{'fraction_non_alphanumeric': 0.05027932960893855, 'fraction_numerical': 0.035381750465549346, 'mean_word_length': 5.107954545454546, '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}}
Study on Combined Soil Purification Tank System Reactor in Treatment of Domestic Sewage

To solve the problems of dead angle and low dissolved oxygen of current soil purification tank system, the combined soil purification tank system reactor was designed to treat domestic sewage by our research group. The results of 10 months indicated that the optimal hydraulic retention time (HRT) were 2.5d; the influent COD concentration fluctuating at 130~350mg/L; the optimal aeration opposition were in the front and the rear end with using the intermittent aeration mode; Under these conditions as above, the COD, NH4+-N, TN and TP average removal rates were 88.8%(S=1.51%), 91.2%(S=1.30%), 89.6%(S=2.15%) and 92.4%(S=2.79%) at (23±2) °C, respectively. Based on the results of trial, the mechanisms of the combined soil purification tank system reactor with higher efficacy in treatment of low concentration sewage are owed to the structure of the waveform and slope, high efficient wetland plants and soil microorganisms of degradation performance and soil matrix of adsorption.