摘要
研究低温下臭氧催化氧化降解养殖水体氨氮的有效途径,并对降解过程中产生的反应副产物进行分析。利用臭氧发生器和催化反应设备,把加入5 mg/L NaBr的养殖水体与臭氧充分混合,在Br-的催化作用下,使臭氧与氨氮产生氧化反应,产生氮气,达到去除氨氮的目的。实验在一个9.2 m3水体、养殖密度为10 kg/m3的封闭循环式冷水鱼养殖系统中,以虹鳟(Oncorhynchus mykiss)为实验动物,在192 h的换水周期内,每24小时采水样1次,检测养殖水体中的pH、溶解氧、氨氮、硝酸盐、亚硝酸盐、悬浮物等水质指标,确定低温下臭氧催化氧化降解养殖水体氨氮的能力和使用方法。研究表明,在Br-的催化作用下臭氧可有效氧化降解养殖水体的氨氮,降解效率可达50.11%,比臭氧直接氧化法高24.31%;降解过程中硝酸盐、亚硝酸盐都有一定积累,但在臭氧的作用下亚硝酸能转化为硝酸盐,亚硝酸盐含量在192 h降至0.089 mg/L,硝酸盐为主要副产物;pH值逐渐下降,192 h降至5.55,养殖过程中可用NaOH-NaHCO3缓冲液进行适当调节。臭氧催化氧化降解氨氮是一种有效的水处理方式,对于冷水性鱼类工厂化养殖的循环水体处理具有重要的实用价值。
With ozone generator and reaction tower, the culture water with 5 mg/L NaBr was fully mixed and the o-zone reacted with ammonia to decompose ammonia into N2. Some experiments were carried out in a recirculating rainbow trout culture system with 9.2 m^3 water and 10 kg·m^3 fish density. During water exchange period of 192 hours, the water samples were tested every 24 hours to analyze pH and concentrations of DO, ammonia, nitrite, nitrate, suspended solids and so on. By the experiments, the ammonia decomposition capacity and application of ozonation could be determined. The results showed that ozonation could effectively decompose the ammonia of aquaculture water in the presence of bromide, and the efficiency of decomposition reached 50.11% which was approximately higher by 24.31% than direct oxygenated efficiency by ozonation. In the experiments, nitrite and nitrate were accumulated, and concentration of nitrite decreased to 0. 089 mg/L on 192nd hour because nitrite was transformed into nitrate as the main nitrogen by-product by ozonation. The pH should be adjusted owing to its gradually descending to 5.55 on 192nd hour. In this experiment, the conditions of DO and suspended solids were suitable for cold water fish. Decomposition of ammonia by ozonation in the presence of bromide was beneficial for cold water fish recirculating culture system.
出处
《中国水产科学》
CAS
CSCD
北大核心
2005年第6期790-795,共6页
Journal of Fishery Sciences of China
基金
科技部科研院所社会公益研究专项基金项目
关键词
氨氮
臭氧
降解
溴
ammonia
ozonation
decomposition
bromide
