria and Epsilonproteobacteria significantly abundant, as well as Gram-positive low GC bacteria in the classes Clostridia and Bacilli. It thus seemed that Deltaproteobacteria, Epsilonproteobacteria, Clostridia and Bacilli might be specifically associated with antibiotic containing environments.     

Optimal aeration control in a nitrifying activated sludge process

An important tool to minimise energy consumption in activated sludge processes is to control the aeration system. Aeration is a costly process and the dissolved oxygen level will determine the efficiency of the operation as well as the treatment results. What aeration control should achieve is closely linked to how the effluent criteria are defined. This paper explores how the aeration process should be controlled to meet the effluent discharge limits in an energy efficient manner in countries where the effluent nitrogen criterion is defined as average values over long time frames, such as months or years. Simulations have been performed using a simplified Benchmark Simulation Model No. 1 to investigate the effect of different levels of suppressing the variations of the effluent ammonium concentration. Optimisation is performed where the manipulated variable for aeration (the oxygen transfer coefficient, K_La) is minimised with the constraint that the average daily flow-proportional ammonium concentration in the effluent should reach a desired level. The optimisation results are compared with constant dissolved oxygen concentrations and supervisory ammonium control with different controller settings. The results demonstrate and explain how and why energy consumption can be optimised by tolerating the ammonium concentration to vary around a given average value. In these simulations, the optimal oxygen peak-to-peak amplitude range between 0.7 and 1.8 mg/l depending on the influent variation and ammonium level in the effluent. These variations can be achieved with a slow ammonium feedback controller. The air flow requirements can be reduced by 1-4% compared to constant dissolved oxygen set-points. Optimal control of aeration requires up to 14% less energy than needed for fast feedback control of effluent ammonium.     

Analysis of N-nitrosamines and other nitro(so) compounds in water by high-performance liquid chromatography with post-column UV photolysis/Griess reaction

Despite their potential carcinogenicity and probable formation during water disinfection processes, little is known about the occurrence of other nitro(so) compounds than a few specific N-nitroso compounds such as N-nitrosodimethylamine (NDMA). An analytical method was developed to monitor various nitro(so) compounds including N-nitrosamines based on the Griess colorimetric determination of nitrite generated by UV-254 nm photolysis of nitro(so) compounds after separation by HPLC (HPLC-Post Column UV photolysis/Griess reaction (HPLC-PCUV)). To differentiate N-nitro(so) compounds (i.e. UV-labile) from other nitro(so) and N-containing compounds (i.e. UV-resistant), a pre-treatment was established by photolyzing solid-phase extracted samples at 254 nm (1000 mJ/cm²) and thus removing N-nitro(so) compounds selectively. Considering a 1000-fold concentration factor and extraction efficiencies (57–83%) during solid phase extraction, the method detection limits ranged from 4 to 28 ng/L for dimethylnitramine and eight N-nitrosamines (EPA 8270 nine nitrosamines mixture except for N-nitrosodiphenylamine). For four pool waters, the UV-resistant groups accounted for more than 78% of the estimated total concentration of nitro(so) and other N-containing compounds (6.1–48.6 nM). Only one unknown UV-labile compound was detected in one pool water (2.0–7.9 nM). NDMA was most frequently detected and N-nitrosodipropylamine (NDPA) and N-nitrosodibutylamine (NDBA) were additionally detected in one pool water. Chloramination of a secondary wastewater effluent with NDMA (0.2 nM) and UV-resistant compounds (7.9 nM) from a pilot-scale municipal wastewater treatment plant led to a significant formation of not only unidentified UV-resistant compounds (67.8 nM) and UV-labile compounds (14.6 nM), but also identified nitrosamines such as NDMA (4.3 nM), N-nitrosopiperidine (1.8 nM), NDPA (0.5 nM), and NDBA (0.5 nM). Overall, the novel HPLC-PCUV system is a powerful screening tool for the detection of (un)known N-nitro(so) as well as other nitro(so) and UV-induced nitrite-producing compounds.     

Use of zero-valent iron nanoparticles in inactivating microbes

Nanoscale zero-valent iron (NZVI) particles were investigated in inactivating gram-positive Bacillus subtilis var. niger and gram-negative Pseudomonas fluorescens bacteria, and the fungus Aspergillus versicolor. NZVI particles were synthesized using NaBH₄ and Fe(NO₃)₃·9H₂O, and the microbial suspensions were subjected to the treatments of NZVI particle suspensions with concentrations of 0.1, 1 and 10 mg/ml for 5 min. Field emission scanning electron microscope (FE-SEM) was used to characterize the synthesized NZVI particles, suspensions and the surface morphologies of the treated agents.FE-SEM images showed that the NZVI particles were spherical with a fairly uniform size of about 20–30 nm, and the iron precipitates FeO(OH) appeared in needle-shape aggregates. When treated directly with NZVI particles under aerobic condition, the surfaces of microbes were quickly coated with needle-shape yellow-brown iron oxides. In this study, complete inactivation was achieved both for B. subtilis var. niger and P. fluorescens when treated with 10 mg/ml NZVI particles with vigorous shaking under aerobic condition. When NZVI particle concentration decreased to 1, 0.1 mg/ml, there was still a complete inactivation for P. fluorescens, while for B. subtilis var. niger the inactivation decreased to 95%, 80%, respectively. However, no inactivation was observed for the fungus A. versicolor when treated the same manner. Physical coating, disruption of membrane and generation of reactive oxygen species have played major roles in the inactivation observed.     

Removing 17β-estradiol from drinking water in a biologically active carbon (BAC) reactor modified from a granular activated carbon (GAC) reactor

Estrogenic compounds in drinking water sources pose potential threats to human health. Treatment technologies are needed to effectively remove these compounds for the production of safe drinking water. In this study, GAC adsorption was first tested for its ability to remove a model estrogenic compound, 17β-estradiol (E2). Although GAC showed a relatively high adsorption capacity for E2 in isotherm experiments, it appeared to have a long mass transfer zone in a GAC column reactor, causing an early leakage of E2 in the effluent. With an influent E2 concentration of 20 μg/L, the GAC reactor was able to bring down effluent E2 to ∼200 ng/L. To further enhance E2 removal, the GAC reactor was converted to a biologically active carbon (BAC) reactor by promoting biofilm growth in the reactor. Under optimal operating conditions, the BAC reactor had an effluent E2 concentration of ∼50 ng/L. With the empty bed contact times tested, the reactor exhibited more robust E2 removal performance under the BAC operation than under the GAC operation. It is noted that estrone (E1), an E2 biodegradation intermediate, was frequently detected in reactor effluent during the BAC operation. Results from this study suggested that BAC could be an effective drinking water treatment process for E2 removal and in the meantime E1 accumulation needs to be addressed.     

Effluent dissolved organic nitrogen and dissolved phosphorus removal by enhanced coagulation and microfiltration

Plants aiming to achieve very low effluent nutrient levels (<3 mg N/L for N, and <0.1 mg P/L for P) need to consider removal of effluent fractions hitherto not taken into account. Two of these fractions are dissolved organic nitrogen (DON) and dissolved non-reactive phosphorus (DNRP) (mainly composed of organic phosphorus). In this research, enhanced coagulation using alum (at doses commonly employed in tertiary phosphorus removal) followed by microfiltration (using 0.22 μm pore size filters) was investigated for simultaneous effluent DON and dissolved phosphorus (DP) fractions removal. At an approximate dose of 3.2 mg Al(III)/L, corresponding to 1.5 Al(III)/initial DON-N and 3.8 Al(III)/initial DP-P molar ratios, maximum simultaneous removal of DON and DP was achieved (69% for DON and 72% for DP). At this dose, residual DON and DP concentrations were found to be 0.3 mg N/L and 0.25 mg P/L, respectively. Analysis of the trends of removal revealed that the DNRP removal pattern was similar to that commonly reported for dissolved reactive phosphorus. Since this study involved intensive analytical work, a secondary objective was to develop a simple and accurate measurement protocol for determining dissolved N and P species at very low levels in wastewater effluents. The protocol developed in this study, involving simultaneous digestion for DON and DNRP species, was found to be very reliable and accurate based on the results.     

Application of Aspergillus oryze and Rhizopus oryzae for Cu(II) removal

Biosorption of copper(II) by the untreated and acid-treated fungal biomass has been studied in both batch and column modes. Two species, Aspergillus oryzae and Rhizopus oryzae, were used in this study. A. oryzae mycelia (undergoing acid-washing) exhibit a clear advantage in Cu(II) removal, compared with other adsorbents. The acid-washing process can strongly enhance the adsorption capacity for A. oryzae mycelia. However, acid-washing does not alter the metal adsorption capacity of R. oryzae mycelia. The result indicates that acid-washing is not only a pretreatment step but also a regeneration step in the heavy metal removal process. These dual purposes, therefore, give the acid-washing biomass an indication of successful prospect.Cultivating A. oryzae in pellet form is an effective means of mycelium immobilization. The method established in this study provides the high-yield, uniformly-sized particles (2–3 mm in diameter), which are effective in solid-liquid separation. This pellet column can completely remove metals before breakpoint. After the breakpoint, a significant amount of Cu(II) removal over a long period has been observed. This is thought to be the result of intracellular uptake.     

The Simultaneous Bioremoval of Cr(III) and Dye by Immobilized <Emphasis Type="Italic">Phanerochaete Chrysosporium</Emphasis>

To attain better removal efficiency and higher toxic resistance, the alginate was used to immobilize Phanerochaete chrysosporium BKM-F-1767 in this study. And according to the characteristics of tannery wastewater, inhibitory effect of Cr(III) to the decolorization was investigated and adsorption kinetics of Cr(III) by the immobilized P. chrysosporium had been established. Furthermore, the Acid Violet 7 and Basic Fuchsin contributed as the experimental dyes in the paper, the removal studies were performed at an initial pH of 4.5. The combined effects of Cr and dyes on the simultaneous removal properties were determined in a batch system at different levels of Cr and dyes. Moreover, the dose-response relationship and a kinetic equation describing the simultaneous removal properties had been established. The results have proved that the immobilized P. chrysosporium has the ability to treat the tannery wastewater.