Ash from poultry feather gasification was investigated as an adsorbent for Cd removal from synthetic wastewater under a range of operational conditions: initial pH (2–8) and salinity (8–38 mS/cm) of wastewater, ash dosage (2.5–50 g/L), Cd concentration (25–800 mg/L) and contact time (5–720 min). The ash was highly alkaline and had low surface area and micropores averaging 1.12 nm in diameter. Chemical/mineralogical analysis revealed a high content of P₂O₅ (39.9 wt %) and CaO (35.5 wt %), and the presence of calcium phosphate, hydroxyapatite and calcium. It contained only trace amounts of heavy metals, BTEX, PAHs and PCBs, making it a safe mineral by-product. Cd adsorption was described best with Langmuir and pseudo-second order models. At pH 5, an ash dosage of 5 g/L, 40 min contact time and 100 mg Cd/L, 99% of Cd was removed from wastewater. The salinity did not affect Cd sorption. The maximum adsorption capacity of Cd was very high (126.6 mg/g). Surface precipitation was the main mechanism of Cd removal, possibly accompanied by ion exchange between Cd and Ca, coprecipitation of Cd with Ca-mineral components and Cd complexation with phosphate surface sites. Poultry ash effectively removes high concentrations of toxic Cd from wastewater.

中文翻译：

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家禽羽毛气化的矿物副产品，用于从高污染的合成废水中去除Cd

在一系列操作条件下，研究了禽羽毛气化产生的灰分作为吸附剂去除合成废水中的Cd：废水的初始pH（2-8）和盐度（8-38 mS / cm），灰分剂量（2.5-50 g） / L），镉浓度（25–800 mg / L）和接触时间（5–720分钟）。灰分是高度碱性的，具有低表面积和平均直径为1.12nm的微孔。化学/矿物学分析表明，P ₂ O ₅含量高（39.9 wt％）和CaO（35.5 wt％），以及磷酸钙，羟基磷灰石和钙的存在。它仅包含痕量的重金属，BTEX，PAH和PCB，使其成为安全的矿物副产品。用Langmuir和拟二阶模型可以最好地描述Cd的吸附。在pH 5下，从废水中去除了灰分5 g / L，接触时间40分钟和100 mg Cd / L，99％的Cd。盐度不影响镉的吸附。Cd的最大吸附容量非常高（126.6 mg / g）。表面沉淀是去除Cd的主要机理，可能伴随Cd和Ca之间的离子交换，Cd与Ca矿物组分的共沉淀以及Cd与磷酸盐表面位点的络合。家禽灰有效地从废水中去除了高浓度的有毒镉。