Treatment of septage in sludge drying reed beds: a case study on pilot-scale beds

International audienceFrench legislation requires, the control of private on-site sanitation systems by local authorities. This will result in a large increase of the quantity of sludge from septic tanks to be treated. Nevertheless, large wastewater treatment plants are not systematically able to treat this sludge because they may have reached their nominal load or they are not so numerous in rural zone to avoid too long transportation. The study concerns both, the feasibility of sludge reed beds devoted to the treatment of septage and the assessment of a simultaneous treatment with aerated sludge. The experiments have been carried out on eight pilot-scale drying reed beds (2m²) planted with Phragmites australis. Two filtration layers of either vegetal compost or sand were tested. The study is focused on the commissioning period (first vegetative year) with a loading rate of 30 kgSS.m-2.yr-1. According to these operational conditions, dewatering efficiencies reached approx. 30% DM during summer but less than 20%DM in winter for each filtration layer and sludge. High removal efficiencies, with an average of 96%, 92% and 89% for SS, COD and TKN respectively, were achieved with septage whereas they were lower for the mixture of aerated sludge and septage. The dewaterability of septage and its filtration behaviour were assessed by several parameters (Capillary Suction Time, bound water) which may be some interesting tools for an optimised loading strategy

Sludge drying reed beds : full and pilot scale study for activated sludge treatment

International audienceSludge drying reed beds have been used for dewatering and mineralization of sludge since the beginning of the 90's, but their insufficient performances in terms of Dry Matter [DM] content and mineralization of the sludge have made necessary new studies. Therefore, 8 pilots of 2m² each and a full-scale plant (13 000 p.e , 8 beds of 470m² in operation for 4 years) have been monitored to examine the influence of the sludge loading rate, the sludge quality and the loading frequency on the dewatering and mineralization efficiencies. Two filtration layers (vegetal compost or sand) and two loading rhythms were tested on pilots which were fed at a loading rate of 25 kgDM.m-2.yr-1 during the first year of operation (commissioning period). Hydraulic behaviour (infiltration rate, outflow), O2 and CO2 relative concentrations in the filtration media, redox potential, pollutants removal and dry matter content were assessed during all the study. The rheological quality of the extracted sludge from full scale beds were assessed and showed that it mechanical behaviour exceed those of sludge of comparable dry matter content, making its spreading easier Therefore, these sludge could easily claim the status of solid and stabilized sludge according to the French regulation. Design and management recommendations (number of beds, loading rates, feeding/rest period) gained from the experiments results are suggested

Development and Validation of a Risk Score for Chronic Kidney Disease in HIV Infection Using Prospective Cohort Data from the D:A:D Study

Ristola M. on työryhmien DAD Study Grp ; Royal Free Hosp Clin Cohort ; INSIGHT Study Grp ; SMART Study Grp ; ESPRIT Study Grp jäsen.Background Chronic kidney disease (CKD) is a major health issue for HIV-positive individuals, associated with increased morbidity and mortality. Development and implementation of a risk score model for CKD would allow comparison of the risks and benefits of adding potentially nephrotoxic antiretrovirals to a treatment regimen and would identify those at greatest risk of CKD. The aims of this study were to develop a simple, externally validated, and widely applicable long-term risk score model for CKD in HIV-positive individuals that can guide decision making in clinical practice. Methods and Findings A total of 17,954 HIV-positive individuals from the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study with >= 3 estimated glomerular filtration rate (eGFR) values after 1 January 2004 were included. Baseline was defined as the first eGFR > 60 ml/min/1.73 m2 after 1 January 2004; individuals with exposure to tenofovir, atazanavir, atazanavir/ritonavir, lopinavir/ritonavir, other boosted protease inhibitors before baseline were excluded. CKD was defined as confirmed (>3 mo apart) eGFR In the D:A:D study, 641 individuals developed CKD during 103,185 person-years of follow-up (PYFU; incidence 6.2/1,000 PYFU, 95% CI 5.7-6.7; median follow-up 6.1 y, range 0.3-9.1 y). Older age, intravenous drug use, hepatitis C coinfection, lower baseline eGFR, female gender, lower CD4 count nadir, hypertension, diabetes, and cardiovascular disease (CVD) predicted CKD. The adjusted incidence rate ratios of these nine categorical variables were scaled and summed to create the risk score. The median risk score at baseline was -2 (interquartile range -4 to 2). There was a 1: 393 chance of developing CKD in the next 5 y in the low risk group (risk score = 5, 505 events), respectively. Number needed to harm (NNTH) at 5 y when starting unboosted atazanavir or lopinavir/ritonavir among those with a low risk score was 1,702 (95% CI 1,166-3,367); NNTH was 202 (95% CI 159-278) and 21 (95% CI 19-23), respectively, for those with a medium and high risk score. NNTH was 739 (95% CI 506-1462), 88 (95% CI 69-121), and 9 (95% CI 8-10) for those with a low, medium, and high risk score, respectively, starting tenofovir, atazanavir/ritonavir, or another boosted protease inhibitor. The Royal Free Hospital Clinic Cohort included 2,548 individuals, of whom 94 individuals developed CKD (3.7%) during 18,376 PYFU (median follow-up 7.4 y, range 0.3-12.7 y). Of 2,013 individuals included from the SMART/ESPRIT control arms, 32 individuals developed CKD (1.6%) during 8,452 PYFU (median follow-up 4.1 y, range 0.6-8.1 y). External validation showed that the risk score predicted well in these cohorts. Limitations of this study included limited data on race and no information on proteinuria. Conclusions Both traditional and HIV-related risk factors were predictive of CKD. These factors were used to develop a risk score for CKD in HIV infection, externally validated, that has direct clinical relevance for patients and clinicians to weigh the benefits of certain antiretrovirals against the risk of CKD and to identify those at greatest risk of CKD.Peer reviewe

Contamination par le PCP d'ecosystemes aquatiques reconstitues : degradation et effets sur les vegetaux

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Fate of chlorinated benzenes in laboratory peat and pozzolona fitters

International audienceThe removal of chlorinated benzenes (CBs) from the compartments and polluted industrial sites is of great public interest for the decontamination of polluted waters and protecting the environment. Biological degradation could be considered as a feasible process to eliminate these compounds from the environment as soil or groundwater.Biological degradation could be seen as a process can be eliminated these compounds in the environment as soil or groundwater. A research program in progress since the year 2007 was initiated to investigate the capacity of eco-remediation of CB-contaminated groundwater using a pilot-scale subsurface flow constructed wetland.A research program in progress since 2007 has been launched to investigate the ability of eco-remediation of contaminated groundwater using a CB wetland pilot scale subsurface flow constructed. In order to assess the removal efficiency of these compounds and to evaluate the biological activities, column experiments were performed.In order to evaluate the removal efficiency of these compounds and to evaluate the biological activities, experiments were carried out column. The fate of three CBs was investigated by feeding spiked tap water through laboratory columns filled with two different solid-state materials: peat and pozzolana.The fate of three CBS was studied by feeding of tap water spiked through laboratory columns filled with two different semiconductor materials: peat and pozzolana. In order to stimulate biological activity, organic matter coming from aged vertical flow constructed wetland was added to the media.In order to stimulate biological activity, organic matter from the vertical flow wetlands constructed age was added to the press. Concentrations of CBs in water effluent and in air and biological activities were monitored during 4 months.breakers concentrations in effluents and in the activities of air and biological parameters were monitored for 4 months. At the end of the experimental period, CB concentrations in the depth of columns were determined and a mass balance was calculated for the CBs.At the end of the experimental period, concentrations of CB in the depth of the columns were determined and mass balance was calculated for CBS. Removal efficiencies of the laboratory columns were >98% in the peat columns and situated around 87% to 95% in the pozzolana columns, indicating the suitability of the experimental systems for the removal of CBs.The removal efficiency of the laboratory columns were> 98% in the columns of peat and located around 87% to 95% in the columns of pozzolana, indicating the relevance of experimental systems for the removal of CBS. Higher effluent CB concentrations from the pozzolana columns were detected.Higher concentrations of CB effluents from the columns pozzolana were detected. Concentration of CBs in ambient air indicates that volatilization was low.breakers concentration in ambient air indicate that volatilization is low. ATP monitoring, reduction of tetrazolium violet, and exopolysaccharide determination indicated considerable biological activity with variations according to column depth and carrier material.ATP monitoring, reduction of tetrazolium violet, and exopolysaccharide determination indicated significant biological activity with variations depending on the depth and column support material

The first international meeting of the Research Initiative on Traditional Antimalarial Methods (RITAM)

The first international meeting of the Research Initiative on Traditional Antimalarial Methods (RITAM) was held at the Regional Dermatology Training Centre (RDTC) of the Tumaini University of Health Sciences, Moshi, Tanzania, on December 8-11, 1999. This Inaugural Meeting of RITAM, jointly hosted by the Global Initiative for Traditional Systems of Health (GIFTS) at Oxford University and the World Health Organization (WHO), was designed to develop a strategy for more effective, evidence-based use of traditional medicines that can also inform malaria-control policy decisions. RITAM was established during 1999 as a network of researchers and other people who are active or interested in the study and use of traditional, plant-based antimalarials. RITAM is a partnership between GIFTS of Health, University of Oxford and the Tropical Disease Research (TDR) Programme of WHO. Malaria is one of the key health issues affecting developing countries, particularly in sub-Saharan Africa and Asia. With increasing drug resistance and the high cost of pharmaceutical drugs, the use of herbal antimalarials is popular. The conference was attended by biologic and social scientists, clinicians, traditional healers, and policy makers from Africa, Asia, Europe, and the Americas. The meeting was funded by the Rockefeller Foundation, the Nuffield Foundation's Commonwealth Programme, WHO's TDR Programme, and direct support to delegates was provided by other funders. The meeting addressed the need for research and policy on the prophylactic and therapeutic effects of medicinal plants as well as on vector control and repellence. There were five main outputs from the meeting: (1) targets for making a significant contribution to the control of malaria through the use of traditional antimalarial methods; (2) methods for achieving these targets, including ethical guidelines; (3) an implementation strategy for moving this field ahead quickly and soundly and for putting research findings into practice; (4) linkages established between researchers working on traditional antimalarial methods, based on agreed research priorities and designed to avoid unnecessary replication; and (5) strengthening the RITAM database of current knowledge on traditional herbal antimalarial methods. Four specialist groups were established to develop the above: (1) policy, advocacy, and funding; (2) preclinical studies; (3) clinical development; and (4) repellance and vector control. These will be coordinated by an executive committee managed by GIFTS. Two meetings are planned in 2000: a natural-products chemistry meeting at WHO in Geneva, Switzerland, in June; and a symposium at the World Congress on Tropical Medicine in Cartagena, Colombia, in August