Sorption of heavy metals on chitosan-modified biochars and its biological effects.
TL;DR: In this article, chitosan-modified biochars were synthesized in efforts to produce a low-cost adsorbent for heavy metal environmental remediation, and the results showed that the coating of chitosa on biochar surfaces could improve its performance as a soil amendment or an adorbent.
About: This article is published in Chemical Engineering Journal.The article was published on 2013-09-01. It has received 309 citations till now. The article focuses on the topics: Biochar & Sorption.
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TL;DR: In this paper, a review of the preparation, characterization, modification, and especially environmental application of biochar, based on more than 200 papers published in recent 10 year, to provide an overview of Biochar with a particular on its environmental application.
1,017 citations
TL;DR: Modification to produce engineered/designer biochar is likely to enhance the sorption capacity of biochar and its potential applications for environmental remediation.
905 citations
TL;DR: This work provides a comprehensive review of recent research on various carbon adsorbents in terms of their surface functional groups and the associated removal behaviors and performances to heavy metals in aqueous solutions.
697 citations
TL;DR: The various synthesis techniques for biochar-based nano-composites and their effects on the decontamination of wastewater are reviewed and the characteristic and advantages of existing synthesis methods are summarized and discussed.
622 citations
TL;DR: In this article, the effect of temperature, production method, and feedstock type on physicochemical and biological properties of biochars and hydrochars was explored, and the results showed that feedstock types could also influence characteristics of the bio-chars.
591 citations
Cites background from "Sorption of heavy metals on chitosa..."
...In addition, many researchers have found that biochar can beused as an alternative adsorbent to remove different kinds of contaminants, including heavymetals, nutrients, and pharmaceuticals, from aqueous solutions [2–5]....
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References
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TL;DR: The application of bio-char (charcoal or biomass-derived black carbon (C)) to soil is pro- posed as a novel approach to establish a significant, long-term, sink for atmospheric carbon dioxide in terrestrial ecosystems.
Abstract: The application of bio-char (charcoal or biomass-derived black carbon (C)) to soil is pro- posed as a novel approach to establish a significant, long-term, sink for atmospheric carbon dioxide in terrestrial ecosystems. Apart from positive effects in both reducing emissions and increasing the sequestration of greenhouse gases, the production of bio-char and its application to soil will deliver im- mediate benefits through improved soil fertility and increased crop production. Conversion of biomass C to bio-char C leads to sequestration of about 50% of the initial C compared to the low amounts retained after burning (3%) and biological decomposition (<10-20% after 5-10 years), therefore yielding more stable soil C than burning or direct land application of biomass. This efficiency of C conversion of biomass to bio-char is highly dependent on the type of feedstock, but is not significantly affected by the pyrolysis temperature (within 350-500 ◦ C common for pyrolysis). Existing slash-and- burn systems cause significant degradation of soil and release of greenhouse gases and opportunies may exist to enhance this system by conversion to slash-and-char systems. Our global analysis revealed that up to 12% of the total anthropogenic C emissions by land use change (0.21 Pg C) can be off-set annually in soil, if slash-and-burn is replaced by slash-and-char. Agricultural and forestry wastes such as forest residues, mill residues, field crop residues, or urban wastes add a conservatively estimated 0.16 Pg C yr −1 . Biofuel production using modern biomass can produce a bio-char by-product through pyrolysis which results in 30.6 kg C sequestration for each GJ of energy produced. Using published projections of the use of renewable fuels in the year 2100, bio-char sequestration could amount to 5.5-9.5 Pg C yr −1 if this demand for energy was met through pyrolysis, which would exceed current emissions from fossil fuels (5.4 Pg C yr −1 ). Bio-char soil management systems can deliver tradable C emissions reduction, and C sequestered is easily accountable, and verifiable.
2,553 citations
01 Jan 2009
TL;DR: In this article, Flannery presented a Biochar Classification and Test Methods for determining the quantity of Biochar within Soils and its effect on Nutrient Transformations and Nutrient Leaching.
Abstract: Preface Foreword by Tim Flannery 1. Biochar for Environmental Management: An Introduction 2. Physical Properties of Biochar 3. Characteristics of Biochar: Microchemical Properties 4. Characteristics of Biochar: Organo-chemical Properties 5. Biochar: Nutrient Properties and Their Enhancement 6. Characteristics of Biochar: Biological Properties 7. Developing a Biochar Classification and Test Methods 8. Biochar Production Technology 9. Biochar Systems 10. Changes of Biochar in Soil 11. Stability of Biochar in Soil 12. Biochar Application to Soil 13. Biochar and Emissions of Non-CO2 Greenhouse Gases from Soil 14. Biochar Effects on Soil Nutrient Transformations 15. Biochar Effects on Nutrient Leaching 16. Biochar and Sorption of Organic Compounds 17. Test Procedures for Determining the Quantity of Biochar within Soils 18. Biochar, Greenhouse Gas Accounting and Emissions Trading 19. Economics of Biochar Production, Utilization and Greenhouse Gas Offsets 20. Socio-economic Assessment and Implementation of Small-scale Biochar Projects 21. Taking Biochar to Market: Some Essential Concepts for Commercial Success 22. Policy to Address the Threat of Dangerous Climate Change: A Leading Role for Biochar Index
1,967 citations
"Sorption of heavy metals on chitosa..." refers background in this paper
...Although it is still unclear whether the C/N ratio criterion is directly applicable to biochars, which do not decompose at the same rate as other amendment, applications of biochars with higher C/N ratios may lead to lower N uptake [22]....
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...The C/N ratios of the as-is biochars in this study are between 97 and 539 whereas a good soil amendment should have a C/N ratio lower than 20; otherwise, it may cause N deficiency of plants [22]....
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TL;DR: The potential to sequester carbon as thermally stabilized (charred) biomass using existing organic resource is estimated to be at least 1 Gt/yr − 1 and biochar, defined by its useful application to soil, is expected to provide a benefit from enduring physical and chemical properties.
Abstract: Agricultural activities and soils release greenhouse gases, and additional emissions occur in the conversion of land from other uses. Unlike natural lands, active management offers the possibility to increase terrestrial stores of carbon in various forms in soil. The potential to sequester carbon as thermally stabilized (charred) biomass using existing organic resource is estimated to be at least 1 Gt yr − 1 and “biochar,” defined by its useful application to soil, is expected to provide a benefit from enduring physical and chemical properties. Studies of charcoal tend to suggest stability in the order of 1000 years in the natural environment, and various analytical techniques inform quantification and an understanding of turnover processes. Other types of biochar, such as those produced under zero-oxygen conditions have been studied less, but costs associated with logistics and opportunity costs from diversion from energy or an active form in soil demand certainty and predictability of the agronomic return, especially until eligibility for carbon credits has been established. The mechanisms of biochar function in soil, which appear to be sensitive to the conditions prevailing during its formation or manufacture, are also affected by the material from which it is produced. Proposed mechanisms and some experimental evidence point to added environmental function in the mitigation of diffuse pollution and emissions of trace gases from soil; precluding the possibility of contaminants accumulating in soil from the incorporation of biochar is important to ensure safety and regulatory compliance.
1,745 citations
"Sorption of heavy metals on chitosa..." refers methods in this paper
...When applied to soils, biochar may not only serve as a carbon sink, but also improve soil fertility by increasing nutrient and water holding capacity [1–3]....
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TL;DR: Specific mechanisms of contaminant-biochar retention and release over time and the environmental impact of biochar amendments on soil organisms remain somewhat unclear but must be investigated to ensure that the management of environmental pollution coincides with ecological sustainability.
1,289 citations
"Sorption of heavy metals on chitosa..." refers background in this paper
...The effectiveness of biochars in immobilizing heavy metals from the environment, however, varies greatly among different types of biochars and could be controlled by several factors including feedstock type, production methods and processing conditions [4,6]....
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...Because of their strong affiliation to heavy metal ions, biocharbased adsorbents have also been suggested as an effective remediation agent to immobilize heavy metals in contaminated soils [4,17]....
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TL;DR: In an effort to better understand the interaction of pyrogenic C and soil organic matter (OM), a range of Florida soils were incubated with a variety of laboratory-produced biochars and CO 2 evolution was measured over more than one year as discussed by the authors.
Abstract: Pyrogenic carbon (biochar) amendment is increasingly discussed as a method to increase soil fertility while sequestering atmospheric carbon (C). However, both increased and decreased C mineralization has been observed following biochar additions to soils. In an effort to better understand the interaction of pyrogenic C and soil organic matter (OM), a range of Florida soils were incubated with a range of laboratory-produced biochars and CO 2 evolution was measured over more than one year. More C was released from biochar-amended than from non-amended soils and cumulative mineralized C generally increased with decreasing biomass combustion temperature and from hardwood to grass biochars, similar to the pattern of biochar lability previously determined from separate incubations of biochar alone. The interactive effects of biochar addition to soil on CO 2 evolution (priming) were evaluated by comparing the additive CO 2 release expected from separate incubations of soil and biochar with that actually measured from corresponding biochar and soil mixtures. Priming direction (positive or negative for C mineralization stimulation or suppression, respectively) and magnitude varied with soil and biochar type, ranging from −52 to 89% at the end of 1 year. In general, C mineralization was greater than expected (positive priming) for soils combined with biochars produced at low temperatures (250 and 400 °C) and from grasses, particularly during the early incubation stage (first 90 d) and in soils of lower organic C content. It contrast, C mineralization was generally less than expected (negative priming) for soils combined with biochars produced at high temperatures (525 and 650 °C) and from hard woods, particularly during the later incubation stage (250–500 d). Measurements of the stable isotopic signature of respired CO 2 indicated that, for grass biochars at least, it was predominantly pyrogenic C mineralization that was stimulated during early incubation and soil C mineralization that was suppressed during later incubation stages. It is hypothesized that the presence of soil OM stimulated the co-mineralization of the more labile components of biochar over the short term. The data strongly suggests, however, that over the long term, biochar–soil interaction will enhance soil C storage via the processes of OM sorption to biochar and physical protection.
1,125 citations
"Sorption of heavy metals on chitosa..." refers methods in this paper
...When applied to soils, biochar may not only serve as a carbon sink, but also improve soil fertility by increasing nutrient and water holding capacity [1–3]....
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