Characterization of Southern Illinois Water Treatment Residues for Sustainable Applications

Abstract

Although they are abundantly available, the specific applicability of water treatment residues (WTRs) is dictated largely by the favorability of physicochemical characteristic properties and mineralogical composition. We have suggested that WTRs have a high potential for remediation application. In addition, the relevant properties that define the beneficial reuse of WTRs may be widely variable due to the influence of the dose, type of coagulant/softening agent, and quality of source water. This study investigated the physical, chemical, agronomic, and mineralogical characteristics of three different types of WTRs that were collected from treatment plants in the Midwestern U.S, in order to compare and assess their suitability for remediating impacted ecosystems, such as abandoned mine lands (AML). An analysis of the results showed that the differences in the properties of the WTR samples were significant. The total metal concentrations by inductively coupled plasma mass spectrometry (ICP-MS) revealed the abundance of Fe, Al, Mn, Cu, and other co-occurring metals. The leachability of metal(loid)s, regulated under the Resource Conservation and Recovery Act (RCRA 8 metals), were below their respective US Environmental Protection Agency (EPA) allowable limits of 5.0, 100, 1.0, 5.0, 5.0, 0.2, 1.0, and 5.0 mg/kg, indicating that the WTRs were non-hazardous to the environment. Comparatively, the Al-WTR showed a significant release of arsenic (As), possibly from livestock waste and pesticide application from farms in the catchment area of the raw water source. The WTRs were alkaline (potential of hydrogen [pH] 7.00-9.10), which suggested a high acidity-neutralizing potential. The Ca:Mg ratio was between 1:7 and 1:1.5 (meq basis), which contributed to a cation exchange capacity (CEC) range of 4.6-16.2 meg/100g. The WTRs also showed adequate capability to supply relevant plant nutrients, such as Zn, Ca, Mg, S, Cu, and Fe, although readily available concentrations of NO 3 -N, P, and K were generally low. Thus, the alkalinity, significant CEC, low metal concentration and the presence of X-ray diffraction amorphous phases and calcites suggested that WTRs could be safely applied as low-cost sustainable alternatives for soil improvement and remediating contaminants such as metal(loid)s in AML.

Application of Alum Sludge in Wastewater Treatment Processes: “Science” of Reuse and Reclamation Pathways

“…The disposal cost in Netherlands stands at a huge sum of US dollar 37-50 million per year while it is US dollar 6.2 million per year in Australia. It is also estimated that the cost of AlS disposal in Ireland will be doubled by the end of the next decade from the present assessment of 15,000-18,000 tons/year of the dried solids, with disposal costs estimated at EUR 2.1 million (US dollar 2.8 million) per year [14][15][16][17][18].…”

Waterworks Sludge: An Underrated Material for Beneficial Reuse in Water and Environmental Engineering

“…The sludge disposal cost in Netherlands stands at a huge sum of US$37-50 million per year while it is $6.2 million per year in Australia. It is also estimated that the cost of WTS disposal in Ireland will be doubled by the end of the next decade from the present assessment of 15,000-18,000 tons/ year of the dried solids [7][8][9][10].…”

Quality of surface water and generation of sludge at water treatment plants

“…According to Ackah et al (2018), the composition of WTP sludges is the main determinant of their beneficial use. In Brazil, there is no current public data on the composition of these residues.…”