Analysis of collection systems for sorted household waste in Spain.

This work analyses the separate collection systems used in Spanish towns with between 5000 and 50,000 inhabitants. The study looks at the systems and their efficiency by means of the indicators fractioning rate, quality in container rate and separation rate. The results obtained are compared with those from a similar study conducted earlier that was applied to towns and cities with populations over 50,000. It can be concluded that the most widely implemented system in Spain involves the collection of mixed waste from kerbside bins and picking up paper/cardboard, glass and lightweight packaging from drop-off points. Findings show that the best system is the one that collects mixed waste, organic material and multiproduct waste door-to-door, and glass from drop-off points. The indicator separation rate made it possible to establish beta regression models to analyse the influence of the following logistic variables: inhabitants per point (people/pt), time (years) and frequency of collection (freq). From these models it can be seen that people/pt has a negative effect on all the fractions, while freq and years have a positive effect in the case of paper.

Comparison of different collection systems for sorted household waste in Spain.

The purpose of this study was to identify the different selective collection systems implemented in Spanish cities and to analyse the efficiency and extent to which the targets proposed by current law are met in each case. After defining the indicators to be used to quantify the efficiency of a selective collection system, a survey was designed to gather the information needed to calculate them. This survey was sent out to all Spanish cities with a population of over 50,000 inhabitants. Four different selective collection systems were also identified. For each of the four cases the indicators were calculated and analyzed to determine which one was the best system. The best values were obtained from the system with separation in five fractions: paper/cardboard, glass and lightweight packaging at drop-off points, organic waste and mixed waste in kerbside bins. Two regression models (linear and exponential) were developed in systems with enough data to explain and predict the variation in the amounts of materials that were separated correctly into containers, depending on the distance between containers and citizens. Nevertheless, the percentages of separation at source of paper/cardboard and lightweight packaging are still far from reaching the targets set by law.