New insights on destruction mechanisms of waste activated sludge during simultaneous thickening and digestion process via forward osmosis membrane.

This study delved into the efficacy of sludge digestion and the mechanisms involved in sludge destruction during the implementation of forward osmosis process for sludge thickening and digestion (FO-MSTD). Utilizing a lab-scale FO membrane reactor for the thickening and digestion of waste activated sludge (WAS), the investigation explored the effects of sludge thickening and digestion in FO-MSTD processes using draw solutions of varying concentrations. The findings underscored the significance of hydraulic retention time (HRT) as a pivotal parameter influencing the swift thickening or profound digestion of sludge. Consequently, tailoring the HRT to specific processing objectives emerged as a key strategy for achieving desired treatment outcomes. In the investigation, the use of a 1 M NaCl draw solution in the FO-MSTD process showcased enhanced thickening and digestion capabilities. This specific setup raised the concentration of mixed liquor suspended solids (MLSS) to over 30 g/L and achieved a 42.7% digestion efficiency of mixed liquor volatile suspended solids (MLVSS) within an operational timeframe of 18 days. Furthermore, the research unveiled distinct stages in the sludge digestion process of the FO-MSTD system, characterized by fully aerobic digestion and aerobic-local anaerobic co-existing digestion. In the fully aerobic digestion stage, the sludge digestion rate exhibited a steady increase, leading to the breakdown of sludge floc structures and the release of a substantial amount of nutrients into the sludge supernatant. The predominant microorganisms during this stage were typical functional microorganisms found in wastewater treatment systems. Transitioning into the aerobic-local anaerobic co-existing digestion stage, both MLSS concentration and MLVSS digestion efficiency continued to rise, accompanied by a decreasing dissolved oxygen (DO) concentration. More organic matter was released into the supernatant, and sludge microbial flocs tended to reaggregate. The localized anaerobic environment within the FO-MSTD reactor fostered an increase in the relative abundance of bacteria with nitrogen and phosphorus removal functions, thereby positively impacting the mitigation of total nitrogen (TN) and total phosphorus (TP) concentrations in the sludge supernatant. The results of this research enhance comprehension of the advanced FO-MSTD technology in the treatment of WAS.

Integrating anaerobic acidification with two-stage forward osmosis concentration for simultaneously recovering organic matter, nitrogen and phosphorus from municipal wastewater.

In order to meet the demand of municipal wastewater for low-carbon treatment and resource recovery, a novel process of anaerobic acidification membrane bioreactor (AAMBR) assisted with a two-stage forward osmosis (FO) (FO-AAMBR-FO) was developed for simultaneously recovering organic matter and nutrients from municipal wastewater. The results indicated that the first FO process concentrated the municipal wastewater to one tenth of the initial volume. The corresponding chemical oxygen demand (COD), ammonia nitrogen (NH4+-N) and total phosphorus (TP) concentration reached up to 2800, 200 and 33 mg/L, respectively. Subsequently, the AAMBR was operated at pH value of 10 for treating the concentration of municipal wastewater, in which the organic matter was successfully converted to acetic acid and propionic acid with a total volatile fatty acids (VFAs) concentration of 1787 mg COD/L and a VFAs production efficiency of 62.36 % during 47 days of stable operation. After that, the NH4+-N and TP concentration in the effluent of the AAMBR were further concentrated to 175 and 36.7 mg/L, respectively, by the second FO process. The struvite was successfully recovered with NH4+-N and TP recovery rate of 94.53 % and 98.59 %, respectively. Correspondingly, the VFAs, NH4+-N and TP concentrations in the residual solution were 2905 mg COD/L, 11.8 and 7.92 mg/L, respectively, which could be used as the raw material for the synthesis of polyhydroxyalkanoate (PHA). Results reported here demonstrated that the FO-AAMBR-FO is a promising wastewater treatment technology for simultaneous recovery of organic matter (in form of VFAs) and nutrients (in form of struvite).

[Effect of oral administration of icariin on periodontitis associated alveolar bone resorption in an osteoporosis mouse model].

PURPOSE: To study the effect of oral administration of icariin (ICA) on periodontitis associated alveolar bone resorption in an osteoporosis mouse model. METHODS: Three-month old, female C57BL/6J mice were randomly divided into 3 groups: normal group (SHAM), ovariectomy + oral smearing of Porphyromonas gingivalis (Pg) + icariin group (OVX+Pg+ICA), ovariectomy+ Pg group (OVX+Pg). On the second week, the mice underwent ovariectomy to induce osteoporosis. On the fourth week, the mice were treated with Pg by oral smearing for 1 week, 1 time/day. The samples were harvested on the 12th week: the left mandibles were harvested to make the sections and histological staining, to analyze the differences of bone resorption areas among the three groups; the right mandibles were harvested for methylene blue staining, to analyze the differences of bone resorption depth among the three groups. Protein from the periodontal tissues were extracted to analyze the differences of osteoblastic related protein expression level among the three groups. SPSS 16.0 software package was used for statistical analysis. RESULTS: Histological analysis of murine femurs and periodontal tissues demonstrated that the model of periodontitis in osteoporosis mice was successfully created in this study. Quantification of the histological staining showed that compared with OVX+Pg group, icariin treatment decreased the depth of CEJ-ABC and the areas of alveolar bone resorption(P＜0.05); Western blot results showed icariin treatment could significantly increase the protein expression level of Runx2, OSX, OCN and OPN in periodontal tissues(P＜0.05). CONCLUSIONS: Icariin treatment can effectively prevent both bone loss in osteoporosis and alveolar bone resorption induced by periodontitis.

Enhanced phosphorus and ciprofloxacin removal in a modified BAF system by configuring Fe-C micro electrolysis: Investigation on pollutants removal and degradation mechanisms.

A modified biological aerated filter (BAF) system configured Fe-C micro electrolysis was applied to enhance phosphorus and ciprofloxacin (CIP) removal. A novel sludge ceramic and sintering ferric-carbon ceramic (SFC) were separately packed into a lab-scale BAF and Fe-C micro electrolysis reactor. The BAF and Fe-C micro electrolysis coupled system was operated about 230days. The enhancement of phosphorus and ciprofloxacin removals by Fe-C micro electrolysis, the degradation mechanisms of CIP and the variations of microbial population were investigated. The removal efficiencies of chemical oxygen demand (CODcr), ammonia (NH4-N), total phosphorus (TP) and CIP reached about 95%, 95%, 80% and 85% in the combined process, respectively. Configuring Fe-C micro electrolysis significantly enhanced phosphorus and CIP removal, whereas had no promotion on N removal. Four main degradation pathways were proposed according to the LC-MS analysis. More than 12 degradation products were detected through the treatment of Fe-C micro electrolysis and only 3 biodegraded products with low concentration were identified in BAF effluent. The high-throughput sequencing analysis showed that the microbial community changed a lot under CIP pressure. The relative abundance of Sphingomonadaceae, Xanthomonadaceae, Bradyrhizobium, Helicobacter and Pseudomonas increased with CIP influent. This study provides a promising process in CIP wastewater treatment.

Chemical characterization of Lycium barbarum polysaccharides and their reducing myocardial injury in ischemia/reperfusion of rat heart.

Polysaccharides were extracted from Lycium barbarum fruits in this work. Fourier transform infrared spectroscopy (FT-IR) and high-performance liquid chromatography (HPLC) have been employed to characterize this polysaccharides in the present study. The results of chemical composition indicated that the L. barbarum polysaccharides were composed of two kinds of monosaccharides, namely glucose and fructose in molar ratios of 1:2.1. The results indicated that the glucose and fructose were the predominant monosaccharides. IR spectrum of L. barbarum polysaccharides revealed a typical peaks of polysaccharides. The results still showed that L. barbarum polysaccharides significantly decreased the myocardium LD level, increased Na(+)-K(+)-ATPase and Ca(2+)-ATPase activities in heart ischemia reperfusion (IR) rats. In addition, L. barbarum polysaccharides still markedly decreased myocardium Bax positive rate and myocardial cell apoptosis and increased Bcl-2 positive rate in a dose-dependent manner. It may be concluded that administration of L. barbarum polysaccharides can prevented the development of cardiovascular diseases.