Pauline Norris

Generation of chlorine by-products in simulated wash water

Free chlorine (FC) reacting with organic matter in wash water promotes the formation of chlorine by-products. This study aims to evaluate the dynamic impact of FC and organic load on the generation of haloacetic acids (HAAs) and trihalomethanes (THMs) in simulated wash water. Lettuce juice was sequentially added into FC solution with FC periodically replenished. Water samples were collected after each lettuce juice addition to measure water qualities and determine HAAs and THMs using US-Environmental-Protection-Agency (EPA) methods. Concentrations of 88-2103 μg/l of total HAAs and 20.79-859.47 μg/l of total THMs were detected during the study. Monobromoacetic, tribromoacetic, chlorodibromoacetic and trichloroacetic acid were the major HAAs components. Chloroform (trichloromethane) was the primary THMs present. A significant correlation of HAAs with chemical oxygen demand and THMs with FC was observed. Results indicated that optimizing wash water sanitizing systems to limit organic matters and maintain minimal effective FC concentration is critical.

Synthesis of activated carbon from coal pitch for mercury removal in coal-fired power plants

Activated carbon (AC) is an effective adsorbent that is used in a wide range of applications. This is due to its high adsorption capacity and fast removal rate. This study evaluated processing conditions for synthesizing AC from coal pitch. The objective was to establish what processing conditions produced AC with the best adsorption performance. Factors such as carbonization temperature, activation temperature, steam flow rate and the addition of additives have been studied. A real-time, fixed-bed mercury adsorption system was used to evaluate the AC prepared from coal pitch. Results showed that the temperature and the KOH mixing rate in the carbonization process play an important role in the formation of the functional groups on the surface of the char. Additionally, the temperature and the steam flow rate in the activation process significantly affects AC surface area and pore distribution, important factors relating to mercury adsorption performance.

Application of fly ash as an adsorbent for Estradiol in animal waste

The contamination of agricultural ground with estrogen compounds through application of animal wastes is a present concern. At the same time, current uses for waste fly ash having high carbon content are limited. To help mitigate these problems, we examine using waste fly ash as a useful adsorbent for Estradiol in pig waste digests. In this study, Estradiol was added to vials containing water and fly ash from several different power plants. After an extraction process, the amount of Estradiol in the water was measured. Commercial activated carbon was also used for comparison purposes. Vials containing varying concentrations of Estradiol and no trapping material were used as a control. The results from this study indicate that fly ash can be used as a trapping material for Estradiol in water, but that commercially available activated carbon can trap about an order of magnitude more Estradiol than the fly ash and that the effects of the fly ash matrix can both inhibit and promote the solvation of Estradiol into water depending possibly upon pH and cation concentration effects. In addition, preliminary extraction studies using pig waste digest indicate that fly ash can be used as adsorbent for Estradiol present in pig waste.