Study on the properties of denitrifying carbon sources from cellulose plants and their nitrogen removal mechanisms

Abstract

Carbon sources of cellulose plants are the promising materials that enhancing the activities of denitrifying bacteria in the groundwater system. To further verify the denitrification performance of cellulose plants and the main factors of affecting the denitrifying system, six cellulose plants from agricultural wastes (wood chip, corn cob, rice husk, corn straw, wheat straw, and sugar cane) were selected for bioavailable organic matter leaching experiments, carbon denitrification experiments, functional bacteria identification, and analysis experiments. The results show that the extracts of cellulose plants contain a mixed carbon sources system including small molecular organic acids, sugars, nitrogen-containing organic components, and esters. The qPCR results showed that the denitrifying bacteria had obvious advantages compare to anaerobic ammonia-oxidizing bacteria during the stable period; the denitrification experiment showed that each of six cellulose plants removed more than 80% of nitrogen, and the denitrification rates reached 1.00–2.00 mg N cm−3·d−1. The supplement of cellulose plants promotes the metabolism rate of denitrifying bacteria, and the additional denitrifying bacteria have little effect on nitrate removal. In summary, the expected denitrification reaction occurred in the cellulose plant system, which is suitable as a carbon source material for water body nitrogen pollution remediation.

Enhanced Biological Nitrate Removal from Groundwater in Humid Tropical Regions Using Corn Cob-Based Permeable Reactive Barriers: A Case Study from Panama

“…The average chemical oxygen demand (COD) concentration observed was 190.65 ± 26.74 mg/L, showing a diminishing trend over time with fluctuations ranging from 150.83 mg/L to 216.67 mg/L. These findings align with other studies using agricultural residues, such as wood chips, corn cobs, rice husks, corn straw, wheat straw, sugarcane straw [56], Typha angustifolia [57], and sugarcane straw [19]. These studies similarly reported an initial release of carbon followed by a gradual decrease.…”

Insight into the Enzymatic Mechanism of Straw Carbon Source and Its Denitrification Availability

“…Zhang et al conducted an analysis of 10 different types of straw leaching solutions, and discovered that the primary constituents were organic acids, carbohydrate and nitrogenous organics, which contained a total of 16 compounds [32]. Similarly, Qi et al carried out experiments on six different types of straw and found that cellulose extracts contained a mixed carbon source system including small molecular organic acids, sugars, nitrogen-containing organic components and esters [33]. However, these studies have their limitations when it comes to component analysis.…”