RO plant experiences with high silica waters in the Canary Islands
RO plant experiences with high silica waters in the Canary Islands
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DOI：
10.1016/s0011-9164(99)00086-7
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发表时间：
1999-11
期刊：
影响因子：
9.9
通讯作者：
E. Darton
中科院分区：
文献类型：
--
作者：
E. Darton
在世界上许多干旱地区，由于缺乏高质量的给水，迫使厂主要么在不受欢迎的二氧化硅水平下运行膜系统，要么限制回收率。高硅盐水会造成严重的不可逆膜污染。限制回收率从来都不是业主们喜欢的选择。在西班牙大加那利群岛的一些地区，长期干旱和对地下水的高需求导致许多业主通过运行高回收率的系统来节约给水供应，从而提高精矿中硅含量。地下水位的降低导致二氧化硅水平远远高于系统设计阶段的预期水平。膜制造商和原始设备制造商（oem）敦促谨慎，建议往往与业主的需求不同，业主希望通过尽可能少的给水来最大化产量。本文介绍了8年的经验，在三个系统运行高达320毫克/升的二氧化硅精矿。其中两个系统的产量分别为780立方米/天和350立方米/天，用于农业用途，第三个系统的产量为1200立方米/天，用于饮用。在两个系统中，采收率降低，安全操作规范达成一致，只有这样，采收率才会缓慢提高。在第三种情况下，产出没有减少。每个系统都产生了所需的水量和水质，尽管常规清洗是必要的，但没有一个系统遇到不可逆转的硅垢问题。本文考虑了所使用的一些设计特征，并得出结论，只要采取安全措施，二氧化硅含量明显高于接受值的操作是可行的。
In many arid regions of the world, the shortage of good quality feed-water is forcing plant owners either to run their membrane systems with undesirable levels of silica or to restrict recovery rates. High silica brines can cause severe and irreversible membrane fouling. Restricting recovery rates is never a popular choice with the owners. A prolonged drought and high demand for ground waters in some areas of Gran Canaria (Canary Islands), Spain, has led many owners to conserve feed-water supplies by running their systems with high recovery rates and consequential high silica levels in the concentrate. The lowering of the water table has caused silica levels far higher than those anticipated at the system design stage. The membrane manufacturers and original equipment manufacturers (OEMs) have urged caution, advice which is often at variance with the needs of the owners, who want to maximize output by using as little feed-water as possible. This paper describes 8 y of experience in three systems operating with up to 320 mg/L silica in the concentrate. Two of the systems are producing 780 m3/d and 350 m3/d, respectively, for agricultural purposes, and the third is making 1,200 m3/d for potable use. In two systems the recovery rates were reduced, safe operating practices were agreed and only then were the recovery rates slowly increased. In the third case there was no reduction in output. Each system has produced the desired water quantity and quality, and although routine cleaning has been necessary, none of the systems have experienced irreversible problems with silica fouling. This paper considers some of the design features used and concludes that operation with silica levels significantly higher than accepted values is practicable, provided safeguards are taken.