Freshwater Utilization Research Articles

Fabrication of superhydrophobic PVDF membrane via catechol/polyamine co-deposition and SiO2 nanoparticles for membrane distillation

Due to the societal development and population growth, the crisis regarding fresh water resources has become increasingly prominent. As a membrane separation technology, Membrane distillation (MD) has emerged as a widely used in the recovery and utilization of fresh water. However, membrane wetting and membrane fouling have hindered the further application of MD. To address these challenges, this work provides a method for fabricating a superhydrophobic composite PVDF membrane using catechol(CA)/polyethyleneimine(PEI) co-deposition, sol-gel growth of SiO2 nanoparticles, and the grafting of long chain perfluorosilane. The surface average roughness of the superhydrophobic membrane was up to 113.04 nm under the optimum conditions. The contact angle of the modified membrane was up to 157.5°, and a sliding angle is 8.0°, confirming its conformity to the Cassie-Baxter model. In addition, the modified membrane not only improved fouling and wetting resistance but also maintained a water flux equivalent to that of the PVDF membrane membrane when treating feeds containing surfactant, organic pollutants, and high salinity. In conclusion, this study provides a simple and feasible method for preparing superhydrophobic modified membrane, which further improves the adaptability of MD process for complex feed systems.

Water Resources Management and Wastewater Treatment in the Democratic Republic of Congo (D.R.C): Application of Galvanic Treatment, Results and Prospectives

The rapid industrial development and population growth increase the utilization of fresh water resulting in an increase of the amount of wastewater. Several Countries face a double challenge with regard to water resources, namely meeting the growing need for water for the population and treating the wastewater generated for application. The toxicity found in these water streams threatens the environment and human health. Hence the urgent need is to treat wastewater. The DRC is not immune from this threat. Its average population growth rate has exceeded the 3% and the number of industries it hosts continues to increase. The wastewater generated by this increasing pressure from urbanization and industrialization must be treated as required in the Congolese legal arsenal. Various factors need to be considered prior choosing the water treatment method. The choice must take into account the imperatives of the moment which are: modernization (local context) and sustainable development (international context). There are several wastewater treatments that are widely used for the removal of toxic elements such as ion exchange, reverse osmosis, chemical precipitation and electro-coagulation just to name a few. The most recent studies have shown that the galvanic technique can be used in the purification of water from domestic and industrial origin to meet drinking water standards. Various researchers have used this technique at laboratory and pilot scale demonstrating its cost-effectiveness as it uses no chemical reagents, consumes less energy and occupies only a small space for processing large flows. However, there are very few studies demonstrating the success of this treatment on an industrial scale. Therefore, this work seeks to understand and master the mechanisms that take place in the galvanic treatment. In addition, this study focuses on the development of a robust prototype that is adaptable to the needs of various users while at the same time being relatively cheap to meet the national needs.

A Review on the selection of the variant Water in Concreting

According to the global agencies of world health organization, world metrological organization and UNICEF, the utilization of fresh water goes on enlarging from twenty century due to overpopulation and frequent implementation of safe accessible water in relative fields, diminishing the quantity and quality available which ultimately causes gap between ecology and environment for livable water. In our construction industry, this safe water can be saved to a large extent by just interchanging this water by various water available viz. seawater, waste water, sewage water and waste wash water based on literature data and studies which show normal and insignificant changes in the strength of cement hardened concrete. This literature based study will provide the base for adoption of waste water a as source in the construction field for preparing the formwork and a small donation towards national water saving programs launched by government of India.