The present investigation has been devoted to assessing the environmental impacts of a local landfill, in the north of Hilla city, Iraq, on the surrounding soils in terms of heavy metal pollution. The concentrations of heavy metals, namely chromium (Cr), copper (Cu), nickel (Ni), and lead (Pb) were measured during, November 2019, at three investigation sites that located at distances of 10 (site 1), 20 (site 2) and 30 m (site 3) from the edge of the mentioned landfill. Soil samples were collected from these sites at a constant depth of 20 cm. The collected samples were air-dried, manually crushed, and sieved through a 2 mm mesh before subjecting them to a chemical digesting process. The concentrations of the targeted metals were measured using an inductively coupled plasma optical emission spectrometry and compared to the standards of the State Environmental Protection Administration (SEPA). The obtained results showed that the highest concentrations of the targeted metals were in site 1, while the lowest concentrations were detected at site 3. Generally, it was found that the concentrations of the studied metals followed the order: Cr>Pb>Ni>Cu. Additionally, it was noticed that all the measured concentrations were within the limitations of the SEPA.
This paper presents an experimental work conducted to study the properties of concrete incorporating (0-100) % of local (in Iraq) crushed limestone (CLS) as a partial replacement of coarse aggregate. Supplementary Cementitious Materials (SCM) such as High Reactivity Metacaoline (HRM) and Rice Husk Ash (RHA) were added to the mixtures to improve the properties of fresh and hardened concrete. The selective mixtures in this study were arranged into three groups, the first without (SCM), the second with (RHA), and the third with (HRM). Each of them (being with different ratios of (CLS) as a coarse aggregate) was tested for comparison with the reference mixtures. The slump and air contents were evaluated for the fresh concrete. The absorption as well as compressive strength (CS) and flexural strength (FS) were evaluated for the hardened specimens after 7 and 28 days. According to the results, the concrete with CLS as a coarse aggregate gained less performance than the ordinary concrete but the (SCM) improved the properties of the concrete mixtures. The results show that the HRM was more effective than the RHA with respect to the mechanical properties.
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