生物改性玉米秸秆处理溢油污染水体的研究

Study on oil-spilled water treated by bio-modification of corn stalks

为了减少石油泄漏对环境产生的严重污染和能源损失,采用固态发酵技术和生物酶技术开发出新的生物改性过程制备溢油吸附剂。采用XRD、BET、SEM手段表征改性玉米秸秆,同时,对吸附剂的投加量(0.1~0.5 g)、初始原油量(5~30 g)以及吸附动力学进行了研究。结果表明,两种改性技术均能降低秸秆的结晶度和比表面积,黑曲霉改性玉米秸秆的吸油量为14.28 g·g^(-1),纤维素酶改性玉米秸秆吸油量在25 g·g^(-1)左右,与原材料(吸油量为4.89 g·g^(-1))相比,吸油效果均有明显提高。改性秸秆对原油的吸附在60min可达到吸附平衡,吸附动力学与准二级动力学模型较好地拟合。利用生物酶和固态发酵技术改性的玉米秸秆是一种高效、环境友好型油污吸附剂。

Oil-spilled wastewater has resulted in many environmental and ecological problems all over the world. In this work, we have developed a new biotechnological procedure by using solid state fermentation and enzymes to produce a biodegradable oil-sorbent from corn stalk. After treatment with 100 U·g^（-1） cellulase for 6 h at 45 ℃, the obtained cellulose-modified corn stalk exhibited high sorption capacity of oils. Aspergillus niger was used for the solid-state fermentation of corn stalk, and the maximum oil sorption could be achieved after 6 days modification, with a solid-liquid ratio of 1 ∶3, and a modification temperature of 30 ℃. SEM was used to characterize the morphology and structural characteristics of the modified and unmodified corn stalks, along with XRD and BET for analyzing changes in crystallinity and surface area. Batch sorption experiments were conducted to investigate the effects of sorbent dose（0.1~0.5 g）and initial oil amount（5~30 g）on the oil sorption capacity. Sorption kinetics was also studied using different kinetic models. The results showed that the sorption of crude oil on modified corn stalk reached equilibrium at 60 min, and the sorption kinetics could be well described by the pseudo-second-order model.The results also indicated that the modification of corn stalk using solid state fermentation and enzyme is an efficient means of producing environment-friendly oil sorbents.