Background: The occurrence of heavy metals in the environment is of important concern due to their TOXICITY and health effects on humans, including cancer. Because metals have been extensively used for centuries in commerce, environmental contamination is widespread; moreover, exposure to metals and metal compounds continues to be a significant public health problem. Electroplating sludge contains heavy metals. Solidification/Stabilization can be used to avoid LEACHING of these metals to the environment. The aim of this study was evaluating the effectiveness of the application of dicalcium phosphate (DCP) and sodium tripolyphosphate (STPP) on Cd, Co, Cu, Ni, Pb and Zn immobilization in dewatered metal plating sludge.Methods: The ratios of STPP and DCP per dry plating sludge were determined to be 0.1%, 0.2% and 0.5% by weight. Metal LEACHING from the solidified plating wastes was assessed using the TOXICITY characteristic LEACHING PROCEDURE (TCLP). The results showed that the concentration of metals in untreated sludge were appropriate to classify this sludge as a hazardous waste as described in The Code of Federal Regulations (CFR) 40 CFR 261.24.Results: DCP and STPP lowered the concentration of metal in the effluent. Increasing DCP concentration from 0.1 to 0.5% decreases the contaminant concentration in the effluent. F or Cd, Pb, Cu and Ni increasing the percentage of STPP in the sludge increases the contaminant’s concentration resulting from TCLP extraction.Conclusion: Immobilization of heavy metals was more effective through application of DCP rather than STPP. Moreover, it may minimize the potential risk of groundwater eutrophication connected with the application of highly soluble phosphate like STPP.

Two fly ashes from municipal solid waste incineration were selected to study their heavy metal LEACHING behavior. The main purpose of this research is to investigate the CHARACTERISTICS of fly ashes and compare the LEACHING of heavy metals in different LEACHING environment. pH and acid neutralization capacity analysis showed that fly ashes were highly alkaline. Fly ashes also contained a variety of heavy metals including Pb, Cu, Cr, Zn, Cd and Ni etc. LEACHING studies showed that the alkalinity of fly ashes raised the pH of LEACHING solution from acidic to basic. Ni, Cu and Zn were strongly bound to ashes and manifested low LEACHING. In contrast, Cr and Cd had high mobility but their LEACHING was inhibited by the low solubility of carbonate Cr and Cd. Pb was highly leachable in the alkaline environment with concentration in the LEACHING solution reached as high as 9.74 mg/L. In addition, the presence of EDTA in the environment also increased LEACHING. Pb concentration was raised to 16.63 mg/L. This could be attributed to the chelating capacity of EDTA which means that the presence of organics in natural environment should be taken into consideration.

Introduction: Modeling energy demand in different energy consuming sectors is a crucial measure for effective management of the energy sector and appropriate policies to increase productivity. The rising importance of energy resources in economic development is evident. Sustainable energy use is crucial for environmental protection and social progress. Understanding the factors affecting energy consumption is essential for effective energy management. Therefore, the purpose of the current study is to investigate the impact of environmental factors on household electricity consumption in Yazd city. Materials and Methods: In the present research, various environmental factors affecting electricity consumption, including air pollution, air temperature in homes, ground surface temperature, and green space were investigated. The effects of these factors on electricity consumption of subscribers were investigated with ANN and  apriori methods. Results: Among the environmental factors, the distance to the regional park, the area of the park, and the amount of vegetation at a distance of 300m have the greatest impact, respectively, and the average summer air temperature, the amount of vegetation at a radius of 500 m, the distance from the local park, and the average summer NDVI have had the smallest effect. Unlike neural network methods, apriori presents relationships between parameters affecting electricity consumption transparently in the form of rules. Conclusion: It's used to identify the most frequently occurring elements and meaningful associations in a dataset. Greenspace can be a mitigation strateegy for reduction of energy consumption.

Contamination of soil with persistent organic contaminants has been of great concerndue to their long-term effects in the environment. Polycyclic aromatic hydrocarbons(PAHs) are a well-known group of organic contaminants characterized bytheir resistance to biodegradation and high hydrophobicity. Mobilization and migrationof PAH compounds in hydrocarbon-contaminated site may endangergroundwater resources. The main objective of this study was to investigate theinfluence of pulverized biochar on immobilization and release CHARACTERISTICS ofmodel PAHs. Column LEACHING test was used to simulate LEACHING of PAH compoundsfrom contaminated solid phase towards aqueous phase. Results showedstrong sorption of both studied PAHs i.e. phenanthrene and pyrene to soil particles,however, at the end of the experiment 5.32% and 0.99% of the initial solid phasecontent of, respectively, phenanthrene and pyrene released into water in unamendedsoil. Application of pulverized biochar could finally reduce mobilization and cumulativerelease of the above-mentioned PAH compounds significantly. Similar trendwas also obtained for sum 16 US EPA PAHs. Variation of pH during the LEACHINGprocess and its contribution to mobilization and release of selected PAH compounds,which has scarcely studied previously, were also addressed. Results indicatedthat pulverized biochar as a cost-effective alternative to other carbon-richamendments e.g. activated carbon can be effectively employed for site remediationpurposes to reduce mobilization of PAHs in soil.