A simple method has been proposed for the removal and degradation of polychlorinated biphenyls (PCBs) from catches using low cost and environmental friendly way. The removal of PCBs from lipid layer to aqueous layer was done by utilizing polyethylene glycol (PEG) as phase transfer agent and photocatalysis technology for its degradation. Experimental involving various types of PEG and concentrations were performed to obtain the highest percentage of removal. The highest total amount of PCBs removal was attained using PEG 400 with concentration of 0.2 M. In order to determine the suitable photocatalyst to use for the degradation study, the physicochemical properties of WO3/SnO2/TiO2 prepared from mechanical mixed and sol-immobilization were compared. In situ and ex situ techniques were explored to determine its influence on removal and degradation of PCBs. Substantial degradation of removed PCBs in ex situ method was achieved in the presence of heterostructured WO3/SnO2/TiO2 photocatalyst prepared by mechanical mixing under visible light. Meanwhile significant total amount of PCBs reduction in mussels was observed under in situ method (with PEG 400, 0.2 M and photocatalyst) compared to control run. Thus, this study displayed conformity of the method with high degradation.

Nanoscale Fe–Pd bimetallic particles were synthesized and used for degradation of lindane (γ-hexachlorocyclohexane) in aqueous solution. Batch studies showed that 5 mg/L of lindane was completely dechlorinated within 5 min at a catalyst loading of 0.5 g/L and the degradation process followed first-order kinetics. GC–MS analysis in corroboration with GC-ECD results showed the presence of cyclohexane as the final degradation product. The proposed mechanism for the reductive dechlorination of lindane involves Fe corrosion-induced hydrogen atom transfer from the Pd surface. The enhanced degradation efficiency of Fe–Pd nanoparticles is attributed to: (1) high specific surface area of the nanoscale metal particles (60 m2/g), manyfold greater that of commercial grade micro- or milli-scale iron particles (∼1.6 m2/g); and, (2) increased catalytic reactivity due to the presence of Pd on the surface. Recycling and column studies showed that these nanoparticles exhibit efficient and sustained catalytic activity.

Biodegradation of chlorinated pesticide γ-hexachlorocyclohexane (lindane) by a nonwhite rot fungus Conidiobolus 03-1-56 is reported for the first time. Conidiobolus 03-1-56, a phycomyceteous fungus isolated from litter, completely degraded lindane on the 5th day of incubation in the culture medium, and GC-ECD studies confirmed that lindane removal did not occur via adsorption on the fungal biomass. Degradation studies using different medium compositions showed that nitrogen/carbon limiting conditions (stress conditions) and presence of veratryl alcohol, induced the secretion of extracellular oxidative enzymes, which enhanced the rate of lindance biodegradation. Under optimum nutrient-limiting conditions, GC-ECD and GC-MS analysis showed complete absence of any degradation metabolite, indicating that lindane was completely mineralized. Assays for tannic acid utilization and lignin peroxidase showed similar enzymatic profiles between Conidiobolus 03-1-56 and standard white rot fungi Pleurotus ostreatus 1200 and Trametes versicolor 1086. Although Conidiobolus 03-1-56 showed a reduced enzyme activity compared to white rot fungi, preliminary evidence indicates that enzymes responsible for lignin degradation by white rots play a key role in lindane degradation by Conidiobolus 03-1-56.