Lost circulation of drilling fluids in fractured reservoirs is one the major chalenges in petroleum industrials. Economical problems related to such phenomena makes its prevention necessary. In this investigation, prevention of lost is studied using lightweight granular materials and the effect of their concentration and size is evaluated. Experiments were carried out using lightweight industrial and mineral granular materials. The results show that a proper mixture of fine and coarse lightweight industrial granules is suitable for minimizing the fluid loss. It is shown that the best mechanism for lost prevention is plugging of the fractures, which is in good agreement with the results of other investigations.

Poly-aluminum chloride (PACL) is an inorganic coagulant used in recent years for the removal of color and turbidity in refining water industry. When coagulants are added to water, some amount of this material dissolves in water and remains in the final refined water. Aluminum is also a material that is found in aluminum coagulants base (Alum and PACL), and little amounts of this material in the water causes many health problems such as dialysis encephalopathy and Alzheimer. Environmental Protection Agency (EPA), has determined the maximum concentrations level (MCL) allowable in drinking water as 0.2 mg/l. Advanced coagulation process is defined as the addition of excess coagulant for the removal of natural organic matter (NOM), as precursors of disinfection by products. It is expressed as the best available process for the treatment and removal of this material. The amount of residual aluminum was studied in conventional and advanced coagulation after adding PACL in jar test. Results showed that mean residual aluminum in enhanced coagulation was more than conventional coagulation. But the amount of residual aluminum in both processes was lower than the MCL recommended by EPA. It can be conclude that using enhanced coagulation by PACL in water, not only causes turbidity and NOM removal, but even with multiplying the coagulant dose, the residual aluminum is less than the recommended maximum concentration level.

Minerals have important role in healthy human nutrition especially calcium and phosphorus that are essential elements of bone. This project carried out to enrich kiwi fruit and banana by these minerals using osmotic dehydration technique. 55% sucrose syrup used as osmotic agent and the concentration of minerals were 1% and 2% experiment completed in 30 and 60 minutes in ambient temperature at the end fruits drained and slightly dried by tissue to eliminate extra syrup. Dry mater as well as calcium and phosphorus content were measured for treated and untreated samples and compare together. Results showed higher calcium gain than phosphorus in both kiwi and banana. Calcium content of banana was 600% higher than untreated fruit in the case of phosphorus kiwi fruit gained 200% of this mineral to initial content. It seems reasonable consumption of enriched fruits instead of synthetic medicines. Calcium absorption is higher than phosphorus. Calcium concentration in the solution increases the absorption of calcium in the fruit. But the process time has no effect on calcium absorption in kiwi fruit in contrast with banana. Phosphorus concentrations and process time has no significant effect on mineral uptake.

Considering the increase of environmental pollutant resulted from agglomerating rubbish and wastes containing stable petroleum-based polymers, substitution of these polymers with bio-polymers and solving their problems and defects in the production process as well as the final products is an important topic. In this study, the possibility of the production of poly lactic acid (PLA)-rice husk composite with acceptable properties, and also the effect of using flame retardant mineral fillers of aluminum three hydrates (ATH) and magnesium di-hydroxide (MDH) on physical and thermal properties of the produced composite were investigated. Results indicated that the density of PLA-rice husk composite was higher than petroleum-based polymers composites (PP/HDPE-rice husk composites); and flame retardant mineral fillers addition led to an increase in the composite density. Also, flame retardant mineral fillers addition decreased the composite water absorption and thickness swelling, in a way that they were comparable with petroleum-based polymers composites. Results of thermal gravimetric analysis (TGA) showed that flame retardant mineral fillers addition also decreased the temperature of the composite weight loss curve peaks, and the weight loss rate toward temperature rising.

Preservation of bone volume immediately after tooth removal might be necessary to optimize the success of implant placement. The aim of this study was to compare bone dimensional changes following tooth extraction without Bio-Oss and with Bio-Oss and a collagen membrane in the dental socket. In this experimental interventional study, thirty subjects who required tooth extraction and implant replacement were selected. Subjects were randomly divided into control (no Bio-Oss) and case (ridge–preservation procedure with Bio-Oss and collagen membrane) groups. The parameters of plaque index, gingival index, bleeding on probing, horizontal ridge width and vertical ridge changes were assessed, immediately and 6 month after extraction. A bone biopsy was taken from the extraction site in the both groups 6 months after surgical treatment. Histological study was performed on all biopsy samples. Finally, paired t-test and Bon Ferroni were applied for data analysis (α < 0.05). Compared to the case group, a significantly greater horizontal absorption was observed in the control group. The ridge height reduction in control group was 3.6 ± 1.5 mm at buccal side and 3 mm at lingual site. In the case group however, they were 0.7 ± 1.4 mm and 0.4 mm at buccal and lingual sides respectively. Biopsies from the grafted sites revealed the presence of trabecular bone, highly mineralized and well structured with a minor percentage of mineralized bone. The amount of connective tissue was significantly higher in the control group compared to the case group. Dental socket preservation approach using Bio-Oss in combination with collagen membrane seems to significantly limit the resorption of dental socket after tooth extraction.

Mineralized collagen has diverse biological advantages, biocompatibility and biodegradability. In this study, the process of mineralization of the protein collagen type I extracted from the scales of white fish (Rutilus Frisii Kutum), was investigated in the Simulated Body Fluid (SBF). During immersion in SBF, tricalcium phosphate crystals were precipitated into collagen nanofibrils. SDS-PAGE electrophoresis confirmed the presence of type I collagen, including 3 spiral strands. Infrared Fourier Transform (FTIR) spectroscopy technique was used to characterize extracted collagen nanofibrils and mineralazied collagen. The presence of 60% of minerals in the mineralized Acid Soluble Collagen (ASC) was confirmed by TGA. DSC was used to determine the denaturation temperature of mineralized ASC at 147.5 °C, indicating a higher thermal stability of mineralized collagen. TEM images showed irregular and dense formation of tricalcium phosphate nanoparticles on collagen nanofibrils. Mineralized collagen protein can provide new insight into producing porous scaffolds for tissue engineering, dental implants, and providing medical equipment.

Metronidazole, as one of the most widely used antibiotics in the world, in addition to various benefits, has significant adverse effects on the environment and animals. The catalytic ozonation process is one of the most successful methods for antibiotics removal. However, it should be noted that this process, like other oxidation processes, has some byproducts that can be toxic in the process effluent.
Under optimum conditions for catalytic ozonation in the presence of MgO nanoparticles, 1 sample was obtained from a reactor after 10 minutes of ozonation. The sample was analyzed by gas chromatography–mass spectrometry (GS-MS) and the intermediates were identified. The mineralization rate was determined using TOC analysis and the toxicity changes were calculated through bioassay with Daphnia magna.
Findings: In the present study, 4 compositions were identified as oxidation intermediates. The mineralization rate was about 93.5% and the 48-hour toxicity unit decreased from 1.24 in the influent to 0.32 in the effluent.
A high mineralization rate was obtained in the process. Nevertheless, it was not complete, and thus, the influent solution was converted from toxic to slightly toxic. In conclusion, we can say that catalytic ozonation process in the presence of MgO nanoparticles can be acceptable for metronidazole removal.

In the present study, the electrochemical coagulation process (electrocoagulation) in the mining industry to remove arsenic ions from the charged leaching solution of PLS (copper processing plant) has been investigated. Samples were obtained by simulating the leaching process by adding trivalent arsenic salt (NaAsO2). The effects of three independent parameters such as pH (X1), electrolysis time (X2), current density (X3) were investigated using the response surface methodology (RSM) to investigate the removal of arsenic from PLS solution. This design includes 17 sets of experiments using electrocoagulation system. In this study, the Box-Benken test design in the response surface method with three numerical factors at three levels was investigated to investigate the interactive effect of process variables to evaluate the efficiency of arsenic removal from leaching solution using electrocoagulation method. The optimal conditions for the electrocoagulation process were determined at pH 6.50, electrolysis time: 114 minutes and electric current density of 65.3 A/m2, with a removal efficiency of 96.88%. The results showed that the ability of electrocoagulation process as a reliable method to remove metal ions, especially arsenic ions from the effluents of the mining industry, especially in mineral processing plants is very desirable.