藻类吸附缓解稻田重金属污染的研究

采用盆栽和稻田污染模拟试验,研究了藻类吸附对稻田土壤中重金属和稻谷中重金属残留的影响。藻静态吸附试验结果表明：1 g普通小球藻吸附Cd、Hg和Cr的能力分别为27.60、17.94和22.52 mg/g·h,椭圆小球藻和梅尼小环藻对重金属也有很强的吸附能力;投放普通小球藻、椭圆小球藻和梅尼小环藻的盆栽试验表明,稻谷Hg、Cd和Cr残留比未投放藻的降低76.53%、65.71和53.57%;Cd污染稻田模拟试验表明,有藻田的稻谷Cd残留比无藻田的降低76.47%,达到国家标准要求。可见,藻对重金属的吸附能力可以在稻田中发挥良好作用,由于藻的吸附作用,3种重金属在稻谷中的残留显著下降。

Algae Absorption Alleviates the Pollution of Heavy Metal in Rice Field

Removing the heavy metal in rice field with algae adsorption was done by means of the potted rice and simulation pollution so as to decrease the remains of heavy metal in rice.Results showed that Chlorella Vulgaris has a stronger adsorption ability to heavy metal with 276.00 mg/L·h adsorption rate on Cd per lg algae,with 179.35 mg/L·h on Hg per 1g algae and with 225.20 mg/L·h on Cr per 1g algae.In three potted rice with Chlorella vulgaris,Chlorella ellipsoidea and Cyclotella meneghiniana,the heavy remains in rice were respectively 0.23 mg/kg（Hg）,0.36 mg/kg（Cd）,0.52 mg/kg（Cr）.In contrast group,the heavy metal remains in rice were respectively 0.98 mg/kg（Hg）,1.05 mg/kg（Cd）,1.12 mg/kg（Cr）.In simulation pollution rice field,the Cd remains in rice was 0.16 mg/kg in group with algae,the other was 0.68 mg/kg.It is thus clear that the adsorption ability of algae on heavy metal was able to play a role in field rice so as to decrease the remains of heavy metal in rice.