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Sewage sludge treatment has become a primary subject in wastewater treatment and energy production. This paper aims to study the feasibility of power generation by incineration from sewage sludge enriched with impurities like heavy metals. For this purpose, we chose Arak wastewater treatment plant (AWWTP) and used calorific bomb test for examination. The experimental results showed that the heating values of sewage sludge are much less than the predicted records. This relates to the heavy metal and impurities content of sludge. These totally involved 5 to 18% of dried biomass. Therefore, we modified the predicting equation of heating value with respect to both water and impurities content of excess sludge. Finally, regarding the sludge characteristics of AWWTP, an annealing hierarchy programming (AHP) was used to find optimal technologies for dewatering and sludge minimization. Here, 21 criteria are classified in three main categories to rank the technologies regarding their costs, risks and performance. By all these means, a practical solution is introduced for optimal sludge management.

Climate change's effect on sea surface temperature (SST) at the regional scale vary due to driving forces that include potential changes in ocean circulation and internal climate variability, ice cover, thermal stability, and ocean mixing layer depth. For a better understanding of future effects, it is important to analyze historical changes in SST at regional scales and test prediction techniques. In this study, the variation in SST across the Persian Gulf and Gulf of Oman (PG&GO) during the past four decades was analyzed and predicted to the end of 21st century using a proper orthogonal decomposition (POD) model. As input, daily optimum interpolation SST anomaly (DOISSTA) data, available from the National Oceanic and Atmospheric Administration of the United States, were used. Descriptive analyses and POD results demonstrated a gradually increasing trend in DOISSTA in the PG&GO over the past four decades. The spatial distribution of DOISSTA indicated: (1) that shallow parts of the Persian Gulf have experienced minimum and maximum values of DOISSTA and (2) high variability in DOISSTA in shallow parts of the Persian Gulf, including some parts of southern and northwestern coasts. Prediction of future SST using the POD model revealed the highest warming during summer in the entire PG&GO by 2100 and the lowest warming during fall and winter in the Persian Gulf and Gulf of Oman, respectively. The model indicated that monthly SST in the Persian Gulf may increase by up to 4.3 °C in August by the turn of the century. Similarly, mean annual changes in SST across the PG&GO may increase by about 2.2 °C by 2100.