Universidade do Estado de Santa Catarina, Departamento de Engenharia Ambiental, Laboratório de Tratamento de Água e Resíduos, Av. Luís de Camões, 2090, CEP 88520-000, Lages, Santa Catarina, Brazil.
Universidade Federal de Santa Catarina, Departamento de Engenharia Química e Engenharia de Alimentos, Laboratório de Engenharia Bioquímica, Campus Universitário Trindade, CEP 88040-900, Florianópolis, Santa Catarina, Brazil.
J Environ Manage. 2018 Jul 1;217:520-530. doi: 10.1016/j.jenvman.2018.03.120. Epub 2018 Apr 7.
Among the methods that are studied to eliminate nitrate from drinking water, biological denitrification is an attractive strategy. Although several studies report the use of denitrifying bacteria for nitrate removal, they usually involve the use of sewage sludge as biomass to obtain the microbiota. In the present study, denitrifying bacteria was isolated from bamboo, and variable parameters were controlled focusing on optimal bacterial performance followed by physicochemical analysis of water adequacy. In this way, bamboo was used as a source of denitrifying microorganisms, using either Immobilized Microorganisms (IM) or Suspended Microorganisms (SM) for nitrate removal. Denitrification parameters optimization was carried out by analysis of denitrification at different pH values, temperature, nitrate concentrations, carbon sources as well as different C/N ratios. In addition, operational stability and denitrification kinetics were evaluated. Microorganisms present in the biomass responsible for denitrification were identified as Proteus mirabilis. The denitrified water was submitted to physicochemical treatment such as coagulation and flocculation to adjust to the parameters of color and turbidity to drinking water standards. Denitrification using IM occurred with 73% efficiency in the absence of an external carbon source. The use of SM provided superior denitrification efficiency using ethanol (96.46%), glucose (98.58%) or glycerol (98.5%) as carbon source. The evaluation of the operational stability allowed 12 cycles of biomass reuse using the IM and 9 cycles using the SM. After physical-chemical treatment, only SM denitrified water remained within drinking water standards parameters of color and turbidity.
在研究的消除饮用水中硝酸盐的方法中，生物反硝化是一种很有吸引力的策略。尽管有几项研究报告了使用反硝化细菌去除硝酸盐，但它们通常涉及使用污水污泥作为生物量来获得微生物群。在本研究中，从竹子中分离出了反硝化细菌，并控制了可变参数，重点是优化细菌性能，然后对水的充足性进行理化分析。通过这种方式，竹子被用作反硝化微生物的来源，使用固定化微生物（IM）或悬浮微生物（SM）去除硝酸盐。通过分析不同 pH 值、温度、硝酸盐浓度、碳源以及不同 C/N 比下的反硝化作用来优化反硝化参数。此外，还评估了操作稳定性和反硝化动力学。负责反硝化作用的生物质中的微生物被鉴定为奇异变形杆菌。反硝化后的水经过混凝和絮凝等物理化学处理，以调整颜色和浊度等参数，使其符合饮用水标准。在没有外部碳源的情况下，使用 IM 进行反硝化的效率为 73%。使用 SM 时，使用乙醇（96.46%）、葡萄糖（98.58%）或甘油（98.5%）作为碳源，反硝化效率更高。操作稳定性的评估允许 IM 重复使用 12 次，SM 重复使用 9 次。经过物理化学处理后，只有 SM 反硝化水的颜色和浊度参数仍在饮用水标准范围内。
