Search results for "Sludge"
showing 10 items of 320 documents
Assessment of the mutagenic potency of sewage sludges contaminated with polycyclic aromatic hydrocarbons by an Ames sludges for fluctuation assay
2003
9 pages, 1 figure, 6 tables.-- PMID: 14587895 [PubMed].
A New Self-Expanding Nitinol Stent (JoStent SelfX) for Palliation of Malignant Biliary Obstruction: a Pilot Study
2004
Background and Study Aims: The JoStent SelfX is a new biliary uncovered self-expanding nitinol stent. The main advantage of this stent in comparison with the gold standard Wallstent is the minimal shortening (< 10%) that occurs during stent deployment. A prospective feasibility study was conducted to evaluate the method of stent implantation and the stent's short-term efficacy. Patients and Methods: Between April 2001 and December 2002, the JoStent SelfX was implanted in 20 patients with inoperable malignant biliary obstructions, mainly caused by pancreatic cancer (12 of 20). All patients underwent sphincterotomy prior to stent insertion. After implantation, laboratory parameters for choles…
Endoscopic treatment of the "sump syndrome" after choledochoduodenostomy: a new technique using an amplatzer septal occluder.
2006
A 58-year-old male patient had been suffering for 35 years from recurrent cholangitis, biliary sludge and infection-induced stone formation after open cholecystectomy because of empyema of the gallbladder and severe acute and delayed postoperative complications. The pathophysiological origin of this chronic "sump syndrome" was a choledochoduodenostomy which had been performed prophylactically at the time of the initial operation. The patient agreed to an experimental treatment option with use of an Amplatzer atrial-septal defect (ASD) occluder for closure of the symptomatic choledochoduodenal fistula. The double-disc occluder was introduced through a 9 French diameter and 90 cm long sheath …
Evaluation of Suitability of Treated Sewage Sludge for Maize Cultivation
2020
The worlds growing population demands more food and creates more waste. Economically viable and environmentally friendly would be to use sewage sludge for agricultural production. There are several limitations for this use – heavy metal content, pathogenic microorganisms, helminths etc.. The different methods of treatment of sewage sludge helps to overcome this problem. The aim of the study is to find the effects of treated sewage sludge on the growth of maize and changes in soil biological activity. Experiments were carried out with dry sewage sludge preparation (SSP) in the such combinations 1) SSP, 2) SSP+PK, 3) SSP+NPK. Controls- loamy soil without additional fertilizer, soil mixed with…
Application of the Oxic-Settling-Anaerobic Process in a Membrane Bioreactor for Excess Sludge Reduction
2017
The main goal of this study was the evaluation of the excess sludge reduction in a MBR for biological nitrogen removal (BNR) through the implementation of the Oxic-Settling-Anaerobic (OSA) process. For this purpose, a MBR pilot plant (42 L volume) was realized according to a pre-denitrification scheme. The whole experimentation was divided into two periods, named Period 1 and Period 2, respectively. In Period 1 the pilot plant was started-up and the excess sludge production was evaluated. In Period 2 the plant configuration was partially modified by inserting an anaerobic reactor into the return activated sludge (RAS) line to realize an OSA configuration. In Period 1, the Yobs resulted equa…
Simultaneous sludge minimization, biological phosphorous removal and membrane fouling mitigation in a novel plant layout for MBR.
2020
Abstract The integration of one anaerobic reactor in the mainstream (AMSR) of a pre-denitritication-MBR was evaluated with the aim to achieve simultaneous sludge minimization and phosphorous removal. The excess sludge production was reduced by 64% when the AMSR was operated under 8 h of hydraulic retention time (HRT). The highest nutrients removal performances referred to organic carbon (98%), nitrogen (90%) and phosphorous (97%) were obtained under 8 h of HRT. In contrast, prolonged anaerobic-endogenous conditions were found to be detrimental for all nutrients removal performances. Similarly, the lowest membrane fouling tendency (FR = 0.65∙1011 m−1 d−1) was achieved under 8 h of HRT, where…
Biological minimization of excess sludge in a membrane bioreactor: Effect of plant configuration on sludge production, nutrient removal efficiency an…
2018
Abstract Excess sludge minimization was studied in a MBR with pre-denitrification scheme. Sludge minimization, nitrogen removal performance and membrane fouling tendency were investigated in two configurations, characterized by a different position of the sludge retention reactor (SRR). In particular, the SRR was placed: i) in the return activated sludge line (Anaerobic Side-Stream Reactor – ASSR configuration) and ii) in the mainstream between the anoxic and aerobic reactor (Anaerobic Main-Stream Reactor – AMSR configuration). The achieved results demonstrated that the ASSR enabled a higher excess sludge reduction (74% vs 32%), while achieving lower biological nitrogen removal (BNR) (TN = …
Integrated fixed-film activated sludge membrane bioreactors versus membrane bioreactors for nutrient removal: A comprehensive comparison
2018
Abstract This research elucidates the pollutants (nutrients and carbon) removal performance and nitrous oxide (N2O) emissions of two pilot plants. Specifically, a University of Cape Town (UCT) Membrane Bioreactor (MBR) plant and an Integrated Fixed Film Activated Sludge (IFAS)-UCT-MBR plant were investigated. The plants were fed with real wastewater augmented with acetate and glycerol in order to control the influent carbon nitrogen ratio (C/N). The short-term effect of the inlet C/N ratio variation (C/N = 5 mgCOD/mgN and C/N = 10 mgCOD/mgN) on the behaviour of both plants was investigated. The results showed that the IFAS-UCT-MBR configuration provided the best performance in terms of poll…
Eubacteria and archaea communities in seven mesophile anaerobic digester plants in Germany
2015
Background Only a fraction of the microbial species used for anaerobic digestion in biogas production plants are methanogenic archaea. We have analyzed the taxonomic profiles of eubacteria and archaea, a set of chemical key parameters, and biogas production in samples from nine production plants in seven facilities in Thuringia, Germany, including co-digesters, leach-bed, and sewage sludge treatment plants. Reactors were sampled twice, at a 1-week interval, and three biological replicates were taken in each case. Results A complex taxonomic composition was found for both eubacteria and archaea, both of which strongly correlated with digester type. Plant-degrading Firmicutes as well as Bacte…
Influence of the initial sludge characteristics and acclimation on the longterm performance of double-compartment acetate-fed microbial fuel cells
2018
Abstract In this work, three double-compartment MFCs (DC-MFC) were operated for 1 month in order to compare their performances in terms of wastewater treatment capacity and electricity production and to get information about how this performance is influenced by the start-up procedure. To do this, they underwent different start-up procedures. One of them (aerobic-starved MFC) was inoculated with 100% fresh aerobic sludge, another (anaerobic-starved MFC) using 100% fresh anaerobic sludge, and finally a third one (aerobic-fed MFC) was inoculated using a mixture 10% fresh aerobic sludge and 90% synthetic wastewater (based on acetate). Then, from this start-up, the cells were operated exactly u…