ABSTRACT
Humic acid (HA) is the main component of natural organic matter that generates carcinogenic byâproducts during disinfection and its removal from water resources is challenging. Biocompatible halloysite (HNTs) nanomaterial decorated with polyaniline (HNTsâPANI) was synthesized via polymerization technique. HNTsâPANI was added to prepare polyethersulfone mixed matrix membranes (MMMs). The influence of HNTsâPANI concentration on HA removal efficiency was studied by varying the HNTsâPANI (0.5, 1 and 1.5 wt%). The characterization studies of MMMs revealed that the addition of HNTsâPANI improved the morphology of the membranes, surface properties, chemical stability and thermal property. The amine and hydroxyl groups within the MMMs improved the membrane wettability. The addition of HNTsâPANI within the MMMs had significantly enhanced the pure water flux and HA filtration. YHP2 MMM with 1 wt% of HNTsâPANI demonstrated sieving coefficient of 0.10 and the highest HA removal efficiency of 91% greater than the neat PES membrane. Furthermore, the antifouling property of the MMMs was studied using HA as foulant. 1 wt% of HNTsâPANI added MMM showed a high flux recovery ratio (94.9%) with low total fouling of 12% and low irreversible fouling of 5%, respectively. Thus, HNTsâPANI was an efficient nanomaterial for enhancing the pure water flux, removal efficiency and antifouling property to treat water contaminated with HA.
Subject(s)
Nanostructures , Water , Aniline Compounds , Carcinogens , Clay , Disinfection , Membranes, Artificial , Water/chemistryABSTRACT
Bone grafting is beneficial in enhancing bones that are lost due to trauma or natural or pathologic process. Autogenous bone, allogenic bone, xenogeneic bone, bone substitutes, and alloplasts can also be used for this purpose. Bone quantity should be adequate for the placement of implants, which necessitate the use of bone grafts before implant placement. OBJECTIVE: This review analyses the different bone graft materials that are used for grafting around implants and evaluate if these grafts yield successful implant osseointegration over a period of time. MATERIALS AND METHODS: The MEDLINE-PubMed database was searched from September 2016 to 10 years previously. Several journals were hand searched and from cross-references. The primary outcome measure that was analyzed was the survival rate of dental implants in the grafted sites at 6 months-1 year, and the secondary outcomes were success rates of dental implants over a period of 3-5 years' follow-up. RESULTS: The search yielded 213 articles. Ultimately, 31 studies meeting the eligibility criteria were selected. The analysis shows that autologous bone grafts can be preferred over allografts and xenografts for grafting implant sites, which showed less complication and high success rate. CONCLUSION: Based on the available data in the current existing studies with a follow-up period of at least 3-5 years, it can be summarized that the autologous bone grafts can be preferred over allografts and xenografts for grafting implant sites since they are stable for at least 3-5 years.
ABSTRACT
Production of a commercially important biodegradable polymer, pullulan, by Aureobasidium pullulans from four agricultural wastes namely wheat bran, rice bran, coconut kernel and palm kernel was evaluated in solid state fermentation. Under the experimental conditions, palm kernel resulted in highest concentration of pullulan (16 g/L) among the four solid substrates. Optimum initial pH and moisture content for pullulan production were found out to be 6.5 and 50% respectively. 18.43 g/L of pullulan was produced from Asian palm kernel with initial pH 6.5 after 7 days of fermentation and yeast like morphology was predominant under this condition. Among different nitrogen sources tried in this study, yeast extract was found to the best. The pullulan produced from palm kernel was characterized by FTIR and (1)H NMR. The results were matching with that of commercial pullulan. Thus, Asian palm kernel appears to be an attractive low cost carbon source for the production of pullulan.