In the present study, the performance of a modified upflow anaerobic sludge blanket (MUASB) reactor–static granular bed reactor (SGBR) series in intermittent operation was analyzed for the treatment of synthetic wastewater. The reactor series was operated with a hydraulic retention time (HRT) of 24 h. The maximum chemical oxygen demand (COD) removal and biogas production of the reactor series obtained during the intermittent operation were 99 ± 0.29% and 0.529 ± 0.03 m3/kg CODdigested, respectively. One‐way analysis of variance (ANOVA) indicated a significant difference in biogas production during continuous and intermittent operations, whereas the COD removal was similar. Intermittent operation of the reactor series yielded a 56.05% increase in biogas production when compared with the continuous operation. The reactor series was maintained stable throughout the operational period. The maximum total suspended solids (TSS) removal and total nitrogen (TN) removal of the reactor series during the intermittent operation were 91.67% and 72.37%, respectively. Intermittent operation of the reactor series can be considered advantageous because of the reduced operational cost and enhanced biogas production in addition to COD removal.
Practitioner Points
Intermittent operation of MUASB–SGBR series in terms of COD removal is evaluated.
COD removal of reactor series was similar in intermittent and continuous operation.
Biogas production in intermittent operation was superior to continuous operation.
Reactor series performance is also compared with continuous operation using one‐way ANOVA.
Background:
Hyaluronic acid (HA) is a naturally occurring biodegradable, high molecular weight, non-sulfated glycosaminoglycan (GAG) polymer known for its excellent biocompatibility. HA-based products are widely used as viscosupplements, dermal fillers, and ophthalmic lubricants in clinical settings. Although animal and bacterial-derived HA are commonly reported, plant-sourced HA is not frequently reported. In this study, we have evaluated various viscoelastic properties of one such plant-based HA solution and propose them as an alternative to existing animal/bacteria-sourced HA.
Materials and Methods:
The viscoelastic properties of plant-sourced HA solution of various concentrations (0.1%, 0.5%, 1%, and 2% in PBS) were studied using a rheometer at 37°C. Flow curves, amplitude sweep studies, and frequency sweep studies were performed and compared for all HA solutions.
Results:
The HA solutions displayed shear-thinning behavior, which is an important characteristic of an injectable biomaterial. The 0.1 and 0.5% HA were found to have viscoelastic properties appropriate for eye lubricants, while 1 and 2% HA solutions showed properties suitable for soft tissue fillers. Frequency sweep studies indicated that all the samples are typically viscoelastic liquids with a loss modulus (G″) higher than the storage modulus (G′). This indicated that the samples needed further processing like crosslinking of HA or using higher molecular weight HA to be suitable as viscosupplements. However, the frequency sweep studies also indicated that these solutions can be used as soft tissue fillers of any type based on the G′ and tan δ values.
Conclusion:
The plant-sourced HA solutions are found to exhibit good shear-thinning properties with viscoelastic properties suitable for eye lubricants and soft tissue fillers. However, to be used as viscosupplements, the viscoelastic properties of HA solutions have to be further modified through non-toxic crosslinking strategies, and hydrophobic derivatives as well as by using high molecular weight HAs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.