Dose-related effects of ketamine for antidepressant-resistant symptoms of posttraumatic stress disorder in veterans and active duty military: a double-blind, randomized, placebo-controlled multi-center clinical trial

This study tested the efficacy of repeated intravenous ketamine doses to reduce symptoms of posttraumatic stress disorder (PTSD). Veterans and service members with PTSD (n = 158) who failed previous antidepressant treatment were randomized to 8 infusions administered twice weekly of intravenous placebo (n = 54), low dose (0.2 mg/kg; n = 53) or standard dose (0.5 mg/kg; n = 51) ketamine. Participants were assessed at baseline, during treatment, and for 4 weeks after their last infusion. Primary analyses used mixed effects models. The primary outcome measure was the self-report PTSD Checklist for DSM-5 (PCL-5), and secondary outcome measures were the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) and the Montgomery Åsberg Depression Rating Scale (MADRS). There were no significant group-by-time interactions for PTSD symptoms measured by the PCL-5 or CAPS-5. The standard ketamine dose ameliorated depression measured by the MADRS significantly more than placebo. Ketamine produced dose-related dissociative and psychotomimetic effects, which returned to baseline within 2 h and were less pronounced with repeated administration. There was no evidence of differential treatment discontinuation by ketamine dose, consistent with good tolerability. This clinical trial failed to find a significant dose-related effect of ketamine on PTSD symptoms. Secondary analyses suggested that the standard dose exerted rapid antidepressant effects. Further studies are needed to determine the role of ketamine in PTSD treatment. ClinicalTrials.gov identifier: NCT02655692.

mTORC1 inhibitor effects on rapid ketamine-induced reductions in suicidal ideation in patients with treatment-resistant depression

Suicide is a public health crisis with limited treatment options. Ketamine has demonstrated rapid and robust improvements in suicidal ideation (SI). The parent study for the secondary pilot analyses presented here was a double-blind, cross-over trial that found pretreatment with the mechanistic target of rapamycin complex 1 (mTORC1) prolonged the antidepressant effects of ketamine. Here we examined the effect of mTORC1 inhibition on ketamine's antisuicidal effects. Twenty patients in a major depressive episode were randomized to pretreatment with oral rapamycin (6 mg) or placebo prior to IV ketamine (0.5 mg/kg). We found ketamine administration resulted in significant improvements across all measures with the largest effect at 24 h with only the Beck Scale for Suicide remaining significant at the two-week follow-up. There were no significant main effects of pretreatment. While these analyses are pilot in nature and overall severity of SI was relatively low, the antisuicidal findings (no effect of rapamycin) being in contrast to the antidepressant effects (prolonged effect with rapamycin), suggest the rapid-acting antisuicidal and antidepressant effects of ketamine may be mechanistically distinct and the trajectories of response, recovery, and relapse may be independent. These findings provide additional evidence of ketamine's antisuicidal effects and highlight the importance of future studies that continue to examine potential differences in mechanisms and trajectory of outcomes.

A robust and reproducible connectome fingerprint of ketamine is highly associated with the connectomic signature of antidepressants

Over the past decade, various N-methyl-D-aspartate modulators have failed in clinical trials, underscoring the challenges of developing novel rapid-acting antidepressants based solely on the receptor or regional targets of ketamine. Thus, identifying the effect of ketamine on the brain circuitry and networks is becoming increasingly critical. In this longitudinal functional magnetic resonance imaging study of data from 265 participants, we used a validated predictive model approach that allows the full assessment of brain functional connectivity, without the need for seed selection or connectivity summaries. First, we identified a connectome fingerprint (CFP) in healthy participants (Cohort A, n = 25) during intravenous infusion of a subanesthetic dose of ketamine, compared to normal saline. We then demonstrated the robustness and reproducibility of the discovered ketamine CFP in two separate healthy samples (Cohort B, n = 22; Cohort C, n = 18). Finally, we investigated the ketamine CFP connectivity at 1-week post treatment in major depressive disorder patients randomized to 8 weeks of sertraline or placebo (Cohort D, n = 200). We found a significant, robust, and reproducible ketamine CFP, consistent with reduced connectivity within the primary cortices and within the executive network, but increased connectivity between the executive network and the rest of the brain. Compared to placebo, the ketamine CFP connectivity changes at 1 week predicted response to sertraline at 8 weeks. In each of Cohorts A-C, ketamine significantly increased connectivity in a previously identified antidepressant CFP. Investigating the brain connectivity networks, we successfully identified a robust and reproducible ketamine biomarker that is related to the mechanisms of antidepressants.

Modulation of the antidepressant effects of ketamine by the mTORC1 inhibitor rapamycin

Twenty-four hours after administration, ketamine exerts rapid and robust antidepressant effects that are thought to be mediated by activation of the mechanistic target of rapamycin complex 1 (mTORC1). To test this hypothesis, depressed patients were pretreated with rapamycin, an mTORC1 inhibitor, prior to receiving ketamine. Twenty patients suffering a major depressive episode were randomized to pretreatment with oral rapamycin (6 mg) or placebo 2 h prior to the intravenous administration of ketamine 0.5 mg/kg in a double-blind cross-over design with treatment days separated by at least 2 weeks. Depression severity was assessed using Montgomery-Åsberg Depression Rating Scale (MADRS). Rapamycin pretreatment did not alter the antidepressant effects of ketamine at the 24-h timepoint. Over the subsequent 2-weeks, we found a significant treatment by time interaction (F(8,245) = 2.02, p = 0.04), suggesting a prolongation of the antidepressant effects of ketamine by rapamycin. Two weeks following ketamine administration, we found higher response (41%) and remission rates (29%) following rapamycin + ketamine compared to placebo + ketamine (13%, p = 0.04, and 7%, p = 0.003, respectively). In summary, single dose rapamycin pretreatment failed to block the antidepressant effects of ketamine, but it prolonged ketamine's antidepressant effects. This observation raises questions about the role of systemic vs. local blockade of mTORC1 in the antidepressant effects of ketamine, provides preliminary evidence that rapamycin may extend the benefits of ketamine, and thereby potentially sheds light on mechanisms that contribute to depression relapse after ketamine administration.

Non-local stresses in highly non-uniformly flowing suspensions: The shear-curvature viscosity

For highly non-uniformly flowing fluids, there are contributions to the stress related to spatial variations of the shear rate, which are commonly referred to as non-local stresses. The standard expression for the shear stress, which states that the shear stress is proportional to the shear rate, is based on a formal expansion of the stress tensor with respect to spatial gradients in the flow velocity up to leading order. Such a leading order expansion is not able to describe fluids with very rapid spatial variations of the shear rate, like in micro-fluidics devices and in shear-banding suspensions. Spatial derivatives of the shear rate then significantly contribute to the stress. Such non-local stresses have so far been introduced on a phenomenological level. In particular, a formal gradient expansion of the stress tensor beyond the above mentioned leading order contribution leads to a phenomenological formulation of non-local stresses in terms of the so-called "shear-curvature viscosity". We derive an expression for the shear-curvature viscosity for dilute suspensions of spherical colloids and propose an effective-medium approach to extend this result to concentrated suspensions. The validity of the effective-medium prediction is confirmed by Brownian dynamics simulations on highly non-uniformly flowing fluids.

Interactive effects of an N-methyl-d-aspartate receptor antagonist and a nicotinic acetylcholine receptor agonist on mismatch negativity: Implications for schizophrenia

N-methyl-d-aspartate glutamate receptor (NMDAR) hypofunction has been implicated in the pathophysiology of schizophrenia, including auditory processing abnormalities reflected by the mismatch negativity (MMN) event-related potential component. Evidence suggesting cognitive benefits from nicotine administration, together with the high rate of cigarette use in patients with schizophrenia, has stimulated interest in whether nicotine modulates NMDAR hypofunction. We examined the interactive effects of ketamine, an NMDAR antagonist that produces transient schizophrenia-like neurophysiological effects, and nicotine, a nicotinic acetylcholine receptor (nAChR) agonist, in 30 healthy volunteers to determine whether nicotine prevents or attenuates MMN abnormalities. Secondary analyses compared the profile of ketamine and schizophrenia effects on MMN using previously reported data from 24 schizophrenia patients (Hay et al. 2015). Healthy volunteers completed four test days, during which they received ketamine/placebo and nicotine/placebo in a double-blind, counterbalanced design. MMN to intensity, frequency, duration, and frequency+duration double deviant sounds was assessed each day. Ketamine decreased intensity, frequency, and double deviant MMN amplitudes, whereas nicotine increased intensity and double deviant MMN amplitudes. A ketamine×nicotine interaction indicated, however, that nicotine failed to attenuate the decrease in MMN associated with ketamine. Although the present dose of ketamine produced smaller decrements in MMN than those associated with schizophrenia, the profile of effects across deviant types did not differ between ketamine and schizophrenia. Results suggest that while ketamine and schizophrenia produce similar profiles of MMN effects across deviant types, nicotinic agonists may have limited potential to improve these putative NMDAR hypofunction-mediated impairments in schizophrenia.

Formation and alteration of airborne particles in the subway environment

Most particles in the rail subway environment are sub-micron sized ferruginous flakes and splinters generated mechanically by frictional wear of brake pads, wheels and rails. To better understand the mechanisms of formation and the alteration processes affecting inhalable particles in subways, PM samples (1-2.5 μm and 2.5-10 μm) were collected in the Barcelona Metro and then studied under a scanning electron microscope. Most particles in these samples are hematitic (up to 88%), with relatively minor amounts of mineral matter (up to 9%) and sulphates (up to 5%). Detailed microscopy (using back scattered and TEM-DRX imaging) reveals how many of the metallic particles comprise the metallic Fe nucleus surrounded by hematite (Fe₂O₃) and a coating of sulphate and chloride salts mixed with mineral matter (including Ca-carbonates, clay minerals and quartz). These observations record the emission of fine to ultrafine FePM by frictional wear at elevated temperatures that promote rapid partial (or complete) oxidation of the native metal. Water condensing on the PM surface during cooling leads to the adsorption of inorganic mineral particles that coat the iron oxide. The distinctively layered polymineralic structure that results from these processes is peculiar to particles generated in the subway environment and very different from PM typically inhaled outdoors.

Effect of relative humidity on preeclampsia

PURPOSE OF INVESTIGATION

The authors aimed to determine the relationship between meteorological variables and hypertension in pregnancy by using data from a national weather database.

MATERIALS AND METHODS

For this population-based observational study, the database of the Korea National Health Insurance (KNHI) Claims of the Health Insurance Review and Assessment Service (HIRA) and Korea Meteorological Administration was used. The 48,275 women with preeclampsia among 2,495,383 women who gave birth were included. Monthly meteorological factors and preeclampsia prevalence for five years were statistically analyzed.

RESULTS

Among temperature, relative humidity, sunlight duration, and rainfall, only relative humidity had a significant inverse correlation with the preeclampsia prevalence (p < 0.001). The other meteorological factors were not associated with preeclampsia.

CONCLUSION

Relative humidity may be a significant factor for of the development of preeclampsia. Further monitoring of weather parameters during the entire pregnancy period may be the best method for verifying the present results in the development of preeclampsia.

Pressure dependent structural changes and predicted electrical polarization in perovskite RMnO₃

High pressure x-ray diffraction measurements on perovskite RMnO3 (R  =  Dy, Ho and Lu) reveal that varying structural changes occur for different R ions. Large lattice changes (orthorhombic strain) occur in DyMnO3 and HoMnO3 while the Jahn-Teller (JT) distortion remains stable. Conversely, in the small R-ion system LuMnO3, Mn-O bond distortions are observed between 4 and 8 GPa with a broad minimum in the JT distortion. High pressure infrared measurements indicate that a phonon near 390 cm(-1) corresponding to the complex motion of the Mn and O ions changes anomalously for LuMnO3. It softens in the 4-8 GPa region, which is consistent with the structural change in Mn-O bonds and then hardens at higher pressures. By contrast, the phonons continuously harden with increasing pressure for DyMnO3 and HoMnO3. Density functional theory methods show that E-phase LuMnO3 is the most stable phase up to the 10 GPa pressure examined. Simulations indicate that the distinct structural change under pressure in LuMnO3 can possibly be used to optimize the electric polarization by pressure/strain.

Role of GABA Deficit in Sensitivity to the Psychotomimetic Effects of Amphetamine

Some schizophrenia patients are more sensitive to amphetamine (AMPH)-induced exacerbations in psychosis-an effect that correlates with higher striatal dopamine release. This enhanced vulnerability may be related to gamma-aminobutyric acid (GABA) deficits observed in schizophrenia. We hypothesized that a pharmacologically induced GABA deficit would create vulnerability to the psychotomimetic effects to the 'subthreshold' dose of AMPH in healthy subjects, which by itself would not induce clinically significant increase in positive symptoms. To test this hypothesis, a GABA deficit was induced by intravenous infusion of iomazenil (IOM; 3.7 μg/kg), an antagonist and partial inverse agonist of benzodiazepine receptor. A subthreshold dose of AMPH (0.1 mg/kg) was administered by intravenous infusion. Healthy subjects received placebo IOM followed by placebo AMPH, active IOM followed by placebo AMPH, placebo IOM followed by active AMPH, and active IOM followed by active AMPH in a randomized, double-blind crossover design over 4 test days. Twelve healthy subjects who had a subclinical response to active AMPH alone were included in the analysis. Psychotomimetic effects (Positive and Negative Syndrome Scale (PANSS)), perceptual alterations (Clinician Administered Dissociative Symptoms Scale (CADSS)), and subjective effects (visual analog scale) were captured before and after the administration of drugs. IOM significantly augmented AMPH-induced peak changes in PANSS positive symptom subscale and both subjective and objective CADSS scores. There were no pharmacokinetic interactions. In conclusion, GABA deficits increased vulnerability to amphetamine-induced psychosis-relevant effects in healthy subjects, suggesting that pre-existing GABA deficits may explain why a subgroup of schizophrenia patients are vulnerable to AMPH.

Absence of significant structural changes near the magnetic ordering temperature in small-ion rare earth perovskite RMnO3

Detailed structural measurements on multiple length scales were conducted on a new perovskite phase of ScMnO3, and on orthorhombic LuMnO3 as a benchmark. Complementary density functional theory (DFT) calculations were carried out, and predict that ScMnO3 possesses E-phase magnetic order at low temperature with displacements of the Mn sites (relative to the high temperature state) of ∼0.07 Å, compared to ∼0.04 Å predicted for LuMnO3. However, detailed local, intermediate and long-range structural measurements by x-ray pair distribution function analysis, single crystal x-ray diffraction and x-ray absorption spectroscopy, find no local or long-range distortions on crossing into the low temperature E-phase of the magnetically ordered state. The measurements place upper limits on any structural changes to be at most one order of magnitude lower than DFT predictions and suggest that this theoretical approach does not properly account for the spin-lattice coupling in these oxides and may possibly predict the incorrect magnetic order at low temperatures. The results suggest that the electronic contribution to the electrical polarization dominates and should be more accurately treated in theoretical models.

Effects of nicotine on the neurophysiological and behavioral effects of ketamine in humans

BACKGROUND

N-methyl-d-aspartate (NMDA) receptor hypofunction has been implicated in the pathophysiology of schizophrenia and its associated neurocognitive impairments. The high rate of cigarette smoking in schizophrenia raises questions about how nicotine modulates putative NMDA receptor hypofunction in the illness. Accordingly, we examined the modulatory effects of brain nicotinic acetylcholine receptor (nAChR) stimulation on NMDA receptor hypofunction by examining the interactive effects of nicotine, a nAChR agonist, and ketamine, a non-competitive NMDA receptor antagonist, on behavioral and neurophysiological measures in healthy human volunteers.

METHODS

From an initial sample of 17 subjects (age range 18-55 years), 8 subjects successfully completed 4 test sessions, each separated by at least 3 days, during which they received ketamine or placebo and two injections of nicotine or placebo in a double-blind, counterbalanced manner. Schizophrenia-like effects Positive and Negative Syndrome Scale, perceptual alterations Clinician Administered Dissociative Symptoms Scale, subjective effects Visual Analog Scale and auditory event-related brain potentials (mismatch negativity, MMN; P300) were assessed during each test session.

RESULTS

Consistent with existing studies, ketamine induced transient schizophrenia-like behavioral effects. P300 was reduced and delayed by ketamine regardless of whether it was elicited by a target (P3b) or novel (P3a) stimulus, while nicotine only reduced the amplitude of P3a. Nicotine did not rescue P300 from the effects of ketamine; the interactions of ketamine and nicotine were not significant. While nicotine significantly reduced MMN amplitude, ketamine did not.

CONCLUSION

Nicotine failed to modulate ketamine-induced neurophysiological and behavioral effects in this preliminary study. Interestingly, ketamine reduced P3b amplitude and nicotine reduced P3a amplitude, suggesting independent roles of NMDA receptor and nAChR in the generation of P3b and P3a, respectively.

Ozonolysate of excess sludge as a carbon source in an enhanced biological phosphorus removal for low strength wastewater

Potential use of the municipal sludge ozonolysate as a carbon source was examined for phosphorus removal from low strength wastewater in a modified intermittently decanted extended aeration (IDEA) process. At ozone dosage of 0.2 g O(3)/g solids, readily biodegradable COD accounted for about 36% of COD from sludge ozonolysate. The denitrification potential of ozonolysate as a carbon source was comparable to that of acetate. Although, the first order constant for phosphorus release with the ozonolysate was half that of acetate, it was much higher than that of wastewater. Continuous operation of the modified IDEA process showed that the removals of nitrogen and phosphorus were simultaneously enhanced by addition of the ozonolysate. Phosphorus release was significantly induced after complete denitrification indicating that phosphorus release was strongly depended on nitrate concentration. Effectiveness of the ozonolysate as a carbon source for EBPR was also confirmed in a track study of the modified IDEA.

The effect of co-existing solutes on arsenate removal with hydrotalcite compound

Hydrotalcite (HTAL-Cl), an inorganic anion exchanger, is of use as an adsorbent for the removal of arsenate (As(V)) in water systems. The adsorption properties of HTAL-Cl for As(V) and the effects of co-existing anions on the As(V) removal performance were investigated in this work. Under the conditions of pH>or=4, the adsorption capacity for As(V) gradually decreased with an increase of pH, but As(V) was removed effectively within the range of pH = 5-8. Co-existing anions interfered As(V) removal, and the effect decreased in the order of HPO(4)(2-) > HCO(3)(-) > SO(4)(2-) > Cl(-). In binary solute systems containing phosphate and As(V), the maximum adsorption capacity of HTAL-Cl was 0.95 mmol g(-1) for phosphate and 0.65 mmol g(-1) for As(V): the total of these values corresponded to the maximum adsorption capacity for As(V) in single solute systems. The adsorption isotherms in these binary solute systems were approximated by the following modified Langmuir equations:As(V): q(As) = 18.7 radicalC(As)/(1 + 21.5 radicalC(P) + 12.8 radicalC(As)), phosphate : q(P) = 33.1 radicalC(P)/(1 + 21.5 radicalC(P) + 12.8 radicalC(As)). The column adsorption experiments showed that the adsorbed As(V) was released by the phosphate adsorption, because phosphate was adsorbed more strongly on HTAL-CL than As(V).

Ozone treatment of wastewater sludge for reduction and stabilization

Ozonation was applied to wastewater sludge for reduction and stabilization. Ozone was found to be very effective at reducing sludge and producing a useful carbon source. An ozone dose of 0.3 g/gDS fulfilled the criteria for the disinfection of class A type biosolids. The sludge treated with 0.5 gO(3)/gDS produced no hydrogen sulfide for a month at 29 degrees C. Ozonation resulted in low pH conditions, which might facilitate the mobilization of heavy metals from sludge. The results of a geotechnical investigation proved that the residuals of ozone-treated sludge did not meet the required properties required for landfill cover without the addition of quick lime.

Fatty acid methyl ester (FAME) technology for monitoring biological foaming in activated sludge: full scale plant verification

Fatty acid methyl ester (FAME) technology was evaluated as a monitoring tool for quantification of Gordonia amarae in activated sludge systems. The fatty acid, 19:1 alcohol, which was identified as a unique fatty acid in G. amarae was not only confirmed to be present in foaming plant samples, but the quantity of the signature peak correlated closely with the degree of foaming. Foaming potential experiment provided a range of critical foaming levels that corresponded to G. amarae population. This range of critical Gordonia levels was correlated to the threshold signature FAME amount. Six full-scale wastewater treatment plants were selected based on a survey to participate in our full-scale study to evaluate the potential application of the FAME technique as the Gordonia monitoring tool. Greater amounts of signature FAME were extracted from the mixed liquor samples obtained from treatment plants experiencing Gordonia foaming problems. The amounts of signature FAME correlated well with the conventional filamentous counting technique. These results demonstrated that the relative abundance of the signature FAMEs can be used to quantitatively monitor the abundance of foam-causing microorganism in activated sludge.

Advanced H2O2 oxidation for diethyl phthalate degradation in treated effluents: effect of nitrate on oxidation and a pilot-scale AOP operation

One of the objectives of this study was to delineate the effect of nitrate on diethyl phthalate (DEP) oxidation by conducting a bench-scale ultraviolet (UV)/H2O2 and O3/H2O2 operations as suggested in a previous study. We also aim to investigate DEP oxidation at various UV doses and H2O2 concentrations by performing a pilot-scale advanced oxidation processes (AOP) system, into which a portion of the effluent from a pilot-scale membrane bioreactor (MBR) plant was pumped. In the bench-scale AOP operation, the O3 oxidation alone as well as the UV irradiation without H2O2 addition could be among the desirable alternatives for the efficient removal of DEP dissolved in aqueous solutions at a low DEP concentration range of 85+/-15 microg/L. The adverse effect in the UV/H2O2 process was significantly greater than that in the UV oxidation alone, and its oxidation was almost halved by the nitrate. However, the nitrate clearly enhanced the DEP oxidation in the O3 oxidation and O3/H2O2 process. Especially, the addition of nitrate almost doubled the DEP oxidation efficiency in the O3/H2O2 process. The series of pilot-scale AOP operations confirmed that about 30-50% of DEP dissolved in the treated MBR effluent streams was, at least, oxidized by the O3 oxidation alone as well as the UV irradiation without H2O2 addition. The UV photolysis of H2O2 was most effective for DEP degradation with an H2O2 concentration of 40 mg/L at a UV dose of 500 mJ/cm2.

Nematic domains and resistivity in an itinerant metamagnet coupled to a lattice

The nature of the emergent phase near a putative quantum critical point in the bilayer ruthenate Sr3Ru2O7 has been a recent subject of intensive research. It has been suggested that this phase may possess electronic nematic order (ENO). In this work, we investigate the possibility of nematic domain formation in the emergent phase, using a phenomenological model of electrons with ENO and its coupling to lattice degrees of freedom. The resistivity due to the scattering off the domain walls is shown to closely follow the ENO parameter. Our results provide qualitative explanations for the dependence of the resistivity on external magnetic fields in Sr3Ru2O7.

A high filtration system with synthetic permeable media for wastewater reclamation

A novel filtration process with synthetic permeable media was investigated for secondary effluent reclamation. Polyurethane was chosen as the filter medium among three tested media. Compressibility and up-flow velocity were changed to determine the optimum operation for the system. An equation was introduced to express the relationship between the removal efficiency and up-flow velocity. In a pilot study, the synthetic medium filtration with compression showed very stable effluent quality without clogging trouble, though the system operated with three times higher filtration rate and much longer backwashing interval than conventional systems.

Association between arterial stiffness and the deformability of red blood cells (RBCs)

The relationship between the flexibility of atherosclerotic vessels and RBC deformability has been investigated. A significant difference of RBC deformability was found among the arterial stiffness groups classified by oscillometric measurement of blood pressure. The deformability was determined by direct microscopic observation of RBCs subjected to shear stress of 0.3 to 40.0 Pa with a rotating rheoscope. The deformability of stiffen group - abnormal pulse wave pattern group or moderate cardiovascular risk group - was found to be much higher than that of normal groups in wide shear stress region (3.0, 10.0, 30.0, and 40.0 Pa). We postulate that the body adapts high shear stress in vivo by making RBCs more distensible, and therefore less likely to rupture under strain or microcirculatory alterations.

Effects of flocculent aggregates on microfiltration with coagulation pretreatment of high turbidity waters

Immersed membrane systems, and those with in-line coagulation, have been extensively applied in drinking water systems. Sedimentation is usually replaced by membrane processes in both systems. In these systems, voluminous flocculent aggregates formed during coagulation could be potential foulants. When raw waters with high turbidity are introduced, particle loadings to membrane due to coagulation pretreatment are enormous and thus could increase fouling. In general, during the rainy season, the turbidity of the Han River water, which supplies drinking water for the City of Seoul, Korea, is more than a hundred times higher than usual. Therefore, effects of floc on membrane fouling were investigated with highly turbid waters. Two turbidity concentrations, 40 and 200 NTU, were formulated by the addition of kaolin (used as a natural particle surrogate) to the Han River raw water. The results showed that the flux decline behaviours of the highly turbid waters were different from those of natural raw water. Coagulation pretreatment was very effective at reducing membrane fouling. Flocculent aggregates showed a negative effect on the flux decline but a positive effect on the membrane cleaning efficiency.

Microbial community in biofilm on membrane surface of submerged MBR: effect of in-line cleaning chemical agent

The objective of this study was to investigate the change in microbial community pattern with the effect of cleaning agent using a quinone profile that is used for membrane in-line chemical cleaning in SMBR. The dominant quinone types of biofilm were ubiquinone (UQs)-8, -10, followed by menaquinone (MKs)-8(H4), -7 and UQ-9, but those of suspended microorganisms were UQ-8, UQ-10 followed by MKs-8(H4), -7 and -11. Both UQ and MK contents decreased with increasing NaCIO dosage and it seems that there is more resistance from UQ compared to MK. In addition, COD and DOC concentrations increased with increasing NaClO dosage up to 0.05 g-NaCIO/g-SS. The organic degradation performance of the microbial community in the presence of NaClO was impaired. The present study suggested that larger added amounts of NaClO caused an inhibition of organic degradation and cell lysis.

Ozonation of membrane bioreactor effluent for landfill leachate treatment

Ozonation of leachate effluent obtained from a Membrane Bioreactor (MBR) process treating a medium-aged landfill leachate was investigated. The sequence of ammonia stripping, membrane bioreactor, and ozonation was used in the experiment. Ozonation of the MBR effluent showed reduction in Chemical Oxygen Demand (COD) and Total Organic Carbon (TOC) with an increase in five days Biochemical Oxygen Demand (BOD5) concentration. About 73% of COD could be removed at an ozone (O3) dosage of 4.2 mg O3 mg COD(-1). The biodegradability indicated by BOD5/COD ratio increased from 0.03 to 0.08 after ozonation at optimum ozone condition. While analyzing the molecular weight distribution, the fraction of molecular weight (MW) greater than 50 kDa of MBR effluent was transferred to MW 10-50 kDa (38%) at an ozone dosage of 810 mg O3. When O3 dosage was increased to 2,025 mg O3, a rapid change occurred in MW > 50 kDa fraction. This fraction was completely broken down into lower molecular weight fractions. This indicates partial degradation of landfill leachate by ozonation. The colour removal from the leachate was found to be greater than 95%. When the ozonated leachate was recirculated into the MBR system, along with an improvement in the performance of MBR, overall COD removal increased from 78% to 83%. Further, the ozone consumption decreased from 6.1 to 3.4 mg O3 mg COD(-1) removed, thus reducing the ozone requirement.

Quantitative analysis of biological effect on membrane fouling in submerged membrane bioreactor

The objective of this study is to investigate solids concentration and extracellular polymeric substance (EPS) effects on the membrane fouling in the submerged membrane bioreactor. The relationship between the solids retention time (SRT) and the amount of EPS is observed in three lab-scale MBRs. Additionally, the EPS effect on membrane fouling is quantified by calculating the specific cake resistance (alpha) using an unstirred batch cell test. By observing the sludge over a long period under various SRT scenarios, a wide range of EPS and membrane fouling data is obtained. These observations provide sufficient evidence of the functional relationship between SRT, EPS and alpha. As SRT decreases, the amount of EPS bound in sludge floc becomes higher in the high MLSS condition (> 5,000 mg/L). The amount of EPS in the sludge floc has positive influence on alpha. A sigmoid trend between EPS and alpha is observed and the functional relationship obtained by dimensional analysis is consistent with the experimental results.

Strain-induced metal–insulator phase coexistence in perovskite manganites

The coexistence of distinct metallic and insulating electronic phases within the same sample of a perovskite manganite, such as La(1-x-y)Pr(y)Ca(x)MnO3, presents researchers with a tool for tuning the electronic properties in materials. In particular, colossal magnetoresistance in these materials--the dramatic reduction of resistivity in a magnetic field--is closely related to the observed texture owing to nanometre- and micrometre-scale inhomogeneities. Despite accumulated data from various high-resolution probes, a theoretical understanding for the existence of such inhomogeneities has been lacking. Mechanisms invoked so far, usually based on electronic mechanisms and chemical disorder, have been inadequate to describe the multiscale, multiphase coexistence within a unified picture. Moreover, lattice distortions and long-range strains are known to be important in the manganites. Here we show that the texturing can be due to the intrinsic complexity of a system with strong coupling between the electronic and elastic degrees of freedom. This leads to local energetically favourable configurations and provides a natural mechanism for the self-organized inhomogeneities over both nanometre and micrometre scales. The framework provides a physical understanding of various experimental results and a basis for engineering nanoscale patterns of metallic and insulating phases.

Application of chemical precipitation for piggery wastewater treatment

Several series of experiments were conducted to investigate the treatment of piggery wastewater using chemical precipitation (CP) where various types of coagulants such as aluminium sulfate (Al2(SO4)3), poly aluminium chloride (PAC), ferric chloride (FeCl3), ferric sulfate (Fe2(SO4)3), ferrous sulfate (FeSO4) and ferrous chloride (FeCl2) were used. Throughout the experiments, CP was found to achieve high removal efficiencies for organic compounds and nutrients (nitrogen and phosphorus) from the piggery wastewater. Experimental results showed the optimal doses of FeCl3, Fe2(SO4)3, FeCl2 and FeSO4 was 2.0 g/L, while 0.31 g/L and 2.5 g/L were the optimum dose for PAC and Al2(SO4)3, respectively. The pH range 4-5 resulted in the best performance to all coagulants except FeCl2 and FeSO4, whose optimum pH were more than 6. Percentage removal efficiencies for COD were in the ranges of 70-80%, 90-95% for SS, 80-90% for organic-N and TP. Those removal efficiencies were achieved within 5 min of operation. Three times of repetition in CP resulted in higher removal efficiencies for COD, SS and colour up to 74%, 99% and 94% respectively, in which Al2(SO4)3 was used as the coagulant. Removal efficiencies of various water quality parameters in a continuously operated reactor were similar to those of the batch experiments. Biodegradable ratios (BOD5/COD) increased up to 65% after the application of CP.

Landfill leachate treatment by yeast and bacteria based membrane bioreactors

Biological treatment of medium-age landfill leachate was investigated on a membrane bioreactor. The experiments were conducted in two 5-L reactors with immersed hollow fiber microfiltration membranes. One reactor was operated with a mixed bacterial culture termed as bacteria based membrane bioreactor (BMBR) while the other with mixed yeast culture termed as yeast based membrane bioreactor (YMBR). The leachate was characterized with a chemical oxygen demand (COD) concentration of 7000-9000mg/L, biochemical oxygen demand (5 days) to chemical oxygen demand ratio (BOD5/COD) of 0.35-0.45 and total Kjeldahl nitrogen (TKN) of 1800-2000mg/L. The performance was assessed with and without ammonia stripping. In both the reactors, the average COD and TKN removal efficiency without ammonia stripping ranged between 52-66 and 14-28%, respectively. The performance of both the membrane bioreactors improved with ammonia stripping in terms of both COD (72-76%) and TKN (82-89%) removal efficiency. Though, the difference in the performance of the BMBR and YMBR was not significant in terms of COD removal, the YMBR showed better removal efficiency in terms of BOD5. The molecular weight cut-off showed that the degradation pathway of the leachate by bacterial and yeast are different. In regard to membrane fouling, the YMBR showed better performance with lower trans-membrane pressure as well as longer operating time. This superior performance of the YMBR could be due to the structure of yeast cells which are larger in size as well as reduced soluble extracellular polymeric substances (EPS) production, which are the main cause of membrane biofouling.

Improvement of denitrification by denitrifying phosphorus removing bacteria using sequentially combined carbon

The effects of sequentially combined carbon (SCC) using a symbiotic relationship of methanol and acetic acid on biological nutrient removal were investigated in both the continuous bench scale process consisting of an anoxic, an aerobic and a final settling tank and intensive batch tests. Compared to the use of respective sole carbon sources, methanol and acetic acid, the use of SCC showed superior removal efficiency of nitrogen (98.3%) and phosphorus (approximately 100%). Furthermore, the use of SCC enhanced simultaneous denitrification and phosphorus uptake by denitrifying phosphorus removal bacteria (DPB), resulting in the highest specific denitrification rate (SDNR) of 0.252 g NO3-N/g VSS/d achieved from the first anoxic zone with methanol of 30 mg COD/I. From batch tests performed under carbon limited anoxic conditions, 1 g of nitrate was used by DPB for P-uptake of 1.19 g. According to this result, 0.205 g NO3-N/g VSS/d was accomplished by normal denitrifiers using methanol, and 0.047 g NO3-N/g VSS/d was achieved by DPB. This research also demonstrated that the increase of poly-beta-hydroxybutyrate (PHB) stored by phosphorus accumulating organisms (PAOs) could be of importance in improving aerobic denitrification. The use of SCC produced the highest P-release in the anoxic zone, indicating the amount of PHB would be higher compared to the use of other sole carbons. Therefore, the SCC could be a very effective carbon source for the enhancement of aerobic denitrification as well.

Comparison of sequentially combined carbon with sole carbon in denitrification and biological phosphorus removal

The sequentially combined carbon (SCC) of methanol and acetic acid was used for the biological nutrient removal (BNR). Its BNR performance was compared with methanol or acetic acid as a sole carbon substrate. Compared to the sole carbon substrate, the use of SCC demonstrated the highest overall TIN removal of 98.3% at a COD ratio of 30 mg COD/l of methanol/50 mg CDO/l of acetic acid. Furthermore, denitrification was more enhanced when methanol was used as one of the SCC, rather than as a sole carbon source. Complete phosphorus removal was accomplished with a non-detectable o-P concentration when SCC was added. This research also showed that aerobic denitrifiers appear to prefer acetic acid to methanol, and the amount of poly-beta-hydroxybutyrate (PHB) stored by P accumulating organisms (PAOs) using acetic acid in the anoxic zone could be another important factor in improving the aerobic denitrification. The SCC was a very favorable carbon source for the aerobic denitrification since acetic acid was utilized more efficiently for P-release in accordance with increase of PHB stored in the cell of PAOs by removing nitrogen first using methanol.

Monitoring of COD as an organic indicator in waste water and treated effluent by fluorescence excitation-emission (FEEM) matrix characterization

The fluorescence excitation-emission matrices (FEEM) of domestic waste water, treated effluent of a waste water treatment plant and receiving river water were analyzed to select wavelengths for the monitoring of organic contents as COD. Excitation/emission wavelengths of 220/350 nm and 270/350 nm for protein-like fluorescence and 240/450 nm and 340/450 nm for humic-like fluorescence were suggested as fluorescence peak emitting wavelength pairs, respectively. Without any pre-treatment, the protein-like fluorescence peaks showed better correlation between COD values and fluorescence intensities than the humic-like fluorescence peaks. No enhanced correlation was observed by removing the suspended solids from the samples using filtration. However, statistical multiple regression methods, using the fluorescence intensities from each peak and the light scattering intensity at 633 nm as variables, resulted in an enhanced correlation, with r2 > 0.9 for the measured and predicted COD values.

Acidic and hydrogen peroxide treatment of polyaluminum chloride (PACL) sludge from water treatment

The water treatment sludge including coagulants cannot be easily removed by conventional dewatering methods. The possibility of hydrogen peroxide (H2O2) oxidation as a pretreatment to enhance the dewaterability of polyaluminum chloride (PACl) sludge from water works was investigated. H2O2 treatment alone was not effective but H2O2 treatment under acidic condition significantly reduced both the cake water content and specific resistance to filtration (SRF), indicating the enhancement of dewaterability and filterability. The filterability after acid/H2O2 treatment was comparable to polymer conditioning and even more dewatered cake than polymer conditioning was produced. By H202 combined with sulfuric acid (H2SO4), leached iron caused Fenton's reaction, which showed a potential to significantly reduce the amount of solids mass and to produce more compact cake with higher filterability.

Change of microbial community structure by respiratory quinone profile at intermittently aerated membrane bioreactor

In the present study, the microbial community structure in an intermittently aerated submerged membrane bioreactor treating domestic wastewater was observed using the respiratory quinone profiles. The effects of different time interval for the aerobic and anoxic period on microbial community structure were examined with 60/90 min (Step 1) and 90/60 min (Step 2) as anoxic/aerobic periods. There was an observable slight difference in microbial community structure between Step 1 and Step 2 in the submerged membrane bioreactor. The dominant quinone types for Step 1 at both anoxic and aerobic conditions were UQ-8 followed by UQ-10 and MK-6, but those for Step 2 were UQ-8, MK-6 and MK-10(H4). The microbial diversity of Step 1 and Step 2 based on the composition of all quinones was 10.6-11.7 and 13.3-13.0 for anoxic and aerobic conditions, respectively. The present results suggest that the introduction of intermittent aeration into the submerged membrane bioreactor has little influence on the bacterial community structure.

Investigation of biological and fouling characteristics of submerged membrane bioreactor process for wastewater treatment by model sensitivity analysis

In this study, a mathematical model for the submerged membrane bioreactor (SMBR) was developed. The activated sludge model No. 1 (ASM1) was modified to be suitable for describing the characteristics of the SMBR, and the resistance-in-series model was integrated into the ASM1 to describe membrane fouling. Using the newly developed model, the biological and fouling characteristics of the submerged membrane bioreactor process for wastewater treatment was investigated by sensitivity analysis. The sensitivity of effluent COD and nitrogen, TSS in the reactor and membrane flux with respect to each parameter (K(h), mu(H), K(S), K(NHH), K(NOH), b(H), Y(H), mu(A), K(NHA), b(A), Y(A), K(m) and alpha) was investigated by model simulation. As a result, the most important factors affecting membrane fouling were hydrolysis rate constant (K(h)) and cross-flow effect coefficient (K(m)). Heterotrophic yield coefficient (Y(H)) had a great influence on effluent quality. Effluent quality was also somewhat sensitive to K(h). Peculiar operating conditions of the SMBR such as long solids retention time (SRT), absolute retention of solids by membrane and high biomass concentration in bioreactor could explain these model simulation results. The model developed in this study would be very helpful to optimize operating conditions as well as design parameters for a SMBR system.

Treatment of landfill leachate by a pilot-scale modified Ludzack-Ettinger and sulfur-utilizing denitrification process

Nitrogen removal efficiency of a pilot-scale system consisted of Modified Ludzack-Ettinger (MLE) followed by sulfur-utilizing denitrification (SUDNR) process was evaluated with a landfill leachate. For SUDNR, a down-flow mode sulfur packed bed reactor (SPBR) filled with sulfur and limestone particles was used. Although total nitrogen removal efficiency of the MLE process was about 80% at the recycle ratio of 4, effluent contained 350-450 mg/L NO(3-)-N. Up to a loading rate of 1.2 kg NO(3-)-N/m3-day, the SPBR could achieve complete removal of nitrate, and nitrate removal rate was kept to that level even at higher loading rate. When a COD/N ratio of MLE process was maintained at 2 instead of 4, more organics with molecular weight less than 500 were utilized for heterotrophic denitrification although denitrification was not complete with the lack of electron donors. Clogging in the SPBR, mainly by the accumulation of nitrogen gas in the pores, could easily be removed by introducing the effluent in an upward direction for 1 min at 1 hr intervals. The proposed treatment system could achieve nitrate free effluent with a slight increase in chemical cost. Furthermore, depending on further COD removal requirement after biological treatment, the proposed treatment system can be an economical solution.

Oxidative treatment characteristics of biotreated textile-dyeing wastewater and chemical agents used in a textile-dyeing process by advanced oxidation process

The oxidative treatment characteristics of biotreated textile-dyeing wastewater and typical chemicals such as desizing, scouring, dispersing and swelling agents used in the textile-dyeing process by advanced oxidation process were experimentally studied. The refractory organic matters remained in the effluent of biological treatment process without degradation may be suitable for the improvement of biodegradability and mineralized to CO2 by combined ozonation with and without hydrogen peroxide. On the other hand, the refractory chemicals contained in the scouring agent A and swelling agent may not be mineralized and their biodegradability may not be improved by ozonation. However, the BOD/DOC ratio of scouring agent B increased from 0.3 to 0.45 after ozonation. Based on the results described above, advanced treatment process involving the ozonation without and with the addition of hydrogen peroxide, followed by biological treatment was proposed for the treatment of refractory wastewater discharged from the textile-dyeing process.

Microbial community structure of membrane fouling film in an intermittently and continuously aerated submerged membrane bioreactor treating domestic wastewater

There was an observable difference in microbial community structure between suspended microorganisms and membrane biofouling film in intermittently and continuously aerated SMBRs. The dominant quinone type of membrane biofouling film in an intermittently aerated SMBR was ubiquinone (UQs)-8, -10 followed by menaquinone (MKs)-8(H4) and -8(H2). But that of the continuously aerated SMBR was UQs-10, -8 followed by MKs-6 and -8(H4). The experimental results also showed that the conditions of an intermittently aerated SMBR may contribute to biofouling by Pseudomonas, Moraxella, Vibrio (quinone type UQ-8), Staphylococcus warneri (quinone type MK-7), Micrococcus sp. (quinone type MK-8(H2)) and Nocardia sp. (quinone type MK-8(H4)), but biofouling in a continuously aerated SMBR may be due to Paracoccus sp. (quinone type: UQ-10) and Flavobacterium species (quinone type: MK-6). The microbial diversities in the intermittently aerated SMBR were 10.9 and 9.4 for biofouling film and suspended microorganisms, respectively. For the continuously aerated SMBR, the results were 10.4 and 10.5 for biofouling film and suspended microorganisms, respectively.

N-methyl-D-aspartate receptor in working memory impairments in schizophrenia: event-related potential study of late stage of working memory process

Working memory (WM) deficit in schizophrenic patients has been well established. Still, underlying biological substrate of the impairment is not clear. Among neurotransmitter hypotheses of schizophrenia, N-methyl-D-aspartate (NMDA) receptor model is mostly supported, considering that NMDA receptor antagonist can elicit both psychosis and cognitive impairment observed in schizophrenic patients. In current study, to test the neuropsychological and the electrophysiological effects of NMDA receptor in WM, event-related potentials (ERPs) of Sternberg's short-term memory scanning task (SMST) were analyzed in 10 healthy subjects under intravenous administration of a subanesthetic dose of ketamine (0.65 mg/kg/h) or placebo (normal saline). Late positive component (LPC) of ERP was hypothesized to reflect later stage of WM. Brief Psychiatric Rating Scale score was significantly increased (t=-5.75, df=9, P<.001) and correct response rate was significantly decreased (t=2.21, df=9, P=.054) after ketamine administration. Neither reaction time nor LPC latency, which reflect memory scanning time, was changed. Amplitude of LPC was significantly reduced after ketamine administration (z=-2.31, number of observations=120, P=.021). In conclusion, NMDA receptor antagonist administration elicited WM deficit both in behavioral and electrophysiological level. Electrophysiological component reflecting later stage of WM was impaired by NMDA antagonist.

Elasticity-driven nanoscale electronic structure in superconductors

The effects of long-range anisotropic elastic deformations on electronic structure in superconductors are analyzed within the framework of the Bogoliubov-de Gennes equations. Cases of twin boundaries and isolated defects are considered as illustrations. We find that the superconducting order parameter is depressed in the regions where pronounced lattice-deformation occurs. The calculated local density of states suggests that the electronic structure is strongly modulated in response to lattice deformations, and propagates to longer distances. In particular, this allows the trapping of low-lying quasiparticle states around defects. Some of our predictions can be directly tested by scanning tunneling microscopy experiments.

Quasiparticle relaxation dynamics in heavy fermion compounds

We present the first femtosecond studies of electron-phonon (e-ph) thermalization in heavy-fermion compounds. The e-ph thermalization time tau(ep) increases below the Kondo temperature by more than 2 orders of magnitude as T=0 K is approached. Analysis using the two-temperature model and numerical simulations based on Boltzmann's equations suggest that this anomalous slowing down of the e-ph thermalization derives from the large electronic specific heat and the suppression of scattering between heavy electrons and phonons.

Modification of ASM No.1 for a submerged membrane bioreactor system: including the effects of soluble microbial products on membrane fouling

In this study, a mathematical model for the submerged membrane bioreactor (SMBR) was developed by combining the activated sludge model (ASM) with a membrane resistance-in-series model. Some modifications were introduced to make ASM to be suitable for describing the characteristics of SMBR. A set of the 1st-order differential equations was established for 13 dependent variables relevant to particles and soluble matters. Performing model simulations for various conditions, the time when a membrane would be fouled could be predicted as well as the effluent quality. From simulation results, F/M ratio and SRT can be considered as major factors of the soluble microbial products (SMP) concentration in a reactor and it is clear that SMP can play an important role in membrane fouling and water quality simultaneously. The model would be very helpful in optimizing operation conditions as well as in designing an optimal SMBR system.

Waste load allocation for water quality management of a heavily polluted river using linear programming

A waste load allocation model using linear programming has been developed for economic water quality management. A modified Qual2e model was used for water quality calculations and transfer coefficients were derived from the calculated water quality. This allocation model was applied to the heavily polluted Gyungan River, located in South Korea. For water quality management of the river, two scenarios were proposed. Scenario 1 proposed to minimise the total waste load reduction in the river basin. Scenario 2 proposed to minimise waste load reduction considering regional equity. Waste loads, which have to be reduced at each sub-basin and WWTP, were determined to meet the water quality goal of the river. Application results of the allocation model indicate that advanced treatment is required for most of the existing WWTPs in the river basin and construction of new WWTPs and capacity expansion of existing plants are necessary. Distribution characteristics of pollution sources and pollutant loads in the river basin was analysed using Arc/View GIS.

The reaction mechanism of catalytic oxidation with hydrogen peroxide and ozone in aqueous solution

The sorption and catalytic oxidation of model compounds (pCBA and phenanthrene) and NOM on FeOOH were investigated using hydrogen peroxide and ozone, respectively. After oxidation with ozone, the hydrophobic, transphilic, and hydrophilic NOM fractions were isolated using XAD-8 and -4 resins to analyze the reaction characteristics. The sorption of pCBA was strongly dependent upon the pH, but phenanthrene exhibited a sorption behavior that was independent of the pH. In the case of NOM, the hydrophobic portion showed higher sorption affinity than hydrophilic and transphilic at pH 7.2. The concentrations of model compounds and oxidants were measured during the oxidations and the efficiency was compared for tests done with ozone alone and those using catalytic ozonation. Through the comparison of the sorption and decomposition of the model compounds, along with the effects of bicarbonate addition, mechanisms for catalytic oxidation with hydrogen peroxide or ozone were proposed, respectively.

Reduction of sludge by ozone treatment and production of carbon source for denitrification

The feasibility of ozone treatment of municipal sludge for sludge reduction and carbon source production has been investigated. Significant accumulation of solubilized organics and unsettlable micro-solids (UMS) was observed at relatively low ozone dosages while mineralization became dominant at higher dosages. Batch denitrification experiments showed that the solubilized organics and the UMS could be utilized as carbon sources for nitrogen removal. In terms of overall sludge reduction, 54% reduction of the total sludge mass could be achieved by ozone treatment at 0.2 g-O3/g-MLSS.

Ozonation of wastewater sludge for reduction and recycling

An ozone treatment system was introduced as an alternative method for municipal sludge treatment and disposal. A pilot-scale facility was built to investigate the feasibility of the ozonation for sludge reduction and recycle. The system consists of three main parts; advanced wastewater treatment, sludge ozone treatment and belt press dewatering. Ozonation of wastewater sludge resulted in mass reduction by mineralization as well as volume reduction by improvement of dewatering characteristics. The supernatant of the ozonated sludge, consisting of solubilized organics and micro-particles, proved to be an effective carbon source for denitrification. A simple economic assessment reveals that the ozonation process can be more economical than incineration for sludge treatment and disposal at small- and medium-sized wastewater treatment plants.

Effects of ozone treatment on the biodegradability of sludge from municipal wastewater treatment plants

The effects of ozone pretreatment on the biodegradability of municipal wastewater sludge were determined. Three types of experiments were conducted: anaerobic digestion, aerobic biodegradation, and denitrification using ozone-treated sludge as a carbon source. For 5 days, ozonated sludge at 0.1 gO3/g-SS showed about 2-3 times greater biodegradation compared to the raw sludge in both aerobic and anaerobic conditions. In anaerobic experiments, biodegradation increased with ozone dosage up to 0.2 gO3/g-SS. Further increase of ozone dosage did not improve the biodegradation. In aerobic condition, about 77% of the ozonated sludge at 0.1 gO3/g-SS could be biodegraded after 15 days and is compared with 36% degradation of the untreated sludge. Most of the biodegradation of the ozonated sludge occurred within 5 days while the raw sludge was biodegraded steadily throughout the experimental period. The biodegradation enhancement of ozonated sludge was confirmed in batch denitrification experiments.

Selective oxidation of allylic sulfides by hydrogen peroxide with the trirutile-type solid oxide catalyst LiNbMoO(6)

Chemoselective sulfur oxidation of allylic sulfides containing double bonds of high electron density due to multiple alkyl substituents or extended conjugation was developed using the composite metal oxide catalyst, LiNbMoO(6), without any epoxidation of the electron-rich double bond(s). Selective oxidation to either the corresponding sulfoxides or the sulfones was realized by controlling the stoichiometry of the quantitative oxidant, H(2)O(2). This new oxidant system had general applicability for chemoselective oxidation of various allylic, benzylic, or propargylic sulfides containing unsaturated carbon-carbon bonds with different electron properties. Various functional groups including hydroxy, formyl, and ethers of THP or TBDMS are compatible under this mild oxidation reaction condition.