Removal and Adsorption Mechanisms of Phosphorus, Cd and Pb from Wastewater Conferred by Landfill Leachate Sludge-Derived Biochar

Abstract

There is a high treatment cost and secondary pollution to the environment due to the high organic content and complex composition in landfill leachate sludge in refuse incineration power plants. Landfill leachate sludge-derived biochar (LLSDB) was prepared via pyrolysis in order to realize its resource utilization and remove pollutants from wastewater. The study focused on the removal of nutrients phosphorus and heavy metals (Cd(II) and Pb(II)) from wastewater through the adsorption process using LLSDB. The investigation also looked into the kinetics and thermodynamics of the adsorption process. It was found that the Freundlich–Temkin–Langmuir model was the best model for describing the initial concentration of total phosphorus, (TP) 0–1.0, 1.0–20, and 20–120 mg/L, respectively, while the Freundlich–Langmuir model was the best model for Cd(II) 100–500 mg/L, Pb(II) 500–5000 mg/L, respectively. Additionally, while the exothermic entropy reduction process for TP (˂1.0 mg/L) was spontaneous, the endothermic entropy increment processes for TP (≥1.0 mg/L), Pb(II) and Cd(II) in wastewater increased with the adsorption temperature. It was inferred for the adsorption mechanism of LLSDB that the adsorption of low concentrations of TP, Cd(II) and Pb(II) from wastewater was mainly physical adsorption, following a linear distribution, while that of high concentrations was mainly chemical adsorption because of a series of chemical reactions; TP, Cd(II) and Pb(II) from wastewater were nicely adsorbed and removed by LLSDB600, which was an incredibly superior strategy for controlling waste with waste.

Adsorption properties of Pb(II) and Cd(II) in acid mine drainage by oyster shell loaded lignite composite in different morphologies

“…At high concentrations, the concentration pressure difference between the solution and the surface of the adsorbent continues to increase, which strongly drives the Pb(II) and Cd(II) in the solution to move rapidly to the surface of OS-M(P) and OS-M(G), increasing the chance of collision and interaction with the active site on the surface of the adsorbent. However, when the concentration is too high, the adsorbent gradually reaches saturation, and excessive positive charge will accumulate on the surface of the adsorbent after adsorption of Pb(II) and Cd(II), and the electrostatic repulsion will make it difficult to continue to adsorb more free metal ions in the solution, so the removal rate will gradually decrease 63 . It can also be seen from Fig.…”

Heavy Metals Contaminants in Honey and Dry-Cured Meat Sold in Northern Nigeria Markets

“…Cadmium is one of 25 compounds that may be hazardous to human health, and because it cannot be eliminated from the body, it frequently accumulates there instead [37]. Food is the main source of cadmium exposure for humans, and the typical adult daily intake is around 0.062-0.088 mg kg -1 [38]. The cumulative intake of 3 to 15 µg of cadmium is the threshold for acute poisoning.…”

Dynamic Shear Responses of Combined Contaminated Soil Treated with Nano Zero-Valent Iron (nZVI) under Controlled Moisture

“…The sources of HMs are diverse and contaminated sites are often exposed to a variety of excess HMs. Notable examples included landfill leachate (Cd(II), Pb(II)) [3], soils near copper mines (Cu(II), Pb(II), Zn(II), Ni(II)) [4], sites near coal gasification plant (V(V), As(III)) [5], etc. These heavy metal ions, once present in the soil, could enter the human body, primarily through the food chain, posing serious health risks, including fatal diseases, damage the nervous and digestive systems and impair immune function [6][7][8][9].…”