Batch Mode Biomethane Production from Anaerobic Digestion of Palm Oil Mill Effluent (POME) with Cassava Peels and Cabbage Waste

Introduction: Biomedical waste (BMW) generated is a matter of great concern as it consists of high levels of hazardous waste. The lack of segregation and disposal policy in India leads to use of such infectious waste in day-to-day life [1]. Lack of awareness about segregation of Biomedical Waste (BMW) at source is a major cause for Hospital Acquired Infection (HAI) and increased risk of contamination of hospital and external environment. Materials & Methods: To address the problem, we decided to train interns and health care workers to increase their awareness about BMW segregation and thereby reduce HAI. The program was run in 3 phases. In the 1st phase need assessment was done as to how important and effective this program would be in controlling HAI. The 2nd phase comprised of identifying the stake holders in the program who will play the key role in implementing the program effectively. The 3rd phase of Biomedical Segregation Program BMWSP focused on the outcomes as enumerated in the Kirkpatrick model [2], viz., participants’ reaction, learning, change in behavior and results. Measuring the impact of the program on the learners at these four levels revealed the effectiveness of the program. Results: To overcome the shortfalls in the Kirkpatrick model we used Logic model which took care of the instructional design. Logic model is better suitable for evaluating BMWSP as it considers inter-relation between constituents in a sequence and their effect on the process as well as product providing the necessary roadmap from the planned work (inputs and activities) to the intended results (outputs, outcomes and impact). It is a sequence of events connecting each other starting with Resources / Inputs, Activities, Outputs, Outcomes and Impact. The model helped medical interns and dental students to understand the importance for BMWSP and also made a significant difference in its implementation. Conclusion: The program helped in making the health care staff more aware about BMWSP. It also increased their knowledge, and helped in implementation of the program. This will significantly reduce HAI and overall benefit the society.

Effect of Agitation on Anaerobic Co-Digestion of Swine Manure and Food Waste

Abstract The synergism of food waste associated with swine manure can provide an increase in biogas production, besides promoting greater stability in the anaerobic co-digestion process. To verify this effect, co-digestion tests were performed in two reactors, one with agitation, and the other without agitation. In both systems, gasometers were used to measure biogas production in an experiment lasting two hydraulic retention times (HRT). On each feeding day, the temperatures of the ambient and of the effluent taken from the reactors were measured, and samples of the food waste and effluent were collected to perform analysis of pH, total solids (TS), volatile solids (VS), fixed solids (FS), volatile acidity (AV), and total alkalinity (TA). In addition, the chemical oxygen demand (COD) was determined every five days, and gas composition was determined at the beginning of the second HRT. As important results, in both reactors a decrease in pH was verified due to the weakening of the buffer effect of the medium. This was due to the low alkalinity found in the food waste, causing an increase in acidity in the contents of the reactors. The volume of biogas produced was higher in the reactor with agitation, which meant an increased efficiency of the process. Finally, a low methane content was verified through chromatographic analyses, indicating a reduction in the activity of the microorganisms present in the medium. Thus, it is concluded that agitation linked to anaerobic co-digestion of swine manure with food waste exerted a positive effect on biogas production.

Co-digestión anaerobia de la fracción orgánica de residuos sólidos urbanos y su lixiviado / Anaerobic co-digestion of the organic fraction of urban solid waste and its leachate

RESUMEN Los residuos sólidos urbanos (RSU), al ser vertidos sin tratamiento apropiado, ocasionan daños severos al medio ambiente influyendo en la calidad de vida de la población; por esta razón actualmente se le presta atención al adecuado manejo de estos residuos. En este trabajo se estudia la reducción de la fracción orgánica (FORSU), de residuos sólidos generados por un grupo poblacional, tomando como referente una de las residencias estudiantiles de la Universidad de Oriente. La generación de FORSU en la residencia es de 0,06 kg/habdía, con un contenido de sólidos totales de 30,9 ± 5,3 %, de los cuáles el 81,7 ± 0,6 % son sólidos volátiles. Se evalúa la digestión anaerobia la FORSU, mediante un sistema de tratamiento en dos etapas. La primera etapa se realiza en un reactor en lote de lecho escurrido, que permitió un tratamiento discontinuo e in situ de la FORSU, en co-digestión anaerobia con un 25 % de estiércol vacuno. En una segunda etapa, se evalúa el tratamiento anaerobio para los lixiviados que se generan en el reactor en lote, empleando un reactor UASB. En el reactor en lote se alcanzó una remoción de sólidos volátiles del 44,1 %, mientras que en el reactor UASB se removió un 81,2 % de DQO. Como resultado la evaluación del sistema de tratamiento, se alcanzó una productividad total de 5,37 LCH4-kgSV -1-d-1.

ABSTRACT Urban solid waste (MSW), when are discharged without proper treatment, causes severe damage to the environment, influencing the population's quality of life. For this reason, attention is currently paid to the proper handling of this waste. This paper studies the reduction of the organic fraction of solid waste (OFMSW), generated by a population group, taking as reference one of the Student Residences of the Universidad de Oriente. The generation of OFMSW in the residence is 0.06 kg/inhabday, with a total solid content of 30.9 ± 5.3%, of which 81.7 ± 0.6% are volatile solids. The anaerobic digestion of OFMSW is evaluated through a two-stage treatment system. The first stage is performed in a drained-bed batch reactor, which allowed discontinuous and in-situ treatment of OFMSW, in anaerobic co-digestion with 25% of cow manure. In a second stage, the anaerobic treatment for the leachates generated in the batch reactor is evaluated, using a UASB reactor. In the batch reactor a removal of volatile solids of 44.1% was achieved, while in the UASB reactor 81.2% of COD was removed. As a result of the evaluation of the treatment system, total productivity of 5.37 L CH4 -kgSV -1-d-1 was achieved.

Biogas Production Potential of Co-Digestion of Pig Droppings with Cow Dung Under Tropical Conditions.

The biogas production potential of animal wastes offers sustainable biogas production, cleaner environment and economic benefits. This work is an investigation into the best blend leading to higher biogas production from two major animal wastes for improved biogas production. The study of biogas production potentials was conducted for pig droppings (PGD) with cow dung (CD) in different mixture ratios of 100: 00, 75: 25, 50: 50, 25:75 and 00:100 to determine the optimum mixture ratio in a 30 litres digesters. The results revealed that 50%PGD + 50%CD is the optimum mixture ratio for the selected animal waste. The first order kinetic model used in the study adequately fitted the experimental data for the digesters.

Co-digestion of Food Waste and Human Excreta for Biogas Production.

The ever increasing cost of fossil fuels and its attendant pollution menace has provided the pedigree to consider alternative sources of energy. An investigation was launched into the design and construction of an Anaerobic Digester system from locally available raw materials using local technology and the production of biogas from food wastes and Human excreta generated within a University campus. The experiment lasted for 60 days using a 40-liters laboratory scale anaerobic digester. The volume of gas generated from the mixture was 84,750cm3 and comprised of 58% CH4, 24% CO2, and 19% H2S and other impurities. The physico-chemistry of the feedstock in the digester revealed an initial drop in pH to more acidic range and a steady increase 4.52 – 6.10. The temperature remained relatively constant at mesophilic range: 22.0ºC– 30.5ºC throughout the study. The Carbon/Nitrogen (C/N) ratio of the feedstock before digestion was within 139:1. Population distributions of the microflora show aerobic and anaerobic bacteria to include Klebsiella spp, Bacillus spp, Escherichia coli, Clostridium spp and a methanogen of the genera Methanococcus. In most developing nations of Sub-Saharan Africa where biomass is abundant, and where biogas technology is in its infant stage, the anaerobic digestion system could be the much awaited solution.