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In this investigation, attempts have been made to study the inhibitive effect of hexamethylenetetramine (HMTA) on carbon steel in 10% HCl (mass%) by weight loss, potentiodynamic polarization, EIS, and AFM. Results indicate that inhibition efficiency (IE) of HMTA increases with the increase in pickling immersion time from 10 to 60 min, and IE also increases with the increase in temperature. At higher temperatures (80°C), the IE values are higher and almost independent of pickling time. HMTA can be adsorbed on the surface of metal and reduce the corrosion rate of metal. HMTA is a kind of mixed inhibitor and can retard both the anodic dissolution and cathodic hydrogen evolution reactions independently. IE increases with the concentration of HMTA. Electrochemistry measurement shows that adsorption follows the Langmuir isotherm and the value of free energies of adsorption (ΔG_ads) is < 0, so the adsorption process can occur automatically. AFM analyses show HMTA can affect the surface roughness and protect metal.

The objective of this study was to examine the applicability of Rosmarinus officinalis, Myrtus communis and Origanum sp. essential oil as fungicide against fungus that grows on leather during pickling and tanning processes. In the study, 2-n-Octyl-4-isothiazolin-3-one containing commercial fungicides were also used for control. During the microbiologic tests (ASTM D 4576-86/ 91), the growth of mould species like Aspergillus niger, Alternaria alternata, Penicillium chrysogenum and Trichoderma auroviride that cause problems in leather industry were also investigated against these essential oil and fungicide.

As a result of this study, it has been determined that oregano essential oil has most effective antifungal activity.

Based on washing and pickling, the Phragmites samples were prepared, and these characteristics of pyrolysis reaction were researched in thermogravimetric analyzer. The influence of reaction factors, such as the metal salt components, metal salt elution rate, biomass samples pore size distribution, heating rate, on the pyrolysis characteristics was investigated. Results showed that, the demineralized methods had significant effects on minerals and the pore structure. The pickling efficiency was 99.8%. Original positions of minerals formed new holes after elution, thus leading to the adsorption quantity of elution sample greater than raw sample. With the demineralizing degree increasing, the mesopore proportion decreased gradually. Improving the heating rate was helpful for pyrolyzing of Phragmites raw samples and elution samples.