Assessment of the robustness of MIL-88A in an aqueous solution: Experimental and DFT investigations

The stability of metal organic frameworks (MOFs) in a water-rich environment is a topic of significant importance, especially for adsorption and water purification applications. MIL-88A containing iron ions and fumaric acid ligands, was synthesized through a water-based viable strategy. The robustness of MIL-88A in aqueous solutions was studied experimentally, through evaluating the chemical, thermal, and hydrolytic stability of this compound by varying the conditions and properties of aqueous solutions. Different characterization techniques were employed to explore the features of the synthesized MIL-88A such as XRD, SEM, FTIR, TGA, UV–vis DRS, zeta potential, and MP-AES measurements. The electronic structure was studied on a model nanocrystal with density functional theory (DFT) calculations. The MIL-88A structure was drastically affected in basic medium as confirmed by the characterization techniques used. MIL-88A became completely amorphous upon exposure to boiling water. The hydrolytic stability results showed that MIL-88A loses gradually its structural integrity in each water cycle

A technoeconomic assessment of biological sludge dewatering using a thermal rotary dryer: a case study of design applicability, economics, and managerial feasibility

The shortage of freshwater in Palestine and the huge competing demands from a variety of users stimulate an urgent need for finding cost-effective, sustainable, and environmentally friendly solutions for the current wastewater treatment processes. For instance, the anaerobic dewatered biological sludge (hereinafter called sludge) produced from wastewater treatment plants (WWTPs), in the West Bank, is considered challenging. To date, the only legal way of sludge disposal is in landfills. This is considered an obsolete solution due to the lack of landscape and improper solid waste management actions. In this study, sludge produced by a WWTP located in Nablus city has been considered. The daily capacity of sludge production at this plant is approximately 15 tons/day. This sludge is usually transferred in huge trucks and eventually dumped in a landfill called Zahrat Al-Finjan (ZL). This process costs about 45,000 ILS/month (~ $12,800/month) with the possibility of generating many hazardous emissions. In addition to this solid waste problem, this WWTP produces biogas as a by-product. Herein, a thermal rotary dryer technology is proposed to reduce the moisture content from 70 to 10$100 k with a simple payback period of 2.7 years. The obtained design parameter, mainly the length to diameter ratio, was around 9.6 with a retention time of 1.8 h. Though these values are within the conventional rotary thermal dryers, one may ask how to convince stakeholders to implement such an approach practically. Therefore, sludge waste management along with technological adaptation was also thoroughly studied via stakeholder theory. Graphical Abstract: [Figure not available: see fulltext.]