镉污染灌溉水入田前快速净化材料和装置研究

为开发灌溉水入田前低成本、快速净化技术,创制了一套农田Cd污染灌溉水的快速净化装置,筛选出四类低成本、环保、高效的Cd净化材料以及材料配比方案。研究表明,不同材料Cd静态和动态吸附效果为赤泥粒石灰石沸石油菜秸秆。模拟灌溉时长3 h,灌水Cd浓度60μg·L~(-1),过水流量53.3 m3·h~(-1)(内径40 cm圆形过水断面),保障净化后水中Cd浓度低于农田灌溉水安全标准(10μg·L~(-1)),Cd污染水净化率≥83.3%,上述四类材料对Cd吸附总量变化范围为344.4~358.2 g·m~(-3),各材料间Cd吸附量无显著差异。净化装置主要工艺参数:进水口径10 cm,壳体内径40 cm,壳体高度65 cm,最大处理水量64.8 m3·h-1,滤层高度45 cm,材料承载体积56.5 dm~3,滤层分为三层,每层由10 cm厚单一材料构成,材料粒径5~8 mm。灌溉水推进速度1.4 m·s~(-1),组合材料处理Cd污染水(10~60μg·L~(-1))净化率85%,材料一次装填可净化Cd 15.2~20.1 g,预计可处理水507~671 m~3,满足0.13~0.18 hm~2单季稻田灌水净化需求(灌水Cd浓度和灌水定额分别以40μg·L~(-1)和3750 m3·hm~(-2)计)。

Study on materials and a device for purifying cadmiumpolluted irrigation water

Irrigation by using cadmium polluted water is one of the important factors lead to increase Cd content in paddy soil, important ma-terials and a device were studied for purifying Cd polluted irrigation water. Four materials were selected as purifyingagen, that was red mud particles, limestone, zeolite and rape straw. Effect of purifying Cd in water was in order as red mud particles>limestone>zeolite>rape straw>>ceramsite and perlite,and Cd adsorption amount in average range of 344.4~358.2 g·m-3. Cd concentration in purified irrigation water was lower than that of irrigation water security standards of China(GB 5084—2005,10μg·L-1)by simulated irrigation duration 3 h,Cd 60μg·L-1 concentration in irrigation water, a water flow rate 53.3 m3·h-1 (40 cm inner diameter circular water section), Cd polluted water purification rate of 83.3%or more. Purifying device described as barrel(inner diameter 40 cm, high 65 cm)with a water inlet and a water outlet, andthe barrel filled with composite purifyingagen 56.5 dm3(φ40 cm, high 45 cm), and maximum water flux 64.8 m3·h-1. Cd 15.22~20.14 g could be removed from irrigation water by the purifying device, is expected to deal with 507.2~671.2 m3 of Cd polluted water, meet the de-mand of 0.13~0.18 hm2 of paddy water purification(irrigation water 3750 m3·hm-2 with Cd 40μg·L-1).