Nutrients Cycle within Swine Production: Generation, Characteristics, Treatment and Revaluation

The swine production generates slurries nutrients rich, which could be revaluated in cereal crops used for its food and energy generation (biogas) for use on the farm. However, the revaluation requires to know their physical–chemical and biological characteristics, which allow giving an adequate transformation (treatment). On the one hand, swine production and consumption market reveal the superiority of emergent countries on meat/cereal (feed) production and swine meat consumption (concentrated population). The food composition and growth phase will influence the swine slurries composition, which is rich in organic matter, macronutrients (N, P) and micronutrients (Cu and Zn). These characteristics will generate odors (organic matter, macronutrients) and ecotoxicology effects (macro/micronutrients) if they are not treated. Moreover, the swine slurries treatment allows revaluated them in agriculture and obtaining energy. Anaerobic technologies (anaerobic lagoon, mixed complete reactors, UASB, among others) are the most used/cost-effective to organic matter removal from swine slurries, obtaining from 0.28 to 0.83 m3 biogas/kg organic matter. Meanwhile, passive technologies (constructed wetlands) are the most used technologies to nutrients and metals removal. Treated swine slurries from constructed wetlands have agronomic properties. Therefore, the nutrients cycle within swine production would favor concepts of revaluation in origin

Odor from anaerobic digestion of swine slurry: influence of pH, temperature and organic loading

Farm slurry management from storage and/or treatment is the main source of odors from swine production, which are determined by factors such as operational variations (organic loading), cleaning of facilities and animal diet (pH) or environmental conditions (temperature). The aim of this study was to evaluate the influence of pH, temperature and organic loading on odor generation during anaerobic digestion of swine slurry. The methodology employed batch experimental units under controlled pH (6.0, 6.5, 7.0 and 8.0) and temperature (20, 35 and 55 °C) conditions. Additionally, an Upflow Anaerobic Sludge Blanket (UASB) system was operated under two Organic Loading Rate (OLR) conditions as Chemical Oxygen Demand (COD) (Phase I: 0.4 g L-1 d-1 of COD, Phase II: 1.1 g L-1 d-1 of COD). Odor (batch and UASB reactor) was evaluated by detection and recognition threshold as Dilution Threshold (D-T). Acidic conditions (pH 6.0) and thermophilic temperatures (55 °C) increased odors (1,358 D-T) and acidified the system (Intermediate/Total Alkalinity ratio (IT/TA): 0.85) in batch experiments. Increasing OLR on UASB reactor reduced odors from 6.3 to 9.6 D-T d-1 due to an increase in the production of biogas (0.4 to 0.6 g g-1 COD removed of biogas)

EJE 07-15 Análisis geográfico para la implantación de sistemas de tratamiento de co-digestión anaerobia de residuos agropecuarios en la provincia de Manabí, Ecuador

RESUMENEn el Ecuador, potencialmente se generan alrededor de 140 mil ton/día de residuos pecuarios (porcinos y bovinos) y alrededor de 8,9 ton/ha de cultivos de transición (maíz y arroz). La generación de residuos agropecuarios trae consigo problemas ambientales, sociales y económicos, por lo que su gestión es prioritaria. La co-digestión anaerobia, es una alternativa tecnológica viable porque a partir de los residuos agropecuarios potencia el valor energético (biogás) y agronómico (residuos estabilizados). En el sector rural, la sostenibilidad de las tecnologías de tratamiento de residuos (re-valorización), depende de la disponibilidad permanente de éstos, condición que puede lograrse con plantas centralizadas. El objetivo de este estudio, fue analizar geográficamente la generación de residuos agropecuarios sobre un espacio geográfico definido por ser altamente productivo a nivel productor agropecuario y necesarios para la implantación teórica de plantas de co-digestión anaerobia para residuos agropecuarios locales, mediante Sistemas de Información Geográfica (SIG) y considerando criterios de sustentabilidad. La metodología se basó en el uso de bases de datos agropecuarios y mapas temáticos de la provincia de Manabí, definida previamente como la zona geográfica con mayor potencial de generación de estetipo de residuos en el Ecuador. La información cartográfica y censal utilizó Procesos de Jerarquía Analítica (PJA) para dar peso a ciertas restricciones y álgebra de mapas para establecer restricciones físicas, ambientales, sociales y económicas que permitan delimitar las zonas sustentablemente adecuadas para estos fines. Los resultados obtenidos, permitieron establecer áreas delimitadas en la zona geográfica de estudio, con mayor (>50 ton Sólidos Volátiles o SV) a menor (< 10 ton SV) potencial energético y agronómico. En conclusión, los modelos geográficos basados en SIG permiten establecer zonas apropiadas para la gestión y planificación en el tratamiento y re-valorización de residuos agropecuarios, es decir es una herramienta eficaz en la toma de decisiones a nivel territorial.Palabras clave: co-digestión anaerobia, estiércol animal, residuos de cultivos, análisis GIS. ABSTRACTIn Ecuador are potentially generated approximately 140,000 ton/day of livestock waste (pigs and cattle) and about 8.9 tonnes / ha of transitional crops (maize and rice). The generation of agricultural waste cause environmental, social and economic problems, therefore its management is a priority. Anaerobic co-digestion from agricultural wastes is a viable technological alternative because it increases its energetic value (biogas) and agronomic properties (stabilized waste). In the rural sector, the waste treatment technologies sustainability depends on the permanent availability of these wastes, condition that can be achieved with centralized plants. The objective of this study was to analyze geographically the wastes agriculture generation on a highly productive geographical space at the agricultural level by this productivity activity, in where will theoretically implant anaerobic co-digestion plants using Geographic Information Systems (GIS) and considering sustainability criteria (social, economic and environmental). The methodology was based on the use of agricultural databases and thematic maps of the Manabí province, which has the highest agricultural potential of this type of waste generation in Ecuador. The cartographic and census information used the Analytical Hierarchy Process (AHP) to give weight to certain constraints and maps algebra to establish physical, environmental, social and economic constraints that allow the sustainable delimitation of areas. The results obtained allowed to establish areas delimited within the study area, with greater (> 50 ton Volatile Solids or VS) to smaller (<10 ton VS) energetic and agronomic potential. In conclusion, geographical models based on GIS allow the delimitation of  ppropriate zones for the management and planning in the treatment and re-valorization of agricultural residues, that is to say it is an effective tool for decision making at territorial level.Keywords: Anaerobic co-digestion, animal manure, crop residues, GIS analysis

Emerging Contaminants and Their Removal from Aqueous Media Using Conventional/Non-Conventional Adsorbents: A Glance at the Relationship between Materials, Processes, and Technologies

Emerging contaminants (ECs) are causing negative effects on the environment and even on people, so their removal has become a priority worldwide. Adsorption and the associated technologies where this process occurs (filtration/biofiltration) have gained great interest, due to its low cost, easy operation, and effectiveness mainly in the removal (up to 100%) of lipophilic ECs (log Kow > 4). Activated carbon continues to be the most efficient material in the removal of ECs (>850 mg/g). However, other conventional materials (activated carbon, clays, zeolites) and non-conventional materials (agro-industrial/forestry/industrial residues, nanomaterials, among others) have shown efficiencies greater than 90%. Adsorption depends on the physicochemical properties of the materials and ECs. Thus, physical/chemical/thermal modifications and nanomaterial synthesis are the most used procedures to improve adsorption capacity. A material with good adsorptive properties could be used efficiently in filtration/biofiltration technologies. Agro-industrial residues are promising alternatives to be used in these technologies, due to their high availability, low toxicity, and adsorption capacities (up to 350 mg/g). In filtration/biofiltration technologies, the material, in addition to acting as adsorbent, plays a fundamental role in operation and hydraulics. Therefore, selecting the appropriate material improves the efficiency/useful life of the filter/biofilter

Heliconia stricta Huber Behavior on Hybrid Constructed Wetlands Fed with Synthetic Domestic Wastewater

Constructed wetlands (CWs) represent a highly efficient, eco-friendly and economic alternative for wastewater treatment in decentralized contexts. The adequate selection of the plants used in CWs plays a decisive role in the successful implementation and operation of this technology type. In this work, we studied the behavior of a native tropical plant (Heliconia stricta Huber) for the removal of organic matter and nutrients within a hybrid CW system fed with synthetic domestic wastewater. This hybrid system was composed of two wetlands, a vertical surface flow (VSF-CW) and a horizontal subsurface flow (HSSF-CW), connected in series and being operated with nominal hydraulic loading rates of 12 and 9 mm day−1, respectively. Results evidenced nitrification (nitrite concentration increased up to three times) but not denitrification because nitrate concentration increased in the final effluent. The average removal efficiencies were 86.8%, 96.4%, and 57.0%, for COD, NH4+ and PO43−, respectively. On the other hand, the apical height, basal diameter, leaf length and width increased in relation to initial measurements (between 0.6–7.1%) in plants of both CWs, which demonstrated the ability of the plants to adapt to the operating conditions of the system. This promising performance observed when using Heliconia stricta Huber opens the need for further research and could be particularly interesting in CWs used in tropical areas

Performance of hybrid biofilter based on rice husks/sawdust treating grey wastewater

An innovative nature-based technology for wastewater treatment is the hybrid biofiltration, which combines complex symbiotic relationships between plants, earthworms and microorganisms with adequate support components. This latter could be optimized using organic supports. The aim of this research was to evaluate the performance of hybrid biofilters based on rice husks/sawdust treating grey wastewater from mining camps. Four biofilters using an active layer (rice husks/sawdust: 50/50%, v/v) at 60(B60) and 45(B45) cm height and operating for 64 days at a hydraulic loading rate between 1 and 5 m3/m2d were monitored. Eisenia foetida Savigny and Cyperus papyrus L. were used as a biotic component. COD, N-NH4+, NO3−, NO2−, PO43− and fecal coliforms were weekly monitored. Results showed that the most efficient HB was using 60 cm as an active layer and operating at 3 m3/m2d, which reported average removal efficiencies for COD, NH4+, NO3−, PO43− and fecal coliforms up to 85, 89, 47, 49 and 99.9%, respectively. Organic support improved the rate growth for Cyperus papirus L. and E. foetida Savigny up to 50%. Hybrid biofiltration using organic residues is low-cost, providing all-encompassing operational and performance features, improving the wastewater reclamation opportunities. HIGHLIGHTS Hybrid biofilters based on rice husks/sawdust at 3 m3/m2d remove efficiently organic matter (85%) and pathogens (99%).; Rice husks/sawdust as support material improve the growth rate organisms (plants, earthworms) by up to 50%.; Hydraulic loading rate is the most influential factor in the organic matter removal.

A Bibliometric-Statistical Review of Organic Residues as Cementitious Building Materials

Climate deterioration and environmental pollution has been widely studied by a wide scientific community. The effects of the ecosystem deterioration impacts directly to human activities. In this scenario, the building industry has increased the pressure on proposing new materials to replace the cementicious component and natural resources (water, sand, gravel, and limestone) on mortar and concrete to reverse this trend. To this end, organic residues can offer opportunities as an available alternative for construction applications. Therefore, this paper aims to broaden the scope of research in this field by investigating the potential use of organic residues as cementicious building material based on bibliometric-statistical analysis using scientific information. A preliminary bibliometric analysis using VOSviewer was carried out to define the keywords co-ocurrence from Scopus database. Type of organic material, constructive use, and its properties (physicochemical, mechanical, and thermal) were extracted from scientific publications. Then, a systematic analysis criteria was defined to limit the scope of the study. Finally, statistical variance analysis and multiple correlation for identifying constructive application were applied. From the co-ocurrence analysis of keywords, we determined that 54% of the selected scientific publications were closely related to the scope of this study. State-of-the-art study established that related researches grew exponentially at a rate of about 30%/year. Moreover, scientific publications reported the use of a wide variety of organic residues, such as wheat, paper, hemp, rice, wood, molluscs, olive, coconut, among others. Mainly, agricultural residues (82%) with building applications related to structural concrete, mortar, bricks, and blocks, had been evaluated. Physicochemical properties from organic residues (extractives content, lignin content, and density) were correlated to mechanical (compressive, flexural and tensile strength) and thermal properties (thermal conductivity). The identification of the physicochemical properties of the organic residues allow us to predict the mechanical and thermal behavior of the material with residues. In summary, agricultural residues are the most promising organic building material due to their abundance and lignin content, exhibiting better mechanic and thermal properties than any other organic residues