Burial Method Research Articles

Isotopic evidence for the influence of typhoons and submarine canyons on the sourcing and transport behavior of biospheric organic carbon to the deep sea

Export of biospheric organic carbon from land masses to the ocean plays an important role in regulating the global carbon cycle. High-relief islands in the western Pacific are hotspots for such land-to-ocean carbon transport due to frequent floods and active tectonics. Submarine canyon systems serve as a major conduit to convey terrestrial organics into the deep sea, particularly during episodic floods, though the nature of ephemeral sediment transportation through such canyons remains unclear. In this study, we deployed a sediment trap in southwestern Taiwan's Gaoping submarine canyon during summer 2008, during which Typhoon Kalmaegi impacted the study area. We investigated sources of particulate organic carbon and quantified the content of fossil organic carbon (OCf) and biospheric non-fossil carbon (OCnf) during typhoon and non-typhoon periods, based on relations between total organic carbon (TOC), isotopic composition (δ13C, 14C), and nitrogen to carbon ratios (N/C) of newly and previously reported source materials. During typhoons, flooding connected terrestrial rivers to the submarine canyon. Fresh plant debris was not found in the trap except in the hyperpycnal layer, suggesting that only hyperpycnal flow is capable of entraining plant debris, while segregation had occurred during non-hyperpycnal periods. The OCnf components in typhoon flood and trapped samples were likely sourced from aged organics buried in ancient landslides. During non-typhoon periods, the canyon is more connected to the shelf, where waves and tides cause reworking, thus allowing abiotic and biotic processes to generate isotopically uniform and similarly aged OCnf for transport into the canyon. Therefore, extreme events coupled with the submarine canyon system created an efficient method for deep-sea burial of freshly produced organic-rich material. Our results shed light on the ephemeral transport of organics within a submarine canyon system on an active tectonic margin.

Decaying characteristics of pig carcass disposal by trench burial method using compost

Decaying characteristics of pig carcass disposal by trench burial method using compost

Site selection for installing plasma incinerator reactor using the GIS in Rudsar county, Iran.

Nowadays, the urban waste disposal and the proper location for doing so is considered as one of the most important urban service issues, which has the potential of causing environmental hazards for the citizens, if not done properly. One of the newest methods of waste burial is using plasma incinerator reactors. Using the advanced technology of plasma reactors in waste disposal has been the subject of study for a considerable number of researchers in the last few years. Moreover, insignificant emissions of environmental pollutants and high efficiency in these reactors have led to a high incentive for using them in the area of urban services. Therefore, finding the proper location for the plasma incinerator reactor in order to minimize environmental hazards is considered as a very important issue. In the present study, different parts of this reactor and its working procedure are presented at first. Then, quantitative and qualitative criteria effective on locating plasma incinerator reactor are presented, and these criteria are given proper weights using analytic hierarchy process (AHP) multi-criteria decision making method. Next, the data were collected for the studying area, and then, weighting, analysis, and presentation of geospatial data were performed using the geographic information system (GIS). Finally, the output map for installing location of the plasma incinerator reactor was developed in three classes of good, average, and bad.

Mechanical, Thermal, Morphological, and Biodegradable Studies of Okra Cellulosic Fiber Reinforced Starch‐Based Biocomposites

ABSTRACTThe aim of present work is to study the behavior of completely biodegradable starch‐based composites containing okra cellulosic fibers in the range from 5 to 25 wt%. The cornstarch matrix and composites were prepared by using urea–formaldehyde as a cross‐linking agent. The cross‐linked cornstarch matrix and its composites were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X‐ray diffraction, and thermogravimetric analysis. Furthermore, thermal and different mechanical properties, i.e., tensile, compressive, and flexural strength of composites, were also studied. The thermal stability of fiber‐reinforced composite was increased as compared to starch matrix. The mechanical properties of composite such as tensile, compressive, and flexural have been found to increase with the increase in fiber content up to 15% loading. The composite specimens tested for tensile, compressive, and flexural strength at 15% fiber loading exhibited values of 17.78 ± 0.89, 33.55 ± 1.67 and 60.1 ± 3.01 MPa, respectively. Furthermore, the matrix and composites were subjected to biodegradation studies through the soil burial method.

Biodegradation study of enzymatically catalyzed interpenetrating polymer network: Evaluation of agrochemical release and impact on soil fertility

A novel interpenetrating polymer network (IPN) has been synthesized through enzymatic initiation using lipase as initiator, glutaraldehyde as cross-linker, acrylic acid as primary monomer and acrylamide as secondary monomer. Biodegradability of synthesized interpenetrating polymer network was studied through soil burial and composting methods. Synthesized hydrogel was completely degraded within 70 days using composting method, while it was 86.03% degraded within 77 days using soil burial method. This was confirmed by Fourier transform Infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM) techniques. Synthesized interpenetrating polymer network hydrogel was used as a device for controlled release of urea and also act as water releasing device. Their impact on soil fertility and plant growth was also studied. The initial diffusion coefficient has a greater value than the later diffusion coefficient indicating a higher fertilizer release rate during the early stage. Fertilizer release kinetic was also studied which showed Non-Fickian diffusion behavior, as the rate of fertilizer release was comparable to the relaxation time of the synthesized matrix. Synthesized IPN enhance the water uptake capacity up to 6.2% and 7.2% in sandy loam and clay soil, respectively.

Analysis of environmental impacts of burial sites

Foot and mouth disease and avian influenza are highly contagious. The foot and mouth disease virus can be transmitted in a number of ways, including close-contact animal-to-animal spread, long-distance aerosol spread, and fomites (inanimate objects, typically fodder and motor vehicles). Many burial sites were constructed in a short time to prevent the rapid spread of the Foot and mouth disease and avian influenza. These carcass burial sites pose a risk of secondary pollution because the sites were constructed without any appropriate or systematic management due to lack of time, equipment, and available labors. In 2011, more than 4700 carcass burial sites were constructed. Approximately 7 million poultry and 3.5 million livestock, including cattle and swine, were buried in farmland. Secondary pollution from these burial sites is a cause of concern. In practice, a number of burial sites were excavated, and the carcasses were reburied or disposed of elsewhere. To minimize risks to the environment and human health, the environmental impacts of the construction methods should be analyzed. This study used life cycle assessment methodology to investigate environmental impacts of the traditional carcass burial construction method and the redisposal construction using aerobic thermophilic microbes. All input data of raw materials and energy usage were collected, and an inventory was established. The burial process contributed to freshwater aquatic ecotoxicity potential, ozone depletion potential, and terrestrial ecotoxicity potential more than the redisposal process. However, the redisposal contributed to abiotic depletion potential, acidification potential, eutrophication potential, global warming potential, human toxicity potential, and photochemical oxidant creation potential more than the burial process.

The study of air-plasma treatment on corn starch/poly(ε-caprolactone) films

In spite of usefulness of synthetic polymers in every aspects of life, the environmental hazards limit their use. Starch based biodegradable polymers is one of the solutions to it. Packaging has a major share in use of synthetic polymers. For packaging application, it is necessary to have good surface and barrier properties of the material. Plasma surface modification of materials is a promising solution to enhance surface properties. In the present paper, cornstarch/poly(ε-caprolactone) (CSPCL) films were treated in air-plasma for different durations of time. The effect of air-plasma treatment on surface properties and biodegradation was studied. The extent of etching was evaluated from weight change (%) study. Changes in surface chemical composition were analyzed using ATR-FTIR and XPS. The contact angle and surface free energy (SFE) study indicate that air-plasma treatment leads to hydrophilization of CSPCL films. The changes in surface topography of plasma processed films were analyzed using AFM and SEM. The roughness caused by etching and increase in surface free energy facilitates the improvement in adhesive properties like printability and peel strength. Changes in barrier properties were studied using water vapor and oxygen transmission rate. Effect of air-plasma treatment on biodegradation of treated and untreated samples was studied by simulating natural biodegradation conditions in a controlled environment using indoor soil burial method and with a single bacterial system comprising of a commonly occurring soil bacterium, Bacillus subtilis MTCC 121. While the soil system is indicative of biodegradation due to macro as well as micro elements, a single microbial system will identify the interaction between the microorganisms and modified surface thus showing the effect of air-plasma treatment on the degradation process. Biodegradation by indoor soil burial method was assessed by measuring loss in tensile properties and growth of soil micro flora on surface by optical light microscopy (OLM). Biodegradation by B. subtilis was assessed by measuring increase in its number along with the changes it brought about in the sample surface by optical light microscopy and SEM. It was observed that such surface modifications enhanced the biodegradation rate along with finding application in packaging field, thus providing a green solution for the increasing packaging utilization and addressing environmental concerns.

Biodegradability Studies of Bio-Composites ofPolypropylene Reinforced By Potato Starch

In this study, poly propylene (PP)/potato starch (PS) blend films are prepared using the two roll mill machine. The biodegradability of the films is investigated by soil burial method over a period of 4 months. The percentage weight loss of the bio-composites in the compost soil burial test is increasing with increasing PS content. The biodegradability of the bio-composites is enhanced with increasing starch content because the PS is easily attacked by microorganisms. Any changes in the various properties of the PP/PS before and after degradation are monitored using weight loss, FTIR spectroscopy, a scanning electron microscope (SEM) for surface morphology, a thermo gravimetric analyzer (TGA) for rapid determination of starch content and a differential scanning calorimeter (DSC) for crystallanity. It can be concluded from the results that use of these bio-composites will reduce the environmental problems associated with waste pollution and the study findings support the predicted application of bio-composites as green-composites or eco-materials.

Dispatches

Dispatches

Tradition and the culture of rights at the crossroads: A literary perspective

Using cultural theories, this article focuses on a literary text that presents a fresh perspective on one of the cultural practices of disposing of a dead body, namely cremation. The scarcity of burial sites is increasingly becoming a concern for municipalities, yet traditional ways of thinking are strongly against cremation. The liberty to investigate the burning issue of cremation as an alternative burial method in this way derives from the fact that through the ages literature (oral and written) has been effectively used by creative writers to offer an allusive quality and fictitious setting which has allowed them to comment on contemporary issues without blatantly seeming to do so. In this sense, the novel Intando kamufi (“Will of the deceased”) by S. Mathaba contributes to various discourses on cremation, either reinforcing or critiquing it.

Biodegradation of Gum tragacanth acrylic acid based hydrogel and its impact on soil fertility

In the present work, biodegradation study of Gum tragacanth-acrylic acid based hydrogel was conducted using soil burial and composting methods. Within 77 days, complete degradation of synthesized hydrogel was observed in the composting method, while 92.29% of degradation was observed in soil burial method. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) techniques gave the evidence and progress of biodegradation at different stages. Impact of biodegradation of hydrogels on soil fertility was studied through macroanalysis of soil before and after biodegradation studies. Plant growth of Phaseolus vulgaris showed that test sample soil was better for plant growth in comparison to the garden soil. Synthesized hydrogel was also evaluated for controlled release of fertilizer. Fertilizer release kinetic through the synthesized matrix showed Non-fickian diffusion behaviour.

Effects of dry method esterification of starch on the degradation characteristics of starch/polylactic acid composites

Maleic anhydride esterified corn starch was prepared by dry method. Esterified starch/polylactic acid (PLA) biodegradable composite was produced via melt extrusion method with blending maleic anhydride esterified corn starch and PLA. The influence of the dry method esterification of starch on the degradation characteristics of starch/PLA composites was investigated by the natural aging degradation which was soil burial method. Test results of mass loss rate showed that the first 30 days of degradation was mainly starch degradation, and the degradation rate of esterified starch/PLA (ES/PLA) was slower than that of native starch/PLA (NS/PLA). Therefore, the damage degree of ES/PLA on the surface and inside was smaller than that of NS/PLA, and the infrared absorption peak intensities of CO, CO and CH were stronger than that of NS/PLA. With the increasing time of soil burial degradation, the damage degree of NS/PLA and ES/PLA on the exterior and interior were gradually increased, whereas the infrared absorption peak intensities of CO, CO and CH were gradually decreased. The XRD diffraction peak intensity of PLA in composites showed an increased trend at first which was then followed by a decreased one along with the increasing time of soil burial degradation, indicating that the degradation of amorphous regions of PLA was earlier than its crystalline regions. When the soil burial time was the same, the diffraction peak intensity of PLA in ES/PLA was stronger than that of NS/PLA. If the degradation time was the same, T0, Ti and residual rate of thermal decomposition of NS/PLA were larger than those of ES/PLA. The tensile strength and bending strength of composites were decreased gradually with soil burial time increasing. Both the tensile strength and bending strength of ES/PLA were stronger than those of NS/PLA.

Study on Preparation of Biodegradable Polyurethane Foam

Biodegradable polyurethane foam (PUF) was prepared by using tung oil and starch as the modifiers, they were mixed with polyether polyol and some other reaction auxiliary agents, and then reacted with toluene diisocyanate (TDI). The structure and thermal stability of products were analyzed based on SEM and TG, and the soil burial method was used to investigate the biodegradability of products. The results indicated that polyurethane foam modified by tung oil and starch has good thermal stability, good mechanical properties and good biodegradability. The degradation rate of PUF modified by 5: 2 of starch/ tung oil was 38% after 120 d.

Natural rubber degradation by laccase and manganese peroxidase enzymes of Penicillium chrysogenum

Natural rubber (NR), or cis-1,4 poly-isoprene, is one of the most important biopolymers. For almost a 100 years, million tons of NR-derived products have been produced by humankind as it is very elastic in nature. These products are mainly made up of NR, which is obtained from the latex of tree Hevea brasiliensis commonly called rubber tree. After usage of these NR products, the disposal of these products is the worldwide solid waste problem. To reduce this problem, microbial degradation of the product should be developed. Microbial degradation is mainly carried out by various microorganisms such as bacteria and fungi. Rubber-degrading organisms were isolated by soil burial method. In the isolated organism, Penicillium chrysogenum effectively degraded the NR sample, and enzyme responsible for degradation was also studied. The present study has showed that it is possible to use this strain to degrade the NR.

Roles of Bacillus megaterium in Remediation of Boron, Lead, and Cadmium from Contaminated Soil

Phytoremediation is an attractive, economical alternative to soil removal and burial methods to remediate contaminated soil. The objective of this study was to investigate the effects of adding different rates of Bacillus megaterium on the capacity of Brassica napus plants to take up boron (B), lead (Pb), and cadmium (Cd) from polluted soils under field conditions. Field experiments were conducted using a randomized complete block design with control (without pollution and B. megaterium application) and B, Pb, and Cd in two doses (0 and 100 mg kg−1), B. megaterium with four doses (no application and 108 cfu B. megaterium ml−1 sprayed at 50 ml plot−1, 100 ml plot−1, 150 ml plot−1). Results indicated that soil pollution treatments significantly decreased seed (SDMY), shoot (SHDMY), root (RDMY), and total dry-matter yield (TDMY) of plants at 42.9, 3.8, 62.6, and 23.4% for B-polluted treatment; 25.8, 8.7, 17.6, and 14.2% for Pb-polluted treatment; and 33.2, 7.0, 14.0, and 16.4% for Cd-treatment without B. megaterium application, respectively. However, the application of B. megaterium ameliorated the negative effects of B, Pb, and Cd at 41.4, 52.7, and 10.9% for B; 24.4, 21.6, and 4.9% for Pb; and 22.8, 22.0, and 3.3% for Cd, respectively. The potentially bioavailable and relatively available fraction of soil B, Pb, and Cd increased with increases in the B. megaterium application but total fraction and stable fraction decreased. It is concluded that the seed and shoot parts of B. napus can be used as hyperaccumulators for plant B, Pb, and Cd remediation according to remediation factors but the shoot is the biggest part of the plant, and thus an important portion of the plant to remove B, Pb, and Cd from the B-, Pb-, and Cd-contaminated soils. To decrease desired concentration for 8 mg B kg−1, 4 mg Pb kg−1, and 3 mg Cd kg−1 in the active rooting zone of soil, approximately 2, 6, and 21 years would be necessary with only 150 ml plot−1 B. megaterium–sprayed soil cultivated with B. napus, respectively.

Research Progress of Disposal Technology for Hyperaccumulator

Phytoextraction of heavy metal polluted environment generates large quantities of hyperaccumulators. How to safely dispose hyperaccumulators has been one of the most important issues in the phytoextraction field. In recent years, disposal technologies for hyperaccumulators have been extensively studied with aim at reduction, recycle and harmless treatment. This paper reviewed the progress in disposal technologies for hyperaccumulators, such as Incineration, composting, burial method and so on. Focused on summaring the disposal technology for arsenic-containing hyperaccumulator Pteris vittata L.. Also pointed out the problems of the current disposal of hyperaccumulator and the possible research direction we should pay attention to in the future, hoping to provide insight into developing harmless disposal or resource-reuse-oriented methods for disposal of the plants used for large scale phytoremediation application．

Enzymatic studies on Natural rubber biodegradation by Bacillus pumilus

Objective: To isolate Natural Rubber degrading Bacteria from soil and to screen the enzymes responsible for Natural Rubber degradation. Methods: Soil burial method was followed for isolation of bacteria. Plate assay method and liquid assay method by using Mineral Salt Medium was followed for screening of bacteria for its capacity to degrade Natural rubber. Degradation was confirmed by weight loss experiment, Scanning Electron Microscopy (SEM) and Fourier Transform Infra-Red (FTIR) studies. Enzymes responsible for Natural rubber degradation were screened and their activity was measured by spectrophotometric method. Results: Isolated organism was identified as Bacillus pumilus. It was able to degrade Natural rubber which was confirmed by weight loss, SEM and FTIR studies. From the current work it was studied that Laccase and Manganese peroxidase were the enzymes which were responsible for Natural rubber degradation. Conclusion: From current investigation, it can be concluded that our isolated bacterial strain Bacillus pumilus have the capacity to degrade Natural rubber and it can be useful in solving the problem caused by waste Natural rubber products in the environment.

Studies on the Performance of Polyester Composites Reinforced with Functionalized Grewia optiva Short Fibers

ABSTRACTThis paper deals with the fabrication and characterization of raw and surface‐modified Grewia optiva fibers reinforced unsaturated polyester (UPE) matrix based composites. Raw and surface‐modified fibers are used in different proportions (10, 20, 30, and 40%) for the fabrication of composites. The fiber proportion is optimized by studying various mechanical properties such as tensile, compressive, and flexural strength of UPE matrix‐based composites. After the optimization of fiber loadings, the optimized samples were evaluated for their physicochemical, thermal, fire retardancy, and biodegradability properties. Physicochemical and thermal stability of the composites is improved after fibers’ surface modification. The effect of different fire retardants (magnesium hydroxide and zinc borate) on the fire‐retardant behavior of polymer composites is also evaluated. Biodegradability of polymer composites is checked by using a soil burial method.

Biodegradation of polystyrene-graft-starch copolymers in three different types of soil.

Materials based on polystyrene and starch copolymers are used in food packaging, water pollution treatment, and textile industry, and their biodegradability is a desired characteristic. In order to examine the degradation patterns of modified, biodegradable derivates of polystyrene, which may keep its excellent technical features but be more environmentally friendly at the same time, polystyrene-graft-starch biomaterials obtained by emulsion polymerization in the presence of new type of initiator/activator pair (potassium persulfate/different amines) were subjected to 6-month biodegradation by burial method in three different types of commercially available soils: soil rich in humus and soil for cactus and orchid growing. Biodegradation was monitored by mass decrease, and the highest degradation rate was achieved in soil for cactus growing (81.30%). Statistical analysis proved that microorganisms in different soil samples have different ability of biodegradation, and there is a significant negative correlation between the share of polystyrene in copolymer and degree of biodegradation. Grafting of polystyrene on starch on one hand prevents complete degradation of starch that is present (with maximal percentage of degraded starch ranging from 55 to 93%), while on the other hand there is an upper limit of share of polystyrene in the copolymer (ranging from 37 to 77%) that is preventing biodegradation of degradable part of copolymers.

Polylactic acid (PLA) biocomposites reinforced with coir fibres: Evaluation of mechanical performance and multifunctional properties

The effects of fibre content (5–30wt%) and fibre treatment on surface morphology, tensile, flexural, thermal and biodegradable properties of polylactic acid (PLA)/coir fibre biocomposites were evaluated via scanning electron microscopy (SEM), mechanical testing, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and soil burial method. Similar decreasing trends were found for tensile and flexural strengths with higher strength values obtained for PLA/treated coir fibre biocomposites. 20wt% treated coir fibres were determined to achieve optimum tensile and flexural strengths of biocomposites. Regardless of fibre treatment, the thermal stability of biocomposites is worsened with increasing the fibre content. The decreased cold crystallisation temperatures of biocomposites further confirms the effective nucleating agent role of coir fibres. The biocomposites undergo much faster degradation than PLA, with the maximum weight loss of 34.9% in treated fibre biocomposites relative to 18% in PLA after 18-day burial, arising from the hydrophilic nature of coir fibres.