Continual and excessive accumulation of coloured contaminants discharged into various water bodies by many industries (textile, leather, paper, dyestuff and plastic) in our environment leading to direct and indirect contamination and pollution of our water system endanger human and aquatic lives. The thermal and photostability nature of these coloured contaminants which makes them difficult to be eliminated from our water system is of great concern. Researchers are continually putting massive attention on the possibilities of improving existing methods and technologies, developing novel strategies, and bring about solutions to subdue these dye-related water contamination problems which will be economically and environmentally friendly. One of the most sustainable technology or method employed in the decontamination and purification of coloured wastewater is adsorption. It possesses several advantages as it has simple and easy design of operation and is highly economical. Metal-organic frameworks (MOFs) play substantial roles under this application as a new class of porous adsorbents that are characterized by a highly crystalline molecular structure and relatively large surface area which is a significant parameter to be considered in adsorption processes. They are also recommended as a good choice of sorbents employed in wastewater purification technologies as a result of their tunable features. This research study aimed at providing a comprehensive review of recent studies on the adsorptive use of MOFs for the removal of these developing organic pollutants from wastewater.

Dyes are visible materials and are considered as one of the hazardous components that make up industrial waste. So it is removed from bodies of water, using various methods. In this regard, the Fenton oxidation process is one of the most effective ways to remove colored contaminants in aquatic environments, which has many applications today.
In this empirical study, the effect of the Fenton oxidation process in the removal of the soluble synthetic dye, Reactive Red 2 (RR2), has been studied. The color removal efficiency of the Fenton process in the presence of ferrous sulfate and hydrogen peroxide at different reaction variables were studied in the Jar Test when initial concentration of the dye was 10 mg/L at constant pH = 3 and lab temperature.
The results showed that concentrations of hydrogen peroxide and iron ions influence the maximum removal efficiency.
According to the survey results, Fenton oxidation is an effective method for the removal of RR2 dye from aqueous solutions.

In this research, the magnetic nanoparticles coated with chitosan have been used to remove the reactive red 120 azo dye from aqueous solution. Chitosan is one of the most well-known biopolymers that can be used as adsorbent for the removal of color contaminants. Fe3O4 magnetic nanoparticles were synthesized by simultaneous combination of FeCl3.6H2O and FeCl2.4H2O, and coated by chitosan polymer with low molecular weight. Then magnetic nanoparticles coated with chitosan were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared radiation (FTIR), X-ray diffraction (XRD) and Vibrating Sample Magnetometer (VSM). Moreover, the effects of three parameters: pH, initial color pollutant concentration and adsorbent dosage on the adsorption were studied. The maximum adsorption about 98.99 percent occurs at pH=4, 150 mg/l of the initial concentration of azo dye and adsorbent dosage of 6 g/l. Adsorption data were fitted with Langmuir and Freundlich isotherm models. The results showed that the adsorption data on magnetic chitosan nanocomposite is more adapted with Freundlich model.

In this study, zinc oxide nanoparticles were synthesized with the addition of Ti (10% mol) and Si (10% mol) by sol-gel method. The properties of samples contaminated with metal cations (SZ, TZ, STZ) were compared with pure zinc oxide (ZnO = Z). XRD, SEM and UV-VIS methods are used to study crystalline phases, morphology and particle size, optical properties and photocatalytic properties of nanoparticles. Photocatalytic properties of the samples were studied under UV exposure for one hour using methylene blue (MB) as a color contaminant in the textile industry. X-ray diffraction results show that all samples are formed at 450 ° C from the crystalline phase of zinc oxide with a vortex composition. The particle size of the samples in the presence of titanium and silicon metal cations is smaller than that of the zinc oxide sample. Investigation of the optical properties of the samples shows an increase in the band gap of the samples relative to the pure zinc oxide sample. The photocatalytic efficiencies of the samples indicate a positive presence of metal contaminants to improve the photocatalytic properties of the samples, such that in the sample with the simultaneous contaminant (STZ), compared to the pure ZnO sample and the individual contaminants ( TZ and SZ) have a higher photocatalytic efficiency.

The widespread use of dyes leads to create problems such as environmental pollution in form of color wastewater discharges to environment and also lead to entering of color effluent into receiving waters. The dye lead to prevent of penetration of sunlight into water and thus photosynthetic processes in surface water were disordered. Therefore the aim of this study is determined the efficiency and effectiveness of magnesium oxide nanoparticles in removal of reactive yellow 3 dyestuff from aqueous.
This study was experimental that effects of variables affecting on the efficiency of dye removal from synthetic wastewater was studied and survived effect of The parameters: pH(5,7,9), reaction time(30,60,90), adsorbent dose (0.1,0.2,0.3 g) and initial dye concentration(30,50,100,150 mg/l).
The results showed that with increasing contact time, adsorbent concentration and color decreasing, removal efficiency increased, as The most efficiency of dye removal was obtained at Ph= 7(55%), adsorbent amount 0.3 g (96.36%), dye concentration 30 mg/l (86%), and contact time of 90 minute (62.2%).
The efficiency more than 90% prepared absorbent in the removal of dyes from aqueous was shown that it can be used as adsorbent effective in treatment processes. So use this technique to remove colored contaminants from aqueous solutions have been proposed.

Dye effluents of some industries contain many toxic, carcinogenic, and mutagenic compounds therefore, wastewater colored contaminants of such industries should be meticulously refined using an appropriate method before discharging waste-water to the environment. Therefore, this study aimed to evaluate the effectiveness of Multi-Walled Carbon Nanotubes (MWCNTS) in dye removal of Acid Black 1 (AB1) from colored wastewater. This laboratory study was conducted in the batch system and MWCNTS were used as absorbents to remove AB1 dye. In fact, this study investigated the effect of various factors influencing dye removal, such as adsorbent dose, initial dye concentration, contact time, and pH. The study results showed that pH=3 is regarded the best pH for the dye removal. The equilibrium time for AB1 dye absorption on MWCNTS was 60 minutes. As dye concentration increased, dye removal rate decreased. Besides, increasing the amount of adsorbent increased the dye removal efficiency and at the absorbent dose of 600 mg/L, dye removal efficiency was reported 98.86% and 94.62% for 30 and 50 mg/L dye concentrations respectively. AB1 dye removal followed Langmuir isotherm and Pseudo-second-order kinetic models. The results of absorption studies revealed that increasing the contact time and the absorbent dose as well as reducing the pH lead to an increase in dye removal efficiency. Overall, the study findings demonstrated that MWCNTS could be used as an efficient absorbent in regard with decolorization of azo dyes from wastewater.

Dye effluents of some industries include many toxic, carcinogenic, and mutagenic compounds; therefore, colored contaminants of such industries should be carefully treated using an appropriate method before discharging wastewater to the environment. This study aimed to evaluate the performance of Multi-Walled Carbon Nanotubes (MWCNTS) as an effective adsorbent in removing Acid Black 1 (AB1) from colored wastewater.
This laboratory study was conducted in the batch system and MWCNTS was used as an adsorbent to remove AB1 dye. The effect of various factors influencing dye removal, such as adsorbent dose, initial dye concentration, contact time, and pH investigated in this study.
The results showed that pH=3 was the best pH for dye removal and the equilibrium time for AB1 dye adsorption on MWCNTS was 60 minutes. As dye concentration increased, dye removal rate decreased. Besides, increasing the amount of adsorbent increased the dye removal efficiency and at the adsorbent dose of 600 mg/L, dye removal efficiency was 98.86% and 94.62% for 30 and 50 mg/L dye concentrations, respectively. Also, AB1 dye removal followed Langmuir isotherm and Pseudo-second-order kinetic models.
The results of adsorption studies showed that by increasing the contact time and the adsorbent dose and reducing the pH, dye removal efficiency was also increased. In addition, MWCNTS could be used as an efficient adsorbent for decolorization of azo dyes from wastewater.

In the last decade, many cases of modified chemical processes for the green synthesis of nanomaterials have been reported. Considering the remarkable properties of nanomaterials and environmental issues, a rapid and biocompatible approach as a new option for the synthesis of copper oxide nanoparticles (CuO-NPs) using Chenopodium album )C.album(leaf extract, as a renewable and non-toxic reducing agent and an effective stabilizer, was presented in this study. It is noteworthy that the current synthesis process can provide the possibility of rapid, cheap, and high efficiency production of CuO nanoparticles with a spherical morphology (135 nm) at ambient temperature and pressure. Optimization of important parameters in the formation of CuO-NPs, such as pH, copper ion concentration, the quantity of leaf extract, and incubation time and temperature was examined. The formation of CuO-NPs was confirmed by UltraViolet-Visible (UV–Vis) spectroscopy, X-Ray Diffraction (XRD), Fourier Transform InfraRed (FT-IR) spectroscopy, and Transmission Electron Microscopy (TEM). Owing to the good stability and superior catalytic activity of the synthesized CuO-NPs, they were used to degrade methylene blue (MB) and rhodamine B (RhB) dyes as water colour contaminants in the presence of NaBH4 at room temperature. The reaction process was monitored using UV-visible measurements at regular intervals. According to the reaction conditions, reduction of MB and RhB occurred at 8 min and 52 min, respectively.

Activated carbon is widely used at various industrial processes such as water and wastewater industries. Activated Carbon (AC) is an adsorbent which is mostly employed for removing dye from aqueous solutions because of its excellent adsorption properties. Therefore، AC is used in the adsorption process in order to remove different pollutants from the wastewater، especially colored contaminants. however; the use of commercial grade of activated carbon is faced with difficulties due to the high price of raw materials. The used newspaper found as a main component of solid wastes can be used for producing of activated carbon. One of the most important industrial pollutants، especially in textile industries، is the dyes that even at low concentrations of one parts per million (ppm) are recognizable by naked eyes. One of the mostly consumed materials in the dye industry is Methylene Blue (MB) which is used for cotton and silk dyeing. Up to now، a great number of methods have been proposed in order to remove dyes from the industrial waste water، among which adsorption is the most acceptable due to its cost effectiveness and the possibility of usage in large scales. The aim of this study is to evaluate the performance of activated carbon produced from the used newspaper for the removal of methylene blue dye in aqueous solution. KOH solution (weighted ratio of 1:3) was used to activation. The carbonization process was applied at 500˚C with the rate of 17˚C/min. After carbonization، the sample was cooled down to room temperature and then washed with distilled water until the pH of the filtered water was stabilized at 7. 5. N2 adsorption at 77K is used to characterize the produced activated carbon using BET isotherm. To evaluate the performance of methylene blue dye removal، the Langmuir، Freundlich، Temkin and Redlich-Peterson isotherms with pseudo-first and pseudo-second order and inter-particle diffusion kinetic models were used. Thermodynamic parameters such as enthalpy (ΔΗ˚)، entropy (ΔS˚) Gibbs free energy (ΔG˚) were also calculated. Based on the results، the values of SBET and VTOTAL were obtained 66. 01 m2/g and 0. 063 ml/g، respectively. According to the R2 and sum of squares for error (SSE%) values and regression curves، the optimum isotherm and kinetic model were determined Freundlich and pseudo-second order ones، respectively. In addition، qmax constant was obtained 68. 03 mg/g for Langmuir isotherm. Kinetic parameters showed the adsorption of methylene blue dye on the activated carbon is endothermic and spontaneous. Also، (ΔG˚) in physical adsorption was changed from 0 to -20 kJ/mol، while the amount of the chemical adsorption will changed between -80 to -400. Finally، the activated carbon obtained from used newspaper in this study showed a better specific surface area and adsorption capacity for methylene blue dye adsorption in compared with other grades. Thus، the production of activated carbon from used newspaper should be considered as a cheaper and more effective alternative.

One of the important properties road pavement and safety is skid resistance. These properties are dependent on numerous factors, such as properties of pavement surface texture and materials used, weather conditions, seasonal changes and road surface contaminants. The aim of this study is to examine the effects ofvarious contaminants on skid resistance of the pavement surface. The existence of contaminants, especially during the first rain after a drought period makes the wet road surfaces slippery and increases the risk of accidents. Some of these contaminants are natural, such as dust and quick sand on the desert areas and some of them are unnatural such as lube oil and rubber particulates produced by tire wear. So, in this study, dust, quick sand, lube oil, rubber particulates, soot and cool color traffic were chosen as contaminants. Asphalt samples were made in Marshall large formats using three continuous grading with Gyratory compression and then by British Pendulum Tester were tested at different temperature and humidity. Test results indicated that contaminants had distinct effects on skid resistance of asphalt pavements. It was also shown that under dry conditions, the minimum value of skidding is when the surface is completely covered with quicksand and under wet conditions; the value of skidding was declined on average of 49 to 55 percent by cool color traffic. Artificial neural network (ANN) and decision tree data-mining methods were employed to analyze the data were derived from the statistical model. Accordingly, it was shown that changes in the type of contaminants cause the greatest change in skid resistance.