The most used flocculants in treatment of waste drilling water are PAM flocculants. But its polymeric monomer often has toxicity. Gelatin is a non-toxic, amphipathic natural macromolecule. The flocculants prepared by gelatin and its application in waste drilling water has not been reported. In the experiment, gelatin was extracted from chrome shavings. Sulfate, citric acid and trypsinase were chosen to hydrolyze gelatin and then collagen solution was obtain. Then NaNO2 was added to seal amino of the collagen molecules. The flocculation effects of collagen solution before and after sealing amino on waste drilling fluid was estimated by its CODcr removal rate and the concentration of suspended solids. The results indicated that after sealing amino, the flocculation effect on waste drilling fluid decreased obviously. And when trypsinase was used as hydrolytic agent, the treatment effect on waste drilling fluid was better. The optimal hydrolysis condition was: pH was 7~7.5, temperature was 37°C, reaction time was 3h and the dosage of trypsinase was 1.5% of the gelatin. Under this condition, the CODcr removal rate was 46.7% and the suspended solid content of waste drilling fluid decreased from 2607mg/L to 730mg/L.

The aminated collagen fiber (ACF) was prepared by modifying collagen fiber (CF) with ethylenediamine and cynuric chloride as crosslinking agent. The appropriate modification conditions were optimized by single factor experiment method. The reaction molar ratio of CNC and -NH2 was 1.4, the reaction time of ice water bath was 3h, the temperature of the second phase was 45°C and the reaction time was 4h, the temperature of the third phase was 70°C and the reaction time was 3h. The content of amino of collagen fiber and aminated were measured by the method of salicylaldehyde. The structures of collagen fiber and aminated collagen fiber were characterized by SEM and FTIR respectively. The adsorption capacities and the content of amino of CF and ACF were observed by dealing with acidic black dyeing and sturgeon skin dyeing wastewater.

Using collagen as the raw material, methyl acrylate and vinyl acetate as the soft and hard monomers, ammonium persulfate as the initiator, a surface sizing agent was prepared by the emulsion polymerization method to modified the collagen. The optimum prepared conditions were got by the single factor experiment, follow as m(soft monomer)/m(hard monomer) for 1:2 or 1:1, m(collagen)/m(monomer) for 1:2, the dosage of initiator for 0.8% of monomers amount, the reaction time for 2h. The FT-IR showed that the grafting reaction between vinyl monomers and collagen happened and the vinyl monomers reacted completely. The particle size distribution of the emulsion indicated that its size distribution was uniform and the average size was 0.117μm. The results of application experiments showed that the tensile strength and tearing strength of paper were stronger than that of base paper for 3 times and 1.9 times, after sizing by using the emulsion. The water-resistance of paper was also improved.

The adsorption of acid black dye NT on collagen fiber (CF) was studied, and the effects of temperature, pH, initial dye concentration, adsorbent dosage and reaction time on the dye adsorption were tested, respectively. The results indicated that the optimal temperature and pH of acid black dye NT absorption were 40°C and 2.0, respectively. For a certain concentration of dyeing, the adsorption capacity decreased with the increasing of adsorbent dosage, but increased along with the extension of the contact time. In addition, the adsorption isotherms and kinetics of acid black dye NT on CF were investigated. By comparison, it was found that the Freundlich equation and Pseudosecond-order kinetic model can better describe the adsorption behavior of acidic black dye on CF. Thermodynamic parameters, such as G, H and S were determined to be-3.445 kJ/mol, 11.2 kJ/mol and 59.6 J/(mol·K), respectively. The results indicated that the adsorption was a spontaneous endothermic nature.

Glyoxylic acid was used to carboxylic collagen protein which obtained by the hydrolysis of gelatin. Al (Ⅲ) was complex to it with aluminium tanning principle in tanning chemistry and the novel flocculent (CGAl) was prepared. Use CODcr removal rate, suspended solid and chroma to indicate the flocculation effect on waste drilling water. The results indicated that when CGAl was used, its dosage was 10.5g/L and the range of pH and temperature were widely. After flocculation, CODcr removal rate was 92.3%, suspended solid decreased from 2115mg/L to 65mg/L, and chroma reduced from 1003 times to 6 times. So the flocculation effect was obviously.