Environmental friendly remediation and recycling method for contaminated soil by combination of Bioleaching and Bioremediation

针对污染土壤的修复和资源的有价化进行了基础实验。具体地说，对突尼斯共和国斯法克斯市系统磷酸农用化肥厂排放的硫酸污染的堆渣进行中和，提取作为资源的石膏(CaSO4)。采用浮选法即矿山技术，可以提取出高纯度的白石膏。添加硫酸铝作为浮选的絮凝剂，成功地提高了石膏的捕收率。通过对石膏细度的检测，确定石膏细度达到了可以用作水泥缓凝剂的细度，根据污染物的硫酸，残渣是一种pH值在1.8左右的强酸。洗涤残渣的强酸溶液与碳酸钙中和。它的pH值变为6，可以通过添加钙碳…来中和从100g的残渣样品中获得了更多的约3g的水相酸，此外，还考察了微生物作用下中和的可能性。使用了三种产氨的细菌：德尔默根霉、黑曲霉和MJKC25。首先，将100g残渣中加入精制水100ml的菌株过滤后种植，将上述芽孢杆菌应用于含上清水的LB琼脂培养基中，观察其生长情况。PH指示剂甲基红颜色由红色变为黄色，证实了各细菌在强酸中的存活和中和作用。当初始pH为4.9~6.3时，从pH升高到7~8时，约4天左右即可确认中和作用。另一方面，当初始pH接近3时，几乎不能确认中和。证实了当排水pH小于等于5时，从上述残留物中可以进行芽孢杆菌的中和处理

A basic experiment was executed aiming at remediation of the polluted soil and valorization for the resource. Concretely, the piling up residue polluted with the sulfuric acid exhausted by the system phosphoric acid agricultural fertilizer factory in the Sfax city of Republic of Tunisia is neutralized and gypsum (CaSO4) that is the resource is extracted. The flotation method that was the mine technology was able to be used to take out high purity White gypsum. It succeeded in the improvement of the collection rate of gypsum by addition of the sulfuric acid aluminum as the flocculent of the flotation. When the gypsum fineness was examined, it was confirmed to reach the fineness that was able to be used as a setting retarder of cement.The residue is a strong acid of about pH1.8 according to the sulfuric acid of the contaminant. A strong acid solution that washed the residue executed neutralizing with calcium carbonate. It became pH6 and possible to neutralize by adding the calcium carbon … More ate of about 3g to aqueous acids obtained from the residue sample 100g.In addition, the possibility of neutralizing by the action of the microorganism was examined. Three kinds of bacilli that generated ammonia, Rhizopus delmer, Aspergillus niger, and MJKC25 were used. First of all, the one that refinement water 100 ml was added to the residue 100 g was filtered, it planted, the above-mentioned bacillus was applied to the LB agar medium including the top water, and it observed it. Living and the neutralizing action of each bacterium in the strong acid were confirmed from the change of the color of methylic red of the pH indicator into yellow from red. When the initial pH is from 4.9 to 6.3, the neutralizing action was confirmed from the rise of the pH to 7 or 8 at the period about the four day. On the other hand, neutralizing was able hardly to be confirmed when the initial pH was near 3. It was verified that the neutralizing processing by the bacillus was possible from the residue in the above-mentioned for the drain of pH 5 or more Less