Low temperature pyrolysis offers a feasible option for wood waste management and the recovery of a variety of useful chemicals. The effect of Chromated Copper Arsenate (CCA) wood preservatives on the yield and composition of various pyrolysis products was investigated in the present research. A novel quantitative 31P NMR methodology has been developed to quantify levoglucosan and levoglucosenone from the pyrolysate of CCA-treated and untreated wood. The CCA treatment on wood had a significant effect on the amount of main carbohydrate derived degradation products of tar. In particular, a higher yield of levoglucosan can be obtained compared to that from untreated wood. Phosphoric acid has proven to be an efficient catalyst to favor levoglucosenone formation. The pyrolysis of CCA-treated wood in the presence of phosphoric acid gave rise to high yields of levoglucosenone, which demonstrated the potential for a new pathway in the rational use of CCA-treated wood waste. Pretreated wood with metal compounds has demonstrated that K2Cr2O7 and CuSO4 salts promote the formation of levoglucosan. The CrO3 treatment was found to favor the formation of levoglucosenone. A kinetic study of the pyrolysis of CCA-treated wood by thermogravimetric analysis has shown that CCA components have a significant influence on the thermal decomposition behavior of CCA-treated wood, which accelerate the weight loss of wood and the oxidation of the char.

Low-temperature pyrolysis offers a feasible option for wood-waste management and the recovery of a variety of useful chemicals. The effect of chromated copper arsenate (CCA) wood preservative on the yield and composition of various pyrolysis products was investigated in the present research. A novel quantitative 31P nuclear magnetic resonance (NMR) spectroscopy methodology has been developed to quantify levoglucosan and levoglucosenone from the pyrolysate of CCA-treated and untreated wood. The CCA treatment of wood had a notable effect on the characteristics of the carbohydrate-derived degradation products of tar. In particular, yields of the important pharmaceutical precursors levoglucosan and levoglucosenone were elevated by 3 and 4.5 times, respectively, when compared with those from untreated wood. Phosphoric acid has proven to be an efficient catalyst to favor levoglucosenone formation. The pyrolysis of CCA-treated wood in the presence of phosphoric acid gave rise to high yields of levoglucosenone, demonstrating the potential for a new pathway in the rational use of CCA-treated wood waste. Pretreatment of wood with metal compounds has demonstrated that K2Cr2O7 and CuSO4 salts promote the formation of levoglucosan. The CrO3 treatment was found to favor the formation of levoglucosenone. A kinetic study of the pyrolysis of CCA-treated wood by thermogravimetric analysis has shown that CCA components have a significant influence on the thermal decomposition behavior of CCA-treated wood and accelerate the weight loss of wood and the oxidation of the char.

Increasing volumes of Chromated Copper Arsenate (CCA) treated wood materials are being removed from service, either as a result of reaching the end of their service life or being replaced with non-treated wood materials. These materials, while not regulated as hazardous wastes, have the potential to leach toxic metals into the environment. Incineration and landfilling are not ideal disposal methods as incineration could result in the volatilization of carcinogenic arsenic and chromium, while landfilling requires the waste to be sorted and placed in appropriately lined landfills to prevent contaminant release. Viable disposal methods must be considered to manage the significant waste stream of CCA-treated wood. This study investigates pyrolysis and electrokinetics (EK) as possible remediation techniques for the treatment of CCA-treated wood waste. A unique bench pyrolysis reactor was designed and optimized over three pyrolysis temperatures for retention of CCA metals within the char and bio-oil pyrolysis products. A batch pyrolysis system was constructed to produce large quantities of pyrolysis char for use in EK experiments. Mass balances were performed across both bench and batch pyrolysis systems, with metal distribution trends ascertained. EK experiments were performed on the char generated during batch pyrolysis as well as CCA-treated wood waste to evaluate the efficiency of coupling the two technologies. These EK studies were performed using pH regulation at the cathode and applying constant current. Distribution of the CCA metals post-EK experiment was determined and removal efficiencies were calculated. The mobility of the CCA metals was evaluated during all phases of this investigation using Toxicity Characteristic Leaching Procedure (TCLP), Synthetic Precipitation Leaching Procedure (SPLP), and Deionized Water Leaches to determine the likelihood of metal leaching under different environmental conditions.

Preserved wood is commonly found in solid waste. Among the different types of preserved wood, CCA wood has received much attention due to the scale of usage and its significant role in soil and water contamination after disposal. As the ash of CCA wood is hazardous, it cannot be burned, and the best available disposal method is thus landfilling. Leaching of the metals from disposed CCA wood in landfills pollutes the environment. To reduce the contamination of CCA, treatment before landfilling is required. Nowadays, ethanol is seen as a promising source of energy. Lignocellulosic materials such as wood are resources for ethanol production. This research focuses on the possibility of producing ethanol from CCA wood. It suggests that production of ethanol will not only be a solution to the disposal but will also generate a clean fuel. The results showed the existence of copper, chromium and arsenic did not have a negative effect on the fermentation, and producing ethanol from CCA wood is feasible. The copper removed by sulfuric acid completely precipitated during the hydrolysis and neutralization. In addition about 50% of the chromium (VI) and also 60% of the arsenic (V) were removed from the leachate by yeast during fermentation. TCLP tests of the hydrolyzed wood leached less than 4 ppm of arsenic while minimal amounts of chromium and copper remained in the hydrolyzed wood which makes landfilling of hydrolyzed wood acceptable. Baker's yeast behaves selectively by uptaking arsenic (V) and chromium (VI) but not arsenic (III) and chromium (III). There is competition between copper and chromium sorption by yeast. The kinetic model for removal of copper and chromium is a zero order model while the appropriate model for uptaking arsenic by yeast is a first order model. The kinetic models confirm that there are different mechanisms of uptaking metals by yeast, a diffusion mechanism for removal arsenic and a surface adsorption mechanism for copper and chromium. As an overall conclusion of this study, using discarded CCA wood as the feed for ethanol production is a sustainable method for disposal of CCA treated wood.

Tighter regulations of harmful substances such as NOx, CO, heavy metals, particles, emissions from commercial plants and automobiles reflect a growing demand for lowering the anthropogenic burdens on the environment. It is equally important to monitor controlling factors to improve the operation of industrial machinery and plants. Among the many me

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