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This review provides a brief overview of the potential applications of hydrochar and its derivatives. It first summarized the key processes of hydrothermal carbonization (HTC) of ...biomass and basic properties of the resulting hydrochar. Most of the efforts of this review is then on reviewing the potential applications of hydrochar in various fields including environment, energy, adsorbent and medical applications. It also discusses different modification and activation methods to produce hydrochar-based engineered carbon materials for enhanced performances in those applications, particularly with respect to their application as low-cost adsorbents for the removal of heavy metals, organics, phosphate and pathogens.
In this work, a novel approach was developed to prepare an engineered biochar from KMnO4 treated hickory wood through slow pyrolysis (600°C). Characterization experiments with various tools showed ...that the engineered biochar surface was covered with MnOx ultrafine particles. In comparison to the pristine biochar, the engineered biochar also had more surface oxygen-containing functional groups and much larger surface area. Batch sorption experiments showed that the engineered biochar had strong sorption ability to Pb(II), Cu(II), and Cd(II) with maximum sorption capacities of 153.1, 34.2, and 28.1mg/g, respectively, which were significantly higher than that of the pristine biochar. Batch sorption experiments also showed that the dosage, initial solution pH, and ionic strength affected the removal of the heavy metals by the biochars. The removal of the metals by the engineered biochar was mainly through surface adsorption mechanisms involving both the surface MnOx particles and oxygen-containing groups.
•Higher temperatures produced higher thermal stability biochars.•Production method showed strong effect on biochar properties.•Biochars showed no statistically significant effects on plant.
This work ...explored the effect of temperature, production method, and feedstock type on the physicochemical and biological properties of biochars and hydrochars. Biochars and hydrochars made at lower temperatures had higher production rates. Higher pyrolysis temperatures not only increased carbon content of biochars but also produced higher thermal stability biochars that did not start to decompose in air after 400–450°C. The production method showed strong effect on biochar properties. Compared to the dry-pyrolysis biochars derived from the same feedstocks, the hydrochars had more acidic pH values and lower carbon contents. The results showed that feedstock types could also influence characteristics of the biochars. None of the chars showed statistically significant effects on plant seed germination and seedling growth and thus could be used as soil amendments. Our findings indicated that biochars with different properties could be developed by changing production conditions to better satisfy their environmental applications.
Background. Human cytomegalovirus (HCMV) is the major viral etiology of congenital infection and birth defects. Fetal transmission is high (30%-40%) in primary maternal infection, and symptomatic ...babies have permanent neurological, hearing, and vision defects. Recurrent infection is infrequently transmitted (2%) and largely asymptomatic. Congenital infection is also associated with intrauterine growth restriction (IUGR). Methods. To investigate possible underlying HCMV infection in cases of idiopathic IUGR, we studied maternal and cord sera and placentas from 19 pregnancies. Anti-HCMV antibodies, hypoxia-related factors, and cmvIL-10 were measured in sera. Placental biopsy specimens were examined for viral DNA, expression of infected cell proteins, and pathology. Results. Among 7 IUGR cases, we identified 2 primary and 3 recurrent HCMV infections. Virus replicated in glandular epithelium and lymphatic endothelium in the decidua, cytotrophoblasts, and smooth muscle cells in bloodvessels of floating villi and the chorion. Large fibrinoids with avascular villi, edema, and inflammation were significantly increased. Detection of viral proteins in the amniotic epithelium indicated transmission in 2 cases of IUGR with primary infection and 3 asymptomatic recurrent infections. Conclusions. Congenital HCMV infection impairs placental development and functions and should be considered as an underlying cause of IUGR, regardless of virus transmission to the fetus.
•MgFe-LDH particles were incorporated into wheat-straw biochar.•Biochar/MgFe-LDH composite showed a strong sorption ability to nitrate.•Biochar/MgFe-LDH composite showed a high selectivity for ...nitrate.•Adsorbent dosage of 5–10g/L was the optimum for nitrate removal.
Mg–Fe layered double hydroxide (MgFe-LDH) particles were incorporated into wheat-straw biochar by liquid-phase deposition. The obtained biochar/MgFe-LDH composite was used to remove nitrate from aqueous solutions. X-ray diffraction patterns demonstrated that LDH particles were successfully deposited onto the carbon surface within the biochar matrix. Adsorption kinetic and isotherm studies and the effects of co-existing anions and adsorbents dosages were investigated using laboratory batch sorption experiments. The biochar/MgFe-LDH composite showed a strong sorption ability to nitrate in aqueous solutions with the Langmuir maximum adsorption capacity of 24.8mg/g. A high selectivity for nitrate of the biochar/MgFe-LDH composite was also observed irrespective of the co-existence of sulfate and phosphate. The biochar/MgFe-LDH composite can thus be potentially used as an alternative adsorbent for the treatment of nitrate-contaminated waters as well as a soil amendment for the reduction of soil nitrate leaching.
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•Invasive plants can be used as pyrolysis feedstock for valued added products.•AP and BP showed similar biochar yields to traditional pyrolysis feedstock.•Biochar production decreases with increasing ...of pyrolysis temperature.•Minimum residence time is linearly correlated with feedstock weight.
In this work, the potential of invasive plant species as feedstock for value-added products (biochar and bioenergy) through pyrolysis was investigated. The product yield rates of two major invasive species in the US, Brazilian Pepper (BP) and Air Potato (AP), were compared to that of two traditional feedstock materials, water oak and energy cane. Three pyrolysis temperatures (300, 450, and 600°C) and four feedstock masses (10, 15, 20, and 25g) were tested for a total of 12 experimental conditions. AP had high biochar and low oil yields, while BP had a high oil yield. At lower temperatures, the minimum feedstock residence time for biochar and bioenergy production increased at a faster rate as feedstock weight increased than it did at higher temperatures. A simple mathematical model was successfully developed to describe the relationship between feedstock weight and the minimum residence time.
Hickory and peanut hydrochars were chemically activated with KOH and H
3
PO
4
and tested for their ability to remove methylene blue and lead from aqueous solutions. The physicochemical ...characteristics of the activated hydrochars determined were surface area, pore volume, and elemental composition. Kinetics and isotherm studies were then conducted on methylene blue adsorption. Compared to their nonactivated counterparts, the chemically activated hydrochars had higher surface areas and more functional groups. Activated hydrochars also had greater methylene blue and lead adsorption rates, which can be attributed to the improved physicochemical characteristics. H
3
PO
4
activated hydrochars removed more contaminants than the corresponding KOH ones.
Biochar is mainly used as a soil amendment and for carbon sequestration; while other applications such as environmental remediation may be equally important. Recently, different engineering methods ...have been developed and used to expand biochar's applications. A systematic literature review on the linkages between the production methods and applications of engineered biochar, therefore, is in critical need. In this work, the production and application prospects of engineered biochar are reviewed comprehensively based on the current literature. The application values and effect of engineered biochar in energy, environment, and agriculture are also expounded. Different from previous ones, this review is more focused on the unique properties and functions of various types of engineered biochars to explain their potential application, particularly environmental application. It not only summarizes recent advances in engineered biochar technology but also offers insights on new directions for development and research of engineered biochar in the future.
Abstract Congenital human cytomegalovirus (HCMV) infection is a major viral cause of birth defects, including microcephaly, neurological deficits, loss of hearing and vision, and intrauterine growth ...restriction. Despite its public health significance, there is no approved treatment for congenital infection during pregnancy; existing antivirals have unacceptable toxicities. The mechanisms of HCMV-induced placental injury, reduced capacity for compensatory development and transmission to the fetus are poorly understood, limiting the development of alternative strategies for clinical management of the disease. Recently, self-renewing, multipotent trophoblast progenitor cells (TBPCs) were reported to reside in the chorion of the human placenta and differentiate into the mature trophoblast subtypes – transport syncytiotrophoblasts and invasive cytotrophoblasts – forming chorionic villi, the functional units of the placenta. HCMV infects TBPCs, reducing the population of progenitor cells and their functional capacity to self-renew, migrate and differentiate. Human TBPCs and chorionic villus explants from first trimester represent relevant models for evaluating efficacies of new antiviral agents in protecting and restoring growth of the developing placenta in response to adverse conditions. Correlating pathology from complications of congenital HCMV infection with impaired development in the tissue environment of anchoring villus explants and defects in TBPC differentiation may enable identification of molecular pathways that could serve as targets for intervention. Here we summarize studies that could open up novel avenues of research on potential therapeutics to sustain placental development, promote differentiation and improve function and pregnancy outcomes.
We investigated human cytomegalovirus pathogenesis by comparing infection with the low-passage, endotheliotropic strain VR1814 and the attenuated laboratory strain AD169 in human placental villi as ...explants in vitro and xenografts transplanted into kidney capsules of SCID mice (ie, mice with severe combined immunodeficiency). In this in vivo human placentation model, human cytotrophoblasts invade the renal parenchyma, remodel resident arteries, and induce a robust lymphangiogenic response. VR1814 replicated in villous and cell column cytotrophoblasts and reduced formation of anchoring villi in vitro . In xenografts, infected cytotrophoblasts had a severely diminished capacity to invade and remodel resident arteries. Infiltrating lymphatic endothelial cells proliferated, aggregated, and failed to form lymphatic vessels. In contrast, AD169 grew poorly in cytotrophoblasts in explants, and anchoring villi formed normally in vitro . Likewise, viral replication was impaired in xenografts, and cytotrophoblasts retained invasive capacity, but some partially remodeled blood vessels incorporated lymphatic endothelial cells and were permeable to blood. The expression of both vascular endothelial growth factor (VEGF)-C and basic fibroblast growth factor increased in VR1814-infected explants, whereas VEGF-A and soluble VEGF receptor-3 increased in those infected with AD169. Our results suggest that viral replication and paracrine factors could undermine vascular remodeling and cytotrophoblast-induced lymphangiogenesis, contributing to bleeding, hypoxia, and edema in pregnancies complicated by congenital human cytomegalovirus infection.
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