Monitoring of heavy metal deposition in Northern Italy by moss analysis

A survey of heavy metal deposition in the mountainous territories of Northern Italy was carried out in 1995-96. Moss samples (mainly Hylocomium splendens) were collected in a dense network of sites (about 3.2 sites/1000 km(2)) and the data of metal concentrations in moss tissues were statistically correlated with environmental and climatic factors, as well as with bulk deposition of elements and elemental concentrations in the soil. Three main geographic patterns of metal concentration in mosses could be defined: (1) Fe, Ni, and Cr, all derived both by soil particulates and anthropogenic emissions connected with ferrous metal manufacturing, were mostly concentrated in Northwestern Italy; (2) Cu and Zn, as typical multi-source elements, showed rather high concentrations with little ranges of variation over the whole area and small peaks reflecting local source points; (3) Cd and Pb reflected long-distance transport and showed highest concentrations in the regions with highest precipitation, especially in the Eastern Alps.     

A proposal for a two-step sampling design to oversample units responding to prescribed characteristics

We introduce a novel method to extract a sample from a finite population where units with desired characteristics are over-represented. The approach is both sequential and adaptive and allows, via suitable compositions of predictive and objective functions, to target specific subsets of the population. We consider the problem of estimation and conjecture the validity of a modified Horvitz–Thompson estimator capable to account for the imbalance induced by the targeting procedure. After discussing how to apply the method to the sampling of geographically distributed units, we investigate its potential via simulations.     

Production of zeolitic materials in pilot scale based on coal ash for phosphate and potassium adsorption in order to obtain fertilizer

Environmental Science and Pollution Research - The use of different types of zeolites (X, Na-P1, and 4A) synthesized by different methods and scales were tested in this work to adsorb nutrients...