Seok-Young Oh &n
Abstract
Factors affecting the sorptive removal of nitro explosives [2, 4, 6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5- triazine (RDX)] to polymer/biomass-derived biochar were investigated through batch experiments. Compared to that of rice straw (RS)-derived biochar, the sorption of TNT and RDX to polymer/RS-derived biochar was greatly enhanced by more than 2.5 and 4 times, respectively. The type and amount of polymer did not significantly affect the sorption of nitro explosives to polymer/RS-derived biochar. Due to increasing aromaticity of biochar and decreasing carbon residues from the polymer, the effect of the pyrolysis temperature at elevated temperatures was not marked. Surface treatment with acid or an oxidant did not significantly change the sorption capacity, suggesting that polymer residues may be strongly responsible for the enhancement. Possible polymer residues were identified via GC-MS analysis. The toxicity characteristic leaching procedure (TCLP) and Microtox bioassay analyses indicated that polymer/RS-derived biochar did not show possible harmful effects. Our results suggest that polymer/RS-derived biochar can be effectively used as a sorbent to remove nitro explosives both in the natural environment and engineered systems. Polymers from biomass are of prime concern and are the cornerstone in terms of varied applications like biofuels, biomedical, and biocomposite applications. Recently, concerns on the environmental pollution and exhaust of natural resources caused by the nonbiodegradable petroleum-based plastics materials have attracted attention on the event of environmentally benign polymers for his or her applications in various industries and other value added utilities. Renewable and abundantly available biopolymers are the foremost viable alternative for the assembly of green materials within the near future. so as to secure the sustainable development for exponentially growing population, the increasing demands for the light-weighted high performance materials and growing concerns over environmental impact of the materials have compelled academic and industrial researchers to develop new materials from alternative or renewable resources. Renewability of resources depends on the supply and life cycle of the raw materials. In recent decades, polymeric materials from renewable biological resources like plants, marine animals, and microbial organisms have increasingly gained the eye of researchers. The polymers which are derived/extracted from the foremost widely available biological renewable resources (agricultural plants, marine animals, and microorganisms) are called “biopolymers.” These polymers are produced as biomass or byproduct during the expansion cycles of organisms. Biopolymers or renewable polymers like cellulose, lignin, starch, pectin, chitin, and xylan are the abundantly available polymers in nature within the sort of plant biomass or other biological sources. Their importance for various applications (biofuels, nanobiocomposites, biomedical, etc.) has been analyzed for several years and still continued. There are alternative ways to convert these biopolymers into various chemicals, fuels, and materials for the advantage of our society. Still there are challenges to develop new methodologies or improved processes for efficient and economic utilization also as conversion of those biopolymers. Biochar is charcoal used as a soil amendment for both carbon sequestration and soil health benefits. Biochar may be a stable solid, rich in carbon, and may endure in soil for thousands of years. Like most charcoal, biochar is formed from biomass via pyrolysis. Biochar is under investigation as a viable approach for carbon sequestration, because it has the potential to assist mitigate heating and global climate change . It results from processes associated with pyrogenic carbon capture and storage (PyCCS). Biochar may increase soil fertility of acidic soils (low pH soils), increase agricultural productivity, and supply protection against some foliar and soil-borne diseases.Regarding its definition in production, biochar is defined by the International Biochar Initiative as "The solid material obtained from the thermochemical conversion of biomass in an oxygen-limited environment". Toxicity is that the degree to which a chemical substance or a specific mixture of drugs can damage an organism. Toxicity can ask the effect on an entire organism, like an animal, bacterium, or plant, also because the effect on a substructure of the organism, like a cell (cytotoxicity) or an organ like the liver (hepatotoxicity). By extension, the word could also be metaphorically wont to describe toxic effects on larger and more complex groups, like the relatives or society at large. Sometimes the word is more or less synonymous with poisoning in everyday usage. Toxicity of a substance are often suffering from many various factors, like the pathway of administration (whether the toxicant is applied to the skin, ingested, inhaled, injected), the time of exposure (a brief encounter or long term), the amount of exposures (a single dose or multiple doses over time), the physical sort of the toxicant (solid, liquid, gas), the genetic makeup of a private , a person's overall health, and lots of other. Acute exposure one exposure to a toxic substance which can end in severe biological harm or death; acute exposures are usually characterized as lasting not than each day . Chronic exposure Continuous exposure to a toxicant over an extended period of your time , often measured in months or years; it can cause irreversible side effects.