生物炭净化造纸废水的效果研究

Application of Biochar to Purification of Papermaking Wastewater

目前以生物炭为代表的生物质对重金属的吸附表现出良好的应用前景。为确定生物炭对造纸废水中污染物的吸附性能,本研究采用自制装置进行试验,将供试基质材料置于同等大小且底部有孔的塑料花盆内,研究生物炭对造纸废水pH值、CODcr和Pb2+的去除效果,并运用正交矩阵分析所有有效变量。结果表明:生物炭能够有效降低不同浓度造纸废水pH值、CODcr和Pb2+含量。在整个试验周期内,生物炭条件下,浓度为50,175,300mg·L-1的造纸废水pH值依次减少0.89,0.86,1.29,生物炭可效降低造纸废水pH;生物炭对造纸废水CODcr去除率为91.88%,在50mg·L-1条件下,去除效果较为稳定,同时还表明,温度对造纸废水CODcr影响较大,CODcr随温度升高增大后减小;生物炭对造纸废水中Pb2+的吸收值明显高于其他两种基质,表明生物炭对Pb2+有较强的吸附能力,且在pH值为6~8时,生物炭对Pb2+的吸附量随着pH的升高呈减小,说明生物炭可作为一种廉价高效吸附剂用于水体污染修,并提供一定的理论基础。

At present, biomass with biochar as the representative in the adsorption of heavy metals shows a good application prospect. In order to determine the adsorption performance of biochar on pollutants in papermaking wastewater, a self-made device was used in the lest. The tested matrix material was put in the same size plastic pots with holes at the bottom to study the removing effect of biochar of pH value, CODcr and Pb2+in papermaking wastewater. Orthogonal matrix analysis was used for all valid variables. Biochar could effectively reduce pH, CODcr and Pb2+content of papermaking wastewater. In the whole testing period, with biological char conditions, pH in the concentration of 50, 175, 300 mg·L-1of papermaking wastewater decreased by0.89, 0.86, 1.29, that the biochar could effectively reduce the pH in papermaking wastewater. CODcr removal rate by biochar in papermaking wastewater was 91.88%. In the 50 mg·L-1condition, the removal effect was relatively stable. The influence of temperature on the CODcr of papermaking wastewater was great. CODcr increased with the increase of temperature and then decreasd. For the absorption of Pb2+in papermaking wastewater biochar had significantly higher role than that of other two kinds of substrates. When the pH value was 6-8, the adsorption amount by biochar on Pb2+decreased with the increase of pH showing that biochar could be used as a cheap and efficient adsorbent to alleviating water pollution.