Yall I, Boughton W H, Knudsen R C, Sinclair N A
Appl Microbiol. 1970 Jul;20(1):145-50. doi: 10.1128/am.20.1.145-150.1970.
The ability of activated sludge to remove phosphates was studied by adding carrier-free (32)P to raw sewage and measuring incorporation of the radioactivity into the cells over a period of time. Radioisotope determinations indicated that 48% of the (32)P radioactivity was removed by 12 hr. However, chemical methods indicated that only 30% of the orthophosphate apparently disappeared from the sewage during this period. Experiments with sludge prelabeled with (32)P indicated that considerable phosphate turnover occurred. The cells released large amounts of radioactivity as they were incorporating fresh phosphates. Starvation in isotonic saline for 18 hr caused the sludge to dump phosphate. When introduced into fresh sewage containing (32)P, the starved sludge removed about 60% of the radioactivity in 6 hr with little phosphate turnover. The ability of sludge to remove (32)P was inhibited approximately 83% by 10(-3)m 2,4-dinitrophenol. This inhibition was at the expense of the cell fraction that contained ribonucleic acid and deoxyribonucleic acid. The sludge cells released orthophosphate when exposed to the chemical agent. Experiments using (45)Ca indicated that calcium phosphate precipitation plays a minor role in phosphate removal under our experimental conditions.
通过向原污水中添加无载体的（32）P并在一段时间内测量放射性在细胞中的掺入量，研究了活性污泥去除磷酸盐的能力。放射性同位素测定表明，12小时内（32）P放射性的48%被去除。然而，化学方法表明在此期间污水中仅约30%的正磷酸盐明显消失。用（32）P预标记污泥的实验表明发生了大量的磷酸盐周转。细胞在掺入新鲜磷酸盐时释放出大量放射性。在等渗盐水中饥饿18小时导致污泥排出磷酸盐。当将饥饿的污泥引入含有（32）P的新鲜污水中时，饥饿的污泥在6小时内去除了约60%的放射性，且磷酸盐周转很少。污泥去除（32）P的能力被10（-3）m 2,4-二硝基苯酚抑制约83%。这种抑制是以含有核糖核酸和脱氧核糖核酸的细胞部分为代价的。污泥细胞在接触化学试剂时释放出正磷酸盐。使用（45）Ca的实验表明，在我们的实验条件下，磷酸钙沉淀在磷酸盐去除中起次要作用。
