In Appreciation: Don L. Boyer (1938–2020)

Environmental Fluid Mechanics -     

Comments on “Simulation of Jeddah multi–port sea outfall” by Abdullah S. Al-Ghamdi [J. Coast. Conserv.] (2010) 14:63–69

In a paper published recently in the Journal of Coastal Conservation, Al-Ghamdi (J Coast Conserv 14:63–69, 2010) analyzes the wastewater multi-pot outfall of Jeddah using CORMIX2 for average ambient conditions. Both the near–field and the far–field mixing are calculated with CORMIX2. It is found in Al-Ghamdi (J Coast Conserv 14:63–69, 2010) that the near-field extends 187.5 m downstream from the diffuser, where the dilution reaches 1,047.8. It is at this same distance, 187.5 m, that the plume touches the water surface. The far-field dilution and plume width is calculated as the plume finally fills the entire water depth at a distance of 18,927 m downstream. From these analyses, it is concluded that local and international standards for treated wastewater are met and that the plume “will not pose any treats to the local venerable environment”. These findings, if correct, will help to protect the surrounding marine environment. However, is argued here that the use of CORMIX2, particularly for the far-field environment is not well justified and that the inherent simplifications in the software and its use, mainly the characterization of the physical environment, undermine the main conclusions.     

Wasser – elementare und strategische Ressource des 21. Jahrhunderts

Background and aim The combination of increasing freshwater demand, limited or regionally decreasing water resources as a consequence of the climate change, and an increasing qualitative burden, lead more and more to the question as to whether the population of particular regions, whole continents or even the entire world will be confronted with a shortage of available water resources in the future. Discussion The resident-specific regenerative water resources of the continents are being quantitatively rated on the basis of an analysis of the three globally relevant water cycles (the marine one, the terrestrial one and the one which is linking both of them). The available amount of water is limited by technical-economical restrictions. This amount is compared with human demands, and the outstanding relevance of the production of biomass (to be used as food, animal feed, primary product or energy carrier) regarding the worldwide water need is discussed. Results From a global point of view there is no water shortage. Scarcities occur only regionally or seasonally. A large portion of the water employed worldwide is used for the production of biomass. Therefore, this sector provides a considerable key to the strategic handling of water. The so-called ‘green water’ is crucial for the production of biomass. However, the common way of balancing water supply and demand often overlooks the importance of the green water on the supply side and thus indicates shortages which de facto do not exist. As to the whole usage of water by humans, in our opinion, the stated quantity of freshwater which is being regenerated every year all over the world has to be corrected considerably. The figure of 40,000?km³ which is often quoted in current literature has to be raised to more than 100,000?km³. Conclusions and perspectives Water shortage is often not a result of limited resources or technologies but is a consequence of missing awareness, failing political volition or insufficient socio-economic potentials. On the basis of a comprehensive water supply/demand balance, which includes all forms of water usage, national and international potentials for the fulfilment of the demand should be analysed in order to be able to develop necessary supply scenarios.     

Metal–organic frameworks for active food packaging. A review

Environmental Chemistry Letters - Food wastage is a major concern for sustainable health and agriculture. To reduce food waste, classical preservation techniques such as drying, pasteurization,...     

生态住宅的水环境规划:I. 水循环

生态住宅已成为住宅建设的发展趋势和潮流,水环境是生态住宅小区的重要组成部分。文章以中信保利达美景度假区为实例,根据度假区建筑总体规划方案,结合当地自然条件和水环境现状,探讨生态住宅小区的水环境规划,全面统一规划住宅小区内各种水系统,提出小区水环境总体规划方案,充分发挥各系统的功能,使其相互衔接、协调与补充。重点对项目所在区域开发前后的水量平衡,水库的水位变化及其安全性,极端气候条件下的库区水量变化及其因应对策,高尔夫球道的用水方案以及项目开发后的水循环模型做了深入探讨,旨在为生态住宅的水环境建设提供范例。