احمد جنیدی

This review article is based on jurisprudential rulings, legal approaches, social aspects, medical and ethical approach perspectives , and clarifies decisions related to the issue of brain death. Correct understanding of the brain death phenomenon in terms of brain structure and functioning, and the attitude of the community towards this phenomenon, and in particular the understanding of the condition of a patient with brain death in the future, will modify the form and content of the type of decision and process of the content. Human after the spirit insufflation will have been moral identity, and this identity remains with him until death and even after it .Brain death is a Neologism that hase propeled Experts in the fields of medicine, theology, law and even public to Try and Challenging the vague secret of death .Consistency Braindeath with absolute death Has serious pros and cons Which each other By resorting to Arguments desired , Try to Proving their alleged tendency views .

This research is a review article with Analytical descriptive and correlational method, by collecting information through the in which the resources include books, articles and electronic resources from the library of the Museum of History of Medicine and Central Library and Electronic Resources in the search engines google scholar, Pubmed , Direct Science, Ovid, SID, Iran medex and in If necessary, other databases have been searched by keywords.

Brain death is accepted in many countries as certain death. Sum Of the arguments seem to brain death is unequivalent exactly to certain death and don’t lapses human from humanity and At least the existence. the concepts of spirit, life and death,can be understood not by their quiddity but by their effect . according to Islamic thoughts , life and death is based on the presentation and separation soul from the body. It is seemed on the Islamic thought basis ,

Brain death isnchr('39')t realy equivalent with certain death because it has not broken relatinsheep between the spirit and body perfectly. From the perspective of medical ethics this is important that be accepted harvesting Vital organs from brain dead patients is cause of death them. Assuming the viability of brain dead patients , harvest any organ that led to his death is morally unacceptable Except with prior permission or substitute decision maker .

Today what has attracted more than each other category of human thoughts is the problem of environmental pollution by heavy metals, which affect the health of humans and humans due to their lack of absorption and the effects of physiologic effects at low concentrations. Cadmium has been identified as a carcinogen due to severe toxic effects on human organs. The sources of cadmium inputs to aqueous solutions include wastewaters from chemical fertilizers, pesticides, mines, melting, building batteries, pigments, stabilizers, and alloys, plating, sewage sludge, plastics and synthetic rubber.The daily intake of this substance is 10-35 μg / liter. Smoking is another source of cadmium exposur. According to Standard 1053 of Iran, the maximum allowable cadmium concentration in drinking water, based on the average daily consumption of drinking water equal to 2.5 liters, for a human with 70 kg is 0.005 mg/l. According to the World Health Organization's 1996 standard, cadmium concentrations in drinking water were limited to 0.003 mg /l. Newadays, There are several removal processes for heavy metals from wastewater such as; chemical deposition, membrane processes, ion exchange, coagulation, flocculation and absorption. However, absorption method is one of the most effective and efficient methods. In fact, it can be argued that in many cases protective shells not only prevent the oxidation of iron, but can also be used for more function. Magnetic oxide nanoparticles are most often used in aqueous solutions due to their many advantages such as high surface to volume ratio, very small size, high reactivity, and better absorption of toxins and heavy metals. But one of the main challenges of pure iron oxide nanoparticles is their high chemical activity, which makes it easy to oxidize against air (especially magnetite) or in acidic aqueous media. This will result in the loss of magnetism and the dispersion of iron oxide nanoparticles. Therefore, in order to prevent this occurrence, providing the appropriate coverage level and developing some effective protection strategies to maintain the stability of magnetic iron oxides is very necessary.Protective shields (especially silica), in addition to stabilizing iron oxide nanoparticles, have the benefits of preventing the accumulation of iron nanoparticles, increasing the compatibility of magnetic nanoparticles with solid matrices in the environment, creating graphene and bonding more nanoparticles with organic ligands, reducing the release rate of the oxygen molecule To the magnetic nuclei and to stabilize the crystalline structure of nanoparticles at high temperatures. A two-step method was used to prepare magnetic nanoparticles coated with silica. In this study, cadmium adsorption was performed on adsorbent Fe3O4 @ SiO2 iron oxide mesopes in a closed reactor within 100 ml echinoderms. In the first step, the iron oxide nanoparticles were synthesized via a simple co-precipitation and then, in the second step, the tetraethyl ortho-silicate was used to coating it. For this purpose, 22 g of Fe2Cl3.6H2O and 8 g of FeCL2.4H2O were mixed to 400 mL of deionized water and the resulting mixture was stirred for 1 h in the presence of nitrogen gas at 80 ° C. Then, 15 mL NH4OH (25 % w/w) was added drop wise to reach pH 9. The produced nanoparticles were collected from the solution using an external magnetic field (1.2 Tesla) and washed several times with ethanol and deionized water and then, dried in an oven at 60 ° C for 24 hours. In the second step, a tetraethyl ethoxylan (TEOS) material was used to mixter of Fe3O4. therefore, the nanoparticle was synthesized in the previous stage with 15 ml of TEOS, 6 ml of ammonia (25%), 80 ml of ethanol (65%) and some of the deionised water injected into the reactor. At the same time, a litttle amount of ammonia used, because it reduces the size of the nanoparticles and increases the number of free groups of silanol (Si-OH) on the nanoparticle surface and activates them. Finally, the supernatant was isolated by magnet and washed five times with distilled water and ethanol and then, dried in an oven at 60 ° C for 24 hours. X-ray diffraction (XRD), infrared spectrometer (FT-IR), transient electron microscopy (TEM) and scanning electron microscope (SEM) were used to study absorbent properties. Discussion of the The calculation of the adsorbent isoelectric point (pHZPC) is an essential part of the adsorption process. The isoelectric point is called the pH where the adsorbant has a neutral load. At this point, due to the low electrostatic interactions between adsorbent and adsorbent, the amount of absorption of pollutants is reduced. However, at pH <pHZPC, adsorption load is negatively charged due to the presence of H + ions and at pH> pHzpc the adsorption load is negatively affected by the presence of active hydroxide ions (OH). The pHZPC of Fe3O4 @ SiO2 nanoparticles is calculated to be about 3.26. Therefore, according to the above, it can be stated that the adsorbent has a negative charge in pH>3/26. The maximum removal percentage and its adsorption capacity were 72.86% and 33 mg/g at pH 5, respectively. In this regard, pH 5 was used to continue the experiments. The cadmium adsorption was investigated at interval of 10–60 min. The results indicated that cadmium adsorption increased with increasing contact time. In the present study, iron oxide magnetite nanoparticles coated with silica as adsorbent in the cadmium adsorption process were used. Then, the effect of important pH and contact time factors on the removal of cadmium from aqueous solutions and kinetic, isotherm and thermodynamic models were investigated. According to studies, It was found that the adsorption reaction rate increased by the adsorbent at initial times. The main reason is the availability of more active cadmium sites on the adsorbent surface, which over time will increase the amount of cadmium removal from the solution.The values of Langmuir and Freundlich isotherms parameters of the cadmium adsorption process by Fe3O4 @ SiO2 are shown in Table 2. The results showed that regression coefficients of Langmuir and Freundlich isotherm models were determined to be 0.984 and 0.957 ,respectively.The values obtained from the kinetic parameters of the first-order, second-order kinetics model are shown in Table 3. This suggests that the adsorption of cadmium on the adsorbent surface is more consistent with and consistent with the Langmuir isotherm model. In order to analyze the results of the cadmium uptake process at the synthesized absorbent level, first-order and pseudo-second order kinetics models were used. According to Table 3, the regression coefficient in a pseudo-second-order kinetic model is higher than that of the pseudo-first kinetics (R2 = 0.991). In addition, in this study, by increasing the solution temperature from 25 to 45 degrees Celsius, the percentage of cadmium removal increased 72.3 to 78.12 percent. Increasing the absorption of pollutants at high temperatures can be due to the combined desire of adsorption sites for metal ions. In this way, the increase in temperature leads to an increase in kinetic energy and an increase in the number of collisions between the adsorbent and the absorbent and decreases the viscosity of the soluble, thus facilitating the addition of absorbed ions to absorption positions . Based on experimental results and regression coefficient, cadmium adsorption on Fe3O4@SiO2 nanoparticles has been followed by a pseudo second-order kinetic and Langmuir isotherm. Finally, the thermodynamic studies showed that the adsorption process is of endothermic and spontaneous nature. Morphology analysis showed that Fe3O4@SiO2 nanoparticles had a size of 15 nm approximately. The results of adsorption kinetics indicate that cadmium adsorption on adsorbent follows a quadratic kinetic model. The obtained optimal conditions for the cadmium adsorption were included, pH 5 and reaction time 30 min. Based on experimental results and regression coefficient, cadmium adsorption on Fe3O4@SiO2 nanoparticles has been followed by a pseudo second-order kinetic and Langmuir isotherm. Examining isothermic models suggests that this process follows the Langmuir isotherm model, which indicates homogeneity and the single-layer absorption process.

Nowadays,due to the irreparable effects imposed on aquatic ecosystems,organisms and humans,the removal of heavy metals and herbicides from water sources has extremely become vital.In recent years, the process of adsorbing contaminants with magnetic nanoparticles has gained lots of attention.Therefore, the present study aimed to synthesize nanoparticles as an adsorbent for adsorption of the contaminants of Pb and 2,4-D from water.

To evaluate the effect of independent variables such as pH(3-11),contact time(0-150min),adsorbent dose(0.2-1.2g/L) and adsorbate concentration(5-50mg/L) on the contaminant removal and determine the optimal conditions, the method of one factor at the time was used by design expert software. Nanoparticles were synthesized via a co-precipitation method and their morphology were characterized by TEM,XRD,FT-IR and SEM. Finally, the experiments were performed on aqueous solution.

Structural analysis revealed that adsorbent has a spherical structure with a Fe3O4 core and SiO2 shell, modified by both amine and thiol functional groups.The results of experiments showed that the maximum adsorption efficiency of single system occurred at pH 5 and contact time 40 min for lead and at pH6 and contact time 90min for 2,4-D.Also the optimal values of adsorbent dose and initial concentration obtained 0.8 g/L and 10 mg/L. In the binary adsorption system,the maximum adsorption efficiency determined at pH 6 and contact time 40 min for lead and contact time 60 min for 2,4-D and adsorbent dose 1.2 g/L.

According to the results,the bi-functional nanoadsorbent could be effectively used for the simultaneous removal of inorganic and organic pollutants from various aqueous solutions.

Humans are always exposed to ionizing radiation that could potentially have harmful effects. The aim of this study was to evaluate the background gamma dose rate, the estimated annual effective dose, and the excess cancer risk assessment in Dargaz. This study was a cross sectional study which was conducted in January- March and July – September 2016. In this study, 5 stations (4 in the main geographical directions and 1 in the center city) were selected based on the map of the city to determine the dose rate of background gamma radiation in outdoor areas. A dosimeter was used (Geiger Müller detector STEP OD-02 with sensitivity of 0-2000 mSv/h) to measure gamma rays. The device was designed to monitore X-rays, gamma rays and beta rays. The results showed that the maximum and minimum mean values of background gamma dose rate were 147±12 nSv/h and 113±11 nSv/h in the center and west-direction of the city, respectively. The annual effective dose for Dargaz residents in outdoor was determined to be 0/15 mSv/yr, and the amount of excess lifetime cancer risk was estimated as 0.6×10-3. The results indicated that there are significant differences between the rates dose in the center and other parts of the city (p≤0.05).

Hospitals are among the major centers in the production of pharmaceutical wastes. Ineffective management and inappropriate disposal of pharmaceutical wastes in various healthcare centers cause environmental problems and threaten human health. Therefore, this study was conducted to determine the composition and amount of the production rate of pharmaceutical wastes in a specialized hospital in Tehran, Iran, in 2017.

This cross-sectional study was conducted in a specialized hospital under the supervision of Iran University of Medical Sciences in Tehran in 2017. For waste sampling, 19 active sections were selected in the present study. Method of separating and weighing wastes was used in this study. Finally, the total amount, production per bed, density, and weight percentage of waste components were determined in the present study.

According to the results, it was shown that the mean value of waste production was 60.14±5.81 kg/day in the studied hospital. Moreover, the waste production rate per bed was 85g/bed/day, and its density was obtained at 356.99±70.26 kg/m2. Results of physical analysis showed that 44.34% of vial and ampoule lesions, 12.4% of syringe lesions, 22.31% of buttocks and serum sets, and 29.24% of various lesions constituted the components. It should be noted that about 67.25% of vial lesions were related to antibiotics. Based on the findings, meroxan, cefazolin, and ciprofloxacin with 19.95%, 17.43%, and 14.56% were reported as the highest rates among the antibiotics, respectively.

According to the obtained results of this study, the presence of household-like and infectious wastes among the components of pharmaceutical wastes indicated the proper separation. Proper separation of wastes leads to a lower amount of wastes and reduces management costs. In this regard, hospital managers should pay more attention to the management of these wastes.

In recent years, in most countries of the world, the provision of a calming environment without disturbing noise has become a need, which has subsequently led to significant growth in noise control techniques. It is now well documented that prolonged over-exposure to the excessive levels of environmental noise not only induces disabling hearing impairment but also contributes to numerous adverse health effects such as stress, irritability, hypertension, cardiovascular diseases, annoyance, and sleep disturbance. Working in noisy environments has also been reported to be linked with increased workplace accidents, aggression and anti-social behaviours. Based on the World Health Organization (WHO), occupational noise accounts for 16% of the disabling hearing loss in adults (more than four million DALYs), with estimates of disease burden ranging from 7% in developed countries to 21% in underdeveloped and developing nations.
There are several methods to reduce the noise pollution and control the sound of the working environment; one of the methods of controlling sound propagation path is the use of insulation and sound absorption. Sound control improvements with using sound absorption materials have provided a suitable opportunity to study noise reduction and acoustic attenuation by using a variety of porous materials. Increasing concerns about the adverse effects of the use of synthetic sound absorbing materials on the health of individuals has provided a favorable ground for the development of research on the use of natural fibers as insulators and absorbents. During the last two decades, there has been considerable interest in the use of lignocellulosic fibres for various purposes such as sustainable acoustic absorbers.  Bio-based composites of acoustic absorbers are mainly biodegradable and non-toxic and have low weight, low density and low cost and can be used as alternatives to the absorbers made of synthetic fibres.
Every year, in Iran, significant amounts of agricultural waste containing lignocellulosic fibres are burnt or disposed of improperly due to the lack of a proper recycling system and reusing mechanisms. However, a large proportion of such waste can be used for various uses. Iran as the second largest producer of dates in the world, and having large date palm plantations, faces the scourge of harvesting and pruning palm trees each year, which are largely suitable for use.
Therefore, the purpose of the present study was to investigate the acoustic behaviour of composite samples made of date palm natural fibres by predicting their sound absorption coefficients with the related experimental models and comparing the results with the data obtained from the experimental tests.

In this study, the natural date palm waste fibers were procured from Tabas city in southern Khorasan province in Iran. Having transferred to the laboratory, the raw DPFs were rinsed with distilled water before being placed inside an oven at 70 °C for 24 hours to dry and get a fixed weight. The DPFs were then cut into smaller pieces by a pair of scissors and crushed and pressed through a 2 mm mesh sieve to make their size fairly homogenous. In order to bind the fibers together and form a composite, polyvinyl alcohol (Sigma-Aldrich) was utilized. PVA is a polymeric chemical binder with high solubility in water and is known to be a biodegradable material reportedly used as natural fiber binder in previous studies.
In order to prepare 5% PVA concentration, 5 g of the substance was first weighed by a scale and later dissolved in 100 ml of distilled water. The solution was then stirred with a magnet at 80 °C for 3 hours. Having prepared the solution, the fibers were soaked with it to bind. The fibers were then shaped by an aluminum mold (by compression molding) to be fitted inside the impedance tube (internal diameter of 100 mm) and form samples with thicknesses of 20, 30 and 40 mm with a constant density of 200 kg/ m3. After the molding process, the samples were left at room temperature for 12 hours to dry completely before being transferred to the laboratory for absorption coefficient measurement. SEM images showed that outer diameter of the DPFs ranged from 200 to 720 μm and the mean diameter, the density and porosity of them were 420 μm, 930 kg/m3 and >80% respectively. The measurement of normal incidence absorption coefficients of the samples with a constant density and three different thicknesses a different air gaps was performed by an impedance tube and based on ISO 10534-2. Afterwards, by creating the appropriate codes in MATLAB software, using the differential equation algorithm, the predicted sound absorption coefficients for the Delany-Bazley, Micky, and Johnson-Champoux-Allard models were calculated. In fact, such algorithm searches for the three parameters until the best fit (minimized difference) is observed between the experimental and theoretical absorption curves. Therefore, the experimental sound absorption curve for the samples of the corresponding date palm fibers was first determined by the impedance tube system. We followed the same method proposed by Atalla and Panneton.

The results from the laboratory data for the three thicknesses of 20, 30 and 40 mm of the sample absorbers of DPF and the impact of the air gaps on their sound absorption coefficients are presented. Using the mathematical model, the sound absorption coefficient in the frequency range of 125-6300 Hz was next coded by MATLAB software. As shown in this paper, the predicted values of the physical parameters of the DPF were measured using differential equation algorithm in the MATLAB software through the available laboratory data such as the thickness, density, airflow resistivity and absorption coefficient. Later, the prediction error rate determined by the JCA model - shown on the right axes is compared to the data obtained from the experiments. The results showed that the sound absorption coefficients of the samples fabricated from date palm fibres, significantly increased with increasing the frequency. Moreover, the increase in the thickness of the samples with a constant density has a major role in attenuating the sound waves, especially in lower frequencies (less than 1000 Hz). Comparison of experimental data and models output showed that by increasing the thickness, the predicted values for the acoustic absorption coefficient of the samples approach the values obtained from the experimental tests. As can be seen, the JCA model has a fair accuracy in predicting the absorption coefficient in different thicknesses compared to the Delany-Bazley and Micki models.
Thus, this model at 20, 30- and 40-mm thickness and lower frequency range (63-1600 Hz) showed different prediction accuracies of 23%, 6% and 11% respectively, while at higher frequency range (1600-6300 Hz) came up with 9%, 6% and 4% prediction accuracies. Thus, such agreement is considered as significant in the higher frequency range. These findings also indicate that the outputs of the JCA model, rather than two other models, are closer to the data obtained from the experimental tests for setting the sound absorption coefficients. It is therefore concluded that the JCA model (compared to the Delaney-Basile and Mickey models) has included more dominant parameters that might impact the physical properties of the samples such as thickness, mass density, sample resistance against airflow, tortuosity, viscous and thermal characteristic length. Introduction of air gap behind the DPF samples in the impedance tube transfers the maximum values of sound absorption coefficient from the upper to the lower frequency range. The results indicate that, as the sample distance from the rigid surface of the backing (up to 30 mm) increases, the sound absorption coefficient at frequencies lower than 1000 Hz will rise as well. As a result, used in this study absorbing materials with an air cavity behind them seems to play a significant role in lower production cost, and thinner layers of absorbing materials yield better absorption coefficients. The reason for this behavior is probably due to the increased impedance of absorbing material. In this case, the acoustic resonance transferred towards lower frequencies and thus improved the values of absorption performance in that range. As a result, it seems that the use of absorbing material, while having a layer of air behind them, can reduce the cost and material consumption. Thus, thinner samples made of coir fibers would provide superior values of sound absorption coefficients.

Date palm fibres have a great potential for attenuating the energy of sound waves. Elevated levels of sound absorption can be attributed to a longer dissipative process of viscous and thermal conduction between air and the absorber.  Therefore, increasing the thickness of the sample will contribute to higher amounts of sound absorption coefficient.
On the other hand, natural fibers are still not as popular as synthetic fibers due to the properties such as low adhesion, high fiber diameter, low resistance to moisture and vulnerability to fungi. Therefore, it is obvious that these factors can affect the absorption coefficient of sound and the quality and durability of acoustic panels made of such natural fibers. In order to eliminate these defects, nanotechnology can be employed to achieve superior properties and better conditions by utilizing the best of these natural materials. Evidently this is the issue that should be taken into account in developing sound absorbers which are originated from the natural fibers.

The efficient hospital waste management requires a detailed  knowledge of  the quantity and type of medical centers generated waste. The most important factor in planning and management of hospital waste is the estimation of the generated waste. It is worth mentioning here that modern methods of waste disposal are necessary, due to the harmful potential of medical waste. A total of 62 hospital under the supervision of Iran University of Medical Science were studied. The data were obtained from waste self-reporting form, the results of biological and chemical tests, and calibration result of medical waste sterilization equipment. It should be noted that the hospitals were divided into three groups of state (H1), private(H2), and the other hospitals (H3) to facilitate the process of study. Thereafter, the obtained data were analyzed in Excel 2013. waste generation rate (kg/bed. Day) is 4.09, 4.12, and 4.9, in state, private, and the other hospitals, respectively.  Based on the results, all hospitals except the four  psychiatry hospitals were equipped with the medical waste sterilization equipment (e.g., autoclave, hydroclave, chemiclave, and dry heat). In addition, all H1, H3, and 98% of  H2  used biological indicators. Furthermore , all H2, H3 and 91.6% of  H1, used chemical indicators. Biological supervision of the hospitals showed the positive and desired results with indicating no microbial growth in 76.4%, 86.4%, and 56.2% of H1, H2, and H3, respectively. According to the results of the research and other similar studies, the process of waste generation and separation, as well as the performance of the waste sterilization equipment need further optimization.

Back ground: Phenol and its derivatives are widely used as raw material in many petrochemical, chemical and pharmaceutical industries. Wastewaters from the industries mentioned above contain Phenolic compounds which are highly hazardous to aquatic life. Therefore, phenolic wastewaters must be specially treated before disposing off the effluents Hybrid aerogel with structure of hydrophobicity was prepared through sol–gel synthesis followed by drying at ambient. The aerogel was used for phenol adsorption from water and the effects of phenol concentration, also contact time were studied. Batch kinetic and isotherm studies were carried out to evaluate the effects of contact time and phenol concentration The Aerogel surface was characterized by nitrogen adsorption at 77 K. The result showed that the maximum adsorption was in the concentration 250 mg L− 1 493/13 mg g− 1. The specific surface area of the synthesized aerogel is 543.4 g m-2, the pore size is 3.24 nm with a porosity of 44 and a contact angle of 156 degrees, The Langmuir model and the pseudo-second-order fited the experimental data the results showed that the phenol adsorption process involved both boundary layer diffusion and inter particle diffusion that hydrophilic and hydrophobic surface of the aerogel is synthesized
main reason for its higher adsorption efficiency phenol.

Unsystematic waste and sewage sludge disposal is a major public health threat. Today, the use of easy, inexpensive, and natural treatment such as compost is one of the main priorities for the treatment of these materials.
In this experimental study, organic waste samples were prepared from household waste and sludge samples were prepared from municipal sewage treatment plant. Reactors R1 and R2 (for compost and vermicompost, waste), and R3 and R4 (for compost and vermicompost, waste and sewage sludge mixtures) were selected. Waste and sludge stabilization were evaluated by some indexes such as: (C/N), (VS), (TOC) and (TC), (FC) and (TP) and (TN).
FINDINGS: The level of VS in R1, R2, R3 and R4 decreased from 89.09, 89.89, 85.29 and 85.29 to 75.58, 64.04, 62.75 and 61.22, respectively. C/N values in R1, R2, R3 and R4 reached 28.08, 22.48, 21.31, and 18.60 during the process. Fecal coliforms in R2, R3 and R4 decreased by 100, 93 and 99%, respectively. The vermicompost quality in R2 and R4 reactors was better than other reactors, but the R4 reactor reached this condition one week later.
According to the results of this study, vermicompost reactor containing organic waste and sewage sludge is well-prepared for the high rate stage of composting process. In order to achieve optimal composting conditions in accordance with valid standards, the composting stage should be included in the work plans.

Due to extensive usage of nitrogenous fertilizers and discharge of industrial and domestic wastewater، nitrate contamination of water is becoming a main environmental concern. High levels of nitrate in drinking water causes serious health problems such as methemoglobinemia in infants and gastric cancer. Because of such health problems، nitrate removal from water is urgent and has been a hot topic over the recent years. Various technologies such as the ion exchange، reverse osmosis، electrocatalytic، adsorption، electrodialysis and biological process، have been used to eliminate nitrate ion from water and wastewater. Nevertheless، these methods have several drawbacks such as high installation and maintenance costs، difficult operation، brine production، membrane fouling، further treatment، slow process and carbon source requirement. A large number of investigators thus have focused on the reduction of nitrate by the electrochemical process usually because of its efficiency، very low sludge production، small area occupation and facile operation. Integration of electrochemical and biological processes as bioelectrochemical systems has been recommended to overcome the potential problems. In bioelectrochemical denitrification، denitrifying microorganisms make use of hydrogen generated at the cathode by the electrolysis of water as an electron donor to reduce nitrate into nitrogen gas. Autohyrogenotrophic denitrifying bacteria commonly adhere to the cathode surface and make a biocathode. Therefore، Cathode electrode material is one of the major factors that affecting in the bioelectrochemistry efficiency. Cathode material can directly affect to denitrifying bacteria attachment، hydrogen production، electron transfer and electrical conductivity. Bioelectrochemical process can be used to eliminate nitrate through a catholic reduction process. Carbon material has high mechanical strength and a rough surface which is ideal for the formation of biofilm as compared with metal materials. However، carbon materials are difficult to apply in large scale processes due to high electrical resistivity that tend to increase electrode ohmic losses. Hence، carbon electrodes are supported by a conductive material current collector such as carbon nanotubes and metallic materials. Carbon nanotubes have a good biocompatibility with bacteria and have not shown negative effect on biofilm formation. It had been reported that carbon nanotubes can facilitate transfer of electrons between bacteria and electrode in bioelectrochemistry. The aim of this study is bio-electrochemical removal of nitrate from wastewater using carbon nanotubes immobilized in cathode. This study has been done in a bathe scale bioelectrochemical rector with a two chambers. Considering that nitrate reduction done in biocathode، carbon nanotube used in cathode for increasing nitrate removal. The effects of pH، current density and retention time were evaluated for nitrate removal in a bio-electrochemical reactor. The highest nitrate reduction rates were occurs in neutral pH and current density of 15 mA/cm2. Furthermore، at current density of 15 mA/cm2 and retention time of 8 hours، the bioelecterochmical system can reduce the nitrate levels to below the environmental standard. The results showed that multi-wall carbon nanotube as cathode modifier increase the nitrate reduction efficiency about 14 persent. The use of multi-wall carbon nanotube can increased biofilm formation and therfor the reduction time for achieving to nitrate standard was reduced.

Formaldehyde (CH2O) is one of the toxic volatile organic compounds which must be removed from polluted air. One of the techniques available to remove is by use of adsorbents. The aim of this study was to evaluate the characteristics and adsorption capacity of modified black bone char (BBC) on CH2O vapor. Subjects and

In this experimental research two types of BBC adsorbents (nomal and modified) were produced. Specific surface area and pore volume of the adsorbent materials were determined using the Brunauer-Emmett-Teller (BET) surface area. The adsorbents structures were analyzed using scanning electron microscopy. The composition of BBC and modified BBC were analyzed by energy dispersive X-ray (EDX) measurement. To investigate breakthrough characteristics and adsorption capacity according to inlet concentration of CH2O on bone chars، adsorption experiments were carried out at 25±1oC under the same conditions.

The specific surface area and pore volume for modified BBC (118. 58m2/g and 0. 374 cm 3/g) were higher than for BBC (105. 24m2/g and 0. 367 cm3/g). The EDX analysis showed that amount of calcium of the modified BBC was less than that of BBC. The results also showed that mean value of equilibrium time of modified BBC was longer than that of BBC (P<0. 05). Moreover، the mean value of adsorption capacity of modified BBC was higher than that of BBC (P<0. 05).

The modification of black bone char promotes porosity and adsorption capacity and can increase the removal efficiency of CH2O in air.

Formaldehyde is one of the toxic volatile organic compounds which is necessary to be removed from polluted air. Photocatalysis is one of existing technologies used for the removal of this compound. This study was performed aimed at determination of the effect of the combination of zinc oxide (ZnO) nanoparticles and bone char (BC) on the photocatalytic removal of formaldehyde gas.

In this experimental study, characteristics of the catalysts produced by specific surface area were determinated using BET method and scanning electron micrograph (SEM). The degradation of formaldehyde gas was studied using UV/BC, UV/ ZnO, and UV/ZnO-BC processes, under the continuous flow mode condition. The effects of initial concentration, relative humidity, and residence time on degradation of formaldehyde gas were investigated.

The results of the BET surface area measurements and SEM images showed agglomeration of ZnO nanoparticle on the pores of the BC surface structure. The SEM imaging from ZnO-BC catalyst showed that the BC particles pores filled with ZnO nanoparticles formed a homogenous surface. Also, the combination of BC with ZnO nanoparticles had a synergetic effect on the photocatalytic degradation of formaldehyde. In UV/ZnO-BC process in the initial concentration range between 2.5-25mg/m3, the degradation efficiency of formaldehyde was between 40% and 73% and the optimum relative humidity was 35%. This effect seems to be due to the strong adsorption of the formaldehyde molecule on BC that results in higher diffusion to the ZnO catalytic surface and that increase in the rate of photocatalysis.

Increase in the formaldehyde degradation by the ZnO-BC composite can be attributed to the synergetic effect of adsorption and subsequent photocatalytic decomposition.

In recent years, poor industrial waste managements have created many crises in human societies. The aim of this study was to investigate industrial waste management located between Tehran and Karaj zone in 2009-2010. This study is descriptive and sectional which was done by site visits, (Iranian environmental protection organization) use of questionnaires, database production and results analysis. The questionnaire consisted of 45 questions mainly about industrial waste; quantity, quality and management. Total number of industries with over 50 personnels, calculated as 283. Class-weighted sampling was used in which the sample size contained 50 industries. Total generated industrial waste was 123451, kg per day. Major hazardous waste generated in industrial sections included: chemical and plastic making. About 45.28% of waste generated disposed by private sectors. Landfill with 62% and reuse with 17% were the first and second alternative of common methods for final disposal of solid waste in this zone. In order to reduce hazardous waste generation in this zone, reuse and recovery maximization of the waste must be noted in short-term. In long-term, some industries such as chemical-plastic and electronics which have high rate of hazardous waste production must be replaced with other industries with low rate production, such as wood-cellulose and paper industries.

Background and aims Rapid population growth, industrial development, urbanization culture propagation and excessive material consumption are the most important factor which caused over increasing of municipal, industrial and agricultural waste in human society. Inappropriate disposal of generated waste in recent years created several environmental menace and crisis in human society. methods For investigation about existent situation of industrial waste generation questionnaire had been used. This questionnaire was catered by Iran environmental protection organization. Aforementioned questionnaire contained 45 questions about combination, quality and quantity of industrial waste. Total number of more than 50 personnel industry was 287. But sample contained 50 randomly selected industries. Gathered data have been analyzed with spss 18. ResultsTotal generated industrial waste was 123451KG per day which had volume equal to 781 cubic meters per day. Generated waste capitation per every worker was 5.8 KG. Maximum frequency of industrial was related to machinery and equipment group which maximum generated waste was related to this industrial group too. Maximum hazardous waste was for inflammable waste with 34 weight percent. Major hazardous waste generating industrial was chemical and plastic making industry. Conclusion yielded result from this investigation has shown that significant relation existed between waste production rate and personnel number. The more personnel are, the more waste production increase.

Discharge of textile colored wastewater industries without providing enough treatment in water bodies, is harmful for human and aquatic organisms and poses serious damages to the environment. Most of conventional wastewater treatment methods don’t have enough efficiency to remove textile dyes from colored wastewater; thus in this research the efficiency of electrocoagulation treatment process with aluminum electrodes for treatment of a synthetic wastewater containing C.I. Reactive Red 198 in batch reactor was studied. The experiment conducted in a Plexiglas reactor with a working volume of 2L that equipped with 4 aluminum electrodes. The effects of operating parameters such as voltage, time of reaction, initial dye concentration and interelectrode distance on the color removal efficiency, electrical energy consumption and electrode consumption were investigated. in the optimum operational condition electrocoagulation, is able to remove color and COD as high as 99.1 and 84.3% in aluminum electrode in 75 minutes at 20 volt and 2 cm interelectrode distance, respectively. Under this condition, operating cost was 2986 rails per cubic meter of treated wastewater. Increase in the interelectrode distance and initial dye concentration,lead to the decrease in efficiency of dye and COD removal.While as the voltage and time of reaction increased, energy consumption, electrode consumption, final pH and color removal, increased too. electrocoagulation process by aluminum electrode is an efficient and suitable method for reactive dye removal from colored wastewater.

Inadequate management of biomedical waste can be associated with risks to healthcare workers, patients, communities and their environment. In this study a comprehensive survey was conducted to obtain information on the management of solid wastes in Qom hospitals. Field visits were made to 2 private and 4 governmental hospitals to collect the required information and weighing the solid wastes generated. In addition, supplementary information was collected using a modified World Health Organization questionnaire. The results showed total the average generation rate of solid waste in Qom hospitals was 3057.55 kg/day. The shares of general, infectious, sharp, and pharmaceutical and chemical solid wastes were 1523.6, 1520.6, 12.72 and 0.93 kg/day, respectively. The results on various aspects of solid waste management indicate that practices in the hospitals do not comply with the principles stated in the respective Iranian regulations. Similarly, the segregation process was inefficient. No information was available concerning the quantity and quality of solid wastes. Development of suitable waste management schemes and plans are strongly recommended. In addition, establishing training programs on proper waste management for all the personnel involved (managers, physicians, nurses, workers) are essential. These actions, plus effective supervision, will result in considerable reductions in hospital solid waste disposal cost

In this research the efficiency of electrochemical treatment process with iron electrodes for treatment of a colored wastewater containing Reactive Red 198 in laboratory scale was studied. The effect of operating parameters such as voltage, reaction time, electrolyte concentration, initial dye concentration and interelectrode distance on the dye removal efficiency have been investigated. The experiments were carried out in a plexiglass reactor. The results indicated that electrochemical process is veryefficient mothod for dye removal and in the operational condition able to remove color and COD as high as 99% and 66.6% respectively in 30 minutes at 40 volts and 1 cm interelectrode distance. This study revealed that when the voltage and reaction time increased and interelectrode distance decreased, energy consumption, final pH and dye removal, would be increased. Increasing electrolyte concentration, resulted in decreasing retention time for dye removal. J. Color Sci. Tech. 3(2009), 97- 105.© Institute for Color Science and Technology.

Background and Hospital wastes pose a serious public health problem. This is primarily caused by the way individual components of the waste is handled. One acceptable method for managing the medical waste is incineration but uncontrolled incinerators can cause emission of pollutants to atmosphere. The objective of this study was to evaluate pollutants emission from hospital waste incinerators in Hamadan. In this investigation, samples were collected from Emam, Syna, Fatemieh, Mobasher Kashani hospital incinerators to determine the level of lead, mercury, cadmium, benzene, toluene. Xylene, carbon monoxide, sulphour dioxide and particulate. Collected samples were analysed using gas chromatograph, atomic absorbtion, spectrometer and smoke meter in the laboratory or by SO2 and CO meter as a direct method in the field. Results show that Mobasher hospital has maximum concentration of metals fume such as lead, mercury, cadmium (1113, 540, 3340 mg/m3, respectively). Mean concentration of sulphour dioxide was 127 ppm and for suspended particulate concentration was 639 mg/m3. In Syna hospital, the concentration of aromatic hydrocarbons including benzene, toluene, xylene and carbon monoxide were maximum (77.46, 108.64, 33.6 mg/m3 and 1041 ppm respectively). It can be concluded that hospital atmospheric pollutants are higher than EPA standards, at least with P<0.05 which can be due to inopportune opening door of combustion chamber, input of excess air mass, low temperature, unmixed solid waste and unsuitable design of the incinerator, and leak or unsuitable pollution control device.