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Thermal remediation involves heating subsurface environments and collecting fluids in order to recover contaminants such as tetrachloroethylene (PCE) and trichloroethylene (TCE). While increasing subsurface temperature can lead to changes in the distribution of contaminants between the solid, liquid, and gas phases, there is also an increased potential for PCE and TCE to degrade. This work was performed to determine the rate of PCE and TCE degradation and products formed in laboratory-scale experiments designed to simulate thermal remediation conditions. The conditions during transport of gas-phase TCE were simulated using flow-through experiments in the temperature range from 60 to 800C. Degradation of TCE was not evident at temperatures of less than 240C; however, chloroacetic acids, which comprised less than 0.1% of the influent TCE on a carbon basis, were detected. At temperatures greater than 300C, TCE readily degraded where the identities of the degradation products were a function of oxygen and water content. With oxygen present, TCE degraded to form CO, phosgene, CO2 with minor amounts of hexachloroethane, PCE, and carbon tetrachloride. Increasing the amount of water vapor was found to decrease the amount of TCE degraded. Vapor recovery systems used during thermal treatments are anticipated to capture these TCE degradation products. However, the amount of missing carbon (~17%) in experiments completed at 800C makes the prospect of recovering all TCE degradation products doubtful. Experiments were conducted using hermetically sealed ampules to simulate heating dissolved phase PCE and TCE over periods of up to 75 days. At 120C, the first-order TCE degradation half-life was 330 days and the degradation products included CO and CO2, glycolate, formate, and chloride. The rate of TCE disappearance was increased with the addition of 1% (wt.) goethite, which suggests that the presence of iron bearing soil minerals can increase rates of TCE degradation during thermal treatment. In contaminated field samples, TCE was found to degrade to form cis-1,2-dichloroethylene at 95C coincident with the formation of hydrogen gas. Degradation of PCE was not evident in field samples or in deionized water and is not expected to degrade during thermal remediation at temperatures below 95C.

The research of this work describes the degradation and conservation of archaeological hair fibers. Chapter I will be a brief overview, with Chapter II following with a literary review and definition of terms. Chapter III focuses on research centered on the structure of hair fibers and their physical and chemical attributes. It will also focus on the archaeological and historical evidence of hair fiber use by humans. This research will help form the backbone of the paper and experiments performed. The next chapter focuses on the degradation of hair fibers in different environments. Hair fibers left in underwater, open air, burial, and arid environments are monitored for degree of degradation and brittleness. The hair fiber types used are four commonly found hair fibers types: coarse wool, fine wool, mohair, and human hair. After deposition, conservation using silicone oil treatment is tested on the degraded hair fibers. When silicone oil treatment proves to be a viable conservation method, the technique is then be applied to two artifacts. The two artifacts used are a Victorian era watch fob made from human hair and hair fibers mixed with tar from the excavation of Kittern in Bulgaria. Chapter VII deals with the conclusions of the experiments as a whole. The degradation of the fibers in different environmental conditions show that burial in acidic sandy clay is the most detrimental to hair fibers, while hair fibers from arid, dry environments are brittle, but well preserved aesthetically. The silicone oil treatments are shown to be viable treatment methods with positive results for all of the fibers tested, including two artifacts, a Victorian watch fob made from human hair fibers and hair fibers mixed with a tar-like substance from the shipwreck Kittern in Bulgaria.

Thermal remediation is an efficient and cost effective method for the removal of organic compounds from the subsurface. However, complete removal of these compounds cannot be achieved by this technology alone. It is generally assumed that bioremediation will provide the polishing steps at thermally treated sites. In this study, soil was collected from a hydrocarbon contaminated site that previously underwent thermal remediation. A microcosm batch study was conducted to determine the impacts of thermal remediation on indigenous microorganisms and their ability to degrade naphthalene. Soils that reached varying peak temperatures were set up in microcosms at temperatures experienced along their respective cooling profiles. Naphthalene degradation was not detected within any of the unamended microcosms within a 6 month time frame, although, archaea growth was detected in the microcosms after 2 months of acclimation, accompanied by iron reduction and significant methane production assumed to have arisen from degradation of methanol.

Thermal remediation is an efficient and cost effective method for the removal of organic compounds from the subsurface. However, complete removal of these compounds cannot be achieved by this technology alone. It is generally assumed that bioremediation will provide the polishing steps at thermally treated sites. In this study, soil was collected from a hydrocarbon contaminated site that previously underwent thermal remediation. A microcosm batch study was conducted to determine the impacts of thermal remediation on indigenous microorganisms and their ability to degrade naphthalene. Soils that reached varying peak temperatures were set up in microcosms at temperatures experienced along their respective cooling profiles. Naphthalene degradation was not detected within any of the unamended microcosms within a 6 month time frame, although, archaea growth was detected in the microcosms after 2 months of acclimation, accompanied by iron reduction and significant methane production assumed to have arisen from degradation of methanol.

During the last few years the agriculture sector is facing danger in many ways. Conversion of agricultural land in non-agricultural uses is one of the main reasons to follow. Why the land is decreasing, how it is converted to non-agricultural purposes is the important matter of concern at present. The study is going to answer why the land is decreasing, how it is converted to non-agricultural uses and what might be the consequences for improper uses of agricultural land. In Bangladesh most of the people live in rural areas and makes Bangladesh predominantly rural. The development in rural seems development of agriculture. But the agricultural land is decreasing day by day. Poverty, rapid population growth, improper uses of land, lack of interest in agriculture, conventional system of irrigation, Real Estate companies etc are playing a critical role for decreasing agricultural land. Besides this, a nature itself is also responsible for land degradation. Flood, drought and salinity due to climate change are very common in Bangladesh thus the result is land degradation. As a result, soil fertility, crop productivity, and food security might be seriously in danger. But it is important to keep full of life this sector for land-scarce country like Bangladesh or else the consequences might be terrible. Food insecurity, unsustainable environment, economic downturn, agricultural productivity decrease and social decay etc are the important matters to consider.   Key words: Land degradation, Agriculture, Land Zoning