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In the present study, the adsorption of Remazol Brillant Green 6B (RBG 6B) on chitin which characterized by BET, FTIR, XRD and SEM analysis was studied. Response surface methodology (RSM) was applied to determine interaction between solution pH, initial RBG 6B concentration and chitin dosage being individual variables and to optimize operating conditions. According to results of variance analysis (ANOVA), the second order polynomial model was statistically significant (P<0.0001) and coefficient of determination value (R2=0.98) was high. It was determined that dye removal efficiency increased when low solution pH and initial RBG 6B dye concentration and high chitin dosage were used. The maximum dye removal efficiency was obtained as 88% at solution pH of 3.0, initial RBG 6B concentration of 75 mg L-1 and chitin dosage of 5.0 g L-1. The isotherms and kinetics studies showed that Freundlich isotherm and pseudo-second-order kinetics model fitted well to the RBG 6B adsorption data.

The intent of this research is the investigation of the nitrate reduction from aqueous solution using biomass (pine cone (PC) and PC activated carbon (PCAC)) – supported zero valent iron nanoparticles (PC-Fe0 and PCAC-Fe0). The synthesis of these nano-bio-composites was based on the reduction of ferrous iron with borohydride, in which PC and PCAC acted as porous-based support materials. The structure of the adsorbents was characterized by SEM, XRD, FTIR and BET analysis. The SEM images revealed that nZVI immobilized on PC-Fe0 and PCAC-Fe0 were spherical and uniformly dispersed on the surface of the stabilizers. Batch experiments indicated that the nitrate removal efficiency decreased with the increase in the initial nitrate concentration and initial pH, but increased with the increase in the sorbent dosage and temperature. The maximum adsorption capacities of PC-Fe0 and PCAC-Fe0 for nitrate were 18.16 and 22.30(mg/g), respectively. The nitrogen mass balance calculations revealed that zero valent iron nanoparticles in both PC-Fe0 and PCAC-Fe0 beads could generally reduce nitrate into ammonium, and nitrite usually was occurred as intermediate. Subsequently, PCAC-Fe0 absorbs completely un-wanted ammonium, while PC-Fe0 releases little ammonium in the solution.

Plant nanotoxicology is an emerging and less-explored area of research for the plant stress biologists. The present study assesses the toxicity of bulk-CuO and nano-CuO (size <50 nm and surface area = 29 m² g^-1) on maize (Zea mays cv. hybrids triple white Hi Tech.) seedlings. Five successive levels of stress (25, 50, 100, 150 and 200 mg L^-1) suspensions of CuO and CuONP were imposed and seedling growth performance was studied along control at 8 days of experiment. Modulation of enzymatic antioxidants (SOD, CAT, APX and POD) and non-enzymatic antioxidants (total phenolics and total flavonoids) activities under both-CuO stresses were investigated in detail to get an overview of their-stress response of maize. Seed germination was completely stopped under 150 and 200 mg L^-1CuONP. Generally, CuONP stress was most violent and 100 mg L^-1CuONP showed the same or more drastic effect in 150 and 200 Cu bulk. Photosynthetic pigments, shoot and root lengths reduced under both stresses by about 50% of control. Soluble proteins and total antioxidants increased gradually till it reached about 200% of control at 150 mg L^-1CuO and about 200-300% at 100 mg L^-1CuONP. In addition, increased reducing power activity coupled with both stresses which reached to 400% of control at 150 mg L^-1CuO and 100 mg L^-1CuONP. Moreover, superoxide dismutase increased by 800% of control at 100 mg. L^-1CuONP.

Biological treatment is one of the most preferable strategies to complete and safe removal of pollutants. Pyrene (PY) is the first member of high molecular weight polycyclic aromatic hydrocarbons (HMW-PAHs) that represents various concerns to biological life and human health. In this study, two different algal strains exhibited different capability to degrade PY along 30 days of incubation in the light. Dry weight, total chlorophyll, and carotenoids were growth parameters that were determined to detect robust of two algal strains to get used of PY as a source of carbon. Oscillatoria sp. could degrade 95% while Chlorella sp. could degrade 78.71 % of PY (50 mg/L) after 30 days of incubation. Both algal strains could completely remove 10 and 30 mg/L of PY. On the other hand, the degradation capability of Oscillatoria sp. was significantly exceeded than Chlorella sp. under the same incubation condition and at (50 and 100 mg/L) of PY.