Co-adsorption of Trichloroethylene and Arsenate by Iron-Impregnated Granular Activated Carbon.

Co-adsorption of trichloroethylene (TCE) and arsenate [As(V)] was investigated using modified granular activated carbons (GAC): untreated, sodium hypochlorite-treated (NaClO-GAC), and NaClO with iron-treated GAC (NaClO/Fe-GAC). Batch experiments of single- [TCE or As(V)] and binary- [TCE and As(V)] components solutions are evaluated through Langmuir and Freundlich isotherm models and adsorption kinetic tests. In the single-component system, the adsorption capacity of As(V) was increased by the NaClO-GAC and the NaClO/Fe-GAC. The untreated GAC showed a low adsorption capacity for As(V). Adsorption of TCE by the NaClO/Fe-GAC was maximized, with an increased Freundlich constant. Removal of TCE in the binary-component system was decreased 15% by the untreated GAC, and NaClO- and NaClO/Fe-GAC showed similar efficiency to the single-component system because of the different chemical status of the GAC surfaces. Results of the adsorption isotherms of As(V) in the binary-component system were similar to adsorption isotherms of the single-component system. The adsorption affinities of single- and binary-component systems corresponded with electron transfer, competitive adsorption, and physicochemical properties.

Impact of polymeric membrane filtration of oil sands process water on organic compounds quantification.

The interaction between organic fractions in oil sands process-affected water (OSPW) and three polymeric membranes with varying hydrophilicity (nylon, polyvinylidene fluoride and polytetrafluoroethylene) at different pHs was studied to evaluate the impact of filtration on the quantification of acid-extractable fraction (AEF) and naphthenic acids (NAs). Four functional groups predominated in OSPW (amine, phosphoryl, carboxyl and hydroxyl) as indicated by the linear programming method. The nylon membranes were the most hydrophilic and exhibited the lowest AEF removal at pH of 8.7. However, the adsorption of AEF on the membranes increased as the pH of OSPW decreased due to hydrophobic interactions between the membrane surfaces and the protonated molecules. The use of ultra pressure liquid chromatography-high resolution mass spectrometry (UPLC/HRMS) showed insignificant adsorption of NAs on the tested membranes at pH 8.7. However, 26±2.4% adsorption of NAs was observed at pH 5.3 following the protonation of NAs species. For the nylon membrane, excessive carboxylic acids in the commercial NAs caused the formation of negatively charged assisted hydrogen bonds, resulting in increased adsorption at pH 8.2 (25%) as compared to OSPW (0%). The use of membranes for filtration of soluble compounds from complex oily wastewaters before quantification analysis of AEF and NAs should be examined prior to application.

Deep Neck Space Infection Caused by Keratocystic Odontogenic Tumor.

Keratocystic odontogenic tumor (KCOT) is a benign cystic intraosseous tumor of odontogenic origin. An infection of a KCOT is not common because KCOT is a benign developmental neoplasm. Moreover, a severe deep neck space infection with compromised airway caused by infected KCOT is rare. This report presents a 60-year-old male patient with a severe deep neck space infection related to an infected KCOT due to cortical bone perforation and rupture of the exudate. Treatment of the deep neck space infection and KCOT are reported.

Desalination of oil sands process-affected water and basal depressurization water in Fort McMurray, Alberta, Canada: application of electrodialysis.

The high content of inorganic species in water used to extract bitumen from the Alberta oil sands and in the groundwater below the oil sands is an increasing environmental concern. These water matrices require treatment before they can be reused or safely discharged. Desalination of the oil sands process-affected water (OSPW) and groundwater, or basal depressurization water (BDW), can be accomplished with deionization techniques such as electrodialysis (ED). In order to achieve the effective ED treatment, OSPW and BDW were pretreated with coagulation-flocculation-sedimentation to remove solid species and turbidity. We demonstrated that a conductivity range for industrial reuse of OSPW and BDW can be achieved with the ED treatment and showed the possibility of applying ED in the oil sands industry. A continuous ED system that reuses the diluate stream as a source for the concentrate stream was designed. The cost of a hypothetical ED water treatment plant in Fort McMurray, Alberta, was estimated to be C$10.71 per cubic meter of treated water.

Three-dimensional volumetric analysis after sinus grafts.

PURPOSE: The purpose of this study was to evaluate the augmentation volume of a sinus graft according to the time and graft materials based on cone-beam computed tomography (CBCT) scans and to assess efficacy of a bioabsorbable membrane. METHODS: Fourteen patients were investigated, and volumetric analysis was performed using OnDemand 3DTM software (Cybermed, Seoul, Korea). CBCT scans were performed on patients before surgery, immediately after surgery, 6 months after surgery, and 1 year after surgery. Following this analysis, the volumetric data were compared with the actual grafted volumes. Bioabsorbable membranes were used in all patients to promote the protection of sinus membranes and to guide bone regeneration. RESULTS: Overall, the average percent volume of graft material that remained 6 months after implantation was 82.0%, and the average percent volume of graft material that remained 1 year after surgery was 60.4%. These reductions in the volume of graft material from immediately after surgery until 6 months or 1 year after surgery were shown to be statistically significant (P = 0.002 and P < 0.001, respectively). CONCLUSION: The slight differences observed among the data indicate that volumetric analysis performed using CBCT can provide highly accurate data. A significant difference was observed in volumetric change over time, but no significant differences were observed between materials. No significant relationship was observed between the resorption of grafted bone and the success rate.

Evaluation of membrane fouling for in-line filtration of oil sands process-affected water: the effects of pretreatment conditions.

Membrane filtration is an effective reclamation option for oil sands process-affected water (OSPW). However, fresh OSPWs contain suspended solids and inorganic constituents in suspended and dissolved forms that can severely foul membranes. Pretreatment of OSPW with coagulation-flocculation (CF) was investigated to determine the effects of different coagulant aids (anionic, cationic, and nonionic polymers) on membrane surface properties and fouling. Our results showed that CF pretreatment effectively enhanced nanofiltration (NF) and reverse osmosis (RO) membrane permeate flux and salt rejection ratio through reducing membrane fouling. It was shown that coagulants and coagulant aids applied to OSPW feedwater can affect membrane physicochemical properties (surface hydrophilicity, zeta potential, and morphology), membrane performance, and the fouling indexes. Membrane rejection of ionic species increased significantly with the inclusion of an anionic coagulant aid and slightly with a cationic coagulant aid. Among three coagulant aids tested, anionic coagulant aids led to the most enhanced membrane performance through increasing membrane surface negativity and decreasing the formation of a fouling layer. Conversely, although cationic coagulant aids were the most effective in reducing OSPW turbidity, the application of cationic coagulant aids promoted the adsorption of foulants on membrane surfaces.

The effect of ionic strength and hardness of water on the non-ionic surfactant-enhanced remediation of perchloroethylene contamination.

The objective of this study is to evaluate the perchloroethylene (PCE) removal by an aqueous surfactant solutions based on influential factors (ionic strength, hardness) of various groundwaters and surface waters contaminated with PCE. The experimental methods used in this study were separatory funnel experiments and batch experiments. Separatory funnel experiments were performed to determine which surfactants are good solubilizers for PCE. Batch experiments were performed to evaluate the effect of ions in sampled water for PCE removal. The results of separatory funnel experiments indicated that the surfactant polyoxyethylene (20) sorbitan monostearate (Tween 60) showed to be a predominant solubilizer for the removal of PCE (87.3%). Separatory funnel experiments also showed that the hydrophilic-lipophilic balance (HLB) number and the chemical structure of the surfactants were good indicators of surfactant effectiveness for removal of PCE from water. The results of batch experiments showed that non-ionic surfactants are affected by the ionic strength of sampled water. The % of PCE removal of the Tween 60 surfactant solution was measured to be 88.3% by batch experiments. This result was affected by the characteristics of the surfactant (HLB, chemical structures) and the ionic strength of water. Therefore, the ionic strength of contaminated water, HLB and chemical structures of surfactants must be considered in surfactant-enhanced remediation.