Preliminary Evaluation of Local Structure and Speciation of Lanthanoids in Aqueous Solution, Iron Hydroxide, Manganese Dioxide, and Calcite Using the L3-Edge X-ray Absorption Near Edge Structure Spectra

We elucidate the application of L₃-edge X-ray absorption near edge structure (XANES) spectra to the local structural analysis of lanthanoids in aqueous solution, iron hydroxide, manganese dioxide, and calcium carbonate. The L₃-edge XANES spectra of lanthanoid compounds showed sharp white lines. The full width at half-maximum (FWHM) values of lanthanoid aqua ions exhibited a convex tetrad curve in the series variation across the lanthanoid series. The variation is attributable to 4f electron orbitals and can be explained by the refined spin-pairing energy theory. For each lanthanoid, the FWHM values of lanthanoid compounds roughly decreased with increasing local coordination numbers. However, they did not faithfully reflect the local coordination sphere of the lanthanoid complex having a high and distorted coordination sphere and were rather sensitive to their chemical forms. The relationship between the magnitude of the FWHM values was determined by the crystal field splitting or degeneracy of 5d orbitals. The systematic variation of FWHM can be explained by the ligand strength of the ligand molecules (-H₂O⁰, -O^-, -OH^-, -CO₃^2-, -Cl^-, and -O^2-) that cause the crystal field splitting. Therefore, the FWHM values of L₃-edge XANES of lanthanoid compounds may be more useful in speciation analysis rather than structural analysis.

Protein-losing enteropathy and erythema caused by egg allergy in a breast-fed infant

A 4-month-old breast-fed girl presented with poor weight gain, and had edema and repeated erythema from 5 months of age. The diagnosis of protein-losing enteropathy (PLE) was confirmed on ^99m Tc-labeled human serum albumin scintigraphy. Specific IgE radioallergosorbent test was class 3 for egg white, class 2 for egg yolk, and negative for other foods. Elimination of egg from the mother's diet and oral epinastine hydrochloride treatment and sodium cromolyn improved hypoalbuminemia, hypogammaglobulinemia, and erythema. PLE and erythema coincident in a breast-fed infant suggests that IgE-mediated allergy may play a leading role in some cases of PLE due to food allergy in infants.

Sources of organic matter in first flush runoff from urban roadways

This study aims to explore the influential sources of organic matter in first flush runoff from urban roadways by comparing organic carbon content and particle size distribution in road dust with those from discharge from vehicles during rainfall. Samples on first flush runoff and road dust were collected from urban roadways. In addition, vehicle drainage was assumed to flow from vehicles during rainfall events, so vehicle wash-off water was collected by spraying water onto the top and from the underside of vehicles to simulate accumulation during a vehicle run. In road dust, the organic carbon content in the <0.2 mm fraction was about twice that of the 0.2-2 mm fraction. The particle size distributions of both first flush runoff and vehicle wash-off water were similar, and particles <0.2 mm contributed to over 95% of the total volume. The dissolved organic carbon concentration in the vehicle wash-off water was considerably higher than that in the road dust/water mixture. The total organic carbon content in road dust was positively correlated with annual daily traffic. Therefore, vehicles were thought to strongly influence the nature of road dust.

Nitrogen behavior during sludge ozonation: a long-term observation by pilot experiments

Sludge ozonation is a promising technology for dealing with the increasing challenge of excess sludge treatment and disposal. However, nitrogen behavior during sludge ozonation and subsequent biological removal remains unclear. To clarify the feasibility and stability of oxidizing organic nitrogen (released during sludge ozonation) in the bioreactor (but not during ozonation), and the best operational conditions for sludge ozonation, nitrogen behavior was investigated by a long-term observation. The results showed that when inlet ozone concentration increased from 30 to 80 mg O3/L, and ozonation time decreased from 29 to 11 h, less soluble organic nitrogen was oxidized to ammonia (from 66.1 to 18.7% of soluble total nitrogen). This can reduce the operational costs of sludge ozonation. Furthermore, it is feasible to convert organic nitrogen to nitrate by biological processes because full nitrification was restored in three weeks after shock loading of organic nitrogen owing to the change in ozonation conditions. After combining sludge ozonation with the anaerobic/oxic process, the mass balance for nitrogen showed that nitrogen in the excess sludge decreased with increasing sludge reduction rate. The decreased nitrogen in the excess sludge was mainly transformed to nitrogen gas by denitrification, whereas nitrogen in the effluent did not increase noticeably.

In vitro synergistic effects of zoledronic acid and calcium on viability of human epithelial cells

OBJECTIVE

Bisphosphonate-related osteonecrosis of the jaw is a common complication with defective wound healing of oral mucosa and frequently occurs in patients receiving zoledronic acid (ZA). The aim of this in vitro study was to investigate whether ZA has a cytotoxic effect at clinically relevant concentrations on epithelial cells when calcium conditions are altered.

METHODS

HaCaT human keratinocyte cells were treated with ZA in the presence of various concentrations of calcium. The concentrations of ZA included submicromolar ones, which are comparable with those found in the plasma of patients. Cell viability and apoptosis were assessed using MTT assay and annexin V flow cytometry.

RESULTS

Under standard culture conditions, cell growth was inhibited at 1 μM of ZA or above, but was unaffected by lower concentrations. However, when calcium concentrations were moderately increased, cell viability was decreased and apoptosis was induced at 0.2-0.3 μM of ZA. Moreover, a 50% reduction in serum in the hypercalcemic medium resulted in a significant decrease in cell viability at a much lower concentration (0.05 μM).

CONCLUSION

These results suggest that clinically relevant concentrations of ZA, which alone have little effects, can be toxic to the epithelial cells depending on the conditions of extracellular calcium.

Removal of high concentration ammonia from wastewater by a combination of partial nitrification and anammox treatment

Attached growth reactors were developed separately for solids retention time (SRT)-controlled partial nitrification and for anaerobic ammonia oxidation (Anammox) treatment, and a new nitrogen removal process is proposed for wastewater containing highly concentrated ammonia. For partial nitrification, an attached growth medium of polyurethane foam was used. Partial nitrification was achieved stably under a SRT of 4 days, and the abundance ratio of NO2(-)-N to the sum of NH4(+)-N, NO2(-)-N and NO3(-)-N was approximately 0.8 after 10 days. Under a SRT of4 days, the amoA gene concentrations of ammonia-oxidizing bacteria increased from 1 x 10(8) to 7 x 10(8) copies/l, whereas the 16S ribosomal RNA (16S rRNA) gene concentrations of nitrite-oxidizing bacteria did not increase. These results indicate that SRT-controlled operation is a promising technology for achieving partial nitrification. For the Anammox treatment, an attached growth medium of non-woven fabric was used. Inorganic nitrogen removal of approximately 80-90% was observed at an inorganic nitrogen loading rate of over 10 kgN/(m3-medium.d) and an influent nitrogen concentration of 400 mgN/l. Our non-woven fabric reactor showed similar or superior Anammox performance to that reported previously. By using a combination of these two rectors, we can develop a method that combines partial nitrification and Anammox treatment for effective and stable nitrogen removal.

Co-digestion of polylactide and kitchen garbage in hyperthermophilic and thermophilic continuous anaerobic process

Two series of two-phase anaerobic systems, consisting of a hyperthermophilic (80°C) reactor and a thermophilic (55°C) reactor, fed with a mixture of kitchen garbage (KG) and polylactide (PLA), was compared with a single-phase thermophilic reactor for the overall performance. The result indicated that ammonia addition under hyperthermophilic condition promoted the transformation of PLA particles to lactic acid. The systems with hyperthermophilic treatment had advantages on PLA transformation and methane conversion ratio to the control system. Under the organic loading rate (OLR) of 10.3 g COD/(L day), the PLA transformation ratios of the two-phase systems were 82.0% and 85.2%, respectively, higher than that of the control system (63.5%). The methane conversion ratios of the two-phase systems were 82.9% and 80.8%, respectively, higher than 70.1% of the control system. The microbial community analysis indicated that hyperthermophilic treatment is easily installed to traditional thermophilic anaerobic digestion plants without inoculation of special bacteria.

Bioaccumulation and primary risk assessment of persistent organic pollutants with various bivalves

Field surveys on persistent organic pollutant (POP) bioaccumulation were conducted with oysters, clams and scallops whose consumption amount accounted for large shares in the total consumption of shellfish in Japan. There was no numerical difference in bioaccumulation characteristics between oysters, clams, scallops, Corbicula and Mytilus galloprovincialis. Therefore, it was clear that the bioaccumulation characteristics in oysters, clams and scallops, which are important for food, could be ascertained by using the monitoring results with Corbicula and M. galloprovincialis which are easily sampled in various water areas in the world. Non-cancer risk (hazard quotient, HQ) and cancer risk (excess cancer risk, ΔR) via shellfish ranged from 10⁻⁸ to 10⁻⁴ and from 10⁻¹¹ to 10⁻⁷, respectively, at sampling points, which showed the risks of POP exposure via shellfish to be low enough. However, concerning the intake of other food, the importance of dieldrin monitoring should be suggested in Japan. Based on these results, the effectiveness of primary risk assessment could be suggested for screening chemicals whose preferential monitoring is needed.

Promotion of polylactide degradation by ammonia under hyperthermophilic anaerobic conditions

The objective of this study was to evaluate the promotion effect of ammonia on the biodegradation of polylactide (PLA) under hyperthermophilic (80°C) and thermophilic (55°C) anaerobic condition. The results showed that PLA was transformed to lactic acid under hyperthermophilic conditions, but that the transformation ratio was negligible under thermophilic conditions. The hydrolysis process can be markedly increased with ammonia addition and microorganism activity. The maximum transformation ratios of the two kinds of PLA used in this study were 65.2% and 51.8%, respectively, with ammonia addition of 4 g N/L over 3 days treatment of anaerobic sludge. After the hyperthermophilic pretreatment, the hydrolysis products were converted to methane by methanogens under the thermophilic and anaerobic conditions. The final methane conversion ratios of the two kinds of PLA after 22 days treatment were 81.8% and 77.0%, respectively.

Applicability of Corbicula as a bioindicator for monitoring organochlorine pesticides in fresh and brackish waters

The applicability of Corbicula as a bioindicator for monitoring organochlorine pesticides (OCPs) in fresh and brackish waters is presented here. Differences in isomer compositions and OCP bioaccumulation levels were analyzed in western Japan and the Pearl River Delta (PRD) in China. Isomer compositions of DDTs, chlordanes, and HCHs were significantly different between the two areas because of their different historical uses and property of the chemicals. This is represented by the (DDE + DDD)/DDT ratio in Corbicula, ranging 4.9-39 in western Japan and 1.1-2.4 in the PRD. However, isomer compositions in Corbicula reflected those in water, and the different patterns in Corbicula likely reflected the usage history. Concentrations of dissolved oxygen, suspended solids, and volatile suspended solids in water, and the difference in species did not influence OCP bioaccumulative levels in Corbicula when conducting biomonitoring. These levels are likely similar to those in Mytilus galloprovincialis. Therefore, Corbicula could be an appropriate bioindicator for monitoring OCPs in fresh and brackish waters.

Analysis of factors affecting the ratio of microcystin to chlorophyll-a in cyanobacterial blooms using real-time polymerase chain reaction

Chlorophyll-a concentration has been used as an indicator to estimate microcystin levels in water bodies. This study examined the microcystin to chlorophyll-a ratio in a fishpond in Japan. The ratio varied spatially and temporally during the six-month field survey, which is consistent with reports by other researchers. We investigated the causes of the variability of the ratio by quantifying microcystin synthetase (mcy) A gene with real-time PCR, so as to observe the growth of microcystin-producing cyanobacteria and Microcystis strains in natural cyanobacterial blooms. The application of real-time PCR enabled corroboration of the relationship between the toxigenicity and the toxicity of the blooms. The microcystin to chlorophyll-a ratio was influenced by the combined effects of the durability of the toxic bloom, and the quantity of microcystin-producing cyanobacteria carrying the mcy A gene, especially toxic Microcystis strains. Cyanobacterial blooms produced more microcystin when high concentrations of microcystin-producing Microcystis aggregated in a stationary state with low growth rates. The variable toxicity of blooms needs to be reflected in accurate and efficient alert systems for toxic cyanobacteria and cyanotoxins.

Behavior of inorganic elements during sludge ozonation and their effects on sludge solubilization

The behavior of inorganic elements (including phosphorus, nitrogen, and metals) during sludge ozonation was investigated using batch tests and the effects of metals on sludge solubilization were elucidated. A decrease of ∼ 50% in the ratio of sludge solubilization was found to relate to a high iron content 80-120 mgFe/gSS than that of 4.7-7.4 mgFe/gSS. During sludge ozonation, the pH decreased from 7 to 5, which resulted in the dissolution of chemically precipitated metals and phosphorus. Based on experimental results and thermodynamic calculation, phosphate precipitated by iron and aluminum was more difficult to release while that by calcium released with decrease in pH. The release of barium, manganese, and chrome did not exceed 10% and was much lower than COD solubilization; however, that of nickel, copper, and zinc was similar to COD solubilization. The ratio of nitrogen solubilization was 1.2 times higher than that of COD solubilization (R(2)=0.85). Of the total nitrogen solubilized, 80% was organic nitrogen. Because of their high accumulation potential and negative effect on sludge solubilization, high levels of iron and aluminum in both sewage and sludge should be considered carefully for the application of the advanced sewage treatment process with sludge ozonation and phosphorus crystallization.

Degradation characteristics of polylactide in thermophilic anaerobic digestion with hyperthermophilic solubilization condition

To test whether hyperthermophilic treatment promotes polylactide (PLA) dissolution and methane conversion under anaerobic digestion conditions, a single thermophilic control reactor (55 °C) and a two-phase system consisting of a hyperthermophilic reactor (80 °C) and a thermophilic reactor (55 °C) were continuously fed with a mixture of PLA and artificial kitchen garbage. In Runs 1 and 2, the PLA dissolution ratios in the two-phase system were 79.2 ± 6.5% and 85.2 ± 7.0%, respectively, higher than those of the control. Batch experimental results indicated that hyperthermophilic treatment could promote PLA dissolution to a greater degree as compared with single thermophilic treatment and that ammonia addition also had a promotional effect on PLA dissolution. In the two-phase system, after hyperthermophilic treatment, dissolved PLA was converted to methane gas under the subsequent thermophilic condition.

Elimination and fate of selected micro-organic pollutants in a full-scale anaerobic/anoxic/aerobic process combined with membrane bioreactor for municipal wastewater reclamation

The occurrence and elimination of 19 micro-organic pollutants including endocrine disrupting chemicals (EDCs) and pharmaceuticals and personal care products (PPCPs) in a full-scale anaerobic/anoxic/aerobic-membrane bioreactor process was investigated. The investigated process achieved over 70% removal of the target EDCs and 50%-100% removal of most of the PPCPs, with influent concentration ranging from ng/L to μg/L. Three PPCPs, carbamazepine, diclofenac and sulpiride were not well removed, with the removal efficiency below 20%. A rough mass balance suggests that the targets were eliminated through sludge-adsorption and/or biodegradation, the former of which was particularly significant for the removal of hydrophobic compounds. The two-phase fate model was employed to describe the kinetics of sludge-adsorption and biodegradation. It was found that the fast sludge adsorption (indicated by mass-transfer rates greater than 10 for most compounds) is responsible for the rapid decline of the aqueous concentration of the targets in the first compartment of the treatment process (i.e. in the anaerobic tank). In contrast, the slow biodegradation proved to be the rate-determining step for the entire degradation process, and the rates are generally positively related to the dissolved oxygen level. On the other hand, this study showed that the removal rates of most targets can reach a quasi-plateau in 5 h under aerobic conditions, indicating that hydraulic retention time of ca. 5 h in aerobic tanks should be sufficient for the elimination of most targets.

Occurrence of selected pharmaceuticals and caffeine in sewage treatment plants and receiving rivers in Beijing, China

The occurrence of nine different types of pharmaceuticals and caffeine were analyzed in various units of three wastewater treatment plants (WWTPs) and their receiving rivers in Beijing, China. Analyte concentrations were determined using ultra performance liquid chromatograph-tandem quadruple mass spectrometers (UPLC-MS/MS) and multiple-reaction monitoring. The studied pharmaceuticals and caffeine were found in all the WWTPs and receiving rivers. Their concentrations in the WWTP influents varied from 38 ng/L of sulpiride to 89.5 microg/L of caffeine, and those in the effluents ranged from 27 ng/L of sulpiride to 2.7 microg/L of erythromycin. Typically, the biological treatment appeared more effective in the removal of pharmaceuticals and caffeine than primary treatment in a WWTP. For an individual compound, the overall removal efficiency varied from one WWTP to the next. Mean values ranged from no removal of carbamazepine to 99.8% removal of caffeine. Most of the compounds in the receiving rivers were present at similar or higher concentrations compared to those in the WWTP effluents. The data set for this study does not include variations in concentrations along receiving waters because there were other point and nonpoint sources discharging to these rivers. The preliminary aquatic environmental risk assessment showed that carbamazepine, erythromycin, and trimethoprim is a potential chronic environmental risk in water bodies in Beijing, China, and is worth further investigation.

Chlorides behavior in raw fly ash washing experiments

Chloride in fly ash from municipal solid waste incinerators (MSWIs) is one of the obstructive substances in recycling fly ash as building materials. As a result, we have to understand the behavior of chlorides in recycling process, such as washing. In this study, we used X-ray absorption near edge structure (XANES) and X-ray diffraction (XRD) to study the chloride behavior in washed residue of raw fly ash (RFA). We found that a combination of XRD and XANES, which is to use XRD to identify the situation of some compounds first and then process XANES data, was an effective way to explain the chlorides behavior in washing process. Approximately 15% of the chlorine in RFA was in the form of NaCl, 10% was in the form of KCl, 51% was CaCl(2), and the remainder was in the form of Friedel's salt. In washing experiments not only the mole percentage but also the amount of soluble chlorides including NaCl, KCl and CaCl(2) decreases quickly with the increase of liquid to solid (L/S) ratio or washing frequency. However, those of insoluble chlorides decrease slower. Moreover, Friedel's salt and its related compound (11CaO.7Al(2)O(3).CaCl(2)) were reliable standards for the insoluble chlorides in RFA, which are strongly related to CaCl(2). Washing of RFA promoted the release of insoluble chlorides, most of which were in the form of CaCl(2).

Kinetic model of thermophilic L-lactate fermentation by Bacillus coagulans combined with real-time PCR quantification

A simple L-lactate fermentation of organic wastes at pH 5.5 and 55 degrees C under nonsterile conditions using Bacillus coagulans can be suitable for L-lactate fermentation of garbage. A mathematical model that simulated the lactate fermentation characteristics of B. coagulans was developed by focusing on the inhibitory effects of substrate, lactate (product) and NaCl, and bacterial growth. Basic fermentation experiments were performed using simple substrates to derive fundamental parameters of growth rate and inhibition effects. The model was then applied to fermentations using simple substrates and artificial kitchen garbage in order to verify its applicability. Microbial concentration, a key state variable of the model was measured using both real-time polymerase chain reaction (PCR) and traditional methods. The results of these methods were compared for experimental cases in which only soluble substrates were used. B. coagulans concentrations were suitably measured using real-time PCR, even when traditional measurement methods for microbial concentrations cannot be used. The results indicate that the developed model and biomass measurement can be used to evaluate lactate fermentations using both simple and complex substrates. These proposed methods would be useful for developing a new bacterial function-based mathematical model for more complex acid fermentations.

Behaviour of selected endocrine-disrupting chemicals in three sewage treatment plants of Beijing, China

Occurrence and fate of eight kinds of selected endocrine-disrupting compounds (EDCs) in three sewage treatment plants (STPs) of Beijing, China was investigated. These EDCs, composed of 4-octylphenol (4-OP), 4-n-nonylphenol (4-n-NP), bisphenol A (BPA), estrone (E1), 17alpha-estradiol (17alpha-E2), 17beta-estradiol (E2), estriol (E3) and 17alpha-ethinylestradiol (EE2), in every step of STPs, were simultaneously analysed by gas chromatography/mass spectrometry after derivatisation. All the EDCs were detected in the influents of three STPs, and BPA was the most abundant compound. The concentrations of EDCs ranged from 36.6 ng/l of 17alpha-E2 (STP C) to 1342.3 ng/l of BPA (STP B) in the influent sewages and from below limits of detection of E2 and E3 (STP C) to 142.5 ng/l of E1 (STP B) in the effluent sewages. The STPs could not remove alkylphenols effectively from the aqueous phase with less than 40% reduction. BPA decreased over 90%, and steroid estrogens achieved considerable reductions from 64.8% of E2 to 94.9% of E3. Generally, biological treatment was more effective in removing alkylphenols, BPA and natural estrogens from the aqueous phase than primary treatment. However, the synthetic estrogen, EE2, was mostly removed by the primary treatment with about 63.5% reduction. It is the first time that the concentration of 17alpha-E2 in the sewage of China was reported in this paper. The compound might have a bearing with the waste effluents of dairy farms around urban area of Beijing.

RO filtration of biologically treated textile and dyeing effluents using ozonation as a pre-treatment

Bench-scale experiments were conducted to investigate the application of ozonation pre-treatment for biologically treated textile and dyeing wastewater to improve performance of the RO process. Based on ozonation experiments, four specific ozone consumptions (SOC), 0, 0.3, 0.6, 4.0 mg O₃/mg DOC₀ were chosen for study of the effects of ozonation on the reverse osmosis (RO) process. Membrane flux was recorded. Also, the permeate water quality parameters such as TOC, conductivity were analyzed. In addition, fouled membrane cleaning was studied. The study further examined the nature and mechanisms of membrane fouling using scanning electron microscopy (SEM) and the energy dispersive X-ray spectrometer (EDS). The effect of ozonation on RO filtration was found to depend on SOC. The study revealed that significant improvement can be achieved in the efficiency of RO filtration by employing ozonation with 0.6 mg O₃/mg DOC₀ SOC. Although the product water purity slightly decreased, the ozonation pre-treatment showed advantages at 0.6 mg O₃/mg DOC₀ SOC for the following: (i) mitigation of flux decline due to membrane fouling; (ii) improvement in foulants cleanability. In addition, hypotheses were put forward to explain the reasons from the aspect of organic matter characteristics changed by ozonation, such as changing on functional groups and molecular weight of organic matter.

Evaluation of a novel oxidation ditch system for biological nitrogen and phosphorus removal from domestic sewage

A novel oxidation ditch system using anaerobic tanks and innovative dual dissolved oxygen (DO) control technology is proposed for biological nitrogen and phosphorus removal from domestic sewage. A continuous bench-scale experiment running for more than 300 days was performed to evaluate the system. Monitoring and controlling the airflow and recirculation flow rate independently using DO values at two points along the ditch permitted maintenance of aerobic and anoxic zone ratios of around 0.30 and 0.50, respectively. The ability to optimize aerobic and anoxic zone ratios using the dual DO control technology meant that a total nitrogen removal efficiency of 83.2-92.9% could be maintained. This remarkable nitrogen removal performance minimized the nitrate recycle to anaerobic tanks inhibiting the phosphorus release. Hence, the total phosphorus removal efficiency was also improved and ranged within 72.6-88.0%. These results demonstrated that stabilization of the aerobic and anoxic zone ratio by dual DO control technology not only resulted in a marked improvement of nitrogen removal, but it also enhanced phosphorus removal.

Toxicity of seven phthalate esters to embryonic development of the abalone Haliotis diversicolor supertexta

The toxicity of seven phthalate esters (PAEs), dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), butylbenzyl phthalate (BBP), di-n-hexyl phthalate (DnHP), di-(2-ethylhexyl) phthalate (DEHP) and di-n-octyl phthalate (DOP) to embryogenesis and larval development of the marine univalve Haliotis diversicolor supertexta was examined by means of two-stage embryo toxicity test. At the blastula stage, the normal embryonic development of H. diversicolor supertexta showed a good dose-response decrease when exposed to DMP, DEP, DBP, BBP, and DnHP. 9-h EC(50) values of DMP, DEP, DBP, BBP, and DnHP were 55.71, 39.13, 8.37, 2.65, and 3.32 mg/l, respectively. 9-h EC(50) values of DEHP and DOP were not available due to their low solubility. The toxicity order of seven tested PAEs was BBP>DnHP>DBP>DEP>DMP>DOP>DEHP. With the completion of metamorphosis as an experimental endpoint, the 96-h no-observed effect concentration values of DBP, DEHP and the other five tested PAEs were 0.022, 0.021, and 0.020 mg/l, respectively. Due to simple obtainment, convenient stimulation to spawn in the lab, greater sensitivity than mature species, and short culture time, the embryos of H. diversicolor supertexta have the potential to be utilized in acute toxicity test for at least PAEs.

Quantification of toxic Microcystis and evaluation of its dominance ratio in blooms using real-time PCR

Microcystins are produced by cyanobacteria carrying microcystin synthetase (mcy) genes in blooms. The present study investigated seasonal variations in concentrations of mcy A and 16S rRNA genes, encoded in the genus Microcystis using real-time PCR, and measured the water quality variables and microcystin concentrations in a hypereutrophic fish pond between June and November 2007. Prior to field survey, the relationship between axenic Microcystis aeruginosa NIES 102 cell abundance and concentrations of mcy A and 16S rRNA genes was determined by real-time PCR in the laboratory. Based on the quantitative relationship, microcystin-producing and total Microcystis cell numbers in the study site were estimated. The average dominance ratio of microcystin-producing strains in the total Microcystis population was approximately 80% and microcystin concentration was highly associated with toxic Microcystis cell numbers equivalent of mcy A gene. It was also observed that total nitrogen concentration was associated with development of Microcystis blooms, and high concentrations of NOx and NH4 increased microcystin production by promoting growth of microcystin-producing Microcystis strains.

Chloride Behavior in Washing Experiments of Two Kinds of Municipal Solid Waste Incinerator Fly Ash with Different Alkaline Reagents

To efficiently reduce and reuse fly ash from incinerators, we suggest trying a new alkaline reagent to neutralize the acid compounds in discharged gas from incinerators and reuse fly ash as the raw material in the cement industry. Normally the washing process includes a pretreatment method to remove chlorides to comply with the strict standards for cement. We examined chloride behavior in washing experiments by X-ray absorption near edge structure (XANES) and X-ray diffraction (XRD) for two kinds of fly ash: (1) fly ash collected in a bag filter with the injection of calcium hydroxide (Ca(OH)₂) for acid gas removal (CaFA), and (2) fly ash collected in a bag filter with the injection of sodium bicarbonate (NaHCO₃) for acid gas removal (NaFA). We found that the insoluble chlorides in both CaFA and NaFA combined calcium chloride (CaCl₂), with some sodium chloride (NaCl) also possibly combined. Under some conditions, the combined CaCl₂ and NaCl were released. In particular, when the liquid/solid ratio was greater than 3 or the washing frequency was doubled, less chlorine, insoluble chlorine, and CaCl₂ were left in the residues of NaFA than in the residues of CaFA. As a result, it is desirable to use NaHCO₃ as the alkaline reagent instead of Ca(OH)₂ in the air pollution control system of incinerators for recycling fly ash as a raw material in the cement industry.

Comparative performance and microbial diversity of hyperthermophilic and thermophilic co-digestion of kitchen garbage and excess sludge

The objective of this study was to evaluate the performance characteristics of a hyperthermophilic digester system that consists of an acidogenic reactor operated at hyperthermophilic (70 degrees C) conditions in series with a methane reactor operated at mesophilic (35 degrees C), thermophilic (55 degrees C), and hyperthermophilic (65 degrees C) conditions. Lab-scale reactors were operated continuously, and were fed with co-substrates composed of artificial kitchen garbage (TS 9.8%) and excess sludge (TS 0.5%) at the volumetric ratio of 20:80. In the acidification step, COD solubilization was in the range of 22-46% at 70 degrees C, while it was 21-29% at 55 degrees C. The average protein solubilization was 44% at 70 degrees C. The double bond fatty acid removal ratio at 70 degrees C was much higher than at 55 degrees C. These results suggested that the optimal operation conditions for the acidogenic fermenter were about 3.1 days of HRT and 4 days of SRT at 70 degrees C. Methane conversion efficiency and the VS removal percentage in the methanogenic step following acidification was around 65% and 64% on average at 55 degrees C, respectively. The optimal operational conditions for this system are acidogenesis performed at 70 degrees C and methanogenesis at 55 degrees C. The key microbes determined in the hyperthermophilic acidification step were Anaerobic thermophile IC-BH at 6.4 days of HRT and Thermoanaerobacter thermohydrosulfuricus DSM 567 at 2.4 days of HRT. These results indicated that the hyperthermophilic system provides considerable advantages in treating co-substrates containing high concentrations of proteins, lipids, and nonbiodegradable solid matter.

Applicability of random cloning method to analyze microbial community in full-scale anaerobic digesters

Microbial communities were analyzed in six full-scale anaerobic digesters and a lab-scale digester using the random cloning method. The purposes were to confirm the applicability, reproducibility, and error range of this method; to discuss the difference in the dominant microbes determined by this method in different operational conditions of temperature (mesophilic and thermophilic) and substrate (garbage, sewage sludge, and livestock waste); and to determine key microbes in each digester. Each sample was analyzed in triplicate. In one of the samples, 373 clones were analyzed to study the composition of microbial community in the digester. Time course analysis was conducted from the start-up period for approximately one year in one of the digesters. Similar microbial diversity was obtained corresponding to the type of substrate change (sewage sludge to garbage). Operational taxonomic units (OTUs) closely related to Coprothermobacter sp. and unidentified bacterium clones TUG14 and TUG22 disappeared during the first 40 d, while OTUs closely related to Bacillus sp. and Clostridium sp. increased later. Microbial diversity in digesters is strongly affected by the operational conditions, and similar microbial diversity can be obtained in triplicate analysis and under similar operational conditions. The present study verified the applicability of this method to discuss the overall difference in microbial communities.

Effect of temperature on performance and microbial diversity in hyperthermophilic digester system fed with kitchen garbage

The objective of this study was to evaluate the performances and microbial diversities for development of the effective hyperthermophilic digester system that consists of hyperthermophilic reactor and hyperthermophilic or thermophilic reactor in series. Lab-scale reactors were operated continuously fed with artificial kitchen garbage. The effect of temperature on the acidification step was firstly investigated. Results indicated that 43.1% of COD solubilization was achieved at 70 degrees C, while it was about 21% at 80 degrees C. The average protein solubilization reached to 31% at 80 degrees C. Methane conversion efficiency following the acidification was around 85% in average at 55 degrees C, but decreased with increasing temperature and methane gas was not produced over 73 degrees C. The upper temperature limits for growth of microbes were secondly observed and shown to be 73 degrees C for acetate oxidizers, 65 degrees C for propionate oxidizers, 70 degrees C for iso-butyrate oxidizers, 80 degrees C for lactate oxidizers and 65 degrees C for protein degrading bacteria in the methane fermenter. As well as, microbes affiliated with methanogens dominated the population below the 65 degrees C, while those affiliated with acidogens were predominant over the 73 degrees C. These results indicated that the hyperthermophilic processes have considerable benefits to treat wastewater or waste containing high concentration of protein.

Removal of endocrine-disrupting chemicals during ozonation of municipal sewage with brominated byproducts control

The decomposition of endocrine-disrupting chemicals (EDCs) including estrone (E1), 17beta-estradiol (E2), estriol (E3), nonylphenol (NP), and bisphenol A (BPA) during ozonation of municipal sewage grabbed from the outlets of primary sedimentation tanks was studied through laboratory-scale experiments. A newly developed in vitro bioassay called nuclear receptor-ligand assay and GC-MS were both utilized to respectively determine the estrogenicity and individual EDCs in the wastewater samples. The original estrogenicity, expressed as the E2 equivalent concentration (EEQC), in the primary effluents was 315-1018 ng/L. Results indicate that the EEQC can be reduced rapidly to below 10 ng/L after ozonation. The appearance of 0.1 mg/L dissolved ozone (DO3), which corresponds to a consumed ozone amount of 0.4 mg per initial TOC (total organic carbon) of wastewater samples, was an appropriate operational parameter to simultaneously achieve efficient EDC removal and control of BrO3- and total organic bromine (TOBr). The presence of suspended solids in the range of 38-67 mg/L exhibited no obvious impact on the removal of nonsorbed estrogenicity. A complete decomposition of E2, E3 and BPA was achieved once 0.1 mg/L DO3 appeared in the primary effluent. The oxidative decomposition of NP was relatively less efficient with a residual concentration of 100 ng/L. This work investigates the feasibility of EDC removal and brominated byproduct control during ozonation of original municipal sewage prior to biological treatment.

Modeling of decomposition characteristics of estrogenic chemicals during ozonation

The purposes of this study were to develop a refined model for simulation of ozonation of estrogenic chemicals under different conditions and to investigate the behaviors of estrogenic by-products using the model. In the cases of ozonation of 17-estradiol (E2), bisphenol-A (BPA) and nonylphenol (NP) in aqueous solution, it can be concluded that the liquid film resistances are larger than bulk resistances, and thus most of the reaction occurs in liquid bulk. E2, BPA and NP are easily decomposed producing by-products of ozonation, but the estrogenicity of these chemicals and the by-products reduced with increase in ozonation time. Through this research, ozonation was shown to be a promising method to decompose E2, BPA and NP and to reduce the estrogenicity of these chemicals.

The performance and microbial diversity of temperature-phased hyperthermophilic and thermophilic anaerobic digestion system fed with organic waste

The objective of this study was to evaluate the performances and microbial diversities for development of the effective hyperthermophilic digester system that consists of a hyperthermophilic reactor and hyperthermophilic or thermophilic reactor in series. Lab-scale reactors were operated continuously fed with artificial kitchen garbage. The effect of temperature on the acidification step was firstly investigated. Results indicated that 20.8% of COD solubilization was achieved at 70 degrees C, with 12.6% at 80 degrees C. The average protein solubilization reached 31% at 80 degrees C. Methane conversion efficiency following the acidification was around 85% on average at 55 degrees C, but decreased with increasing temperature and methane gas was not produced over 73 degrees C. As well, bacteria affiliated with the methanogens dominated the population below 65 degrees C, while those affiliated with acidogens were predominant over 73 degrees C. These results indicated that the hyperthermophilic process has considerable benefits to treat wastewater or waste containing high concentration of protein.

Characteristics of electrolysis, ozonation, and their combination process on treatment of municipal wastewater

The characteristics of municipal wastewater treatment by electrolysis, ozonation, and combination processes of electrolysis and aeration using three gaseous species (nitrogen [N2], oxygen [O2], and ozone [O3]) were discussed in this research using ruthenium oxide (RuO2)-coated titanium anodes and stainless-steel (SUS304) cathodes. Electrolysis and electrolysis with nitrogen aeration were characterized by a rapid decrease in 5-day biochemical oxygen demand (BODs) and total nitrogen and a slow decrease in chemical oxygen demand (COD). In contrast, ozonation, electrolysis with oxygen aeration, and electrolysis with ozone aeration were characterized by transformation of persistent organic matter to biodegradable matter and preservation of total nitrogen. The best energy efficiency in removing BOD5 and total nitrogen was demonstrated by electrolysis, as a result of direct anodic oxidation and indirect oxidation with free chlorine produced from the chloride ion (Cl-) at the anodes. However, electrolysis with ozone aeration was found to be superior to the other processes, in terms of its energy efficiency in removing COD and its ability to remove COD completely, as a result of hydroxyl radical (*OH) production via cathodic reduction of ozone.

Production of biogenic manganese oxides by repeated-batch cultures of laboratory microcosms

We investigated the production of manganese (Mn) oxides using repeated-batch bioreactors maintained over long periods under laboratory conditions. Freshwater epilithic biofilms were used as the initial inocula. The bioreactors yielded suspended solids that could remove 0.1 mM dissolved Mn(II) within a few days. Chemical titration, X-ray absorption near-edge structure spectroscopy, and X-ray diffraction analysis revealed that the Mn(II) had been converted to poorly crystallized layer-type Mn(IV) oxides, which were similar to known biogenic Mn oxides from pure bacterial cultures. Spherical or rod-shaped Mn microconcretions occurred in the suspended solids; transmission electron microscopy showed that these structures likely resulted from the microbial activity but not represent living cells. Instead, the presence of encapsulated, sheathed, and hyphal budding cells in the suspended solids indicated that a range of Mn-depositing bacteria contributed to the Mn oxide formation. To our knowledge, our data represent the first observation of production of such Mn oxides in a laboratory microcosm wherein a range of Mn-depositing bacteria coexist. The fact that sorption of trace Zn(II) and Ni(II) ions onto the suspended solids co-occurred with the removal of dissolved Mn(II) emphasizes the important role of Mn-oxidizing microorganisms in the fates of trace or contaminant metals in the aquatic environment.

Effects of pH and temperature on products and bacterial community in L-lactate batch fermentation of garbage under unsterile condition

Acidogenesis fermentation of artificial garbage without sterile condition was conducted in batch mode to investigate effects of cultivation pH (5.5, 6.0, 6.5) and temperature (45, 50, 55 degrees C). Bacteria exiting natively in the garbage were utilized in this study; in turn, no specific seed was inoculated. The results indicated that only one set of operational conditions (pH 5.5 and 55 degrees C) led to L-lactate fermentation. Obtained yield of lactate based on initial carbohydrate was around 0.5 and optical purity of L-lactate was around 99%. In this study, three typical cases, which were L-lactate, racemic lactate and butyrate fermentation, were observed depended on sets of cultivation pH and temperature. Microbial structures of typical cases were also identified with using 16S rDNA libraries. The analysis indicated that Bacillus coagulans produced L-lactate. Lactobacillus amylolyticus, which produces racemic lactate, and Clostridium thermopalmarium, which produces butyrate, were also detected on each typical sample. L. amylolyticus and C. thermopalmarium would be eliminated by setting cultivation temperature of 55 degrees C and above, and pH 5.5 and below, respectively. From a series of this study, operational conditions of pH 5.5 and temperature of 55 degrees C would be potentially suitable for L-lactate fermentation of garbage with view of efficiency and stability of its production.

The removal of estrogenic activity and control of brominated by-products during ozonation of secondary effluents

The purposes of this study were to investigate the behavior of brominated by-products, such as bromate ion and total organic bromide, formed during ozonation for the removal of estrogenic activity in sewage effluents and to propose operation parameters for the ozonation process. It is necessary to reduce the E(2) equivalent concentration of estrogenic activity in secondary effluent treated by 90% of the initial one. To do so, ozonation until dissolved ozone concentration increased to 0.1mg/L (which corresponds to approximately 1mg O(3)/mg DOC(0) [consumed ozone per initial DOC] of consumed ozone for the effluent in this study) is proposed as an operation parameter for ozonation without the formation of brominated by-products.

Semi-continuous L-lactate fermentation of garbage without sterile condition and analysis of the microbial structure

In order to develop a simple L-lactate fermentation of organic wastes, acidogenic fermentation was investigated in semi-continuous culture at 55 degrees C with using unsterilized artificial garbage as feedstock. And, sludge from a thermophilic acidification reactor was inoculated at the start of the fermentation. The effects of pH and hydraulic retention time (HRT) on performance of L-lactate production were discussed in a series of operational conditions with regard to long-term stability. The best operational conditions for L-lactate fermentation are proposed to be 55 degrees C, pH 6 and HRT of 10 days to get the highest yield of lactate based on initial carbohydrate in the feedstock. The yield of 0.74 and produced L-lactate optical purity of 96.7% were obtained on these operational conditions. Another L-lactate fermentation, which were semi-continuous and batch mode operations, were conducted to present reproducibility of the fermentation. Microbial structures in the semi-continuous fermentations were analyzed with using 16S rDNA libraries, and Bacillus coagulans was shown to be the most predominant species in the L-lactate fermented cultural broth.

Ozonation parameter for removal of oestrogenicity from secondary effluent without by-products

The purposes of this study are to investigate ozonation characteristics, to evaluate oestrogenicity and to confirm behaviours of by-products during ozonation of secondary effluent. For the ozonation of secondary effluent, TOC was decreased only 10% when 4 (mgO3/mgC) of ozone consumption per initial TOC. However, UV254 and SUVA was decreased approximately 65% until ozone consumption of 2 (mgO3/mgC). Ozonation was also shown to be very effective for decrease of oestrogenicity in secondary effluent. Bromate ion started to form obviously when the ozone consumption per initial TOC exceeded 2 (mgO3/mgC) and increased while the time of ozonation became longer. From these results, ozone consumption per initial TOC was shown to be an appropriate operation parameter to reduce SUVA effectively and E2 equivalent concentration to less than 0.1 nM without significant formation of bromate ion, and its value was determined to be 2 (mgO3/mgC) in ozonation of secondary effluent.

Microbial population dynamics in a thermophilic methane digester fed with garbage

The diversity of microbial communities in three full-scale thermophilic anaerobic digesters which treated garbage, sewage sludge and livestock wastes (hereafter called TGD, TSD and TLD, respectively) was investigated using 16S rDNA clone libraries in triplicate. The population dynamics of TGD were also studied. The purposes were to show the microbial diversity in each reactor and to suggest which key microbes in a thermophilic methane digester fed with garbage, including a check of reproducibility and the suggestion of an error range in this molecular biology method. 736 clones were identified, and the maximum error was estimated to be around +/-10% for the same OTU (operational taxonomic unit) and for most detected OTUs. The most frequently detected OTU shows a close relationship to Uncultured bacterium clone MBA08, Unidentified bacterium clone TUG22 and Uncultured archaeal symbiont PA204 in TGD, TSD and TLD, respectively. The microbial population dynamics in TGD were studied over a period of 90 days, and the occupying ratios of Bacillus infernus and Methanothermobacter wolfeii were shown to change with the change in VFA concentration. From the dynamic change and characteristics of the microbes, it is concluded that Bacillus infernus and Methanothermobacter wolfeii played an important role and were recommended as key microbes in TGD.

Manganese(IV) oxide production by Acremonium sp. strain KR21-2 and extracellular Mn(II) oxidase activity

Ascomycetes that can deposit Mn(III, IV) oxides are widespread in aquatic and soil environments, yet the mechanism(s) involved in Mn oxide deposition remains unclear. A Mn(II)-oxidizing ascomycete, Acremonium sp. strain KR21-2, produced a Mn oxide phase with filamentous nanostructures. X-ray absorption near-edge structure (XANES) spectroscopy showed that the Mn phase was primarily Mn(IV). We purified to homogeneity a laccase-like enzyme with Mn(II) oxidase activity from cultures of strain KR21-2. The purified enzyme oxidized Mn(II) to yield suspended Mn particles; XANES spectra indicated that Mn(II) had been converted to Mn(IV). The pH optimum for Mn(II) oxidation was 7.0, and the apparent half-saturation constant was 0.20 mM. The enzyme oxidized ABTS [2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)] (pH optimum, 5.5; Km, 1.2 mM) and contained two copper atoms per molecule. Moreover, the N-terminal amino acid sequence (residues 3 to 25) was 61% identical with the corresponding sequence of an Acremonium polyphenol oxidase and 57% identical with that of a Myrothecium bilirubin oxidase. These results provide the first evidence that a fungal multicopper oxidase can convert Mn(II) to Mn(IV) oxide. The present study reinforces the notion of the contribution of multicopper oxidase to microbially mediated precipitation of Mn oxides and suggests that Acremonium sp. strain KR21-2 is a good model for understanding the oxidation of Mn in diverse ascomycetes.

Development of biological filter as tertiary treatment for effective nitrogen removal: Biological filter for tertiary treatment

A biological filtration process applicable to tertiary treatment of sewage for effective nitrogen removal was developed. It consisted of a nitrification filter (Filter 1) and/or a polishing filter with anoxic and oxic parts (Filter 2). A pilot plant set at a municipal sewage treatment plant was operated for 525 d with feed of real sewage. The maximum apparent nitrification rate in Filter 1 in winter was 0.54 kg N/m3- filter-bed d. In Filter 2, the maximum denitrification capacity was 4 kg N/m3 filter-bed d) in winter. SS was stably removed and high transparency water was obtained. The target water quality (SS, BOD, and T-N5 mg/L) was accomplished in winter with the LV of 202 m/d in Filter 2, which corresponds to 0.24 h of HRT. These results proved that this process is compact, stable, convenient to install, and cost effective to build and operate as tertiary treatment to remove nitrogen effectively.

Application of biological activated carbon anaerobic reactor for treatment of hazardous chemicals

An expanded-bed anaerobic reactor with granular activated carbon (GAC) medium has been developed to treat wastewaters that contain a high concentration of inhibitory and/or refractory organic compounds as well as readily degradable organic compounds. The process is characterised by a combination of two removal mechanisms; adsorption on GAC and biological degradation by microorganisms grown on GAC. Applicability of the reactor to treatment of phenol, chloroacetaldehyde (CAA), pentachlorophenol (PCP) and tetrachloroethylene (PCE) was discussed based on experimental data. All chemicals focused on here were removed well and stably at a removal efficiency of more than 98% even during starting operation and shock load operation. Chemicals in influent that exceeded biological degradation capacity was initially adsorbed on GAC and then gradually degraded, and hence the adsorptive capacity of GAC was regenerated biologically. These results proved that a biological activated carbon anaerobic reactor was effective for treatment of wastewater containing hazardous chemicals, especially for strongly absorbable chemicals, as well as readily degradable organic compounds at high concentration.

Operation of a new sewage treatment process with technologies of excess sludge reduction and phosphorus recovery

This paper shows the potential application of a new sewage treatment process with technologies of excess sludge reduction and phosphorus recovery. The process incorporated ozonation for excess sludge reduction and crystallisation process for phosphorus recovery to a conventional anaerobic/oxic (A/O) phosphorus removal process. A lab-scale continuous operation experiment was conducted with the ratio of sludge flow rate to ozonation tank of 1.1% of sewage inflow under 30 to 40 mgO3/gSS of ozone consumption and with sludge wasting ratio of 0.34% (one-fifth of a conventional A/O process). Throughout the operational experiment, a 60% reduction of excess sludge production was achieved in the new process. A biomass concentration of 2300 mg/L was maintained, and the accumulation of inactive biomass was not observed. The new process was estimated to give a phosphorus recovery degree of more than 70% as an advantage of excess sludge reduction. The slight increase in effluent COD was observed, but the process performance was maintained at a satisfactory level. These facts demonstrate an effectiveness of the new process for excess sludge reduction as well as for phosphorus recovery.

Control of bromate ion and brominated organic compounds formation during ozone/hydrogen peroxide treatment of secondary effluent

Ozonation and ozone process combined with hydrogen peroxide have been identified as new technologies for direct or indirect reuse of wastewater. This study aims to establish appropriate conditions to control the formation of BrO3 and brominated organic compounds during O3/H2O2 treatment of secondary effluents of sewage. When the H2O2/O3 mole ratio of injection was above 0.5 and the DO3 concentration was below 0.1 mg/L, BrO3 was controlled as well as treatment purpose was completed. TOBr formation in O3/H2O2 treatment was also completely controlled.