ABSTRACT
A multi-stage microaerobic biological fluidized bed reactor was used for the pretreatment of synthetic wastewater containing high concentration of acrylic acid (AA). The effect of influent load was investigated and the intermediate products of acrylic acid degradation were analyzed. It indicated that the removal rate of AA was above 95% with effluent acrylic acid less than 150 mg x L(-1) and COD removal rate of 15%-30%, under the following conditions: hydraulic retention time of 12 h, waste water temperature of 25 degrees C, influent acrylic acid concentration of 3 000-9 000 mg x L(-1), volume load of 6.0-18.0 kg x (m3 x d)(-1). The main intermediate products of acrylic acid degradation were acetic and propionic acids. The multi-stage microaerobic biological fluidized bed reactor can transform each 1.00 mol acrylic acid into 0.22 mol acetic acid and 0.36 mol propionic acid, and achieve the pretreatment of acrylic acid wastewater at high loads.
Subject(s)
Acrylates/isolation & purification , Bioreactors/microbiology , Waste Disposal, Fluid/methods , Wastewater/chemistry , Acrylates/metabolism , Aerobiosis , Biodegradation, EnvironmentalABSTRACT
OBJECTIVE: To study the protective mechanism of Lyceum barbarum polysaccharides (LBP) on ovarian tissue in female senile rat. METHODS: Senile rats of 14 months old were divided randomly into model group, positive drug group, LBP low dosage group, LBP medium dosage group and LBP high dosage group. SD female rats of 4 months old formed a youth group. 30 days after administration,rat blood was taken, radioimmunoassay was employed to determine the levels of estrone and progesterone and enzyme immunoassay was used to determine the levels of IGF-I. Then ovarian tissue was taken to determine the levels of IGFBP-1 and IGFR. RESULTS: Daily oral LBP(60,40,20 mg/kg body weight) for 30 days significantly recovered uterine atrophy and restored serum IGF-I level, estrone and progesterone levels that were decreased in elder rats, reduced the expressing of IGFBP-1 in ovarian tissue that were increased in elder rats. CONCLUSION: LBP has a notable protection on rat ovarian system.
Subject(s)
Aging , Estradiol/blood , Insulin-Like Growth Factor I/analysis , Lycium/chemistry , Ovary/drug effects , Polysaccharides/pharmacology , Animals , Female , Insulin-Like Growth Factor Binding Protein 1/metabolism , Ovary/metabolism , Polysaccharides/administration & dosage , Progesterone/blood , Radioimmunoassay , Random Allocation , Rats , Rats, Sprague-Dawley , Receptors, Somatomedin/metabolismABSTRACT
High-concentration acrylate wastewater was treated by an electrocatalytic reduction process. The effects of the cation exchange membrane (CEM) and cathode materials on acrylate reduction were investigated. It indicated that the acrylate could be reduced to propionate acid efficiently by the electrocatalytic reduction process. The addition of CEM to separator with the cathode and anode could significantly improve current efficiency. The cathode materials had significant effect on the reduction of acrylate. The current efficiency by Pd/Nickel foam, was greater than 90%, while those by nickel foam, the carbon fibers and the stainless steel decreased successively. Toxicity of the wastewater decreased considerably and methane production rate in the biochemical methane potential (BMP) test increased greatly after the electrocatalytic reduction process.
