改性红土应急除藻及水质改善评价:水库现场应用

Evaluation of Modified Red Soil for Algal Bloom Removal and Water Quality Improvement——in situ in a Reservoir

蓝藻水华是中国乃至全世界范围内最严重的水环境问题之一。蓝藻水华的控制特别是应急除藻技术中,改性黏土絮凝沉降被认为是最具前景的除藻技术,目前国内外已研发出各类改性黏土材料。该文以广东省广泛分布的天然红土为材料,通过FeCl3改性以提高其除藻效率,并利用自主研发的喷洒艇在省内某发生蓝藻水华的水库进行工程应用。工况为:每小时FeCl3絮凝剂20 kg,红土100 kg,喷洒面积20000 m2。结果表明,改性红土喷洒后1 h,蓝藻被高效絮凝沉降至水库底部,表层蓝藻的去除率超过95%;同时能显著降低水体中的氮磷浓度、浊度,增加透明度,且对水体pH、Fe浓度无显著影响。因此,上述改性红土是一种高效、低廉、环境友好的除藻材料,可应用于蓝藻水华的应急处理。

Cyanobacteria bloom is one of the most serious water environment problems in China and even in the world.Modified clay flocculation is considered as the most prospective technology for cyanobacteria bloom removal,especially for emergent treatment.At present,various modified clay materials have been developed in domestic and overseas.In this paper,the natural laterite which widely distributed in Guangdong Province was modified by FeCl3 to improve its algal removal efficiency,and the flocculant was sprayed with a self-developed boat in a reservoir which dominated by cyanobacteria bloom.The working conditions were 20 kg FeCl3 flocculant and 100 kg laterite per hour,and treating area was 20000 m2.The results showed that after spraying the modified laterite,cyanobacteria was flocculated and settled to the bottom of the reservoir with high efficiency,and the removal rate of surface cyanobacteria was more than 95%.At the same time,it can significantly reduce the concentration of nitrogen and phosphorus and turbidity in water,increase the transparency,and also there were no significant changes of pH and Fe in water body.Therefore,the modified laterite is an efficient,cheap and environmentally friendly algal removal material,and can be used in the emergency treatment of cyanobacteria bloom.