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A new biochar (N-BC) was fabricated by incorporating high-density positively charged quaternary ammonium groups into the pristine biochar without any adsorption for phosphate. N-BC can highly efficiently remove phosphate with an optimal pH of 5.0, a maximum experimental adsorption capacity of 30 mg of P/g, and an adsorption equilibrium time of 180 min. The predicted pore diffusion coefficient D (the diffused surface area of the adsorbate for unit time) for phosphate adsorption by N-BC was 5.3 × 10-9 cm2/s. N-BC can still capture phosphate in the copresence of anion Cl- with a molar concentration 50 times that of phosphate. The exhausted N-BC was completely regenerated using a 10 wt % NaOH solution and further reused without any observable loss in adsorption capacity. Moreover, N-BC yielded â¼324 bed volumes (BV) of wastewater containing 1 mg P/L phosphate and 50 mg/L Cl- before breakthrough occurring (<0.1 mg P/L in effluent) in a fixed-bed column operation system. The introduced quaternary ammonium groups covalently bound to biochar played a dominant role in phosphate sequestration by N-BC through forming the out-sphere complexation with phosphate. All results imply that it is of promising prospect for N-BC practical application for phosphate purification from waters. The present study provided a new strategy to expand the application of biochar, usually serving as an adsorbent for cationic pollutants, to the purification of anionic pollutants such as phosphate from waters.
RESUMO
BACKGROUND: Several types of surgeries have been used in the treatment of congenital ptosis, but the optimal methods and materials for this treatment are unknown. PURPOSE: The study aims to evaluate the comparative effectiveness and safety of various surgical methods and materials for treatment of congenital ptosis. METHODS: We performed comprehensive searches of five databases, two clinical trial registries and one gray literature database from inception to January 2022 for related trials to include in this study. Meta-analysis was performed to evaluate the effect of surgical methods and materials on the primary outcomes: margin reflex distance 1 (MRD1), palpebral fissure height (PFH), and degree of lagophthalmos; and secondary outcomes: undercorrection, entropion, corneal epithelial defects, wound dehiscence, recurrence, infection, and cosmetic outcomes. RESULTS: A total of 14 trials evaluating 909 eyes of 657 patients were included in our study. Compared with the levator plication, the frontalis sling significantly increased the MRD1 (MD = - 1.21; 95% CI [- 1.69, - 0.73]), and the levator resection significantly increased the PFH (MD = 1.30; 95% CI [0.27, 2.33]). For the frontalis sling surgical patterns, the fox pentagon was significantly better than the double triangle at improving the degree of lagophthalmos (MD = 0.70; 95% CI [0.32, 1.08]), while the opened pattern provided statistically better cosmetic outcome than the closed frontalis sling. Analysis of surgical material showed that absorbable sutures significantly increased the MRD1 (MD = 1.16; 95% CI [0.60, 1.72]) compared to non-absorbable sutures when used in levator plication; frontalis sling surgeries performed with silicon rods significantly increased the PFH (MD = 0.88; 95% CI [0.29, 1.47]) compared to those performed with Gore-Tex strips, while autogenous fascia lata provided statistically better aesthetic outcome for lid height symmetry and contour. CONCLUSION: Different surgical methods and materials appear to affect different aspects of the congenital ptosis treatment outcome. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .