Landfill leachate treatment by immediate one-step lime precipitation, carbonation, and phytoremediation fine-tuning

Optimization of atmospheric carbonation in the integrated treatment immediate one-step lime precipitation and atmospheric carbonation. The case study of slaughterhouse effluents

“…In this way, this effluent can only be treated by unconventional treatment processes (e.g., advanced oxidation processes or adsorption processes). Low COD removals in the lime precipitation process has also been found in the treatment of winery wastewaters [5] and landfill lechate [8]. On the other hand, high COD removals were obtained for SWW1 (86.9-91.0%) and SWW2 (73.5-80.6%), similar to those obtained by Tariq et al [21].…”

“…Despite the high calcium removal, the was not a limiting factor in the AC process to drop pH to neutral values, as was observed by Ramalho et al [8]. Ramalho et al [8] observed that the calcium concentration was totally consumed during the AC process, leading to a decrease in pH from only 12.5 to 10.1, after 32 days of AC. The calcium removal is justified by the formation of calcium carbonate (Eq.…”

“…organic matter, phosphorus, and nitrogen), they are not designed to remove high concentrations of these compounds, so on-site pre-treatment is required [1,2]. The integrated process, immediate one-step lime precipitation (IOSLM) followed by atmospheric carbonation (AC), has been used as a pretreatment for industrial wastewaters, such as explosives [3], vinasse from sugarcane ethanol industry [4], winery [5], cheese whey [6], urban wastewaters [7], and landfill leachate [8]. This integrated solution is recognized for its low cost, simplicity, eco-friendly technology and high efficiency in removing contaminants, like organic matter and nitrogen (Madeira et al [3].…”

“…Lately, the capture of atmospheric CO 2 has deserved the attention of several researchers [10]. In AC process, the atmospheric CO 2 is transferred to aqueous phase reducing the pH, but long retention times are needed to reduce pH of the effluent [8]. Madeira et al [3] and Prazeres et al [4] observed that the AC process in the presence of sludge precipitate (resulting from the IOSLM process) needs a long time to reduce the pH from 12 to 8, but significant advantages in the removal of ammoniacal nitrogen was observed (Madeira et al [3].…”

“…In addition, since the transfer of the CO 2 to water must be maximised, the reactor area/volume (A/V) ratio in the AC process is very important. According to the literature, low reactor A/V ratios such as 3.78 m 2 /m 3 [3], 6.23 m 2 /m 3 [4], 4.63 m 2 /m 3 [6], 5.00 m 2 /m 3 [7], and 5.00-6.67 m 2 /m 3 [8] have been used in the AC process. However, it is not possible to establish any relationship between these reactors A/V ratios and the carbonation time, as the characteristics of effluent (e.g.…”