沉积物对粪固醇的吸附行为研究

采用批量振荡法模拟粪固醇在沉积物-水两相中的迁移,考察了温度、盐度、pH值、浓度对沉积物吸附粪固醇的影响.结果表明,温度升高不利于沉积物对粪固醇的吸附,但有利于粪固醇溶解度的增加;沉积物有机质中亲水性基团向水体中释放,不利于粪固醇的吸附;盐度升高和水体中粪固醇初始浓度增大皆有利于沉积物对粪固醇的吸附;pH值增高或降低皆抑制沉积物对粪固醇的吸附;沉积物中粗胡敏素对粪固醇吸附贡献较大,矿物质对粪固醇吸附贡献较小;温度、盐度、pH值和粪固醇浓度的变化,对粪醇/(粪醇+加氢胆固醇)、粪醇/24-乙基粪醇、粪醇/胆固醇、24-乙基粪醇/谷甾醇、24-乙基粪醇/(24-乙基粪醇+加氢谷甾醇)5个质量比指标的影响较小,其质量比指标可以作为粪便污染的指示物.

Adsorption behaviors of faecal sterols by sediments

The transference of faecal sterols between sediments and water via volume oscillation method was simulated,effects of temperature,salinity,pH and concentration of faecal sterols on the adsorption behaviors were investigated.There were some negative effects on the adsorption of faecal sterols by sediments but positive ones on increase of solubility of faecal sterols with increase of temperature.Meanwhile,the adsorption of faecal sterols by sediments was inhibited by release of hydrophilic groups in organic matters into water.There were some positive effects on the adsorption with increase of either salinity or initial concentration of faecal sterols in water,while the adsorption was inhibited by either increase or decrease of pH.Role on the adsorption of crude humin in the sediments was much more important than minerals.Besides,with the variations of temperature,salinity,pH and concentration of faecal sterols,there were few changes in the mass ratio of coprostanol /(coprostanol+cholestanol),coprostanol/24-ethylcoprostanol,coprostanol/cholesterol,24-ethyl coprostanol/sitosterol and 24-ethyl coprostanol /(24-ethyl coprostanol +sitostanol).Thus,these five indices of mass ratio could be used as indicators of faecal contamination.