Empty bed contact time: The key for micropollutant removal in activated carbon filters.

The removal of micropollutants from wastewater is an emerging issue that currently concerns the wastewater sector the most. Granular Activated Carbon (GAC) has gained recognition as a suitable technology for dealing with this problem. This study assesses the performance of six GAC-filters for the removal of micropollutants installed as final treatment step at a municipal wastewater treatment plant. The influence of the GAC-type and the Empty Bed Contact Time (EBCT) on the filter performance was evaluated. The breakthrough behaviour of 13 selected micropollutants as well as the removal of the Dissolved Organic Carbon (DOC) and UV absorption at 254 nm were investigated. Besides, the adsorbed DOC (qDOC) was introduced as assessment parameter (adsorbed and biodegraded DOC), instead of the commonly used treated bed volume. Finally, Size Exclusion Chromatography (SEC) with online DOC and UV254nm detection was applied for a better understanding of the influent and effluent characteristics. The results showed that the pore size distribution is a crucial feature of the activated carbon. A balanced proportion of macro-, meso­ and micropores may play a role in the better removal of micropollutants in presence of DOC. Regardless of the GAC-type, a minimum EBCT between 20 - 30 min was necessary. We proved that a short EBCT would not fully use the sorption capacity, whereas a long EBCT would increase the carbon demand without improving of the removal. Lastly, according to the SEC results, after a short operation time no difference between the influent and effluent chromatographable fractions (DOC and UV254nm) was observed.

Implications of biological activated carbon filters for micropollutant removal in wastewater treatment.

Granulated Activated Carbon (GAC) filtration is a common process for advanced wastewater treatment. In such filters, the removal of organic substances results from adsorptive as well as biological processes. This work investigated the potential of biological processes and their influence on GAC-filter performance. During 32 months, the removal of micropollutants,Dissolved Organic Carbon (DOC) and the spectral absorption coefficient was monitored in six GAC-filters. The effects of pre-treatment (cloth- and/or membrane-filtration), EBCT (from 6 - 35 min) and GAC-type were evaluated. Likewise, the impact of the influent´s fluctuations in temperature, flow and concentration (ammonia, nitrate, and soluble reactive phosphorus (sRP)) were analysed. Biological processes were tracked by the frequency of backwashing, oxygen consumption, removal of poorly absorbable micropollutants and production of transformation products. Pre-treatment influenced biofilm growth significantly. Membrane filtration delayed the first backwashing event by 122 d in comparison to cloth-filtration, where the first backwash was conducted after only 21 d. Removal of poorly absorbable substances was observed early on (40 - 50 d). Parallel operation contributed to a better utilisation of the GAC-capacity and the biological removal potential. Influent nitrogen species > 0.5 mg N/L promoted biofilm growth, whereas sRP seemed to have no effect. The developed biofilm and optimal operating conditions led to longer life spans of the GAC-filters, making carbon usage rates comparable to those from PAC applications. The results suggest that biological processes accounted for about 25 - 42% of the totally removed DOC at the end of the operation.

Tertiary phosphorus removal to extremely low levels by coagulation-flocculation and cloth-filtration.

Higher standards in the European Water Framework Directive and national directive demand advanced wastewater treatment for removal of nutrients and organic micropollutants before the discharge into water bodies. Systematic investigations regarding relative dosage and filtration processes for removal of flocculated solids are currently lacking. In this study, the performance of technologies for advanced removal of total phosphorus down to <100 µg/L with pile cloth-filtration (CF) and membrane filtration was verified and synergy effects for the removal of other contaminants were identified. The results show that an over-stoichiometric addition of coagulants of >5 mol Me3+/mol sRP was necessary to achieve soluble reactive phosphorus (sRP) concentrations of <50 µg/L in the effluent. After the coupled process of tertiary phosphorus removal and solids removal, the soluble non-reactive phosphorus (sNRP) concentration regulates the lowest total phosphorus effluent concentration. sNRP is also partially, but not completely, removed by the use of coagulants. CF has proven to be an alternative technology for the removal of phosphorus and total suspended solids below the detection limit.

High-resolution mapping and modeling of anammox recovery from recurrent oxygen exposure.

Oxygen inhibits anammox, a bioconversion executed by anoxic ammonium oxidizing bacteria (AnAOB). Nonetheless, oxygen is mostly found in the proximity of AnAOB in nitrogen removal applications, being a substrate for nitritation. The experiments performed to date were mostly limited to batch activity tests where AnAOB activity is estimated during oxygen exposure. However, little attention has been paid to the recovery and reversibility of activity following aerobic conditions, of direct relevance for bioreactor operation. In this work, anoxic and autotrophic reactor cultivation at 20 °C yielded an enriched microbial community in AnAOB, consisting for 75% of a member of the genus Brocadia. High-resolution kinetic data were obtained with online ammonium measurements and further processed with a newly developed Python data pipeline. The experimentally obtained AnAOB response showed complete inhibition until micro-aerobic conditions were reached again (<0.02 mg O2 L-1). After oxygen inhibition, AnAOB recovered gradually, with recovery times of 5-37 h to reach a steady-state activity, dependent on the perceived inhibition. The recovery immediately after inhibition was lowest when exposed to higher oxygen concentrations (range: 0.5-8 mg O2 L-1) with long contact times (range: 9-24 h). The experimental data did not fit well with a conventional 'instant recovery' Monod-type inhibition model. Yet, the fit greatly improved by incorporating a dynamic growth rate formula accurately describing gradual activity recovery. With the upgraded model, long-term kinetic simulations for partial nitritation/anammox (PN/A) with intermittent aeration showed a decrease in growth rate compared to the instant recovery mode. These results indicate that recovery of AnAOB after oxygen exposure was previously overlooked. It is recommended to account for this effect in the intensification of partial nitritation/anammox.

Gut microbiota, dietary intakes and intestinal permeability reflected by serum zonulin in women.

PURPOSE: Increased gut permeability causes the trespass of antigens into the blood stream which leads to inflammation. Gut permeability reflected by serum zonulin and diversity of the gut microbiome were investigated in this cross-sectional study involving female study participants with different activity and BMI levels. METHODS: 102 women were included (BMI range 13.24-46.89 kg m-2): Anorexia nervosa patients (n = 17), athletes (n = 20), normal weight (n = 25), overweight (n = 21) and obese women (n = 19). DNA was extracted from stool samples and subjected to 16S rRNA gene analysis (V1-V2). Quantitative Insights Into Microbial Ecology (QIIME) was used to analyze data. Zonulin was measured with ELISA. Nutrient intake was assessed by repeated 24-h dietary recalls. We used the median of serum zonulin concentration to divide our participants into a "high-zonulin" (> 53.64 ng/ml) and "low-zonulin" (< 53.64 ng/ml) group. RESULTS: The alpha-diversity (Shannon Index, Simpson Index, equitability) and beta-diversity (unweighted and weighted UniFrac distances) of the gut microbiome were not significantly different between the groups. Zonulin concentrations correlated significantly with total calorie-, protein-, carbohydrate-, sodium- and vitamin B12 intake. Linear discriminant analysis effect size (LEfSe) identified Ruminococcaceae (LDA = 4.163, p = 0.003) and Faecalibacterium (LDA = 4.151, p = 0.0002) as significantly more abundant in the low zonulin group. CONCLUSION: Butyrate-producing gut bacteria such as Faecalibacteria could decrease gut permeability and lower inflammation. The diversity of the gut microbiota in women does not seem to be correlated with the serum zonulin concentration. Further interventional studies are needed to investigate gut mucosal permeability and the gut microbiome in the context of dietary factors.

Whealth study: women's reports of childhood abuse.

Most samples of adult women will contain a significant proportion who have been or are currently in abusive relationships. While past research has linked childhood abuse of girls to adult health concerns, little is known about the process through which women retrospectively reconcile these experiences. This article reports on data collected in an ongoing project on midlife women's health. Twenty-seven of 50 urban, middle-class participants in this phase of the project reported childhood abuse experiences. In the analysis, several aspects of these experiences were identified: definitions of abuse; recontextualizing abuse; responsibility for abuse; abuse avoidance; and experiences of multiple abuse. The women's discourse reflected a number of ideologies that provide a context in which women negotiate their understandings of these childhood experiences. This article provides insight into our understanding of abuse. It addresses the fundamental issue of promoting a worldview that precludes child abuse while leaving adult survivors with options for "moving on."

The pharmacotherapy of depressive illness in adolescents: an open-label comparison of fluoxetine with imipramine-treated historical controls.

BACKGROUND: This open-label, 6-week clinical trial investigated the response to fluoxetine in medication-naive adolescents hospitalized for treatment of major depression. METHOD: A total of 52 consecutively admitted patients (mean age = 15.7 years) fulfilling Research Diagnostic Criteria for unipolar, nonpsychotic major depression received fluoxetine monotherapy (mean dose = 33.2 mg/day) in conjunction with psychosocial therapies. Outcome was assessed weekly using the Hamilton Rating Scale for Depression (HAM-D) and the Clinical Global Impressions Scale (CGI). Response in this cohort was compared with that observed in 28 historical controls treated with imipramine (mean dose = 217 mg/day) who were consecutively admitted patients to this same facility and assessed in an identical, standardized, open-label protocol. RESULTS: HAM-D scores decreased by a mean of 13.2 in the fluoxetine group compared with 10.2 in the group receiving imipramine (p<.002). The mean percentage decreases in HAM-D scores in the 2 groups were 54.3% and 41.4%, respectively (p<.003). The percentages of patients classified as responders based on a final CGI score of 2 or less were 48.1% and 17.9%, respectively (p = .009). Medications were generally well tolerated with only 5 patients failing to complete the full 6 weeks of their original treatment. CONCLUSION: In spite of the uncontrolled nature of these data, the findings add to recent evidence suggesting more favorable response to selective serotonin reuptake inhibitors than tricyclics in adolescents with depressive illness.

Early childhood attention deficit hyperactivity disorder predicts poorer response to acute lithium therapy in adolescent mania.

We compared the response to acute lithium therapy in 30 adolescents, 13-17 years of age, with mania and a prior history of early childhood attention deficit hyperactivity disorder (ADHD) to a sex- and age-matched control group of adolescent manics without premorbid psychiatric illness. Response to treatment was assessed daily over the course of 28 days using measures of global clinical improvement and severity ratings on the Bech-Rafaelsen Mania Scale (BRMS). BRMS scores decreased by a mean of 24.3 in the subgroup without prior ADHD compared to 16.7 in patients with ADHD (P = 0.0005). The average percent drop in BRMS scores over the study period in these two subgroups was 80.6% and 57.7%, respectively (P = 0.0005). Time to onset of sustained global clinical improvement was also assessed using Kaplan-Meier survival methods and possible covariates of time to improvement were tested in a Cox proportional hazards model. Median time to onset of sustained improvement was lengthened significantly in patients with early ADHD (23 days) compared to those without it (17 days; log rank chi2 = 7.2, P = 0.007). The results suggest that early childhood ADHD defines an important source of heterogeneity in bipolar illness with developmental, clinical, and neuropharmacogenetic implications.

Irritable bowel syndrome. An exploration of the patient perspective.

Although research into the etiology of irritable bowel syndrome (IBS) is extensive, this is not true for the patient experience of IBS. International population studies indicate that 15-20% of persons suffer from IBS. IBS is one of the eight most common somatic symptom complexes that account for 23% of visits to primary care physicians. This article details the journey of IBS sufferers in their attempt to understand and manage their illness through documenting patient perceptions of the origin of the illness, their search for treatment, their present management strategies, and their need for information and control. A grounded theory approach is used. Clinical practice protocols reflect the state of knowledge surrounding IBS: The variables are many and diagnosis and outcomes are uncertain. Further, our data suggest there is a desperate need for support groups and opportunities for patients, physicians, and supportive others to share experiences and concerns.

Recovery and relapse in adolescents with bipolar affective illness: a five-year naturalistic, prospective follow-up.

OBJECTIVE: This study was a 5-year naturalistic prospective follow-up of 54 consecutive admissions of adolescents to a university inpatient service with a diagnosis of bipolar I affective illness. METHOD: Subjects received structured clinical evaluations every 6 months after entry to establish time to recovery and subsequent relapse. Regression models were used to identify predictors of differential course. RESULTS: Rate of recovery varied by polarity of episode at time of entry, with quick recovery observed in subjects with pure mania or mixed states, and a protracted index episode in subjects with pure depression. Multiple relapses were most often seen in subjects with mixed or cycling episodes at intake. CONCLUSIONS: Polarity of illness may have utility in identifying bipolar adolescents with a more recurrent illness. Comparison with adult data suggests that recurrence risks may vary as a function of age at onset or stage of the disease process.