Characteristics, adsorption behaviors, Cu(II) adsorption mechanisms by cow manure biochar derived at various pyrolysis temperatures.

With the aims of exploring the effectiveness of Cu(II) adsorption performed by cow manure biochars (CMBCs) for the treatment and recycling of livestock wastes, the physicochemical characteristics and Cu(II) adsorption behaviors of CMBCs at various pyrolysis temperatures (T) were analyzed. CMBCs displayed surface heterogeneity and the dominant Cu(II) adsorption reactions were chemical adsorption, including mineral co-precipitation and cations exchange, was account for 93.75% - 97.01% of the adsorption contribution. Pearson correlation analysis and quantitative analysis showed that the adsorption capacity of co-precipitation (Qcp) and cations exchange (Qci) were significantly positively correlated with ash content and cations exchange capacity (p < 0.01), respectively. The quantitative relationships between total adsorption capacity (Qt), Qcp or Qci and T are Qt = 54.01 + 0.39exp(0.0051 T), Qcp = 71.80-101.91exp(-0.0024 T), Qci = 12.25 + 311.73exp(-0.0093 T) and Qt = 0.93 Qci + 0.91 Qcp + 7.70.