Utilizing acid mine drainage sludge and coal fly ash for phosphate removal from dairy wastewater

Abstract

This study aims to investigate a new and sustainable approach for the reuse of industrial by-products from wastewater treatment. The dairy industry produces huge volumes of wastewater, characterized by high levels of phosphate that can result in eutrophication and degradation of aquatic ecosystems. This study evaluated the application of acid mine drainage (AMD) sludge, coal fly ash, and lignite as low-cost adsorbents for the removal of phosphate from dairy wastewater. Material characterization using X-ray fluorescence, X-ray diffraction, and Brunauer-Emmett-Teller surface area analysis revealed significant amounts of crystalline/amorphous Fe/Al/Si/Ca-based minerals and large surface areas of AMD sludge and fly ash. Batch adsorption isotherms were best described using the Freundlich model. The Freundlich distribution coefficients were 13.7 mg(0.577) L(0.423) g(-1) and 16.9 mg(0.478) L(0.522) g(-1) for AMD sludge and fly ash, respectively, and the nonlinearity constants suggested favourable adsorption for column applications. The breakthrough curves of fixed-bed columns, containing greater than 10 wt% of the waste materials (individual or composite blends) mixed with sand, indicated that phosphate breakthrough did not occur within 100 pore volumes while the cumulative removal was 522 and 490 mg kg(-1) at 10 wt% AMD sludge and 10 wt% fly ash, respectively. By contrast, lignite exhibited negligible phosphate adsorption, possibly due to small amounts of inorganic minerals suitable for phosphate complexation and limited surface area. The results suggest that both AMD sludge and fly ash were potentially effective adsorbents if employed individually at a ratio of 10 wt% or above for column application.

Using Modified Fly Ash for Removal of Heavy Metal Ions from Aqueous Solution

“…e change in crystal structure of the unmodified and modified FAN particles is evaluated according to the XRD patterns presented in Figure 4. As reported in our previous research [21] and some other research studies [3][4][5]24], the XRD spectrum of the FA demonstrates that the structure of FA0 particles is composed of mullite, quartz, and hematite while the FAN particles has a zeolite P (Na 6 Al 6 Si 10 O 32 .12H 2 O or NaP) structure (at 2θ � 13°, 2θ � 16°, 2θ � 27°, and 2θ � 55°).…”

Integrating EDDS-enhanced washing with low-cost stabilization of metal-contaminated soil from an e-waste recycling site

“…Previous results showed that CFA provided a large surface area (212 m 2 g À1 ) and was composed of 12% merwinite (Ca 3 Mg(SiO 4 ) 2 ), 4% calcite (CaCO 3 ), and 2% portlandite (Ca(OH) 2 ). It also contained a large quantity of poorly crystalline (amorphous) Fe and Al oxides (5700 and 6760 mg kg À1 , respectively), which are equivalent to an acid neutralizing capacity of 54.3% CaCO 3 (Wang et al, 2013;.…”

Simple Technology to Convert Coconut Shell Waste into Biochar; A Green Leap Towards Achieving Environmental Sustainability

“…Biochar was produced by auger reactor, this treatment can reduce greenhouses gases and make energy balance (Brassard et al, 2018) Utilization of acid mine drainage sludge and coal fly ash for phosphate removal from dairy wastewater Acid mine drainage sludge and coal fly ash can be combined to reduce phosphate from wastewater. Acid mine drainage sludge can utilize to biochar to reduce phosphate (Y. R. Wang et al, 2013) Removal heavy metals from contaminated soil Biochar was pyrolized at 350 o C for a hour under 0.1 m 3 h -1 nitrogen flow, after this treatment biochar was prepared by steam activation at 800 °C for 45 min in an atmosphere with 71% water vapor in nitrogen. Biochar can remove heavy metals content such as Cu(II), Cd(II), and Ni(II) in soil polluted (Uchimiya et al, 2010) Effect of cassava waste biochar on sorption and release behavior of atrazine in soil Biochar was used to sorption and desorption test to remove atrazine in latosol.…”