Novel Biotechnology for Removal of Soluble Radionuclides and Possible Potential Reduction of Terrorist Impact

人们认识到的核废料处理问题限制了核电的可接受性，尽管这是目前化石燃料的唯一替代品。绿色能源仍然需要10-20年的发展，即使到那时也不能完全满足需要。目前的核废料处理是可以的，但最好的方法是昂贵和/或不是很有选择性。一个令人担忧的问题是用于恐怖活动的被盗核材料的黑市，水供应污染是一个威胁，如果知道快速、便携的清理技术，这种情况就不太可能发生。同样的技术也可以用来改进核废料处理。目前，离子交换方法已经足够，但最好的方法过于昂贵。精细分割的材料是最好的，但很难制造成流动柱。我们现在需要比商业材料更好的材料，结合精细划分但与列兼容的格式，而且更便宜。开发了一种利用微生物酶合成磷酸铀酰(H UP)的新型离子交换剂。这对于去除放射性核素137Cs、90sr和60Co来说是非常好的。韩国对核废料的试验表明，与商业产品相比，其有效性、放射性稳定性和经济性都很高。诀窍是，细菌以HUP为模板，在其表面形成一个支撑的高表面精细分隔层(纳米层)，并控制晶体生长，有效地制造离子交换生物纳米层(涂层)。在做所有这些之前，细菌首先把自己粘在海绵上(通过粘连的“手臂”：粘连)，穿上大衣，然后死亡，但留下(辐射稳定的)活性酶，以便合成更多的HUP大衣。问题是铀具有放射性。对于已经具有放射性的废物来说，这并不重要，但不会受到公众的欢迎。幸运的是，无毒的锆和钛的相关磷酸盐也是离子交换者。它们被认为是结晶性差的固体(实际上，这是获得金属选择性的更好方法)，但它们以前从未被认为是用于离子交换的BIONANOLAYER。第一个目标是开发一种基于生物锆钛磷酸盐(涂层)的纳米层状生物无机离子交换剂，并测定涂层海绵对放射性同位素的选择性。使用时，过滤海绵被填充到流动柱中，但柱可能会被部分堵塞，从而失去效力。第二个目标是开发一种具有低通道和堵塞效应的生物反应器，利用磁共振成像作为一种工具，非侵入性地跟踪反应器内部的金属积累过程和流动，以最大限度地减少堵塞，以最低的成本获得最大的效率/容量。根据核磁共振数据开发的预测数学模型的使用，将帮助我们在寻找便携式、有效过滤器的过程中取得成功。第三个目标是廉价地生产材料(我们可能需要大量的材料，快速)，这得益于之前的成本分析(欧盟报告，1995)，该分析表明，制造成本与商业方法相当。我们将通过使用一种天然植物产品作为我们的饲料材料来制造离子交换大衣，并通过在含糖的工业废物上预先培养细菌来降低这些成本。这些方法在以前的项目中得到了演示，并使用HUP材料处理真实的核废料进行了原理证明。但人们对基于Zr/TiP的离子交换器知之甚少，对从起始生物纳米层制备最佳离子交换材料所需的生物合成后化学处理几乎一无所知。我们将利用最先进的生物膜技术、固态化学和核磁共振技术来生产和评估一种全新的材料，这种材料是坚固的，不能用化学方法制造，将填补现有材料和我们需要的材料之间的巨大差距。我们将把这一过程拍成电影，以获得最大的影响

Perceived problems of nuclear waste treatment limit the acceptability of nuclear power even though this is the only current alternative to fossil fuels. Green energies still require 10-20 years of development and even then will not completely suffice. Current nuclear waste treatment is OK but the best methods are expensive and/or not very selective. A worrying problem is the black market of stolen 'nuclear' materials for terrorist activities, with pollution of water supplies as one threat This will become less likely if fast, portable clean-up technology is known to be available. The same technology could be used to improve nuclear waste treatment. Currently ion exchange methods suffice but the best are too expensive. Finely-divided material is best but is difficult to fabricate into flow-through columns. We need now materials, better than the commercial ones, combining finely divided yet column-compatible formats, and cheaper. .A new type of ion exchanger was developed which utilises a microbial enzyme to synthesise hydrogen uranyl phosphate (H UP). This is excellent for removal of the radionuclides 137Cs, 9OSr and 60Co. Tests against nuclear wastes in S. Korea showed high effectiveness, radiostabilly & economy compared to commercial products. The trick is that the bacteria template the HUP as a supported high-surface finely divided layer (nanolayer) onto their surfaces and control crystal growth to make, effectively, an ion-exchange bionanolayer (overcoat). Before doing all this, the bacteria first stick themselves (via sticky 'arms' :adhesions) onto a spongy support, don their overcoats and then die but leave behind the (radiostable) active enzyme for more HUP overcoat synthesis. The problem is that uranium is radioactive. This does not matter for wastes which are already radioactive, but would not be popular for public use. Fortunately, the related phosphates of the non-toxic Zr and Ti are also ion exchangers. These are laid down as poorly-crystalline solids (actually this is a better way to obtain metal selectivity) but these have never been considered as BIONANOLAYERS for ion exchange before. The 1st OBJECTIVE is to develop a nano-layered bioinorganic ion exchanger based on bio-Zr,Ti phosphates (overcoats) & determine the selectivity of the coated sponges for the radioisotopes. For use the filtration sponge is packed into a flow-through column but the columns can get partially blocked, losing effectiveness. The 2nd OBJECTIVE is to develop a bioreactor with low channelling and blockage effects using magnetic resonance imaging as a tool to follow metal accumulation processes and flows noninvasively within the reactor Itself, in order to minimise the blockages and achieve maximal efficiency/capacity at lowest cost. The use of predictive mathematical models developed from the MRI data, will help us cut comers In our quest for portable, effective filters. The 3rd OBJECTIVE is to produce the material cheaply (we may need a lot of it, fast), helped by a previous cost analysis (EU report,1995) which showed that the manufacturing costs are comparable to commercial methods. We will undercut these costs by using a natural plant product as our feed material to make the ion exchanging overcoat and by growing the bacteria beforehand on sugary industrial wastes. The methods were demonstrated in previous projects, and proof of principle was shown using the HUP material to treat real nuclear waste. But not so much is known about the Zr/TiP-based ion exchangers and almost nothing about the postbiosynthesis chemical processing needed to produce the best ion exchange material from the starting bionanolayer. We will utilise state of the art biofilm technology, solid state chemistry and MRI to produce and evaluate a completely new material which is robust, which cannot be made chemically and which will fill the huge gaps between what is available and what we need. We will make a movie of the process for the biggest impact