Environmental Engineers

The world is currently facing the water crisis brought about by the deterioration in its
quality and the difficult access to its resources due to ever-growing demand in largescale consumer sectors such as agriculture, industry and tourism. Consequently,
increasing pressure on water resources is experienced in the world as the outcome of
the strong population growth, continued urbanization and rapid industrialization,
together with numerous discharges of polluted waters into watercourses. Strategies
have been developed throughout the world for improving both the quality and access to
water in a sufficient quantity. Thus, different technologies, both established and
emerging ones, are presently utilized in view to treat wastewaters, including those of the
mining origin. The present work reviews the different uses of water in the mining
industry and identifies different sources of polluted waters. It analyses wastewater
treatment techniques in view of their application specifically to the treatment of
wastewaters from the DR Congo mining industry. As such, this work identifies itself as
part of an effort to contribute to the improvement of wastewater management practices
in the DR Congo mining industry as well as improved access and sustainable use of
water resources.

Issues causing increased water stress and availability throughout the world are complex. The importance of supply-side issues arising from increasing urbanization, causing localized levels of water stress, is described. Further, while the world population has doubled over the last 50 years, water use has tripled. Water use rates have increased (from 400km 3 per year per billion people in 1965, to the current level of 600km 3 per year per billion people in 2015), as a result of population growth with its associated food and energy implications, and dietary shifts of populations. Water demands in 2025 are projected to be 1500km 3 per year, or 60% more than volumes in 2015. The findings in a case study in the Zambezi River basin indicate that while climate change is projected as 25% of the projected impact to future water security issues, 75% of water security issues are attributable to population increases (and its related food, energy, and changing dietary habits) and hence, population increases represent a greater threat to water security.

In this work, cost analysis of commonly used RO method, UltraViolet method and the new Pressure Cooker method is performed. These methods studied here relate to the production of potable water which meets the World Health Organization (WHO) standards. The advantages of the use of the Pressure Cooker method over the two other methods for undeveloped countries are explained. The results show that not only the Pressure Cooker method is most economical but also is very versatile as far as its use in rural India or other underdeveloped countries are concerned.

In this study, the solid wastes produced from a hospital and the present waste management procedures were investigated. The management of solid wastes of the hospital were discussed and some novel waste management techniques were determined to treat the solid wastes. The solid wastes should be collected in special coloured bags, they should be labelled and should be stored in special storage area, and should be disposed by the licensed companies according to Waste Management Regulation. The application of the waste separation at the source throughout the hospital decreases the waste disposal fees. The management of hazardous wastes coming from the hospital should be handled as proposed by the Waste Management Regulations.

In this study, the relationship between porosity and compressive strength for porous concrete (PC) was
investigated. The effect of mixture design parameters particularly, water-to-cement ratio (W/C) and size of aggregate on
the porosity and compressive strength of PC was evaluated. To investigate the role of W/C and aggregate size on this
testing procedure, the experiments were performed on specimens of two aggregates size and four range of W/C. The
PC mixtures were made with W/C in the range of 0.28-0.34, 350kg/m3 cement content and 19.5mm and 9.5 maximum
size of aggregate. PC mixes were made from each aggregate and were tested. The results showed that the W/C and
aggregate size are key parameters which significantly affect the porosity of PC. Investigation of compressive strength
and porosity for the various mix designs showed a clear dependence on these parameters. The measured values fall
within the expected range obtained from a review of the literature. Compressive strength of coarse porous concrete
(CPC) is smaller than compressive strength of fine porous concrete (FPC) and the porosity of CPC are bigger than
porosity of FPC. In general, increased W/C yields a smaller porosity and higher compressive strength. This approach
can reduce the number of trial batches needs for target performance of PC samples

In this review, we summarize the recent research progress on the preparation and catalytic performance of meso-and macroporous metal oxide or mixed metal oxide (including manganese oxides, cobalt oxides, iron oxides, chromium oxides, and perovskite-type oxides) catalysts and their supported transition metal and noble metal catalysts for the oxidative removal of typical volatile organic compounds (VOCs), which were prepared using the hard-templating and polyvinyl alcohol-protected reduction methods, respectively. Most of these porous catalysts performed well for the addressed reactions, which was associated with their surface areas, adsorbed oxygen species concentrations, lowtemperature reducibility, interactions between noble metal or metal oxide and support as well as porous structures. In addition, the perspectives for developing high-performance catalytic materials and novel VOCs removal technologies are also proposed.