Influence of Cellulose on the Anoxic Treatment of Domestic Wastewater in Septic Tanks: Statistical Analysis of the Chemical and Physico-Chemical Parameters

Cellulose is a very common polymer in domestic wastewater (WW), representing a not negligible part of the organic substance contained in sewage. To date, many studies have highlighted the feasibility of reusing this compound in several ways (e.g., building sector, wastewater treatment, energy production, etc.) after its separation from domestic WW. However, studies about the impact of the absence of cellulose on the chemical and physico-chemical parameters of a biological process are still lacking. In this work, two pilot-scale plants were used to simulate an anoxic treatment of WW in septic tanks, with and without cellulose (CWW and NCWW, respectively), for three months. The results of the monitoring highlighted that T, pH, and electrical conductivity (EC) remained almost constants, in both cases. The Spearman correlation coefficients (SCC) for turbidity (TUR), total suspended solids (TSS), and color (COL) indicated a higher removal in the case of CWW (65%, 66%, and 56%, respectively). Organic substance and nitrogen forms showed a similar behavior with and without cellulose, but in the case of CWW, N-NH3 was highly negatively correlated with TUR (SCC: −0.54), TSS (−0.49), and COL (−0.39). A biological denitrification process was highlighted in both cases. Despite these differences, when statistically analyzing the trends of the chemical and physico-chemical parameters for CWW and NCWW, a significant difference due to the absence of cellulose was excluded. These results will be useful to the scientific community, as they exclude that the operational parameters of anoxic treatments and the effectiveness on pollutants removal can be affected in the case of preliminary cellulose separation from domestic WW for recovery/reuse purposes

Conservation of the Archaeological Finds from Roman Period

A degree of preservation of iron artefacts depends on the type of underground environment and the type of corrosion products formed on their surface. This paper analyses the conditions of an archaeological artefact made of iron, which was found to originate from the Roman period. The iron corrosion products, goethite, lepidocrocite and magnetite (determined by the X-ray diffraction method) have been noticed in the corrosion products of the artefact. The ion chromatography analysis has revealed chloride and sulphate anions, pointing to the necessity of having artefacts treated in adequate solutions immediately after their excavation. It has been found that the EDTA solution is very efficient in the process of desalination of the artefact. The aim of this study was to determine the influence of the corrosion product types and the effects of applying the EDTA solution, otherwise not commonly used for desalination of iron objects. This method was applied here due to the complex structures of the found archaeological artefacts and the presence of copper alloys besides iron. The aim of this paper is to determine the type of influence corrosion products have on an artefact and to determine the effect of desalination treatment