Process optimization to enhance utilization efficiency of precipitants for chloride removal from flue gas desulfurization wastewater via Friedel's salt precipitation.

The treatment cost for Cl- removal by Friedel's salt precipitation depended significantly on utilization rate of the precipitant aluminate. In this study, effects of Ca/Al molar ratio, reaction time, temperature and Al/Cl molar ratio were investigated to maximize Al utilization rate for Cl- removal from flue gas desulfurization wastewater. Batch results showed that the maximum Al utilization rate of 55.8-60.3% was obtained at Ca/Al ratio of 3.00, reaction time of 90 min, temperature of 35 °C and Al/Cl ratio of 0.50 regardless of the initial Cl- concentration. The precipitate obtained at the highest Al utilization rate had the highest interlayer spacing, the best crystal integrity, and the strongest binding energy of the Al-OH bond. The optimized condition made ion exchange between Cl- and OH- easier, and obtained more stable Friedel's salt structure to adsorb Cl-. Pilot-scale results showed that maximizing Al utilization rate with low dosages of precipitants had insignificant effects on the removal of Mg2+, Ca2+ and sulfate compared to the strategy to maximize Cl-, but enhanced Al utilization rate from 38.2% to 56.4%. Economic analysis showed that enhancing Al utilization rate greatly reduced treatment cost of the Friedel's salt precipitation method by 30.5%, and made the two-stage desalination process more feasible and worth popularizing.

A two-stage desalination process for zero liquid discharge of flue gas desulfurization wastewater by chloride precipitation.

A two-stage desalination process was developed to achieve zero liquid discharge (ZLD) of flue gas desulfurization (FGD) wastewater by precipitating chloride as Friedel's salt. Influential factors for Friedel's salt precipitation, including dosage, reaction time, concentration of sulfate, were investigate by batch tests. Batch results showed that at calcium to aluminum molar ratio of 3.0, the optimal chloride removal and the highest crystallinity of Friedel's salt were obtained. Sulfate impeded Friedel's salt precipitation by competitive inhibition mechanism, and thus calcium sulfate removal was designed in advance of chloride removal. Batch results and long-term results of bench-scale experiments showed that magnesium and part of sulfate were effectively removed by lime addition in Stage I of the proposed process, and then the remaining sulfate and 48.1 % of chloride were precipitated as ettringite and Friedel's salt in Stage II. The effluent of the two-stage process was alkaline with low turbidity, and had considerable desulfurization capacity. Techno-economic evaluation showed that the two-stage process is technically feasible, economically viable and environmentally friendly technology for ZLD of FGD wastewater.

Pelvic plexus block to provide better anesthesia in transperineal template-guided prostate biopsy: a randomised controlled trial.

BACKGROUND: To evaluate the efficacy of pelvic plexus block (PPB) in relief pain during transperineal template-guided prostate biopsy (TTPB), compared with conventional periprostatic nerve block (PNB). METHODS: From July 2016 to August 2017, 245 patients who were performed TTPB in Clinical Medical College of Yangzhou University were recruited. The patients were randomized into three groups using a random number table. Group-1 received prostate capsule local anesthesia with 22 ml of 1% lidocaine. Group-2 additionally received PNB on the basis of Group-1. To perform PNB, 5 ml 1% lidocaine was injected into the region of prostatic neurovascular bundle situated in the angle of prostate-bladder-seminal vesicle. Group-3 received prostate capsule local anesthesia plus PPB (5 ml of 1% lidocaine injection into the pelvic plexus which located on lateral to the bilateral seminal vesicle apex). The patients' pain and satisfaction were evaluated by visual analogue scale and visual numerical scale, respectively. RESULTS: The age, total prostate volume, PSA and the number of cores were comparable among the three groups. The visual analog scale scores of group-3 were significantly lower than group-2 during biopsy (P = 0.003). Conversely, the visual numeric scale scores were higher in group-3 (P = 0.039). Both the group-2 and group-3 outperformed the group-1 in alleviating pain and had a higher quantification of satisfaction. There were no significant differences in the pain scores or the satisfaction scores at 30 min after the procedure among the three groups. CONCLUSIONS: The analgesic efficacy of PPB guided by Doppler ultrasound in TTPB was better than that of PNB and both were superior to no nerve block. TRIAL REGISTRATION: ChiCTR-IOR-17013533 , 01/06/2016.

Effect of Atmospheric PM2.5 on Expression Levels of NF-κB Genes and Inflammatory Cytokines Regulated by NF-κB in Human Macrophage.

Exposure to PM2.5 induces systemic inflammation, and the NF-κB signaling pathway plays an important role in the inflammation process. We aim to clarify whether the expression of NF-κB gene family affects inflammation caused by PM2.5. Human monocytic cells (THP-1) were induced to differentiate into macrophages using phorbol myristate acetate. The macrophages were then treated with 100, 200, and 400 µg/ml of PM2.5 for 12, 24, and 48 h, respectively. Then, we determined the survival rate of macrophages through the MTT assay. The TNF-α and CRP levels in the cell culture medium were measured through enzyme-linked immunosorbent assay. The NF-κB1, NF-κB2, RelA, RelB, and Rel mRNA levels in macrophages were measured with reverse transcriptase-polymerase chain reaction. As a consequence, the survival rate of macrophages decreased with increasing PM2.5 exposure time and dose. The TNF-α levels in PM2.5-treated groups were lower as compared with the control group and in contrast to the NF-κB mRNA levels at all exposure times. The TNF-α level in the 400-µg/ml group and the NF-κB1, NF-κB2, RelB, and Rel mRNA levels in all PM2.5-treated groups were found to be higher at 24 h than at 12 h. Furthermore, the TNF-α, CRP, and NF-κB2 mRNA levels in the group treated with 400 µg/ml PM2.5 were higher at 48 h that at 12 and 24 h. On the other hand, the NF-κB1, RelA, RelB, and Rel mRNA levels in all PM2.5-treated groups were lower as compared to levels of TNF-α, CRP, and NF-κB2 mRNA. The levels of NF-κB genes and inflammatory cytokines demonstrated different correlations at different exposure times. Therefore, we conclude that PM2.5 reduces the survival rate of macrophages. As macrophages are exposed to PM2.5, the NF-κB gene family expression is increased, which subsequently affects inflammatory factor levels.

Caffeine and dithiothreitol delay ovine oocyte ageing.

The intracellular glutathione levels and developmental competence of aged oocytes after parthenogenetic activation, somatic cell nuclear transfer and intracytoplasmic sperm injection in the presence or absence of caffeine or dithiothreitol (DTT) were examined. The following results were found: (1) ovine oocytes were fully aged 30 h post-onset of maturation culture; (2) the appropriate concentrations of caffeine and DTT for oocyte culture were 5 mM and 1 mM, respectively; (3) when nuclear transfer-reconstructed embryos were treated with caffeine or DTT following fusion, no increase in the frequency of development to blastocyst was observed (P > 0.05), but the cell numbers of blastocysts increased (P < 0.05); (4) both caffeine and DTT increased the blastocyst formation rates of intracytoplasmic sperm-injected embryos (P < 0.05); (5) caffeine increased the glutathione content of aged oocytes (P < 0.05). The glutathione content of DTT-treated aged oocytes was higher than that of oocytes matured for 36 h (P < 0.05). In conclusion, caffeine and dithiothreitol delay oocyte ageing but only to a limited extent.