دوماهنامه مهندسی شیمی ایران
پیاپی 121 (خرداد و تیر 1401)

Clinoptilolite is a cheap and abundant zeolite. They are alumino-silicate that play important role in water and wastewater treatment. The clinoptilolite are characterized by using XRD, FT-IR. The best method of modification and operating conditions were detected. Clinoptilolite was papered from Manzarieh (Qom Province) and then was crushed by ball milling to reduce the size to below 400 nm. The spectrophotometer was utilized to detect the removal efficiency. Addition of adsorbent to solution containing nitrate and sulfate ions has been carried out with the thorough investigation of main parameters such as type of modification, the amount of adsorbent to pollutant concentration, contact time and pH. The results show that clinoptilolite has important characteristics in removing ions from water. Furthermore modification of zeolite can improve the efficiency of adsorbent. Type of modification plays an important role in removing total iron and phosphate ions. The modified zeolite can remove nitrate up to 94% and sulfate ion up to 98 % at different pH and concentrations. Increasing contact time could improve removal efficiency. The ratio of adsorbent to initial concentration and pH were investigated as important factors. The study shows that clinoptilolite can be used as a promising and low-cost adsorbent for removal of nitrate and phosphate ions from aqueous solution.

In this study, the application of bio-acid leaching method based on the use of lemon juice to extract copper and zinc metals from mobile printed circuit boards has been investigated. Three important factors were investigated include lemon juice concentration, Solid / Liquid (S/L) ratio, and hydrogen peroxide (H2O2) concentration. Response surface methodology (RSM) was used to optimize the effective factors. The results showed that for particles with a size of 150 to 180 μm at a constant temperature of 20 ° C and time 4 h under optimal conditions including 1.41% (w/v) S/L ratio, 12.2% (v/v) H2O2 and 74% (v/v) lemon juice, copper and zinc recovery efficiencies are 89% and 73%, respectively. Moreover, the artificial neural network was used to predict the extraction of copper and zinc metals as a function of the studied factors. To validate the model, laboratory results were considered as evaluation data. The results of neural network modeling showed high accuracy to predict the target variable. The values of MRE, MSE, and R2 were 9.485, 15.254, and 0.9356% for the copper extraction model and 1.854%, 1.094, and 0.9963% for the zinc extraction model, respectively.

Increased energy demand and lack of clean water as a result of urbanization, population growth, and climate change have become global challenges. Membrane technology can play a special role in water purification, desalination and supplying process water required by power plants. Membrane processes have certain advantages, including high quality water with easy maintenance, low chemical sludge effluent, selectivity and selective transfer of desired components, appropriate adaptability and applicability in integrated processes, low energy consumption, environmental friendliness and good controllability. Also, using this technology in batteries and fuel cells and select the right material and membrane structure, there will be the ability to produce clean, sustainable and efficient electrical energy. Sustainable energy is a type of energy that can be used indefinitely without affecting the environment and the depletion of the resource. In addition, the use of membrane processes in the production and the purification of biofuels and the separation and recovery of gaseous pollutants are other important issues studied in water and energy industry.

By improving technology at recent years, some new environmental problems created. Electronic waste is one of the important problems. Recycling of e-wastes is limited. Just some countries by using traditional methods are recycling e-wastes. Pyrometallurgy and hydrometallurgy are two recycling methods for e-waste. These traditional methods are expensive and non-ecofriendly. Bioleaching is a new and efficient method for e-waste recovery which by interacting microorganisms helps to metal recovery. In this article biorecovery of Cu, Al, Ni, Zn, Mn, Mg, Ba, Cr, and Fe from printed circuit boards using one-step bioleaching was studied. To this purpose computer printed circuit boards were fined and the particle size was in the range of 75-149 micron. Penicillium simplicissimum was adapted to 1% (w/v) of computer printed circuit boards. After adaptation and bioleaching process Cu, Al, Ni, Zn, Mn, Mg, Ba, Cr, and Fe were bioleached about 94%, 99/8%, 100%, 100%, 61%, 81%, 46%, 26%, and 100% respectively. This paper proved the great potential of the bio-hydrometallurgical route to recover base metals from electronic wastes using fungi.

In the recent years, bioengineered cardiac tissues are of particular significance because of the extremely limited ability of the myocardium to self-regenerate. In this article, the recent advancements in the development of experimental in vitro platforms for next generation of the diagnostics and therapy validation are reviewed. Specially, here the present progress of the microfluidics technology application such as micro/nano fibers, micropatterning, and 3D bioprinting with sacrificial material or with microfluidic channels for the development of cardiovascular systems’ biofabrication at the tissue- and organ levels is described. With all the improvements in this field, there are still difficulties in prolonged cells viability, thick tissue fabrication for higher mimicry levels, and scaffolds mechanical stability in vivo. Until now, microfluidic methods pave the way for in vitro recapitulating of cardiovascular tissue for drug testing and providing basic knowledge of organ’s functions. In the future, with novel microphysiological systems, the transition from bench to bedside will be accelerated.

In the present study, three-component alumina-chitosan-clay nanocomposite (Al/Cs/C) using in situ polymerization method was evaluated as an efficient and a low-cost adsorbent for the removal of methyl orange dye as an anionic contaminant from aqueous solutions. Activated alumina is a porous mineral adsorbent that was selected as the substrate of the nanocomposite. In order to improve the physical properties of alumina and make an environmentally friendly adsorbent, chitosan biopolymer was used as a composite reinforcement. In continued, the clay particles were applied to increase the adsorption capacity of the adsorbent and modification of the composite. The various structural analysis including X ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM) were evaluated to study the morphology of the fabricated samples. The highest adsorption capacity for the prepared adsorbent was 133.33 mg/g, according to Langmuir isotherm. There is a good agreement between the pseudo second order kinetics and the experimental data.