Showing 18 results for Removal
M Aghanejad, A.r Mesdaginia, F Vaezi,
Volume 2, Issue 1 (7-2009)
Abstract
Backgrounds and Objectives: Now a days modified activated sludge ways are used for standard removing nutrient substances from waste water that is named Enhanced biological phosphorus removal One of the most suitable ways is Anoxic-Oxic(A/O) process. The goal of this research is investigation and solving existing problems of Khoy power plant(P.P) waste water treatment plant(WWTP)and optimizing of phosphorus removal in it.
Materials and Methods: This research is done full scale in this treatment plant. The treatment plant was operating with extended aeration process, and some problems had, so in the first stage with in investigation of total efficiency, problems and their reasons determined. In the second stage after operational modifications existing problems was solved and real efficiency of treatment plant particularly for phosphorus(P) removal determined. In the third stage changes, system converted to A/O process and new system was tested with Changing parameters like food/microorganism(F/M), return sludge ratio(RAS)and sludge retention time(SRT)
Risults: In the first stage the most important problems were over concentration of BOD,TSS, and P in effluent of treatment plant and overgrows of alga observed in parts of treatment plant and effluent receiving conduit. The main reason of high concentration of P was considered releasing of sludge. In the second stage operating condition modification efficiency of P removal increased from 50to 62 percent. In the end of third stage value of P removal reached to %82 and the most suitable of anoxic contact time was determined 3to4 hours, SRT terry day and F/M ratio o.12,that the most effective change has been the decrease of SRT to three days.
Conclusion: Adjusting of operating factors like SRT,RAS, sludge processing way in WWTP can increase P removal in them with in total efficiency remaining, such as in this case it was %12. In waste water treatment particularly for P removal the A/O process is suitable so in this project its effect on P removal efficiency has been %20.
A.r Yazdanbakhsh, A Sheikh Mohammadi, M Sardar, H Mohammadi, M Zarabi,
Volume 2, Issue 4 (3-2010)
Abstract
Backgrounds and Objectives: A great part of organic compounds cause more pollution in natural waters meet, are chemical dye material. Azo dyes have more usage in different industries. Azo dyes not only give undesirable dye to the water but also have mutation potential and carcinogenesis effects in human and cause the production of toxic substances in water environments.The purpose of this study is investigation of iron powder, hydrogen peroxide and iron powder-hydrogen peroxide processes in removal of acid yellow 36 dye from aqueous solutions.
Materials and Methods: This study was conducted in laboratory scale. At this experiment synthetic solution was made from acid yellow 36 dye, and the removal of acid yellow 36 dye was studied by iron powder, hydrogen peroxide and iron powder- hydrogen peroxide processes .Also effect of dye concentration, pH solution, hydrogen peroxide concentration, iron powder concentration and the time of contact on decolorization, were evaluated.
Results: The results showed that iron powder - hydrogen peroxide process, compared to two other process has high decolorization power. Removal efficacy of iron powder-hydrogen peroxide process with H2O2 =23.33 ml / L, pH =3, iron powder 2000 mg/L and 60 minute ,was about 97.9%
Conclusion:In general this investigation showed that , this method (Iron powder-hydrogen peroxide process) has high efficiency for removal of Azo dyes. But application this method in the industry, should be economically evaluated.
N Daneshi, H Banejad, R Pirtaj Hamedani, H Farajee,
Volume 3, Issue 3 (10-2010)
Abstract
Backgrounds and Objectives: Due to copper and zinc elements toxicity, a greatly attention to removal of those in order to reduce environmental pollution exist. This experiment was conducted to investigate the study of the effect of gravity single layer rapid sand filter on heavy metals (zinc and copper) removal efficiency in aquatic condition in different phosphate concentration.
Materials and Methods: this study applied a gravity single layer rapid sand filter with silica sand media. Experiments conducted for all of the states of Cooper and Zinc concentration in 25, 75, 125 and 175 ppm at different phosphate concentration present by varied discharge. Each state of Solutions pumped on top of the bed and discharge adjusted. Samples taken fromeffluent then acidified immediately with nitric acid. Metals concentration perused by atomic emission spectrometer with ICP source. Collected data analyzed by SPSS software.
Results: Founds from this study shown that maximum removal efficiency for copper and zinc was 98.89%and 78.60%respectively effect of discharge,metal concentration and phosphate concentration factors in removal efficiency of zinc and cooper, discharge and phosphate concentration bilateral effect on cooper removal efficiency, phosphate concentration andmetal concentration bilateral on zinc removal efficiency, are significant in 1%. In addition, phosphate concentration and discharge bilateral effect, metal concentration and discharge bilateral effect are significant on zinc removal efficiency in 5%. Finally, bilateral effects of discharge and metal concentration also metal concentration and phosphate concentration have not significant effect on cooper removal efficiency.
Conclusion: Gravity single layer of rapid sandy filter with silica sand media in order to cooper removal in low concentration can be used successfully. This method in high concentration of cooper and also different concentration of zinc had not successful result but in this condition, may be use
of a series of filter with more depth
B Karimi, M.h Ehrampoush, M Mokhtari, A Ebrahimi,
Volume 4, Issue 1 (5-2011)
Abstract
Background and Objectives: Wet air oxidation (WAO) is One of the advanced oxidation process which reduce organic matter concentration from industrial wastewater, toxic and non biodegradable substances and, solid waste leachate,etc. In this study the efficiency of wet air oxidation method in leachate treatment generating from Esfahan Composting factory was Evaluated.
Material and Methods: The experiment was carried out by adding 1.5 Lit of pretreated leachate sample the steel reactor with the volume of 3L. The reactor then underwent10 bar pressure at different temperature (100, 200 and 300 °C) and various retention time (30, 60 and 90 min). Leachate sample in 18 stages from composting factory in Isfahan in the volume of 20 Lit was taken and the WAO method, was used for pre-treatments. Removal efficiency of COD, BOD, NH4-N, NO3 and TSS were examined.
Results: The results showed that the removal efficiency was more than 35% for COD, 38% for BOD, and 85% for TSS within one hour of reaction. The Maximum removal efficiency obtained in this study were 53.3% for NH4-N and 73.9 % forNO3-N.
Conclusion: the results indicate that the reaction temperatures are the most important factors affecting degradation of organic matter. COD and BOD5 removal efficiency by WAO process increased as the time of reaction went up. In addition, BOD5/COD ratios of the effluents, which are generally regarded as an important index of biodegradability of leachate sample, were determined and improved grately as it reached to 84%. TheWAO process presented in this paper is considered an efficient process for pretreatment of leachate, as the COD, BOD5 and NO3 reduction observed in leachate samples.
E Hoseinzadeh, A.r Rahmani,
Volume 4, Issue 4 (3-2012)
Abstract
Background and Objectives: The disposal of waste tires has become an increasingly important issue worldwide in recent years. Tires not only take up large amounts of valuable landfill space, but also create fire hazards and provide a refuge for disease- carrying creatures. The goal of this study was to produce activated carbon from scrap tires .Adsorption of Acid Black1 (AB1) in aqueous solution as a pollutant by the activated carbon was also investigated.
Materials and Methods: Activated carbon was prepared from scrap vehicle tires using a thermo-chemical activation method. The chemical composition and solid structure of prepared activated carbon were analyzed using Scanning Electron Microscopy (SEM) coupled with energy dispersive spectrometry (EDS) and Nitrogen Sas. Micro pore volumes of the sample were determined by the application of the BET and BJH.
Results: Predominant composition of prepared activated carbon was C (83.274%) and with area surface of 44.226 and 35.747 m2/gr observed by BET and BJH methods, respectively. Mean pore diameter was 52 nm. The result of this study showed that increasing of initial dye concentration and pH would lead to decrease of adsorption/removal of dye but by increasing of sorbent dosage and contact time, adsorption/removal of dye increased.
Conclusion: As the results of present study it can be concluded that the production of the activated carbon from scrap tires, can provide a two-fold environmental and economic benefit a recycling path is created for scrap tires of vehicles, and a new suitable adsorbent is produced for pollutants removal.
Mohamad Taghi Samadi, Roghaye Nourozi, Mohamad Hadi Mehdinejad, Reza Aminzadeh,
Volume 5, Issue 4 (2-2013)
Abstract
Backgrounds and Objectives: Determination of arsenic(As) in drinking water has received increasing interest due to its detrimental effects on health. The aim of this research is to investigate effect of coating coral limestone using aluminum sulfate as an adsorbent on the arsenic(V) removal efficiency from aqueous solution.
Materials and Methods: In this laboratory scale study, we prepared coral lime granules using mesh 30 during several stages. Then, we investigated the arsenate removal efficiency under different conditions and changing main factors including pH, contact time and amount of no coated and aluminum sulfate-coated adsorbent. Moreover, we fitted our results with Langmuir and Freundlich models and kinetic data with pseudo- first order, pseudo- second order and modified pseudo- first order models.
Results: We found that increasing pH from 3 to 10 at arsenate concentration of 500 ppb and 5 g/l adsorbent and 120 min contact time, removal efficiency for no coated and coated adsorbent was reduced from 100 to 86.2% and from 100 to 92.2% respectively. Increasing concentration of both adsorbents from 1 to 5 g/l at contact time 120 min increased the removal efficiency from 76 to 99.2% and from 66.3 to 91.1% respectively. Arsenate removal efficiency was directly proportional with the amount of adsorbent and contact time and reversely proportional with the initial concentration of arsenate and pH. The removal efficiency of the coated adsorbent was more than uncoated adsorbent. Langmuir was the best sorption isotherm model for arsenate in these two processes and absorption kinetic was well described with second order models.
Conclusion: Excellent removal efficiency, cost-effectiveness process, and lack of environmentally harmful substances make application of the Persian Gulf offshore corals a reasonable adsorbent to remove environmental contaminants such as arsenate.
Hafez Golstanifar, Simin Nasseri, Amir Hossin Mahvi, Mohamad Hadi Dehghani, Anvar Asadi ,
Volume 5, Issue 4 (2-2013)
Abstract
Background and Objectives: The contamination of nitrate (NO3−) in groundwater resources causes two adverse health effects: induction of “blue-baby syndrome” (methemoglobinemia), especially in infants, and the potential formation of carcinogenic nitrosamines. The aim of this research is to investigate nitrate removal from groundwater using alumina nanoparticles and to determine the adsorption isotherms.
Materials and Methods: This analytical-descriptive study was carried out at lab-scale, under batch conditions, and at room-temperature. The structure of alumina nanoparticles was determined using XRD, SEM, and TEM techniques. The concentration of nitrate in the solutions was determined by spectrophotometer at wavelengths of 220 and 275 nm. In addition, we investigated the impact of the important operational parameters including initial dose of Al2O3 (0.06-0.25 g/l), initial concentration of the solution (50- 300 mg/l), contact time (5-60 min), and pH (3-9). Moreover, we used Freundlich and Langmuir isotherm models to calculate equilibrium constant.
Results: It was found that nitrate removal efficiency increased as we increased contact time, initial concentration and pH in batch system. A maximum of 60% nitrate removal was achieved under following conditions: 60 min contact time, pH 5, and initial nitrate concentration of 300 mg/l as N. The obtained results showed that the adsorption of nitrate by Nano-Gamma-Alumina follows Langmuir isotherm equation with a correlation coefficient equal to 0.982.
Conclusion: Overall, our findings showed that the alumina nanoparticles can be used as an effective adsorbent to remove NO3 from aqueous solutions.
Roohan Rakhshaee, Zahra Zamiraee, Somaieh Baghipour, Mohammad Panahandeh,
Volume 5, Issue 4 (2-2013)
Abstract
MicrosoftInternetExplorer4
Background and Objectives: Azolla Filiculoides as a non-living fern was used in a
batch system to remove "Basic Blue 3", which is a cationic dye and a
carcinogenic agent.
Materials and Methods: We used a batch system by applying certain concentrations of dye contaminant
and in the presence of a certain amount of adsorbent under optimum conditions.
The main groups presenting in the Azolla cell wall were evaluated by
acidification and alkalization of Azolla's media and then potentiometric
titration with standard basic and acidic solutions.
Results: It was
observed that the removal efficiency of dye using non-living Azolla in
accordance with the Langmuir isotherms was 82% for the initial dye
concentration of 200 mg/lit under reaction conditions consisting of contact
time 6 h, pH= 6, temperature 25 ˚C, and dose 5 g/lit. Q
max (maximum
uptake capacity) by the activated Azolla at three temperatures 5, 25 and 50 ˚C
was 0.732, 0.934, and 1.176 mmol/g respectively. ΔG (Gibbs free energy changes)
was obtained for these temperatures as -0.457, -0.762, and -1.185 kJ/mol
respectively.
Conclusion: Removal of
basic blue 3 using Azolla is an economically and effective method.
Mohammad Ali Baghapour, Babak Jahed, Gholam Hossein Joshani,
Volume 6, Issue 3 (12-2013)
Abstract
Background and Objectives: Increasing waste tiers production has made the recycling of this solid waste a critical issue in the world. On the other hand, it seems contamination of groundwater to the petroleum pollutant like gasoline is a great threat to the health of societies in developing countries. The main objective of this study was gasoline removal from aquatic environment by waste tire derived activated carbon.
Materials and Methods: In this study for preparation of activated carbon from waste tires, KOH was used for chemical activation process. We used argon gas to prevent precursor oxidation . We applied N2 gas and BET isotherm for characterization of the prepared activated carbon texture. Isothermal and kinetic models were used for defining gasoline adsorption characteristic to adsorbent, and thermodynamic studies were used to determine the effect of temperature.
Results: Characterization results revealed that SBET and VTOTAL were 111.702m2/g and 0.124cc/g respectively. Langmuir and pseudo-second order models were the best isotherm and kinetic models for prediction of the adsorbent behaviors to adsorb gasoline. The Gibbs free energy changes were negative at all temperatures applied.
Conclusion: Produced activated carbon has desired surface area and adsorptive capacity for gasoline adsorption in aquatic environments and it seems preparation activated carbon from waste tiers is cheap, effective and environment friendly.
Marzieh Razavi, Mosen Saeedi, Ebrahim Jabaari,
Volume 6, Issue 3 (12-2013)
Abstract
Background & Objectives: In this study, treatability of wastewater from a laundry unit was investigated by applying electrocoagulation method in which two pairs of aluminum and iron electrodes were utilized. Electrocoagulation is a noble treatment method suitable for different kinds of wastewater which has been given a considerable attentions by researchers recently. Applying direct current to two or several suitable metallic electrode in a batch reactor containing effluent would result in flocks of metal hydroxide.
Materials & Methods: We studied the effect of different operational parameters such as pH, electrodes distance, intensity of electrical current, and type of electrodes on the treatment efficiencies.
Results: Aluminum electrodes showed better effects on the treatment efficiencies in nitrate and COD removal. Maximum phosphate removal (99.93%)took place at pH=7 using Al electrodes. Whereas, in the case of iron electrode, maximum nitrate and COD removal efficiencies were about 97.60 and 80% at pH=9 and pH=6 respectively. Operational cost analysis showed that the corresponding costs of Al application as an electrode is different from that of iron electrode application.
Conclusion: Although application of both iron and aluminum electrodes lead to obtaining considerable removal phosphate, nitrate and COD, iron electrodes could result in reasonable removals to meet Environmental Standards with lower operational costs.
M Hajsardar, S.m Borghei, A.h Hassani, A Takdastan,
Volume 9, Issue 1 (6-2016)
Abstract
Background and Objectives: In order to optimize wastewater nitrogen removal and to reduce the problems of entering nutrients in final receptors, for example, a lake, partial nitrification, as a novel nitrogen removal method, was studied.
Materials and Methods: The efficiency of simultaneous nitrification and denitrification (SND) in partial nitrification through nitrification/denitrification in fixed-film reactor was surveyed. In this process, ammonium was converted to nitrite by ammonium oxidizing bacteria (AOB) but the activity of nitrite oxidizing bacteria (NOB) was limited at low dissolved oxygen (DO) level. The inflection points of oxidation-reduction potential (ORP) profile were used as the indicators of process optimization.
Results: This research showed that in period 2 at fixed DO level of 0.5 mg/L, nitrite accumulation rate (NAR) was higher than period 1 in which DO was declined from 1 to 0.5 mg/L. In contrast to period 1, SND efficiency was reduced in period 2. In period 3, by increment of the carbon to nitrogen ratio (C/N) to 12.5, NAR increased to 71.4 % and SND efficiency increased to 96.7%. In the long term analysis of proposed method, SND efficiency was, at least, 90%.
Conclusion: Proper C/N ratio and minimum DO level resulted in higher nitrogen removal efficiencies than the operation in which DO was decreased during aerobic phase. By using a fixed-film reactor and without considering an anoxic step, at DO level of 0.5 mg/L, maximum SND efficiency and maximum NAR would be achieved.
N Rastkari, F Izadpanah ,
Volume 9, Issue 1 (6-2016)
Abstract
Background and Objective: Formaldehyde is a toxic volatile organic compound, which its removal from polluted air is essential. One of the techniques available for removing such compounds is photocatalytic degradation. The aim of this study was to investigate the photocatalytic degradation of gaseous formaldehyde on TiO2 nanoparticles coated on reduced graphene oxide
Materials and Methods: The synthesized reduced graphene oxide- TiO2 nanocomposite was characterized using SEM, EDS, and FTIR spectra. The photocatalytic activity of prepared reduced graphene oxide- TiO2 nanocomposite was investigated for degradation of gaseous toluene under different operational conditions such as different initial concentration, flow rate, and time.
Results: The photocatalytic degradation efficiency of the RGO-TiO2 nanocomposite was much higher than P25 TiO2. The photocatalytic degradation efficiency of the RGO-TiO2 nanocomposite decreased by increasing the flow rate so the flow rate is a key factor for the use of RGO-TiO2 nanocomposite as a photocatalyst. The results showed that the photocatalytic degradation rates decreased from 89 to 30% with increasing formaldehyde initial concentration from 0.1 to 1 ppm.
Conclusion: This research indicated that RGO-TiO2 nanocomposite can be effectively used as suitable photocatalyst to remove gaseous pollutants. One of the advantages of the as-prepared composite was using visible light instead of UV to activate the oxidation process.
N Rouniasi, Sm Monavari, Ma Abdoli, M Baghdadi, A Karbasi,
Volume 11, Issue 2 (9-2018)
Abstract
Background and Objective: Water pollution due to heavy metals is a critical and increasing problem worldwide. In this study, removal of cadmium and lead heavy metals using a graphene oxide (GO) adsorbent was examined.
Materials and Methods: GO nanosheets were synthesized through Hummer’s method, and its characterizations were examined using FTIR, XRD, and SEM. The effect of independent variables pH, contact time and initial concentration of the solution on removal efficiency of Cd2+and Pb2+ using response surface methodology was evaluated according to Box-Behnken experimental design. Applying quadratic model, adsorption rate of Cd2+ and Pb2+ achieved 99%. ANOVA was applied for statistical analysis of responses.
Results: According to SEM images, the average size of graphene oxide sheets was 1 to 3 µm. After optimization through RSM, the adsorption capacity for Pb2+ and Cd2+ was 136 mg/g and 68 mg/g, respectively. Examination of the isotherms suggested that Cd2+ and Pb2+ adsorption follows Langmuir and Freundlich isotherm, respectively.
Conclusion: the results show that the graphene oxide performed well in removing both Cd2+ and Pb2+ ions from aqueous solutions. The most influential parameters on the above-mentioned heavy metals adsorption were pH of the solution and the initial concentration.
Sh Goodarzi, Gh Shams Khoramabadi, M Esmaty, Ma Karami, A Hossein Panahi,
Volume 12, Issue 2 (9-2019)
Abstract
Background and Objective: Wastewater from pharmaceutical industry has high chemical oxygen demand as a result of the presence of organic drugs and antibiotics. In order to meet the environmental requirements, several treatment methods like chemical and electrochemical methods have been widely applied due to their high ability to remove organic compounds from pharmaceutical wastewater. Therefore, the present study aimed to evaluate the efficiency of chemical coagulation/Electro-Fenton treatment method to degrade the organic matter-containing pharmaceutical industry wastewater.
Materials and Methods: The experimental tests were carried out using batch mode. The chemical coagulation process was evaluated as a function of aluminum chloride concentration (25-300 mg/L) and pH (3-10). The effluent from chemical coagulation process was transferred to Electro-Fenton reactor. Effects of H2O2 concentration (100-4000 mg/L), reaction time (up to 120 min), voltage (10-30 V), and pH (3-10) were evaluated. The removal efficiency was determined in term of COD removal.
Results: The results showed that the highest removal of COD in the chemical coagulation was 49% (coagulant dose of 200 mg/L, and pH of 7). In addition, the Electro-Fenton process could be eliminating of 93.5% of COD at the optimum conditions concentration (100 mg/L H2O2, voltage of 20, pH of 3, and contact time of 30 min).
Conclusion: According to the results, it can be concluded that the combination of chemical and electrochemical processes was found to be effective methods for treatment of pharmaceutical wastewater in comparison to the application of each process separately. To reach to the maximum removal efficiency, the environmental parameters should be carefully controlled at their optimum values in each single process.
Reza Nazarpoor, Masumeh Farasati, Abolhasan Fathaabadi, Mohamad Gholizadeh,
Volume 13, Issue 1 (4-2020)
Abstract
Background and Objective: Synthetic wetlands are engineering systems that use natural plants, soils and organisms to purify municipal polluted water and remove nitrate.
Materials and Methods: In this study, three systems were considerd as soil culture, three systems as plant cultivation on floating plates and three other systems without plant and porous bed as. The experiments were done three times within six months. The hydraulic retention times were 1, 3 and 5 days. The experimental design consisted of a factorial split-plot design. The analysis of variance showed that the efficiency of nitrate removal was affected by the type of constructed wetland, HRT, and temperature changes (p≤0.01).
Results: At the HRT of 1 day, the average efficiency of nitrate removal by the soil culture, plant cultivation on floating plates and control were 14.34%, 12.09% and 10.51%, respectively. At the HRT of 3 days, the average efficiencies were 17.62%, 15.76% and 13.54%, respectively. At the HRT of 5 days, the efficiencies were increased and they were 17.75%, 17.66% and 16.08%, respectively.
Conclusion: The results showed that the soil culture were more efficinet in removing nitrate .Also, the Cyperus alternifolius plant has the potential of nitrate phytoremediation.
Iman Omidi, Hamed Forootan, Majid Mazhar, Hossein Mohammad Karimi Yazdi, Mohammad Mehdi Barjesteh,
Volume 13, Issue 4 (2-2021)
Abstract
Background and Objectives: SO2 pollution has become a serious concern. The aim of this study is SO2 removal from JP-4 fuel combustion.
Materials and Methods: Experiments were performed by thermogravimetric analysis at different temperatures and various SO2 concentration. Kinetic study of non-catalytic gas-solid reaction was performed using mathematical modeling based on random pore model.
Results: The pore size distribution curve was obtained. The structural parameters of the random pore model were measured as r=1.92×10-5, ε0=0.64, S0=1.27×106 and ψ=3.81. Thermogravimetry diagram and conversion-time curves were extracted. Fractional reaction modeling is obtained based on gas reactant.
Conclusion: The obtained kinetic parameters can be used to design flue gas desulfurization systems at low temperatures.
Farah Rashadi, Nahid Navidjouy, Ali Ahmad Aghapour, Mostafa Rahimnejad,
Volume 14, Issue 3 (12-2021)
Abstract
Background and Objective: Microbial fuel cell (MFC) is a new green technology that uses the catabolic ability of microorganisms to produce bioenergy while simultaneously removing organic matter and other wastewater contaminants. Electrode material is one of the factors affecting the performance of microbial fuel cells. The aim of this study was to investigate the performance of microbial fuel cells in COD removal and bioenergy production from synthetic and real beverage wastewater.
Materials and Methods: In this research, a two-chamber microbial fuel cell with Nafion membrane and aerated cathode was set up using two electrodes made of carbon felt and flat graphite after being contacted by synthetic wastewater with a concentration of COD 5000 mg/L and real beverage wastewater. Organic matter removal efficiency and voltage, power density and maximum current were determine.
Results: Experimental results showed that maximum COD removal efficiency of 92 % was achieved in synthetic wastewater and with a carbon felts electrode. In this condition, maximum voltage, power density and output current density of 469 mV, 175.28 mW/m2, and 855 mA/m2, were obtained, respectively. However, by using real industrial wastewater (beverage), maximum removal efficiency of COD, voltage, power density and output current density, related to carbon felt electrodes were obtaines as 84 %, 460 mV, 91/65 mW/m2, and 635 mA/m2, respectively.
Conclusion: The findings showed that synthetic wastewater outperforms microbial fuel cells in terms of bioelectric production and organic matter removal as compared to real wastewater (beverage). The reason for the decrease in the cell performance might be the presence of solids and other confounding pollutants in real wastewater.
Mahboub Saffari,
Volume 16, Issue 3 (12-2023)
Abstract
Background and Objective: Nowadays, the use of biochar as a new and suitable adsorbent to remove inorganic pollutants from water sources has grown significantly. The present study was conducted to evaluate the effects of biochar physical modifications compared to unmodified biochar on nickel (Ni) removal efficiency in aqueous solutions.
Materials and Methods: After the production of cypress cones biochar (RB), biochar particles (<164 µm) were crushed into very small (<26 µm) dimensions (BMB) using a planetary ball mill and after evaluation their various properties by SLS, BET, FTIR and SEM techniques, their application (RB and BMB) in optimizing the Ni removal from aqueous solutions were evaluated using the response surface methodology (RSM: Box-Behnken design).
Results: Based on the results, the physical modification of biochar (BMB) decreased the particle size by 6.2 times, increased the specific surface area by 4.9 times, increased (containing oxygen) and decreased (aliphatic and OH stretching groups) of specific functional groups and finer surface morphology, compared to RB. The use of BMB in the aqueous solution caused an increase of 9.7% (on average) in the removal of Ni compared to the RB sample. The fitting of the data obtained from Ni removal in the Box-Benken model in both adsorbents shows the appropriate prediction of this model in the optimization of Ni removal from aqueous solutions.
Conclusion: According to the results of this research, the physical modification of biochar, as a simple, cheap, and environmentally friendly method, due to the increase in the efficiency of Ni pollutant removal, can be introduced as a suitable method in the activation of biochar, which further research is required based on the type of biochar and various pollutants.
