RELIEF: Reducing Environmental impact of the Leather-tanning Industry with Electron beam Facilities

皮革生产是墨西哥等许多官方发展援助受援国经济的重要贡献者。墨西哥中部的瓜纳华托地区拥有大约350家制革厂，这些制革厂对当地环境造成了重大影响，导致供水受到广泛污染，生态系统中毒。虽然已经实施了一些法规来限制制革业产生的污染，但这些法规很少得到执行，对改善当地环境也没有什么作用。皮革生产过程包括许多不同的阶段，从腌制阶段开始，在屠宰场和制革厂之间运输时保存动物皮。然后，生皮经过几个步骤，统称为鞣房操作，以准备用于鞣制阶段的生皮。鞣制是一个过程，其中化学品用于在加工的生皮（胶原蛋白）中的蛋白质链之间产生交联。这种交联是由鞣剂引起的，如硫酸铬（III），它与蛋白质链发生化学键合。这些交联使皮革更耐用，比原始皮革更不易受到霉菌和细菌的破坏。鞣制过程与工业生产塑料的过程非常相似，后者使用电子束在长链烃之间产生交联，使材料更耐用。鞣制阶段被认为是污染的最重要原因，对当地环境的影响最大。未使用的铬（III）通常作为废水处理，然后进入当地的生态系统。我们建议用电子束设备取代传统的鞣制阶段，以电子束在皮革中产生交联，与电子束用于在塑料中产生交联的方式相同。在这个项目中，我们将研究电子束对生物样品的影响，以估计在蛋白质链的破坏超过交联对皮革的强化之前的最大辐照剂量。我们将研究用于蛋白质链之间桥接的潜在试剂，重点关注对环境影响最小的试剂。将在墨西哥从制革厂的角度研究电子束设施的要求，这项研究还将确定其他将受益于电子束设备的行业。这项研究的结果将被用来进行电子加速结构和束流传输线的初步设计研究。该项目将研究各种选择，例如是否使用固定的宽光束或扫描皮革的小光束。该项目是一项初步研究，旨在证明电子束皮革鞣制工艺的可行性，并确定最终产品最有可能的设计方案。这将包括电子束对生物材料影响的初步研究，电子束鞣制所需的可能化学过程的基础研究，以及最终产品的初步设计研究。

Leather production is a vital contributor to the economy in many Official Development Assistance (ODA) recipient countries, such as Mexico. The Guanajuato region in central Mexico is home to approximately 350 tanneries, which have caused a substantial impact to the local environment, resulting in widespread pollution of water supplies and poisoning of the ecosystem. While regulations have been implemented to attempt to limit pollution produced by the tanning industry, these are rarely enforced and do little to improve the local environment.The leather production process consists of many different stages, starting with the curing stage to preserve the animal skins while they are transported between the slaughterhouse and the tannery. The hides then undergo several steps, collectively known as the beamhouse operations, to prepare the hides for the tanning stage. Tanning is a process whereby chemicals are used to create crosslinking between protein chains in the processed hide (collagen). This crosslinking is caused by the tanning agent, such as Chromium(III) Sulphate, which chemically bonds to the protein chains. These crosslinks make the leather more durable and less prone to damage from mould and bacteria than the original hide. The tanning process is very similar to the process used to industrially manufacture plastic, where an electron beam is used to create crosslinking between long-chain hydrocarbons to make the material more durable.The tanning stage is considered to be the most significant cause of pollution with the largest impact on the local environment. The unused Chromium(III) is often disposed of as wastewater, which then gets into the local ecosystem. We propose to replace the conventional tanning stage with an electron beam facility to create crosslinking in the leather with an electron beam, in the same way as electron beams are used to create crosslinking in plastics. An additional organic chemical, such as an aldehyde or acrylate, will be used to create the "bridges" between protein chains.In this project, we will study the effect of an electron beam on a biological sample to estimate the maximum irradiation dose before the damage to the protein chains outweighs the strengthening of the leather from crosslinking. We will investigate potential reagents for the bridging between protein chains, focussing on reagents with minimal environmental impact. A study of the requirements of an electron beam facility from the perspective of the tanneries will be undertaken in Mexico and this study will also look to identify other industries that would benefit from such as device. The outcome of this study will be used to undertake an initial design study of the electron accelerating structure and the beam transport line. This will investigate options such as whether to use a stationary, wide beam or a small beam that scans across the leather.This project is an initial study to demonstrate the feasibility of an electron beam leather tanning process and to identify the most likely design options for a final product. This will include an initial study of the impact of an electron beam on biological material, a basic study of the likely chemical process required for electron beam tanning, and the initial design study of a final product.