Search results for "removal"
showing 10 items of 316 documents
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…
Sequential batch membrane bio-reactor for wastewater treatment: The effect of increased salinity
2016
In this work, a sequential batch membrane bioreactor pilot plant is investigated to analyze the effect of a gradual increase in salinity on carbon and nutrient removal, membrane fouling and biomass kinetic parameters. The salinity was increased by 2 g NaCl L-1 per week up to 10 g NaCl L-1. The total COD removal efficiency was quite high (93%) throughout the experiment. A gradual biomass acclimation to the salinity level was observed during the experiment, highlighting the good recovery capabilities of the system. Nitrification was also influenced by the increase in salinity, with a slight decrease in nitrification efficiency (the lowest value was obtained at 10 g NaCl L-1 due to lower nitri…
SORPTION OF CD2+ AND CU2+ IONS FROM AQUEOUS SOLUTIONS BY ALGINATE AND ALGINATE/PECTIN GEL BEADS.
2012
Removal of toxic metal ions from natural waters, wastewaters and contaminated sites is of great importance for the health of living organism and for environmental protection (1). Alternatively to the conventional chemical treatments, such as precipitation, reverse osmosis, etc, that are expensive and of high environmental impact, the use of low cost and environmental friendly sorbent materials is a very promising new technology for meal ions removal (2,3). The most investigated sorbent materials are of organic origin derived from the natural biomass (algae, fungi, bacteria) and from industrial processes, such as wood, agriculture, fishery, textile manufacturing, etc. Also some inorganic mat…
Advanced Strategies for Food-Grade Protein Production: A New E. coli/Lactic Acid Bacteria Shuttle Vector for Improved Cloning and Food-Grade Expressi…
2019
Food-grade production of recombinant proteins in Gram-positive bacteria, especially in LAB (i.e., Lactococcus, Lactobacillus, and Streptococcus), is of great interest in the areas of recombinant enzyme production, industrial food fermentation, gene and metabolic engineering, as well as antigen delivery for oral vaccination. Food-grade expression relies on hosts generally considered as safe organisms and on clone selection not dependent on antibiotic markers, which limit the overall DNA manipulation workflow, as it can be carried out only in the expression host and not in E. coli. Moreover, many commercial expression vectors lack useful elements for protein purification. We constructed a &ld…
Evaluation of the time required to perform three retreatment techniques with dental microscope and ultrasonic activation for removing filling materia…
2018
Background When endodontic treatment fails, retreatment consists of the complete removal of the root canal filling material for thorough cleaning and reobturation. Various techniques are available for the filling removal procedure, which present varying degrees of efficacy, and take a varying length of time to perform. The aim of this study was to compare the time required to carry out reciprocating, rotary, and manual techniques with dental microscope and ultrasonic activation for removing filling material from root canals. Material and Methods Ninety-nine extracted single-rooted teeth with straight and oval-shaped canals were selected. The samples were instrumented with ProTaper Gold Syst…
Comparison of postoperative morbidity between piezoelectric surgery and conventional rotary instruments in mandibular third molar surgery: a split-mo…
2020
Background The extraction of impacted third molar teeth is a common procedure in maxillofacial surgery. The aim of this study was to compare of piezoelectric surgical technique with the one with conventional rotary instruments in terms of edema, trismus and pain, in mandibular third molar surgery. Material and Methods 20 individuals with symmetrically impacted lower mandibular third molars and 40 teeth were included in the study. Third molars on the left side of each patient were removed with piezosurgery, while the counterparts on the right side were removed with conventional rotary instruments. Postoperatively, the same antibiotic, analgesic, and mouthwash were recommended to both groups.…
Classification of impacted mandibular third molars on cone-beam CT images
2014
Background: Neurological involvement is a serious complication associated to the surgical removal of impacted mandibular third molars and the radiological investigation is the first mandatory step to assess the risk of a possible post-operative injury to the inferior alveolar nerve (IAN). The aim of this study was to introduce a new radiological classification that could be normally used in clinical practice to assess the relationship between an impacted third molar and mandibular canal on cone beam CT (CBCT) images. Material and Methods: CBCT images of 80 patients (133 mandibular third molars) were independently studied by three members of the surgical team to draw a classification that co…
Bilateral inverted and impacted maxillary third molars: a case report
2015
Bilateral inverted third molar impaction is an extremely rare condition. We reported the case of a 50-year-old female patient with bilateral inverted and impacted maxillary third molars. Both were asymptomatic and pathology free clinically and radiographically. Surgical extraction of these inverted third molars with inaccessible positions requires an aggressive bone removal on the tuberosity bilaterally. Moreover, it contains a high risk of displacement of the inverted third molar into the maxillary sinus. Conservative management was the choice, with the patient's agreement, and the inverted third molars were left in situ. Key words:Bilateral inverted, maxillary third molar, upper impacted …
Influence of operator’s professional experience in the postoperative course after surgical extrac-tion of the impacted lower third molar: A pilot stu…
2020
Background Third molars are present in 96.6% of humans, although they do not always erupt completely. Between 9.5% and 73% of them remain impacted. Surgical removal of impacted third molars is the most common practice in oral and maxillofacial surgery. This procedure results in traumatism and, consequently, the postoperative phase will involve symptomatology. It is uncommon to find studies that directly relate postoperative symptomatology and the operator's experience. The aim of this study was to determine the differences regarding postoperative symp-tomatology in patients undergoing the bilateral extraction of lower impacted third molars and according to the operator's experience. Materia…
Effectiveness of intra-alveolar chlorhexidine gel in reducing dry socket following surgical extraction of lower third molars: a pilot study
2015
Background: Dry socket is one of the most studied complications in dentistry and several studies have sought an effective and safe method for its prevention and treatment. The aim of this study was to evaluate the effectiveness of intra-alveolar gel chlorhexidine in preventing dry socket after the surgical removal of third molars. Material and Methods: The sample involved the treatment of 40 patients who required extraction of third molars impacted, which were randomly assigned to research groups: experimental group (chlorhexidine gel 0.12%) and control group (placebo gel). Performed the extraction was administered 1 mL of chlorhexidine gel or 1 mL of placebo gel within the socket. The remo…