{'fraction_non_alphanumeric': 0.016220600162206, 'fraction_numerical': 0.009732360097323601, 'mean_word_length': 5.427083333333333, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
XYLIDINE-POLLUTED GROUNDWATER PURIFICATION
 Adsorption experiments and breakthrough calculations

Xylidine is a carcinogenic component originating from missile fuel, and it often dominates in polluted groundwater in the areas of abandoned Soviet missile bases in Eastern Europe. One of the possible processes for its removal is adsorption onto granulated activated carbon. However, the corresponding equilibrium relationships as well as information on the process kinetics are not available. In this work Langmuir's and Freundlich's isotherm parameters were obtained from batch adsorption equilibrium tests. Initial concentration of 2,4-xylidine was varied in the range of 200-300 mg/L in the experiments. The solid phase diffusion coefficient was obtained from the batch kinetic runs. The breakthrough curves were measured during dynamic experiments in two packed bed columns with diameters of 16 and 26 mm. The obtained experimental curves were compared to those calculated by the Thomas and Rice methods. In some cases a satisfactory fit was achieved, but in several cases more advanced modelling methods should be used for better prediction of the xylidine-contaminated groundwater breakthrough profiles in a packed bed r eactor.