The need to design low-cost adsorbents for the detoxification of industrial effluents has been a growing concern for most environmental researchers. So modelling of experimental data from adsorption processes is a very important means of predicting the mechanisms of various adsorption systems. Therefore, this paper presents an overall review of the applications of adsorption isotherms, the use of linear regression analysis, nonlinear regression analysis, and error functions for optimum adsorption data analysis.

https://downloads.hindawi.com/journals/jchem/2017/3039817.pdf

Modelling and Interpretation of Adsorption Isotherms

The rapidly increasing population, depleting water resources, and climate change resulting in prolonged droughts and floods have rendered drinking water a competitive resource in many parts of the world. The development of cost-effective and stable materials and methods for providing the fresh water in adequate amounts is the need of the water industry. Traditional water/wastewater treatment technologies remain ineffective for providing adequate safe water due to increasing demand of water coupled with stringent health guidelines and emerging contaminants. Nanotechnology-based multifunctional and highly efficient processes are providing affordable solutions to water/wastewater treatments that do not rely on large infrastructures or centralized systems. The aim of the present study is to review the possible applications of the nanoparticles/fibers for the removal of pollutants from water/wastewater. The paper will briefly overview the availability and practice of different nanomaterials (particles or fibers) for removal of viruses, inorganic solutes, heavy metals, metal ions, complex organic compounds, natural organic matter, nitrate, and other pollutants present in surface water, ground water, and/or industrial water. Finally, recommendations are made based on the current practices of nanotechnology applications in water industry for a stand-alone water purification unit for removing all types of contaminants from wastewater.

/pdf/a-review-of-removal-of-pollutants-from-water-wastewater-p40ax32731.pdf

A Review of Removal of Pollutants from Water/Wastewater Using Different Types of Nanomaterials

Remediation of wastewater using various nano-materials

Water purification for human use, ecosystem management, agriculture, and industry is emerging as a leading global priority. Access to sufficient clean water ultimately requires improvements over the current state of water filtration technology. Membrane technologies for water purification have been actively pursued for decades, but with recent innovation of both analytical and fabrication tools, more advanced membrane technologies are surfacing. Here, we review the design, development, and application of new membrane materials, fabrication methods for controlling the filtration size regime, analytical tools for performance testing, and molecular modeling for transport and separation. Membrane chemical stability, fouling, and environmental impact as open questions are also presented.

Membrane materials for water purification: design, development, and application

A critical review on recent advancements of the removal of reactive dyes from dyehouse effluent by ion-exchange adsorbents

The studies of the kinetics and isotherms adsorption of the Reactive Black 5 (RB5) onto bentonite clay were explored in a batch study in a laboratory. The maximum RB5 adsorption conditions of bentonite clay were optimized such as shaking speed (100 rpm), temperature (323 K), pH (10), contact time (40 min), initial dye concentration (170 mg·L−1), and particle size (177 µm). The adsorbent surface was characterized using Fourier Transform Infrared Spectroscopy spectroscopy. The mechanisms and characteristic parameters of the adsorption process were analyzed using two parameter isotherm models which revealed the following order (based on the coefficient of determination): Harkin-Jura (0.9989) > Freundlich (0.9986) and Halsey (0.9986) > Langmuir (0.9915) > Temkin (0.9818) > Dubinin–Radushkevich (0.9678). This result suggests the heterogeneous nature of bentonite clay. Moreover, the adsorption process was chemisorption in nature because it follows the pseudo-second order reaction model with R2 value of 0.9998, 0.9933 and 0.9891 at 25, 75 and 100 mg·L−1 RB5 dye in the solution, respectively. Moreover, based on the values of standard enthalpy, Gibbs free energy change, and entropy, bentonite clay showed dual nature of exothermic and endothermic, spontaneous and non-spontaneous as well as increased and decreased randomness at solid–liquid interface at 303–313 K and 313–323 K temperature, respectively.

Adsorptive Removal of Reactive Black 5 from Wastewater Using Bentonite Clay: Isotherms, Kinetics and Thermodynamics

The drawbacks associated with activated carbon, mainly cost, have resulted in the continuing search for inexpensive adsorbents easily and abundantly available as waste materials. The current review presents the results of using different forms of date palm (DP) waste as low-cost biosorbents, highlighting effects of contact time, pH, the dose and size of the adsorbent particles, initial metal concentrations and the effects of pre-treatment on the adsorption efficiency of copper (Cu2+). The results of studies using the raw DP trunk fiber suggested the equilibrium time was approximately 2 h, with a significantly high removal of Cu2+ during the initial 1 h at acidic pH values of 5-6, which indicated the interference of H+ ions with metal ions at low pH values. The raw DP trunk fiber was tested with initial particle sizes of 75-251 μm and adsorbent dosages in the range of 0.4-5.0 g L-1. The best adsorption efficiency was obtained at the smallest particle size and the maximum dosage. The use of different initial Cu2+ concentrations resulted in a 10% decrease in removal, but the adsorption capacity was increased three-fold with an initial concentration of 20-100 mg L-1. A significantly higher removal efficiency of Cu2+ was achieved using the modified DP waste than with the raw trunk fiber for all experimental parameters and operational conditions owing to the increased functional groups on the modified adsorbents. The reviewed literature confirmed the efficiency of DP waste for the adsorption of heavy metals, but the use of the raw or even modified DP waste for the large-scale treatment of wastewater is still a concern owing to the cost effectiveness, availability and requirement for DP waste on a massive scale. Further research for physical modifications of the raw DP waste that employs cost-effective techniques, such as using the DP waste in the form of dehydrated carbon and media filters are required.

/pdf/removal-of-heavy-metals-from-wastewater-using-date-palm-as-a-3v2yhjzauc.pdf

Removal of heavy metals from wastewater using date palm as a biosorbent: a comparative review

http://cfile222.uf.daum.net/attach/131D5A3D4DB77FC029373E

Roof-harvested rainwater for potable purposes: application of solar collector disinfection (SOCO-DIS).

In this study, we investigated catalytic nitrate removal using nanoscale zerovalent iron (NZVI) supported Cu–Pd bimetallic catalyst (Cu–Pd/NZVI) in a continuous reactor system. Control experiments showed that Cu, Pd, and a proper supply of H2 are essential for relatively sustainable nitrate (30 mg/L NO3–-N) reduction in continuous mode. When we optimized operational parameters to enhance removal efficiency and N2 selectivity, we finally achieved complete nitrate removal with 48% N2 selectivity at 9 h. During a longevity test (200 h reaction), excellent removal was observed (>91% in 24 h) with 42–60% N2 selectivity. However, removal gradually decreased to 13% in 200 h with increasing nitrite production. X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy analysis revealed that both the support (NZVI) and the Cu(0) oxidized after continuous denitrification. This indicated that loss of NZVI reductive capacity and the oxidation of Cu(0) to Cu(I) and Cu(II) deactivated nit...

Muhammad Tahir Amin

Papers

A Review of Removal of Pollutants from Water/Wastewater Using Different Types of Nanomaterials

Adsorptive Removal of Reactive Black 5 from Wastewater Using Bentonite Clay: Isotherms, Kinetics and Thermodynamics

Removal of heavy metals from wastewater using date palm as a biosorbent: a comparative review

Roof-harvested rainwater for potable purposes: application of solar collector disinfection (SOCO-DIS).

Catalytic Nitrate Removal in Continuous Bimetallic Cu–Pd/Nanoscale Zerovalent Iron System