The reasonable disposal of plant biomass containing heavy metals (HMs) is a difficult problem for the phytoremediation technology. This review summarizes current literature that introduces various ...disposal and utilization methods (heat treatment, extraction treatment, microbial treatment, compression landfill, and synthesis of nanomaterials) for phytoremediation plants with HMs. The operation process and technical parameters of each disposal method are different. HMs can migrate and transform in different disposal processes. Some disposal and utilization methods can get some by-products. The main purpose of this paper is to provide reference for technical parameters and characteristics of various disposal and utilization methods, so as to choose and use the appropriate method for the treatment of plant biomass containing HMs after phytoremediation.
•There are various methods for the treatment of plant biomass with heavy metals.•Heavy metals can migrate and transform in different disposal processes.•The operation process and technical parameters of each disposal method are different.•Many factors should be considered in choosing a reasonable disposal method.•The combination of multiple disposal methods can be considered.
The municipal solid waste (MSW) landfill in Vientiane, Laos, which receives > 300 tons of waste daily, of which approximately 50% is organic matter, has caused serious environmental problems. This ...study was conducted to investigate the accumulated levels of heavy metals (HMs) (cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn)) in water (surface and groundwater), soil, and plants between dry and wet seasons according to the standards of the Agreement on the National Environmental Standards of Laos (ANESs), Dutch Pollutant Standards (DPSs), and the World Health Organization (WHO), respectively. Although no impact of pollution on the surface water was observed, the levels of Cr and Pb in the groundwater significantly exceeded the basics of ANESs and WHO in both seasons. The pollution caused by Cd and Cu reached the eco-toxicological risk level in the landfill soils and its vicinity. The vegetable
, which is consumed by the nearby villagers, was seriously contaminated by Cr, Pb, Cu, and Zn, as the accumulation of these toxic metals was elevated to much greater levels as compared to the WHO standards. For the grass
(elephant grass), the quantities of HMs in all plant parts were extreme, perhaps due to the deeper growth of its rhizome than
. This study is the first to warn of serious HM pollution occurring in the water, soil, and plants in the MSW landfill of Vientiane, Laos, which requires urgent phytoremediation. The indication of what sources from the MSW principally cause the pollution of HMs is needed to help reduce the toxicological risks on Lao residents and the environment in Vientiane as well.
•No clear winner in HTL of biomass can be identified so far.•Process intensification can help HTL to win.•Fast heating combined with short residence time helps increase biocrude yield of HTL.•Static ...mixing of pre-heated water with biomass solution offer high heating rates.•Key issue for HTL of biomass is to develop a plug-flow reactor.
Hydrothermal liquefaction (HTL) is a promising technology for converting wet plant biomass directly to liquid fuels and chemicals. However, some aspects of the technology are not fully understood and still disputed. The reactor material constraints and difficulties coupled with the formation of unwanted products are the main challenges limiting the applications of the technology. In addition, heat and mass transfer limitations in the reaction system result in a lower conversion efficiency and selectivity, of which the later would make it difficult and expensive for products separation, purification, and/or modification of the products. This paper discusses the challenges and current status of possible solutions to the challenges, focusing on the need of developing a special plug-flow reactor for scaling up of the HTL process.
More than 32.5 million American adults suffer from osteoarthritis, and current treatments including pain medicines and anti-inflammatory drugs only alleviate symptoms but do not cure the disease. ...Here, we have demonstrated that a biodegradable piezoelectric poly(L-lactic acid) (PLLA) nanofiber scaffold under applied force or joint load could act as a battery-less electrical stimulator to promote chondrogenesis and cartilage regeneration. The PLLA scaffold under applied force or joint load generated a controllable piezoelectric charge, which promoted extracellular protein adsorption, facilitated cell migration or recruitment, induced endogenous TGF-β via calcium signaling pathway, and improved chondrogenesis and cartilage regeneration both in vitro and in vivo. Rabbits with critical-sized osteochondral defects receiving the piezoelectric scaffold and exercise treatment experienced hyaline-cartilage regeneration and completely healed cartilage with abundant chondrocytes and type II collagen after 1 to 2 months of exercise (2 to 3 months after surgery including 1 month of recovery before exercise), whereas rabbits treated with nonpiezoelectric scaffold and exercise treatment had unfilled defect and limited healing. The approach of combining biodegradable piezoelectric tissue scaffolds with controlled mechanical activation (via physical exercise) may therefore be useful for the treatment of osteoarthritis and is potentially applicable to regenerating other injured tissues.
Momilactones A (MA) and B (MB) are the active phytoalexins and allelochemicals in rice. In this study, MA and MB were purified from rice husk of
cv. Koshihikari by column chromatography, and ...purification was confirmed by high-performance liquid chromatography, thin-layer chromatography, gas chromatography-mass spectrometry, liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS), and ¹H and
C nuclear magnetic resonance analyses. By in vitro assays, both MA and MB exerted potent inhibition on α-amylase and α-glucosidase activities. The inhibitory effect of MB on these two key enzymes was greater than that of MA. Both MA and MB exerted greater α-glucosidase suppression as compared to that of the commercial diabetic inhibitor acarbose. Quantities of MA and MB in rice grain were 2.07 ± 0.01 and 1.06 ± 0.01 µg/dry weight (DW), respectively. This study was the first to confirm the presence of MA and MB in refined rice grain and reported the α-amylase and α-glucosidase inhibitory activity of the two compounds. The improved protocol of LC-ESI-MS in this research was simple and effective to detect and isolate MA and MB in rice organs.
The COVID-19 pandemic has imposed a heavy burden on health care systems and governments. Health literacy (HL) and eHealth literacy (as measured by the eHealth Literacy Scale eHEALS) are recognized as ...strategic public health elements but they have been underestimated during the pandemic. HL, eHEALS score, practices, lifestyles, and the health status of health care workers (HCWs) play crucial roles in containing the COVID-19 pandemic.
The aim of this study is to evaluate the psychometric properties of the eHEALS and examine associations of HL and eHEALS scores with adherence to infection prevention and control (IPC) procedures, lifestyle changes, and suspected COVID-19 symptoms among HCWs during lockdown.
We conducted an online survey of 5209 HCWs from 15 hospitals and health centers across Vietnam from April 6 to April 19, 2020. Participants answered questions related to sociodemographics, HL, eHEALS, adherence to IPC procedures, behavior changes in eating, smoking, drinking, and physical activity, and suspected COVID-19 symptoms. Principal component analysis, correlation analysis, and bivariate and multivariate linear and logistic regression models were used to validate the eHEALS and examine associations.
The eHEALS had a satisfactory construct validity with 8 items highly loaded on one component, with factor loadings ranked from 0.78 to 0.92 explaining 76.34% of variance; satisfactory criterion validity as correlated with HL (ρ=0.42); satisfactory convergent validity with high item-scale correlations (ρ=0.80-0.84); and high internal consistency (Cronbach α=.95). HL and eHEALS scores were significantly higher in men (unstandardized coefficient B=1.01, 95% CI 0.57-1.45, P<.001; B=0.72, 95% CI 0.43-1.00, P<.001), those with a better ability to pay for medication (B=1.65, 95% CI 1.25-2.05, P<.001; B=0.60, 95% CI 0.34-0.86, P<.001), doctors (B=1.29, 95% CI 0.73-1.84, P<.001; B 0.56, 95% CI 0.20-0.93, P=.003), and those with epidemic containment experience (B=1.96, 95% CI 1.56-2.37, P<.001; B=0.64, 95% CI 0.38-0.91, P<.001), as compared to their counterparts, respectively. HCWs with higher HL or eHEALS scores had better adherence to IPC procedures (B=0.13, 95% CI 0.10-0.15, P<.001; B=0.22, 95% CI 0.19-0.26, P<.001), had a higher likelihood of healthy eating (odds ratio OR 1.04, 95% CI 1.01-1.06, P=.001; OR 1.04, 95% CI 1.02-1.07, P=.002), were more physically active (OR 1.03, 95% CI 1.02-1.03, P<.001; OR 1.04, 95% CI 1.03-1.05, P<.001), and had a lower likelihood of suspected COVID-19 symptoms (OR 0.97, 95% CI 0.96-0.98, P<.001; OR 0.96, 95% CI 0.95-0.98, P<.001), respectively.
The eHEALS is a valid and reliable survey tool. Gender, ability to pay for medication, profession, and epidemic containment experience were independent predictors of HL and eHEALS scores. HCWs with higher HL or eHEALS scores had better adherence to IPC procedures, healthier lifestyles, and a lower likelihood of suspected COVID-19 symptoms. Efforts to improve HCWs' HL and eHEALS scores can help to contain the COVID-19 pandemic and minimize its consequences.
Repeated bolus injections are associated with higher costs and poor compliance and can hinder the implementation of global immunization campaigns. Here, we report the development and preclinical ...testing of patches of transdermal core-shell microneedles-which were fabricated by the micromoulding and alignment of vaccine cores and shells made from poly(lactic-co-glycolic acid) with varying degradability kinetics-for the preprogrammed burst release of vaccine payloads over a period of a few days to more than a month from a single administration. In rats, microneedles loaded with a clinically available vaccine (Prevnar-13) against the bacterium Streptococcus pneumoniae induced immune responses that were similar to immune responses observed after multiple subcutaneous bolus injections, and led to immune protection against a lethal bacterial dose. Microneedle patches delivering preprogrammed doses may offer an alternative strategy to prophylactic and therapeutic protocols that require multiple injections.
Electrochemical processes have been known as a very efficient method for the industrial wastewaters treatment, especially for the removal of heavy metal ions. In this work, we would like to provide a ...method that not only effectively treats heavy metal ions but also carries out the process with a notable selectivity rate. An electrochemical cell with conductive carbon fibers cloth cathode and Platinum coated titanium panel anode (5 × 5 cm), low voltage supply energy of 10 V, and pH value of 6.8 is designed to remove Coppers, and Nickels out of the solutions contains Nickel Sulfate and Copper Sulfate (0.06 M).
There are modifications applied to the electrode to improve its conductivity and durability, the two factors that may effect directly on the efficiency of the whole process. The result we obtained shows a good and promising data with high removal efficiency (up to 97%) during the 20 h working time. Together with the removal process, the properties of electrode materials are also well investigated. With the conductive carbon cloth shows its superiority, the electrochemical cell in this work become a very versatile system. In that manner, we provide a system which is not only can treat the wastewater, but also creating energies such as hydrogen and oxygen, collecting of heavy metals in hydroxide form, and can be easily improved to a continuous process with higher efficiency and larger application.
Furthermore, the affection of electrode arrangement is carefully studied and revealed its properties, providing a chance applying the method to actual industrial purpose. With a close, medium and far distance of the two electrodes we arrange, the result of removal heavy metal ions is differently achieved (97, 96.5 and 71%). Technical problems appear during the process seems to be minor and could be solved quickly by a simple solution which will be described in the later part. However, a single effective process to treat the wastewater we introduced here is just the beginning. A continuous system which can be operated for a longer time, more effective and creating a decent amount of energies would be welcome to investigate.
•There are no additives required.•A pair of excellent electrodes was provided.•The arrangement of electrodes directly effects to the efficiency of the work.•A promising versatile electrochemical system was introduced.•There are plenty of spaces for the method to be improved.
► First study on torrefaction of stump for bioenergy application. ► Stump can achieve higher energy densification factors. ► Torrefied stump requires longer grinding time than torrefied wood.
A fixed ...bed reactor has been developed for study of biomass torrefaction, followed by thermogravimetric (TG) analyses. Norway spruce stump was used as feedstock. Two other types of biomass, poplar and fuel chips were also included in the study for comparison. Effects of feedstock types and process parameters such as torrefaction temperature and reaction time on fuel properties of torrefied solid product were investigated. The study has demonstrated that fuel properties, including heating values and grindability of the investigated biomasses were improved by torrefaction. Both torrefaction temperature and reaction time had strong effects on the torrefaction process, but temperature effects are stronger than effects of reaction time. At the same torrefaction temperature, the longer reaction time, the better fuel qualities for the solid product were obtained. However, too long reaction times and/or too higher torrefaction temperatures would decrease the solid product yield. The torrefaction conditions of 300°C for 35min resulted in the energy densification factor of 1.219 for the stump, which is higher than that of 1.162 for the poplar wood samples and 1.145 for the fuel chips. It appears that torrefied stump requires much longer time for grinding, while its particle size distribution is only slightly better than the others. In addition, the TG analyses have shown that untreated biomass was more reactive than its torrefaction products. The stump has less hemicelluloses than the two other biomass types. SEM analyses indicated that the wood surface structure was broken and destroyed by torrefaction process.
The emergence of the SARS‐CoV‐2 pandemic and airborne particulate matter (PM) pollution has led to remarkably high demand for face masks. However, conventional respirators are intended for single use ...and made from nondegradable materials, causing serious concern for a plastic‐waste environmental crisis. Furthermore, these facemasks are weakened in humid conditions and difficult to decontaminate. Herein, a reusable, self‐sustaining, highly effective, and humidity‐resistant air filtration membrane with excellent particle‐removal efficiency is reported, based on highly controllable and stable piezoelectric electrospun poly (l‐lactic acid) (PLLA) nanofibers. The PLLA filter possesses a high filtration efficiency (>99% for PM 2.5 and >91% for PM 1.0) while providing a favorable pressure drop (≈91 Pa at normal breathing rate) for human breathing due to the piezoelectric charge naturally activated by respiration through the mask. The filter has a long, stable filtration performance and good humidity resistance, demonstrated by a minimal declination in the filtration performance of the nanofiber membrane after moisture exposure. The PLLA filter is reusable via common sterilization tools (i.e., an ultrasonic cleaning bath, autoclave, or microwave). Moreover, a prototype of a completely biodegradable PLLA nanofiber‐based facemask is fabricated and shown to decompose within 5 weeks in an accelerated degradation environment.
The piezoelectric nanofibers of poly (l‐lactic acid) (PLLA) are employed to fabricate a reusable, moisture‐resistant, and highly effective facemask filter with long‐term biodegradability. The PLLA filter could offer an eco‐friendly solution to preventing the transmission of highly infectious viruses and resolving the environmental crisis caused by the massive use of current permanent plastic facemask filters.
PDF
