The Investigation Of Aniline In Site Pollution And The Study Of Aniline Removal On Wastewater In Pollution Sources In A Chemical Works

Aniline is a significant chemical material, widely used in industry areas of national defense, dyeing, rubber, textiles, paper, the glaze pottery, plastic, paint, polyurethane, dyestuffs, pesticides, medicines and special fiber and so on. At present, the country produce more than 80,000 t aniline every year, aniline has more than 150 downstream, about 30,000 t substance of aniline will out to environment in the world every year. From 1952, our country start to produce aniline, until the late 1980s always was the seller market, at beginning of 1990s there was "aniline hot" in domestic market. Now has 25 process units of aniline, the total production capacity is about 250,000 t, ranked 9th in the word. As the chemical industry developing, demand of aniline is rising obviously, thereby the amount of aniline enter into the environment will be more and more large, and the harm to the environment will be bigger and bigger.Aniline is a highly toxic material, with effect to "cancer, distortion, mutation" or suspicious effect, aniline belong to the compound of ammonia of benzene, long-term contact to this type of mass will cause aniline poisoning, or even cause liver cancer or bladder cancer. In 1977, 129 of the priority of environmental pollutants was published by the United States, aniline include in it. Aniline has belonged to "the blacklist" in the European Communities list. At the same time aniline is taken precedence to the blacklist of "the priority of environmental pollutants in fourteen types" in our country. It is generally believed in the medical profession that the rising morbidity of some malignant disease has a close relationship with aniline pollution.Now, the site pollution has become a global problem, and the chemical plant that produce aniline will cause this problem. Most of our suburb has come in for different degree of pollution. Cadmium, chromium, arsenic, plumbum, etc. has over proof or close to the quality standards of soil environment (gb15618-1995) of grain, vegetables, and fruit in many localities.The site pollution will lead to food quality continuously declined, at the same time; the contaminants at the root of pollution can be accumulated in plant, enriched by food chain to human body and animal body, and do harm to human health and animal health, cause cancer and other diseases. Toxic waste stack at will and soil polluted by pesticides will cause water pollution which by erosion, carry and infiltration of rainwater. A large number of waste water containing aniline not only do harm to the environment but also cause serious threat to drinking water of mankind. So, how to control the discharge of aniline pollutants effectively has become a common concern.This paper uses chlorine dioxide and Fenton reagent two oxidizers combined to degrade the aniline of N-Phenylglycinonitrile wastewater in a chemical plant in Shuangliu county of Chengdu city. The aim is to seek rules of aniline in the wastewater based on these two methods, and to offer a theoretical basis for management of the wastewater. The chief research is:1. Uses chlorine dioxide to degrade the wastewater in the first. Study influence of aniline removal rate on basic factors such as pH, initial consistency of chlorine dioxide, reaction time, temperature, etc. The results indicate: the aniline removal rate can achieve 71.35% in pH 6, temperature 55℃, chlorine dioxide solution 4mL, and reaction time 20min. There are mainly two types of intermediate production in the reaction of chlorine dioxide and aniline: Para-aminophenol and azobenzene. The reaction between chlorine dioxide and phenols with the first production of chinone, the further production of simple organic acids and inorganic acids, and when azobenzene synthesize though couple the neutral free radical of aniline;2. Uses Fenton reagent to degrade the wastewater after the first step, study influence of aniline removal rate on basic factors such as pH, mole ratio between H2O2 and Fe2+, initial consistency of H2O2, reaction time, temperature, etc. The results indicate: the aniline removal rate can achieve 91.17% in pH 3, temperature 70℃, mole ratio between H2O2 and Fe2+ is 3:1, addition of H2O2 is 4000mg/L, and reaction time 5h.The intermediate production in the reaction of Fenton reagent and aniline is butene diacid, the intermediate production can be mineralized into carbon dioxide and water when the addition of Fenton reagent is large.