Application of KHSO5 for remediation of soils polluted by organochlorides: A comprehensive study on the treatment's efficacy, environmental implications, and phytotoxicity.

Soil pollution caused by complex organochloride mixtures has been increasing in many parts of the world in recent years; as a result, countless numbers of people are exposed to dangerous pollutions; hence, the treatment of organochlorides-polluted soils is gaining considerable attention. In this study, the potential of unactivated peroxymonosulfate (KHSO5) in remediating soil co-contaminated with trichlorophenol, para-dichlorobenzene, and para-chloro-meta-cresol was investigated. In addition, the treatment's collateral effect on critical soil properties was explored. The result revealed that treating 10 g of soil with 20 mL of 5 mM KHSO5 for 60 min could oxidize 70.49% of the total pollutants. The pH of the soil was decreased following the treatment. The significant decrease, (p < 0.05), in the soil organic matter following the remediation has affected cation exchange capacity, and available nitrogen. It was also observed that the treatment reduced the ß-glucosidase, urease, invertase, and cellulase activities significantly, (p < 0.05). The treatment, on the other hand, brought negligible effects on available phosphorus, available potassium, and particle size distribution. The phytotoxicity tests, which included seed germination and root elongation and soil respiration tests revealed that the treatment did not leach toxins into the treated soil. The treatment method was found to be relatively ecofriendly and cost effective.

Activating soil microbial community using bacillus and rhamnolipid to remediate TPH contaminated soil.

Soil petroleum contamination has become a global environmental problem. In order to develop a new soil remediation technology, this study established bacteria isolation, surfactant toxicity matching and petroleum contaminated soil remediation practice. The simulated field remediation showed that inoculating the soil with Bacillus methylotrophicus and adding 500 mg kg-1 rhamnolipid (N + RL) to soil can remove 80.24% of aged total petroleum hydrocarbons (TPHs) within 30 days. In particular, although the remediated soil has inoculated sufficient bacterial suspension, the microbial abundance of Bacillus was not a significantly dominant genus after remediation, especially in N + RL (0.73% of the total), but the colonies of indigenous petroleum-degrading bacteria (such as Massilia and Streptomyces) increased significantly. The interaction among genera has been further proved to drive soil non-specific oxidases (such as polyphenol oxidase, laccase and catalase) to remove TPHs. This indicates that the interaction among microorganisms, rather than the degradability of exogenous degrading bacteria, plays more critical role in the degradation of organic pollutants, which enriches the traditional understanding of micro-remediation of contaminated soil. It can be concluded from the obtained results that the remediation of pollutants can be achieved by adjusting the purification capacity of the microbial community and the natural environment.