摘要
采用改性粉煤灰对含磷废水进行净化,考察了pH、吸附剂用量、吸附时间和吸附温度对净化效果的影响。结果表明:(1)当pH为9时,磷净化率达到最大值。(2)当改性粉煤灰用量为30g/L时,磷净化率可达99.53%,磷净化后质量浓度为0.91mg/L,达到《污水综合排放标准》(GB8978—1996)中二级标准限值(1.0mg/L);当改性粉煤灰用量为40g/L时,磷净化率可达99.75%,磷净化后质量浓度为0.48mg/L,达到GB8978—1996中一级标准限值(0.5mg/L)。(3)改性粉煤灰对废水中磷的净化速度较快,吸附5min即可使吸附过程达到平衡;进一步提高吸附时间,磷净化率及净化后浓度几乎不再变化。(4)吸附温度对磷净化率的影响较小,当吸附温度为20～40℃时,磷净化率为97.00%～98.62%。(5)改性粉煤灰对磷的吸附等温线较符合Freundlich方程,且1/n=0.374,吸附过程易进行,改性粉煤灰可作为磷的吸附剂用于废水中磷的净化。
The purification of phosphate contained wastewater by sulfuric acid modified fly ash was investigated to determine the effect of pH,adsorbent dosage,reaction time and temperature on purification efficiency.The results showed that the optimum pH for phosphate removal was 9.The removal percentage of phosphate increased with increasing the adsorbent dosage.When the initial phosphate concentration was 193.30 mg/L and the adsorbent dosage was 30 g/L,the phosphate concentration would decreased to 0.91 mg/L,gave the removal percentage of 99.53%.The adsorption of phosphate by modified fly ash was highly effective,for the maximum purification efficiency could be achieved in 5 min.There was a relatively wide temperature range for the adsorption process,and the effect of temperature on removal efficiency was negligible when it ranged 20-40 ℃.The adsorption data were well fitted by Freundlich isotherm model with the 1/n was 0.374,the results revealed that it was feasible to remove phosphate from the waste water by the modified fly ash.
出处
《环境污染与防治》
CAS
CSCD
北大核心
2010年第9期21-24,共4页
Environmental Pollution & Control
基金
河南省教育厅自然科学项目(No.2008B610013)
关键词
粉煤灰
改性
磷
净化
fly ash
modification
phosphate
purification
