Experimental research on bypass evaporation tower technology for zero liquid discharge of desulfurization wastewater

<p>Zero liquid discharge (ZLD) of wastewater has become the trend of environmental governance after the implementation of ‘The Action Plan for Prevention and Treatment of Water Pollution’ in China, desulfurization wastewater has gained more attention due to its complex composition and heavy metals. However, current technologies for ZLD have some shortcomings such as high cost and insufficient processing capacity, ZLD cannot be achieved actually. This paper proposes a new evaporation drying technology. An independent bypass evaporation tower was built, part of the hot flue gas before the air preheater was introduced into the evaporation tower for desulfurization wastewater evaporation, and the generated dust after evaporation was discharged back to the flue duct before electrostatic precipitator. This paper reports on the performance of desulfurization wastewater evaporation and the characteristics of evaporation products in depth and makes a comprehensive discussion of the impact on the existing equipment based on the self-designed evaporation tower. Research suggests that this technology has high system reliability and little effect on subsequent equipment and provides theoretical and practical data. Due to environmental policies and huge market demand for ZLD of desulfurization wastewater, bypass evaporation tower technology has a great application prospect in the future.</p

Research on Wind Vector Measurement of Coherent Doppler Lidar Based on Particle Swarm Optimization Algorithm

Coherent Doppler wind Lidar (CDWL) is a lidar based meteorological detection device, mainly used to measure wind speed and direction in the atmosphere. Peak value extraction is a very important step in wind field inversion of CDWL. It is a difficult problem to extract peak value from many CDWL raw data. To solve this problem, a particle swarm optimization (PSO) algorithm is proposed in this paper to process CDWL raw data. PSO algorithm is simple and easy to implement, can be parallelized, has strong adaptability, and has excellent global search ability, fast convergence ability and strong robustness of population optimization algorithm. Therefore, the PSO algorithm has advantages in extracting Doppler peaks from large amounts of raw data. The PSO algorithm is applied to CDWL time domain simulation signal and measured data processing, compared with other peak extraction methods. The results show that the average peak accuracy of PSO algorithm reaches 0.992. Compared with the wind vector fitted by other peak extraction methods, the PSO algorithm has no error within the detection distance of 2000 meters, and can detect further and more accurate wind vectors, improving the accuracy and reliability of data analysis

Optimization of ALA-SDT for UMR-106 cells in vitro.

<p>UMR-106 cells were treated with 0–10 mM 5-ALA for 2–12 house and during the last 2-h culture, the cells were exposed to MTT for determine the optimal concentration of 5-ALA by the survival of cells. Furthermore, the cells were treated with 0–4 mM and exposed to ultrasound at 2.0 W/cm² for 5 minutes, followed by determining the survival of cells. In addition, the cells were treated with 2 mM 5-ALA for 2–12 hours and the intracellular contents of PpIX in individual groups of cells were determined longitudinally using a fluorescent microscope and spectrophotometer. Moreover, the cells were treated with 2 mM 5-ALA and then with ultrasound for 1–15 minutes, followed by determining the survival rates of cells. Finally, the cells were treated with vehicle as the Control, 2 mM 5-ALA or/and ultrasound for 7 minutes and the viability of individual groups of cells was determined by MTT. Data are representative fluorescent images or expressed as the mean ± SD of individual groups of cells from three separate experiments. A. The dose effects of 5-ALA on the survival of cells. B. The dose effect of ALA_SDT on the survival of cells. C. The fluorescent images (magnification x 400) of intracellular PpIX. D. The quantitative analysis of intracellular PpIX. E. The time effect of ALA-SDT on the survival of cells. F. The effect of ALA-SDT on the viability of cells. *P<0.05, **p<0.01 vs. the Control.</p

ALA-SDT significantly reduces the mitochondrial membrane potential (ΔψM) and promotes high levels of ROS production in UMR-106 cells.

<p>UMR-106 cells were treated, as described above, and stained with JC-1 or DCFH-DA. Subsequently, the changes in the ΔψM and ROS production in individual groups of cells were determined by fluorescent imaging and spectrophotometer. Data are representative images (magnification x400) or expressed as the means ± SD of individual groups of cells from three separate experiments. A. Fluorescent images of JC-1 staining. B. Quantitative analysis of ΔψM. C. Fluorescent images of ROS production. D. Quantitative analysis of ROS production. *P<0.05, **p<0.01 vs. the Control. #p<0.05 vs. the ultrasound alone.</p

The dynamics of 5-ALA metabolism in tumors and ALA-SDT mediated inhibition on the growth implanted osteosarcoma in mice.

<p>BALB/c nude mice were inoculated with UMR-106 cells to induce solid tumor and the tumor-bearing mice were treated with 250 mg/kg 5-ALA. The contents of generated PpIX in the tumors or surrounding tissues of individual mice were evaluated longitudinally at the indicated time points. In addition, the tumor-bearing mice were treated with vehicle alone as the Control, with 5-ALA (ALA), ultrasound or both as the ALA-SDT daily for 10 consecutive days. The volumes of tumor were monitored daily. Data are expressed as the mean ± SD of individual groups (n = 3 per group for the measurement of PpIX, n = 10 per group for measurement of in vivo tumor growth). A. The dynamics of PpIX generation in the tumor. B. The growth of implanted tumors in mice. *P<0.05, **p<0.01 vs. the Control.</p

Overlooked Role of Coexistent Hydrogen Peroxide in Activated Peracetic Acid by Cu(II) for Enhanced Oxidation of Organic Contaminants

Cu(II)-catalyzed peracetic acid (PAA) processes have shown significant potential to remove contaminants in water treatment. Nevertheless, the role of coexistent H2O2 in the transformation from Cu(II) to Cu(I) remained contentious. Herein, with the Cu(II)/PAA process as an example, the respective roles of PAA and H2O2 on the Cu(II)/Cu(I) cycling were comprehensively investigated over the pH range of 7.0–10.5. Contrary to previous studies, it was surprisingly found that the coexistent deprotonated H2O2 (HO2–), instead of PAA, was crucial for accelerating the transformation from Cu(II) to Cu(I) (kHO2–/Cu(II) = (0.17–1) × 106 M–1 s–1, kPAA/Cu(II) –1 s–1). Subsequently, the formed Cu(I) preferentially reacted with PAA (kPAA/Cu(I) = (5.84 ± 0.17) × 102 M–1 s–1), rather than H2O2 (kH2O2/Cu(I) = (5.00 ± 0.2) × 101 M–1 s–1), generating reactive species to oxidize organic contaminants. With naproxen as the target pollutant, the proposed synergistic role of H2O2 and PAA was found to be highly dependent on the solution pH with weakly alkaline conditions being more conducive to naproxen degradation. Overall, this study systematically investigated the overlooked but crucial role of coexistent H2O2 in the Cu(II)/PAA process, which might provide valuable insights for better understanding the underlying mechanism in Cu-catalyzed PAA processes

Schematic diagram of the sonication device.

<p>Schematic diagram of the sonication device.</p

ALA-SDT inhibits the proliferation and promotes the apoptosis of implanted osteosarcoma cells in vivo.

<p>The PCNA expression and the frequency of apoptotic cells in tumor sections from the different groups of mice were characterized by immunohistochemistry and TUNEL assays, respectively. Data are representative images (magnification x 400) or expressed as the mean % ± SD of in individual groups of tumors (n = 10 per group). A. Immunohisochemsitry for PCNA expression. B. Quantitative analysis of the frequency of PCNA+ tumor cells. C> The TUNEL analysis of apoptotic cells in the tumors. D. The Quantitative analysis of apoptotic tumor cells. *P<0.05, **p<0.01 vs. the Control. #p<0.05 vs. the ultrasound alone.</p

ALA-SDT induces osteosarcoma cell apotosis in vitro.

<p>UMR-106 cells were treated with vehicle (Control), 2 mM 5-ALA or/and ultrasound for 7 minutes, cultured for 6 hours and the percentages of apoptotic cells were determined by flow cytometry. In addition, the cells damages of individual groups of cells were characterized by TEM. Data are representative images of individual groups of cells from three separate experiments. A. Flow cytometry analysis of apoptotic cells. B. TEM analysis of cell damages (Magnification×20000). The white arrows indicate apoptotic bodies.</p

Immunohistochemsitry analysis of the levels of apoptosis-related regulators in the tumors.

<p>The levels of BcL-2, Bax, p53 and caspase 3 expression in the tumor sections from the different groups of mice were characterized by immunohistochemistry. Data are representative images (magnification x 200) or expressed as the mean ± SD of the IOD from the different groups of mice (n = 10 per group). A. Immunohisochemsitry analysis. B. Quantitative analysis of the IOD values. *P<0.05, **p<0.01 vs. the Control. #p<0.05 vs. the ultrasound alone.</p