| With enhancement of environment protection consciousness of people, the study of new-type green water-treatment had become the focus competitively both at home and abroad.γ-PGA was a kind of the high molecular weight polymers, which was produced in large-scale fermentation, could dissolve in the water, was complete biodegradable, LMPGA(low molecular weight PGA) developed byγ-PGA had the good scale inhibition and corrosion inhibition performance, measuring up standard of green water treatment.The main research contents of the thesis were hydrolyzation ability and biodegradable ability ofγ-PGA, scale and corrosion inhibition performance of LMPGA as water treatment.1.γ-PGA was hydrolyzed at different temperature and pH value, relative molecular weight of it was measured by means of SEC method. The temperature and pH value were two important factors for hydrolyzation ofγ-PGA, not only affected the hydrolyzation velocity, but also affected the ultimate hydrolyzation degree.γ-PGA was usually stable, but acid,alkaline and high temperature accelerated the hydrolyzation ofγ-PGA. Preparation of LMPGA was studied, the optimal method was heating up in condition of low pH value and high temperature. All kinds of relative molecular weight PGA was prepared by controlling the different hydrolyzation time.2. The biodegradability ofγ-PGA was measured by means of TOC, the biodegradation ratio was higher than 38.7% after 10 days, 70.3% after 28 days. According to OECD 301 standard,γ-PGA was easily biodegradable polymer.3. The scale inhibition performance of LMPGA was measured by means of static scale inhibition method. LMPGA had optimal scale inhibition performance when its relative molecular weight was 5000 Da. The rate of scale inhibition increased along with LMPGA dosage increased. When the concentration of LMPGA was up to 20mg/L, the rate of scale inhibition was 88%. Furthermore, the influence of the factors as Ca2+ concentration,pH value,temperature and reaction time to the rate of... |
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