ABSTRACT
Huge amounts of spent denitration catalysts are produced annually as waste from the flue gas denitration process, which will cause resource waste and environmental pollution. It is important to develop an efficient method for the recovery of metals from spent denitration catalysts. In this work, the leaching of vanadium (V) from the spent denitration catalyst by the sulfuric acid/oxalic acid combined solvent was investigated. Factors that influence the leaching rate of V have been studied. Results showed that the optimal leaching rate was 95.65% by 20 wt % sulfuric acid and 0.3 mol·L-1 oxalic acid with a liquid-to-solid ratio of 20 mL·g-1 at 140 °C for 7 h. For further study of the leaching process, the leaching mechanism of V was explored subsequently. Results indicated that sulfuric acid provided a strongly acidic environment, which was beneficial to transformation, complexation, and redox reactions of V in the mixed acid leaching system. Meanwhile, oxalic acid with excellent complexation and reducing-dissolving properties promoted the formation of stable water-soluble VO2+. The "complex effect" generated from the combined acids was greatly favored for leaching V from the spent denitration catalyst.
ABSTRACT
Fluctuating sensorineural hearing lossï¼FSNHLï¼ is a special type of sensorineural hearing loss, which can be manifested in many clinical diseases. In this paper, some clinical diseases associated with FSNHL are summarized, such as Meniere's disease, large vestibular aqueduct syndrome, acute low frequency sensorineural hearing loss, delayed endolymphatic hydrops, autoimmune inner ear disease and syndromes leading to FSNHL. The pathogenesis, diagnosis and treatment of FSNHL were summarized in order to improve clinicians' understanding of FSNHL, reduce the probability of misdiagnosis of related diseases and improve the prognosis of patients.
Subject(s)
Endolymphatic Hydrops , Hearing Loss, Sensorineural , Meniere Disease , Humans , Endolymphatic Hydrops/complications , Meniere Disease/complications , Hearing Loss, Sensorineural/etiology , Syndrome , PrognosisABSTRACT
Over the last 30 years, cochlear implant (CI) has been dedicated to improving the rehabilitation of hearing impairments. However, CI has shown potential detrimental effects on vestibular function. For children, due to atypical symptoms and difficulty in cooperating with vestibular function tests, systematic and objective assessments of vestibular function with CI have been conducted sparsely. This review focuses on the impact of vestibular function in children with CI and summarized the evaluation of vestibular function in children. In addition, some recommended strategies are summarized and proposed.