Avances en reciclaje y gestión de residuos

Municipal solid waste (MSW) is an attractive renewable carbohydrate resource. MSW has a naturally high carbohydrate content that can be utilized as a carbon and energy source for bacterial cultivation. There is industrial interest in implementing MSW as a sustainable cultivation medium for biological production in biorefinery platforms. The present study investigated the potential of MSW as a carbon and energy source for Escherichia coli. For this purpose, MSW was initially fractionated and processed to yield a liquid (LMSW) and a dry solid fraction (DSMSW). In contrast to DSMSW, the liquid fraction had a natural high sugar content of 21 g L-1. By further applying enzymecatalyzed hydrolysis to DSMSW, a hydrolyzate concentration of 114 g L-1 was achieved. The two MSW fractions were evaluated separately as carbon and energy sources for E. coli in batch and fed-batch cultivations.

This review presents the recent state of Dynamic membrane (DM) technology as the alternative for Ultrafiltration, Microfiltration and membrane bioreactor (MBR) system. DM technology involves the application of physical materials such as mesh or clothes as a barrier that enhances the formation of a cake layer on their surfaces. This technology has been used extensively in local filtration processes. DM has a lower risk of membrane fouling, lower capital cost and requires little energy compared to MBR. The performance of DM was evaluated to obtain a suitable method for membrane filtration technology. Further suggestion to encourage the application of this technology in wastewater treatment plant was given.

Background: Hospitals produce a substantial amounts of waste. To understand the potential role of employees in reducing waste, we surveyed healthcare workers in the cardiac catheterization laboratory-a resource-intensive hospital area – about their personal practices regarding sustainability at work and at home.

Methods and results: We surveyed 52 full-time employees of the University of Michigan Cardiac Catheterization Laboratories using an anonymous online survey. Employees included all individuals working in a patient care capacity, such as physicians, nurses, technicians, medical assistants and administrators. Paired t-tests compared responses to parallel questions about recycling and energy saving habits between work and home. A total of 42 of 52 (80.8%) respondents completed the survey with 12 (28.6%) physicians and 30 (71.4%) non-physicians. Recycling and energy saving habits were more evident on average at home than in the workplace across the majority of areas examined. Comparing sustainability habits between subpopulations, physicians were found to engage in energy saving habits at home significantly less often than non-physician employees (mean score, 2.3 versus 2.9; p=0.0014) and employees under 40 years of age engaged in energy saving habits significantly less at work than employees over 40 years of age (mean score, 1.7 versus 2.1; p=0.0322).

Abstract Rice straw fibers, considered in this work are a good source for synthesized amorphous carbon thin film (ACTF) hence; it has 64% cellulose linen fibers. We study the structure and properties of ACTF as new adsorbents to study the individual adsorption characteristics of sodium ions from synthetic water. Batch tests, used to study the influence of pH, contact time, and temperature, on the ion adsorption on activated carbon. We found that the pseudo-secondorder kinetic model and by Langmuir isotherm would portray contact time of sodium adsorption and isothermal adsorption steadies, respectively. Also the adsorption process of sodium ions on activated carbon is stronger depends on pH. The maximum adsorption capacities of sodium on activated carbon were 107, 120 and 135 mg g-1 at 35, 45, and 65°C. The thermodynamic parameters explain that the adsorption of sodium ions on novel ACTF was a spontaneous process and endothermic reaction. According to adsorption studies, activated carbon suitable for ion chromatography or desalinate sodium ion in ion exchange process in the hybrid desalination process with insignificant loss of adsorption capacity. However, the ACTF has better properties than any other carbon materials that got from an agricultural by-product.

Abstract All data suggest that microbial community structures or samples of sludge with a content of phosphate between 8 and 12.3% were very similar but distinct from those containing phosphate at 1.8%. In all samples analyzed, ubiquinones, menaquinone and fatty acids were the main components. Dominance and E5 suggested that a large number of organisms belonging to the b and subclasses Proteobacteria and Actinobacteria from higher GMC Grampositive bacteria, respectively, were present. Denaturing gradient gel electrophoresis analysis revealed at least 6-10 predominant DNA bands and numerous other fragments in each sample. Five major denaturing gradient gel electrophoresis fragments from each of 1.8% and 11.8% phosphate containing sludge samples, respectively, were successfully isolated and sequenced. Phylogenetic analysis of the sequences revealed that both 3% and 15% phosphate -containing sludge samples shared three common phylotypes which are separately associated with new bacterial groups of subclass C Proteobacteria, two E5 containing Actinobacteria, and Caulobacter spp. The subclass Proteobacteria. Phylogenetic analysis revealed useful phylotypes unique for both samples sludge. Therefore, changes in the phosphate content did not affect the composition and quantity prevailing microbial population, although specific phylotypes could not be unambiguously associated with EBPR.

A large amount of solid waste that is being generated by the Municipality, such as markets, is left generally unmanaged. The waste collection and disposal does not contend with the amount of waste generated per day as a result garbage are scattered. Market areas produce not only a large quantity of solid waste but also generate different types of waste. Because the market areas generate different types of waste, they need to be managed properly in order to avoid the detrimental effects it could have on the environment, health, and ecosystem. This paper will therefore present the challenges and problem associated with managing the solid waste generated by the three main markets (Mwanakwerekwe, Darajani and Mikunguni) which make up the Zanzibar municipality. Several methods were used to conduct this study including questionnaires, interviews and direct observations. The results of the study showed that the daily amount of solid waste generated by Mwanakwerekwe, Darajani and Mikunguni were 9,296 kg per day, 4,648 kg per day and 830 kg per day, respectively. The study also revealed several shortcomings in connection with the solid waste managements in the markets including low quality, inadequate storage and transportation facilities, an informal dump site, insufficient collection frequency of solid waste, low level of awareness and education of solid waste management and lack of enforcement of regulations by law enforcement. This study proposes several methods to improve solid waste management starting with the provision of adequate dustbins and skips, and also including an increase of collection frequency, increasing public awareness, involvement of private sector and separation of bio-degradable and non-biodegradable waste. The logical conclusion is that all the informal dump sites should be replaced by Kibele dump sites.