多功能便捷式水下化学增氧器的研制及其净水效果研究

Development of a multifunctional and portable underwater chemical oxygenator and its water purification effect

机械增氧作为一种常规增氧技术曾得到广泛应用,但其能耗高、扰动大、影响水运和自然美观,且对水下增氧能力有限。为了提高水下溶解氧(DO)水平,本文利用自行设计的一种兼有脱氮除磷作用的便捷式水下化学增氧器来探讨其最优增氧条件,并对比了水下化学增氧器(装置组)、机械增氧曝气机(曝气组)和未增氧水体(空白组)的水质情况。结果表明:装置组在30%H_(2)O_(2)、25 g Na_(2)CO_(3)、放置深度为60 cm、增氧器中混合矿物材料质量为2.4 kg的最优条件下,对受试水体经过18 d的处理,水下溶解氧(DO)能维持在3 mg·L^(−1)左右,对受试水体中的总氮(TN)、总磷(TP)、氨氮(NH_(4)^(+)-N)和高锰酸盐指数的去除率分别为55.86%、71.45%、61.70%和82.04%,表现出较好的净水效果。但装置组的DO浓度低于曝气组,这可能与最优条件下控制了液体增氧剂的滴速,以延缓DO的释放速度,提高O_(2)利用率,减少对土著微生物的扰动破坏有关。本研究为充分发挥水下化学增氧器的增氧作用,为黑臭水体的修复实践提供了一种新技术和新装备。

Background,aim,and scope As a conventional oxygenation technology,mechanical aeration has been widely used as a traditional aeration technology,but it has high energy consumption,large disturbance,affects water transportation and natural aesthetics,and has limited ability to add oxygen to the water.In order to improve the level of dissolved oxygen(DO)in the underwater layer,a self-designed portable underwater chemical oxygenator,with the function of removing nitrogen and phosphorus,was used to explore its optimal oxygenation conditions,and compared the water quality of underwater chemical aerator(device group),mechanical aerator(aeration group)and non-oxygenated water body(blank group).Materials and methods This paper optimizes the conditions from the modification and selection of substrate(environmental minerals),screening of membrane materials,and condition optimization for the structural design and condition optimization of the underwater aerator.At the same time,the repair effect of the submersible ecological medium box under the aeration enhancement was discussed.Results The results showed that the optimal conditions of the device group were 30%H_(2)O_(2),25 g Na_(2)CO_(3),placement depth of 60 cm,and 2.4 kg of mixed mineral material in the aerator.After 18 days of treatment,the DO was maintained at about 3 mg·L^(−1).The removal rates of TN,TP,NH_(4)^(+)-N and permanganate index in the tested water body were 55.86%,71.45%,61.70% and 82.04%,respectively,which shows good water purification effect.Discussion The water quality of the test water body was effectively improved,however,the DO concentration of the device group is lower than that of the aeration group,which may be related to controlling the drop rate of liquid oxygenate under the optimal conditions,so as to delay the release rate of DO,improve the oxygen utilization rate,and reduce the disturbance and damage to indigenous microorganisms.Conclusions The research results can give full play to the oxygenating effect of the underwater chemical oxygenator and provide a new technology and equipment for the restoration practice of black and odorous water bodies.Recommendations and perspectives An underwater oxygenator was established to provide a new idea to increase the DO concentration in water and treat black and odorous water bodies.