A shortage of land for waste disposal is one of the serious problems that faces urban areas in developing countries. The Sulaimaniyah Governorate, located in the north of Iraq, is one of the major cities in the Kurdistan Region of the country, covering an area of 2400 km² with a population of 856,990 in 2016. Currently, there is no landfill site in the study area that meets scientific and environmental criteria, and inappropriate solid waste dumping is causing negative environmental impacts. The process of landfill site selection is considered a complex process and is restricted by numerous factors and regulations. This paper proposes multi-criteria decision-making (MCDM) methods in a model for landfill site decision. The model assumes the input of two groups of factors that need to satisfy the optimal values of weight coefficients. These groups of constants are natural factors and artificial factors, and they included thirteen selected criteria: slope, geology, land use, urban area, villages, rivers, groundwater, slope, elevation, soil, geology, road, oil and gas, land use, archaeology and power lines. The criteria were used in the geographic information system (GIS), which has a high capacity to process and analyze various data. In addition, multi-criteria decision-making (MCDM) methods followed by the weighted linear combination (WLC) method were used to derive criteria weightings using a matrix of pair-wise comparison. Finally, all the multi criteria decision methods were combined to obtain an intersection of the suitability index map for candidate landfill sites. Seven appropriate sites for landfill were suggested, all of which satisfied the scientific and environmental criteria which were adopted in this study.

Using a safe and easy-to-apply economic flocculant to replace alum is necessary to expand and enhance the water quality in rural regions where traditional water treatment is unavailable. The seed of Moringa oleifera is locally available in large volumes and is feasibly economical. A compatibility and applicability research of the easily accessible local Moringa oleifera seed extract (MOSE) was conducted to examine its potential utilization to lessen various degrees of water turbidity at 30 ± 2 °C. The study concerns the optimum dosage of MOSE to give high turbidity removal efficiency in the water. Experiments were carried out for nine turbidity samples: 5, 10, 15, 30, 50, 70, 100, 200, and 300 NTU. The turbidity removal efficiency of up to 89% was achieved for high initial turbid water 300 NTU. However, for low turbid water, its potential efficiency declined. The results demonstrate that the de-oiled extract is substantially more efficient than the crude extract in agglomerating colloidal particles of low initial turbidity samples and achieved up to 76% removal rate. The results of the ANOVA confirmed that the regression model was significant at (p < 0.05) for residual turbidity after the treatment process. The study also demonstrates that a pseudo-first-order kinetic model matched well the nature of the removal of colloidal particles with MOSE in water to form flocs. The study also indicates that the characteristics of water treated with crude MOSE produce little change in electrical conductivity and salinity. However, the hardness and alkalinity of water decreased significantly depending on the initial hardness and the amount of MOSE applied (p < 0.05).