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Graphene oxide (GO) is an amphiphilic, water dispersible, chemical derivative of graphene. Widely used as a pathway to obtain graphene, it also has a number of interesting applications by itself due to its ability to form covalently and non-covalently bonded organic–inorganic hybrids and polymer composites. Thus, GO-based composites are used in numerous applications in membrane and coating technologies. It is important that due to the presence of functional acidic groups, GO possesses tunable physicochemical properties like a negatively charged polyelectrolyte and can be used as stimuli responsive membranes, membranes that can interact with environment and switch their properties on demand. Thus, ionic/ molecular separation, water purification, selective sensing, and stimuli responsive properties have already been demonstrated in the laboratory. Good mechanical strength and conductivity (in its partially reduced form) make it attractive for the construction of the membranes for energy devices and sensors. However, concentration and distribution of the functional groups on GO molecules is difficult to control. It makes GO materials difficult to standardize, produce, and apply in industry. To this end, it is important to highlight recent achievement in the synthesis of GO as well as in design of GO-based energy devices, corrosion inhibiting coatings, and biomedical devices with improved working performances to evoke interest on mass production of GO with improved formulation.

Microplastics are commonly recognized as environmental and biotic contaminants. The prevalent presence of microplastics in aquatic settings raises concerns about plastic pollution. Therefore, it is critical to develop methods that can eliminate these microplastics with low cost and high effectiveness. This review concisely provides an overview of various methods and technologies for removing microplastics from wastewater and marine environments. Dynamic membranes and membrane bioreactors are effective in removing microplastics from wastewater. Chemical methods such as coagulation and sedimentation, electrocoagulation, and sol-gel reactions can also be used for microplastic removal. Biological methods such as the use of microorganisms and fungi are also effective for microplastic degradation. Advanced filtration technologies like a combination of membrane bioreactor and activated sludge method show high microplastic removal efficiency.

Now mechanical water treatment technology is getting wide use gradually. This new technology is changing the work way of conventional water plants in practice. In the process of water treatment, the filter process is a very important step. In this paper, the strength and deformation of upper filter system which includes upper filter frames and upper filter plates were analyzed with ANSYS and useful results are got. Finally, according to the analysis results, the paper combined theory with practice, pointed out the disadvantage of design and provided the optimized advice about the upper filter system design.

There are over 100 different types of pathogens that can be found in contaminated water. Contaminated drinking water due to inadequate and unsanitary disposal of sewage and excreta continue to pose a threat to the health in many communities in developing countries. Groundwaters, surface waters, and distribution systems are at risk. Waterborne disease outbreaks are rising due to increasing vulnerable populations, political upheaval, and high numbers of refugees in developing countries. Natural disasters such as flooding and droughts due to climatic changes may also be affecting global water quality. As we move into the next century, it will be important to arm drinking water utility personnel with current and comprehensive information regarding waterborne pathogens and the importance of maintaining vigilance in their control.

The removal of chromium (VI) from water with used cigarette filters was studied by batch contact experiments. The effects of contact time, pH, dosage of the filters, and temperature on the yield of Cr(VI) removal were investigated. The results show that the reaction of Cr(VI) and the filters reaches equilibrium in 2 h, and pH value has a significant role on the reaction. The efficacy of Cr(VI) removal rises with decreasing pH as well as with an increasing amount of filters, but changes little with temperature between 30 and 50 °C. Experiments at 30 °C, a pH of 1, with a 250:1 solution to filters ratio, and simulation with a Langmuir model indicate that one kilogram of filters remove 9.5 grams of Cr(VI) at most.