TITLE:
Partial Nitrification Performance of Gel-Immobilized Fillers and Application to Leather Wastewater Treatment
AUTHORS:
Chenguang Wu, Hong Yang
KEYWORDS:
Leather Wastewater, Gel-Immobilized Fillers, Partial Nitrification, Organics
JOURNAL NAME:
Open Access Library Journal,
Vol.11 No.7,
July
31,
2024
ABSTRACT: In this study, gel-immobilized fillers were used to conduct partial nitrification experiments, including a small-scale experiment in the laboratory and a pilot experiment in a leather factory. The performance of the filler for partial nitrification was investigated by the small-scale experiment under the reactor start-up condition with low initial ammonia oxidizing bacteria (AOB) relative abundance. Then pilot experiment was carried out for the application of the filler in leather wastewater treatment. Broadening the direction for the application of gel-immobilized fillers. Provide technical parameter reference and optimization basis for the application of gel-immobilized fillers in leather wastewater treatment. The partial nitrification in the small-scale reactor (SR) achieved an ammonia nitrogen oxidation rate (AOR) of 27 - 29 mg∙(L∙h)−1 and a nitrite nitrogen accumulation rate (NAR) of more than 94%. After an 82-day shutdown period, SR recovered its performance and continued to improve. High-throughput sequencing confirmed that AOB was enriched with a relative abundance of 32% and the percentage of nitrite oxidizing bacteria (NOB) was less than 0.01%. A pilot reactor (PR) was built using real leather wastewater as raw water. The experimental results showed that the normal performance of gel-immobilized fillers for partial nitrification was affected against the background of an average influent water quality of 537 mg∙L−1 ammonia nitrogen concentration and 2990 mg∙L−1 chemical oxygen demand (COD). Leather wastewater organics persistently affected PR nitrification. The growth of AOB was inhibited. Organics removal should be emphasized prior to nitrification, and the addition of an advanced oxidation process for organics is essential.