Several New Techniques For Research On Environment Pollution Remediation Treatment And Detection

With the social process of industrialization, the problem in environmental pollution is getting worse, seriously affecting people's quality of life and health, which has attracted extensive attention. At present, the techniques of remediation on pollutants are mainly physical, chemical and biological methods. Microbial treatment on environmental pollutants is an important area of research in environmental pollution control because of its simpleness, low cost, safety and reliability, no secondary pollution and good treatmen effect. The development in this area has created a great demand on analytical chemistry. The electrochemical techniques, especially stripping voltammetry, for the trace analysis of metal ions offer special advantage due to their high sensitivity, ease of application, low cost, high selectivity and accuracy. Based on the remediation treatment on environmental pollutants, as well as the improvement of detection methods, this thesis presents the following research.1. The dynamic process of degradation of naphthalene with Pseudomonas aeruginosa was studied with UV-Vis spectrophotometry, based on different absorption of P. aeruginosa and polycyclic aromatic hydrocarbons naphthalene in different wavelengths, and the process of bacterial growth on the kinetic parameters (A ,μm andλ) were estimated. According to a series of translation of absorbance in the wavelength of absorption of P. aeruginosa, the results reflecting the extent curve of naphthalene degradation was obtained.2. Pseudomonas aeruginosa immobilized multiwalled carbon nanotubes was used as a novel kind of solid-phase extraction adsorbents of heavy metals, and the adsorption process was studied. The concentration of copper ion in the aqueous solution was was detected on the MES modified electrode with stripping voltammetry. The adsorption process of copper was rapid and equilibrium was attained within a short time without taking any special measures. Based on the electrochemical results, the kinetics and equilibrium were systematically examined. The pseudo-second-order kinetic model was used to correlate the kinetic experimental data and the kinetic parameters were evaluated. The Langmuir and Freundlich models were applied to describe the adsorption isotherms.3. A bentonite modified carbon ionic liquid electrode (BTT-CILE) for the simultaneous determination of lead and cadmium with square wave anodic stripping voltammetry (SWASV) was prepared. Bentonite could enrich trace Pb²⁺ and Cd²⁺ of solution to reach the electrode surface, thereby greatly reducing the detection limit of the ion. Compared to non-modified carbon paste electrode, this electrode has a high sensitivity. The detection limits are 5×10^-10 mol L^-1 and 1×10^-10 mol L^-1 for Cd²⁺ and Pb²⁺ respectively. The results indicated that the sensor can be used for the actual wastewater Cd²⁺ and Pb²⁺ detection.4. Based on photocatalytic effect of TiO₂, the photocatalytic degradation of chromium (â…¥) and polycyclic aromatic hydrocarbons naphthalene have been studied. The experimental results show that the pH value of reaction system has an effect on he efficiency of photocatalysis, and the adsorption extent of chromium (â…¥) on TiO₂ determine its photocatalytic efficiency. According to the study about photocatalytic reduction of chromium (â…¥) with the existence of naphthalene, the efficiency of their photocatalytic degradation has been significantly improved, which shows that they co-exist have a stronger promotion. In addition, the kinetics process of photocatalytic reduction of chromium (â…¥) was studied. By fitting the reduction data, it was found that the reduction process is in line with the Langmuir-Hinshelwood kinetic curve.