高钙酿酒沼渣制备生物炭吸附剂及其土壤改良性能

Utilization of High Calcium Biogas Residue for Biochar Adsorbent Preparation and Its Soil Improvement Properties

为解决酿酒沼渣的资源化问题,采用热解法制备沼渣生物炭,通过批量吸附试验和盆栽试验考察其吸附性能和土壤改良性能.结果表明:700℃下限氧热解1.5 h所制备的高钙沼渣生物炭,初始pH为10时,吸附量最大,投加10 g·L^(-1)的沼渣生物炭对实际废水COD、NH_(4)^(+)-N和TP的去除率分别可达45.29%、56.10%和86.33%,吸附符合拟一阶动力学模型和Langmuir等温吸附,属于物理吸附.吸附后生物炭表面C、N、P、O元素含量显著增加,出现新的N-H、P=O基团.当投加5%的吸附后生物炭时,土壤中速效磷、速效钾及有机质的含量均显著提高,小白菜生长得到促进.本研究探索了“一处理两用”的策略,为酿酒沼渣处置和资源回收提供了一种本土方法.

In order to solve the problem of resource utilization of brewing biogas residue,the biochar prepared by brewing biogas residue was added into garden soil.A batch incubation and absorption experiments were carried out with the amended soils to study the improvement of biochar addition on adsorption availability and soil physicochemical properties.Results show that:the high calcium biochar prepared by oxygen limited pyrolysis method at 700℃for 1.5 h behaved best with initial pH 10,the removal rates of COD,NH_(4)^(+)-N and TP in actual wastewater by adding 10 g·L^(-1) biogas biochar can reach 45.29%,56.10%and 86.33%,respectively.Langmuir isothermal model and pseudo-first-order kinetic equation were more consistent with its adsorption characteristics,indicating the physical adsorption were the main adsorption modes.The contents of C,N,P and O elements on the biochar surface increased significantly with new N-H and P=O groups generated after the adsorption.The available phosphorus,available potassium and organic matter in soil were significantly increased with 5%of adsorbed biochar added which could promote the growth of Chinese cabbage well.This study explored a‘one treatment but two uses’approach,which provides an application prospect for the disposal and resource recovery of biogas residue.