In the last decades high population growth has increased the demand of energy, leading to excessive use of fossil fuels. Due to this crescent demand and need of clean fuels, many studies focused on the hydrogen production as alternative energy source. Biological hydrogen production is interesting due to two main reasons: the use of a renewable energetic source and the easy operation of the productive plants at ambient temperature and pressure [1]. The use of cheaper sources, as wastewater with considerable amount of organic fraction, makes the hydrogen production a sustainable process, since the treatment of the wastewater is mandatory for pollution control and hydrogen is a by-product of this process [2]. Several factors affect the hydrogen production in anaerobic reactors as temperature, pH, type and operational condition of reactor, procedure of inoculation, source and processing of the inoculum, wastewater type, among others. The characteristic of the wastewater is extremely important since hydrogen production will depend on the organic contents, being the carbohydrates the main compounds of interest in the process, Moreover, the composition of macro (N, P, S) and micronutrients (K, Mg, Ca, Fe, Mn, Co, Cu, Mo, Zn) is essential for the metabolism and can affect hydrogen production. Among the macronutrients, nitrogen is the most requested for the microorganism and metabolism can be altered due to deficiency or excess this nutrient in the medium.
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