Optimal Design of a Hybrid Membrane System Combining Reverse and Forward Osmosis for Seawater Desalination

In this work we study Forward Osmosis (FO) as an emerging desalination technology, and its capability to replace totally or partially Reverse Osmosis (RO) in order to reduce the great amount of energy required in the current desalination plants. For this purpose, we propose a superstructure that includes both membrane based desalination technologies, allowing the selection of only one of the technologies or a combination of both of them seeking for the optimal configuration of the network. The optimization problem is solved for a seawater desalination plant with a given fresh water production. The results obtained show that the optimal solution combines both desalination technologies to reduce not only the energy consumption but also the total cost of the desalination process in comparison with the same plant but operating only with RO.

SMEs and Level 2 BIM, the Way Forward

The UK construction industry comprises a very high proportion of SMEs that is companies employing up to 250. A Department for Business, Innovation and Skills research paper, found that SMEs had a 71.2% share of work in the construction industry. Micro and small firms (i.e. those employing up to 50) had a share of 46.7% of work (Ive and Murray 2013). The Government has high ambitions for UK construction. Having been found by successive government commissioned studies to be inefficient and highly fragmented, ambitious targets have been set for the industry to achieve 33% reduction in costs and 50% faster delivery by 2025. As a significant construction client, the Government has mandated the use of Level 2 BIM from 2016 on publicly funded projects over £5 million. The adoption of BIM plays a key role in the 2025 vision but a lack of clarity persists in the industry over BIM and significant barriers are perceived to its implementation, particularly amongst SMEs. However, industry wide transformation will be challenging without serious consideration of the capabilities of this large majority. Many larger firms, having implemented Level 2 BIM are now working towards Level 3 BIM while many of the smaller firms in the industry have not even heard of BIM. It would seem that fears of a ‘two tier’ industry are perhaps being realised. This paper builds on an earlier one (Mellon & Kouider 2014) and investigates, through field work, the level of Level 2 BIM implementation amongst SMEs compared to a large organisation. Challenges and innovative solutions identified through collected data are fully discussed and compared. It is suggested that where the SME perceives barriers towards adoption of the technologies which underpin BIM, they may consider collaborative methods of working as an interim step in order to work towards realising the efficiencies and benefits that these methods can yield. While the barriers to adoption of BIM are significant, it is suggested that they are not insurmountable for the SME and some recommendations for possible solutions are made.