Treatment of Dyeing and Finishing Plant Wastewater by Using Gutingkeng Geological Materials

• Main Authors: WU,YA-WEN, 吳雅文
• Other Authors: LU, HSUEH-YU
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/3v4pzk

碩士 === 國立中正大學 === 地球與環境科學研究所 === 108 === In dyeing and finishing industry, using surfactants to complex with heavy metals is the most common way to increase the solubility of functional heavy metals. Subsequently, the wastewater contain various organic substances and inorganic heavy metals, which are hardly to be removed due to the high concentration of surfactants. Traditionally, wastewater is treated by more expensive methods, such as activated carbon adsorption and resin ion exchange. However, mudstone is one of the common geological material in south Taiwan, It has the advantages of high adsorption capacity and economic expenses. In this study, the efficiency of mudstone from south Taiwan is evaluated for removing heavy metal zinc from the dyeing and finishing wastewater. Due to the lower electric charge (+2) under oxidation state, zinc is mostly hydrated and has a relatively high solubility than those with valence of (+3). In this study, the results show that the reaction rate of adsorption of the mudstone is very high. The mudstone could remove over 80% of zinc in less than three minutes, which demonstrates that the process of adsorption may involve strong chemical bonding. In addition, the results show that the amount of zinc removal increased with the pH level and reaches the maximum at pH 10, which indicates that the surface of the clay minerals possesses more negative charges to adsorb hydrated zinc positive-charged ions in wastewater. The experiments were conducted at different concentrations (0-50 mg/L) and pHs (4,7,10). After testing the models of linear, Langmuir and Freundlich, the adsorption process in this study is best fitted with Freundlich isotherm models. In this study, multiple spectroscopes including Raman, FTIR and XRD were also used to analyze the chemical and mineralogical properties of the mudstone before and after the adsorption experiments. The results can evaluate the functional groups are responsible to the adsorption reactions.