Energy requirements for the continuous biohydrogen production from Spirogyra biomass in a sequential batch reactor

The current energy market requires urgent revision for the introduction of renewable, less-polluting and inexpensive energy sources. Biohydrogen (bioH2) is considered to be one of the most appropriate options for this model shift, being easily produced through the anaerobic fermentation of carbohydrate-containing biomass. Ideally, the feedstock should be low-cost, widely available and convertible into a product of interest. Microalgae are considered to possess the referred properties, being also highly valued for their capability to assimilate CO2 [1]. The microalga Spirogyra sp. is able to accumulate high concentrations of intracellular starch, a preferential carbon source for some bioH2 producing bacteria such as Clostridium butyricum [2]. In the present work, Spirogyra biomass was submitted to acid hydrolysis to degrade polymeric components and increase the biomass fermentability. Initial tests of bioH2 production in 120 mL reactors with C. butyricum yielded a maximum volumetric productivity of 141 mL H2/L.h and a H2 production yield of 3.78 mol H2/mol consumed sugars. Subsequently, a sequential batch reactor (SBR) was used for the continuous H2 production from Spirogyra hydrolysate. After 3 consecutive batches, the fermentation achieved a maximum volumetric productivity of 324 mL H2/L.h, higher than most results obtained in similar production systems [3] and a potential H2 production yield of 10.4 L H2/L hydrolysate per day. The H2 yield achieved in the SBR was 2.59 mol H2/mol, a value that is comparable to those attained with several thermophilic microorganisms [3], [4]. In the present work, a detailed energy consumption of the microalgae value-chain is presented and compared with previous results from the literature. The specific energy requirements were determined and the functional unit considered was gH2 and MJH2. It was possible to identify the process stages responsible for the highest energy consumption during bioH2 production from Spirogyra biomass for further optimisation.

Fukushima-derived radionuclides in sediments of the Japanese Pacific Ocean coast and various Japanese water samples (seawater, tap water, and coolant water of Fukushima Daiichi reactor unit 5)

We investigated Ocean sediments and seawater from inside the Fukushima exclusion zone and found radiocesium (134Cs and 137Cs) up to 800 Bq kg-1 as well as 90Sr up to 5.6 Bq kg-1. This is one of the first reports on radiostrontium in sea sediments from the Fukushima exclusion zone. Seawater exhibited contamination levels up to 5.3 Bq kg-1 radiocesium. Tap water from Tokyo from weeks after the accident exhibited detectable but harmless activities of radiocesium (well below the regulatory limit). Analysis of the Unit 5 reactor coolant (finding only 3H and even low 129I) leads to the conclusion that the purification techniques for reactor coolant employed at Fukushima Daiichi are very effective.

Photocatalytic Degradation of Anthracene in Closed System Reactor

Polycyclic aromatic hydrocarbons (PAHs) represent a large class of persistent organic pollutants in an environment of special concern because they have carcinogenic and mutagenic activity. In this paper, we focus on and discuss the effect of different parameters, for instance, initial concentration of Anthracene, temperature, and light intensity, on the degradation rate. These parameters were adjusted at pH 6.8 in the presence of the semiconductor materials (TiO2) as photocatalysts overUVlight. The main product of Anthracene photodegradation is 9,10-Anthraquinone which isidentified and compared with the standard compound by GC-MS. Our results indicate that the optimum conditions for the best rate of degradation are 25 ppm concentration of Anthracene, regulating the reaction vessel at 308.15 K and 2.5 mW/cm(2) of light intensity at 17 5mg/100 mL of titanium dioxide (P25).

Caracterización de bacterias filamentosas en el funcionamiento de un reactor aerobio de la planta de tratamiento de aguas residuales de origen cervecero

La actividad industrial y el desarrollo material y económico, han traído como consecuencia la contaminación del aire, agua y el suelo; lo que ocasiona modificaciones físicas químicas y biológicas que han producido un deterioro en la calidad del agua, dando como resultado problemas de contaminación que afectan tanto la productividad de los sistemas como la salud humana. A las aguas de composición variada provenientes de uso municipal, industrial, comercial, agrícola, pecuario, o de cualquier otra índole, ya sea privada o pública que han sufrido una degradación o alteración en su calidad original se le conoce como agua residual. Este trabajo tiene como objetivo “Caracterizar las bacterias filamentosas en el funcionamiento de un reactor aerobio de la planta de tratamiento de aguas residuales de origen cervecero” para ello se estudió durante varios meses los parámetros físico-químicos y biológicos para poder así controlar de las bacterias filamentosas y así evitar en un futuro problemas de operación o poder controlar su crecimiento y por ende, ecológicos dentro del sistema de lodos activados. La identificación se realizó tomando muestras en el reactor aerobio y realizándole la tinción de Gram para posteriormente ser vistos en un microscopio de una resolución de 100x; luego se caracterizaron las bacterias juntas con los parámetros de operación del tanque de lodos por muestra y los resultados encontrados fueron la presencia de filamentos Microtrix Parvicella, Tipo 021N, y Sp1 (llamada así por no ser identificada, ni encontrada en la literatura), esta es una nueva especie encontrada, ya que es propia de este reactor aerobio y crecen principalmente en aguas cerveceras y por deficiencia de nutrientes en el sistema. Este trabajo nos permitió conocer la dinámica que existe entre los parámetros fisicoquímicos y los microorganismos que se encuentran en un biorreactor Aerobio. Esto nos llevó a comprender mejor el funcionamiento de estos sistemas dentro de plantas de aguas residuales de tipo industrial. ABSTRACT Industrial activity and the physical and economic development have resulted in contamination of air, water and soil, causing physical chemical and biological changes that have produced deterioration in water quality, resulting in pollution problems affects the productivity of the systems and human health. A varied composition waters from municipal, industrial, commercial, agricultural, livestock, or any other use, whether private or public who have suffered a degradation or alteration in their original quality is known as residual water. This work aims to "characterize filamentous bacteria in the operation of an aerobic reactor plant wastewater treatment brewer origin" for this physicochemical and biological parameters were studied for several months to thereby control bacteria stringy and avoid future problems in operation or to control their growth and thus ecological This work aims to "characterize filamentous bacteria in the operation of an aerobic reactor plant wastewater treatment brewer origin" for this physicochemical and biological parameters were studied for several months to thereby control bacteria stringy and avoid future problems in operation or to control their growth and thus ecological within the activated sludge system. This work allowed us to understand the dynamics between physicochemical parameters and microorganisms found in an aerobic bioreactor. This led us to better understand the operation of these systems within plants industrial wastewater.