In this paper, a series of bio-adsorbents (LR-NaOH, LR-Na2CO3 and LR-CA) were successfully prepared by modifying Licorice Residue with NaOH, Na2CO3 and citric acid, which were used as the adsorbents to remove Cu2+ from wastewater. The morphology and structure of bio-adsorbents were characterized by Fourier Transform Infrared, SEM, TG and XRD. Using static adsorption experiments, the effects of the adsorbent dosage, the solution pH, the adsorption time, and the initial Cu2+ concentration on the adsorption performance of the adsorbents were investigated. The results showed that the adsorption process of Cu2+ by the bio-adsorbents can be described by pseudo-second order kinetic model and the Langmuir model. The surface structure of the LR-NaOH, LR-Na2CO3 and LR-CA changed obviously, and the surface-active groups increased. The adsorption capacity of raw LR was 21.56 mg/g, LR-NaOH, LR- Na2CO3 significantly enhanced this value up to 43.65 mg/g, 43.55 mg/g, respectively. After four adsorption-desorption processes, the adsorption capacity of LR-NaOH also maintained about 73%. Therefore, LR-NaOH would be a promising adsorbent for removing Cu2+ from wastewater, and the simple strategy towards preparation of adsorbent from the waste residue can be as a potential approach using in the water treatment.
Humans are susceptible to influenza. The influenza virus spreads quickly and behave seasonally. The seasonality and spread of influenza are often associated with meteorological factors and have spatio-temporal differences. Based on the influenza cases and daily average meteorological factors in Lanzhou from 2014 to 2017, this study firstly aimed to analyze the characteristics of influenza incidence in Lanzhou and the impact of meteorological factors on influenza activities. Then, SARIMA(X) models for the prediction were established. The influenza cases in Lanzhou from 2014 to 2017 was more male than female, and the younger the age, the higher the susceptibility; the epidemic characteristics showed that there is a peak in winter, a secondary peak in spring, and a trough in summer and autumn. The influenza cases in Lanzhou increased with increasing daily pressure, decreasing precipitation, average relative humidity, hours of sunshine, average daily temperature and average daily wind speed. Low temperature was a significant driving factor for the increase of transmission intensity of seasonal influenza. The SARIMAX (1,0,0)(1,0,1)[12] multivariable model with average temperature has better prediction performance than the university model. This model is helpful to establish an early warning system, and provide important evidence for the development of influenza control policies and public health interventions.
A series of hydrogels as biosorbents to remove heavy metal ions (Pb2+, Cu2+, and Cd2+) were prepared using Radix Isatidis residues as material grafted with acrylic acid and acrylamide. The surfaces of Radix Isatidis residue/acrylic acid-co-acrylamide (RIR/AA-co-AM), Radix Isatidis residue/polyacrylamide (RIR/PAM3), and Radix Isatidis residue/polyacrylic acid (RIR/PAA4) hydrogels have a sponge-like, three-dimensional, and highly microporous structure. The hydrogels all have considerable swelling properties and the swelling rate of RIR/PAA4 is the highest at 9240%. The hydrogels all possess high adsorptivity to Pb2+, Cu2+, and Cd2+. Under optimized conditions, the maximum adsorption capacity of RIR/AA-co-AM hydrogel is 655.4 mg/g for Pb2+, 367.2 mg/g for Cd2+, and 290.5 mg/g for Cu2+. The maximum adsorption capacity of RIR/AA-co-AM hydrogel for Cd2+ and Cu2+ is slightly lower than that of RIR/PAA4. In addition, the adsorption process of RIR/AA-co-AM for heavy metal ions conforms with the pseudo-second-order kinetic equation and Langmuir adsorption isotherm. Based on the microstructure analysis and adsorption kinetics, electrostatic adsorption and ion exchange are identified as the mechanisms for the hydrogels removal of heavy metal ions from water. It infers that hydrogels from Chinese herb residue can be used to effectively remove heavy metals from wastewater and improve the reutilization of Chinese herb residue.
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