A feasible approach was studied for utilizing the harvested Lemna minor to treat Ni-Electroplating Waste Water (NEWW). The Lemna minor was pyrolyzed under oxygen-limited condition at various temperatures to produce biochar firstly and the optimal biochar was selected according to the yield of biochars and the adsorption capacity of biochars to treat the simulated Ni-containing wastewater. A combination method of pre-precipitation and biochar adsorption was proposed and validated by treatment of an actual NEWW. Results indicated that the biochar fabricated from Lemna minor at 400 °C (LM400) was the optimal biochar for Ni²⁺ adsorption and the adsorption capacity of LM400 was 41.68 mg/g. Precipitation with 5.0 g/L Ca(OH)₂ succeeded by two-step adsorption with LM400 could yield qualified treatment streams when the actual NEWW was treated. Moreover, the adsorption mechanism of biochars to Ni²⁺ could mainly be ascribed to the complexation and ion-exchange reactions of Ni²⁺ in wastewater with the oxygen-containing functional groups and K⁺ ions of the biochar according to the results of FTIR and XRD. This study shows that Lemna minor is a viable raw material to produce strong adsorption biochar, which could be used as excellent adsorbents for heavy metals, such as Ni, Cu and Zn. Meanwhile, the actual NEWW treated with the combined process of two steps could meet discharge requirements.

研究了一种可行的方法，利用收获的小Lemna处理镍电镀废水（NEWW）。首先将Lemna minor在氧气限制条件下在不同温度下热解以生产生物炭，然后根据生物炭的产量和生物炭的吸附能力来选择最佳生物炭，以处理模拟含镍废水。提出了一种沉淀与生物炭吸附相结合的方法，并通过实际的污水处理进行了验证。结果表明，Lemna minor在400°C（LM400）制备的生物炭是Ni ²⁺吸附的最佳生物炭，LM400的吸附量为41.68 mg / g。用5.0 g / L Ca（OH）₂沉淀当用实际的NEWW处理时，通过LM400两步吸附成功地产生了合格的处理物流。此外，根据FTIR和FTIR分析结果，生物炭对Ni ²⁺的吸附机理主要归因于废水中Ni ²⁺与生物炭中含氧官能团和K ⁺离子的络合和离子交换反应。XRD。这项研究表明，Lemna minor是生产强吸附性生物炭的可行原料，可以用作重金属（如Ni，Cu和Zn）的优良吸附剂。同时，经过两步组合处理的实际NEWW可以满足排放要求。