Kleerebezem R, Mendez R
University of Santiago de Compostela, Department Chemical Engineering, Chemistry Faculty, Spain.
Water Sci Technol. 2002;45(10):349-56.
In this paper we describe an alternative flow-chart for full treatment of wastewaters rich in organic substrates, ammonia (or organic nitrogen), and sulfate, such as those generated in fish cannery industries. Biogas generated during anaerobic pretreatment of these wastewaters is rich in hydrogen sulfide that needs to be removed to enable application of the biogas. Nitrogen elimination is traditionally achieved by subsequent nitrification and denitrification of the effluent of the anaerobic reactor. Alternatively, the hydrogen sulfide in the biogas can be applied as an electron donor in an autotrophic post-denitrification step. In order to study whether sufficient hydrogen sulfide containing biogas for denitrification was produced in the anaerobic reactor, the biogas composition as a function of the anaerobic reactor-pH was estimated based on a typical wastewater composition and chemical equilibrium equations. It is demonstrated that typical sulfate and nitrogen concentrations in fish cannery wastewater are highly appropriate for application of autotrophic post-denitrification. A literature review furthermore suggested that the kinetic parameters for autotrophic denitrification by Thiobacillus denitrificans represent no bottleneck for its application. Initial experimental studies in fixed-film reactors were conducted with sodium sulfide and nitrate as an electron donor-acceptor couple. The results revealed that only moderate volumetric treatment capacities (< 1 g-NO3- N l(-1) day(-1)) could be achieved. Mass balances suggested that incomplete sulfide oxidation to elemental sulfur occurred, limiting biomass retention and the treatment capacity of the reactor. Future research should clarify the questions concerning product formation from sulfide oxidation.
在本文中，我们描述了一种用于全面处理富含有机底物、氨（或有机氮）和硫酸盐的废水的替代流程图，比如鱼类罐头厂产生的废水。这些废水厌氧预处理过程中产生的沼气富含硫化氢，需要去除硫化氢才能使用该沼气。传统上，通过对厌氧反应器出水进行后续的硝化和反硝化来实现氮的去除。或者，沼气中的硫化氢可作为自养型后反硝化步骤中的电子供体。为了研究厌氧反应器中是否产生了足够用于反硝化的含硫化氢沼气，基于典型的废水成分和化学平衡方程估算了作为厌氧反应器pH函数的沼气成分。结果表明，鱼类罐头厂废水中典型的硫酸盐和氮浓度非常适合应用自养型后反硝化。此外，文献综述表明，反硝化硫杆菌进行自养反硝化的动力学参数并不构成其应用的瓶颈。在固定膜反应器中进行了以硫化钠和硝酸盐作为电子供体 - 受体对的初步实验研究。结果表明，只能实现中等的容积处理能力（<1 g-NO3-N l(-1) 天(-1)）。质量平衡表明，硫化物氧化为元素硫不完全，限制了生物量的保留和反应器的处理能力。未来的研究应阐明有关硫化物氧化产物形成的问题。
