Life cycle assessment and life cycle costing of advanced anaerobic digestion of organic fraction municipal solid waste.

The aim of this study is the evaluation of the environmental sustainability by means of Life Cycle Assessment (LCA) and economic profitability through Life Cycle Costing (LCC) of the 18 anaerobic digestion (AD) configurations carried out on Organic Fraction Municipal Solid Waste (OFMSW) at three Substrate Inoculum (S:I) ratios (1:2, 1:1 and 2:1) for three different inoculum incubation times (0, 5 and 10 d). The adopted approach was the eco-efficiency perspective, coming from the combination of technical, environmental (LCA) and economic (LCC) perspectives. The main findings of the study were that increasing both the S:I ratio and the inoculum incubation time (5 and 10 d) the environmental impacts decreased, and economic profitability increased. The lowest values of Climate Change were achieved by the AD performed with both inocula WAS and CAS for 10 d at S:I equal to 2:1: 28.67 and 27.72 kg CO2 eq respectively. The minimum AD plant size for which all the 18 AD configurations was economically profitable after 5 y of amortization was 30,000 t/y of OFMSW. Capital and operational costs decreased by increasing the incubation time of the inoculum and the S:I ratio, since higher specific biogas rate was reached, and smaller AD bio-reactor volume were adopted because hydraulic retention time decreased. The AD plant size, for which maximal revenues and minimal capital and operational costs were detected, was 50,000 t/y OFMSW. Among all the AD configurations, the environmental sustainability and economic profitability were reached by test perfomed with inocula WAS and CAS incubated for 5 and 10 d at the highest S:I ratio 2:1.

CO2 capture on natural zeolite clinoptilolite: Effect of temperature and role of the adsorption sites.

In this study, the adsorption capacity of the low-cost zeolite clinoptilolite was investigated for capturing carbon dioxide (CO2) emitted from industrial processes at moderate temperature. The CO2 adsorption capacity of clinoptilolite (a commercial natural zeolite) and ion-exchanged (with Na+ and Ca2+) clinoptilolite were tested under both dynamic (using a fixed-bed reactor operating with 10% vol. CO2 in N2) and equilibrium conditions (measuring single component adsorption isotherms). The dynamic CO2 adsorption capacity of bare clinoptilolite and ion-exchanged clinoptilolite were evaluated in the temperature range from 293 K to 338 K and the obtained breakthrough curves were compared with those of the commercial zeolite 13X (Z13X). Although the adsorption capacity of Z13X exceeded those of bare clinoptilolite and ion-exchanged clinoptilolite at 293 K, the clinoptilolite exhibited the highest CO2 uptake at a moderate temperature of 338 K (i.e. 25 % higher than Z13X). This feature appears in agreement with the lower isosteric heat of CO2 adsorption on clinoptilolite compared to the other samples. The surface species affecting the qiso and adsorption capacity were investigated through the FTIR spectroscopy using CO2 as probe molecule. As a whole, it has been observed that CO2 forms linear adducts onto K+ and Mg2+ cations of the bare clinoptilolite, and carbonate-like species onto its basic sites. With the Na-exchanged clinoptilolite, Na+ ions led to a decrease in surface basicity and to the formation of both single (Na+···OCO) and dual (Na+···OCO⋯Na+) cationic sites available for the formation of linear adducts. As a result of the remarkable adsorption capacity of clinoptilolite at 338 K, this material appears to be a promising adsorbent for the direct CO2 removal from different flue gases sources operating at such temperatures.

Full scale treatment of ASR wastes in a modified rotary kiln.

A plant, designed for the thermo-valorisation of tyres, was specifically modified in order to treat Automobile Shredder Residue (ASR). Results from two full-scale combustion experiments, carried out on large ASR feeding lots (thousands of tons) indicate the proposed technology as a potential route to help the fulfilling of impending 95% reuse and recovery target set by the End of life Vehicle (ELV) Directive (January 2015). The paper describes the main operational troubleshot occurred during the first experiment (emissions at the stack out of regulatory limits and problems of clogging on the conveyer belt) and the consequent upgrading solutions (pre-treatment, introduction of waste double low-flow screw feeder and a cyclone prior to the main fan, modification of rotatory kiln inlet) adopted to allow, during the second long-term experiment, a continuous basis operation of the plant in full compliance with the discharge limit to the atmosphere. Characterization of both ASR and combustion residues allowed to quantify a 18% of combustion residues as not dangerous waste while only the 2% as hazardous one. A pre-treatment for the reduction of fines in the ASR was recommended in order to achieve the required energy recovery efficiency.

On the ASR and ASR thermal residues characterization of full scale treatment plant.

In order to obtain 85% recycling, several procedures on Automotive Shredder Residue (ASR) could be implemented, such as advanced metal and polymer recovery, mechanical recycling, pyrolysis, the direct use of ASR in the cement industry, and/or the direct use of ASR as a secondary raw material. However, many of these recovery options appear to be limited, due to the possible low acceptability of ASR based products on the market. The recovery of bottom ash and slag after an ASR thermal treatment is an option that is not usually considered in most countries (e.g. Italy) due to the excessive amount of contaminants, especially metals. The purpose of this paper is to provide information on the characteristics of ASR and its full-scale incineration residues. Experiments have been carried out, in two different experimental campaigns, in a full-scale tyre incineration plant specifically modified to treat ASR waste. Detailed analysis of ASR samples and combustion residues were carried out and compared with literature data. On the basis of the analytical results, the slag and bottom ash from the combustion process have been classified as non-hazardous wastes, according to the EU waste acceptance criteria (WAC), and therefore after further tests could be used in future in the construction industry. It has also been concluded that ASR bottom ash (EWC - European Waste Catalogue - code 19 01 12) could be landfilled in SNRHW (stabilized non-reactive hazardous waste) cells or used as raw material for road construction, with or without further treatment for the removal of heavy metals. In the case of fly ash from boiler or Air Pollution Control (APC) residues, it has been found that the Cd, Pb and Zn concentrations exceeded regulatory leaching test limits therefore their removal, or a stabilization process, would be essential prior to landfilling the use of these residues as construction material.

PM0.1 emissions during diesel trap regeneration.

A nanostructured spinel-type oxide catalyst (CoCr2O4) prepared by solution combustion synthesis was developed and deposited over a SiC wall-flow trap for diesel particulate removal. Bench tests proved that, after soot loading, the developed trap enables a faster and more complete regeneration at 550 degrees C than a commercial Pt-catalyst based trap or a noncatalyzed trap. On the other hand, secondary nanoparticle emission occurs during the fast regeneration promoted by the CoCr2O4-catalyzed trap. This is a likely consequence of oxidative fragmentation of the trapped soot agglomerates. This problem can be resolved by performing a "mild" regeneration at lower temperatures (e.g., 450 degrees C).

Valor de la historia clinica con relacion a la urodinamia en el diagnostico de la incontinencia urinaria femenina / Value of health history in relation to urodinamy in the diagnosis of female urinary incontinence

Evaluar el valor del diagnóstico clínico de la Incontinencia Urinaria de Esfuerzo (IUE) frente al diagnóstico urodinámico de estabilidad vesical. Es un estudio de validez diagnóstica de corte transversal, donde se analizaron 100 historias clínicas de pacientes que consultaron a la Clínica de Incontinencia Urinaria del Instituto Materno Infantil de Bogotá en el período comprendido entre el 1o de enero de 1995 al 31 de diciembre de 1997. El 32 por ciento de las pacientes consultaron por sintomatología de incontinencia de esfuerzo pura, 5 por ciento de incontinencia de urgencia pura y 63 por ciento de incontinencia urinaria mixta. La urodinamia reportó 74 por ciento de pacientes con detrusor estable y 26 por ciento con detrusor inestable. Los síntomas de incontinencia urinaria de esfuerzo tienen una sensibilidad del 97 por ciento y una especificidad del 68 por ciento para el diagnóstico de IUE. Los síntomas de incontinencia urinaria de urgencia tienen una sensibilidad de 68 por ciento y una especificidad de 23 por ciento para el diagnóstico urodinámico de vejiga inestable.Los métodos clínicos (historia clínica y examen físico), no poseen la suficiente sensibilidad y especificidad como métodos diagnósticos únicos en in continencia urinaria de esfuerzo. Por lo tanto, se recomienda en el estudio de toda paciente que consulta por incontinencia urinaria, realizar una historia clínica adecuada, examen físico completo, examen neurológico, prueba de Bonney, Q-tip, parcial de orina, urocultivo, cistoscopia (cuando esté indicada) y urodinamia. Lo cual llevará a un diagnóstico más preciso y al manejo correcto de la patología que padece