A national systematic literature review for aflatoxin M1 in commonly consumed cheese brands in Iran: Human health risk assessment by Monte Carlo simulation.

Cheese is popular in Iran because of its high nutritional value; therefore, it is necessary to control this product regarding health risk factors, particularly aflatoxin M1 (AFM1). This research reviewed AFM1 in various varieties of cheese in Iran to assess the potential health risks associated with consuming these products for different age groups. In this regard, all accessible papers from different databases were screened between June 27, 2000 and October 10, 2022 b y systematic research and then considering the selection criteria of the studies; finally, 22 articles were selected for the current review. The amount and prevalence of AFM1 were calculated and separated based on the cheese variety, and the sampling location; health risk assessment (HRA), statistical, uncertainty, and sensitivity analysis for AFM1 of cheese for different age groups were performed. The study results for 2143 samples showed that the overall average AFM1 for cheese is 160 ± 175 ng/kg, below the European Commission (EC) regulation (250 ng/kg). AFM1 contaminated 72.42% of all cheese samples, and 13% of these contaminated samples had a higher AFM1 than the EC regulation. Cheese varieties were ranked based on average levels of AFM1 as white pasteurized > traditional > creamy > probiotic > Lighvan, and this ranking was obtained based on sampling locations as market > dairy factories > livestock farms. Based on the HRAs, from the perspective of the liver cancer risk (LCR), the margin of exposure (MOE), and the hazard index (HI) approach, it can be concluded that cheese produced in Iran, in terms of AFM1, particularly for children, poses serious health risks. Accordingly, it is imperative to carefully consider implementing suitable management methods to inhibit the growth of aflatoxin B1 (AFB1) in livestock fodder, and training in sanitary production and processing of dairy products according to world standards is suggested for industrial and traditional cheese producers across Iran.

Novel fabrication of the recyclable Bi7O9I3/chitosan and BiOI/chitosan heterostructure with improved photocatalytic activity for degradation of dimethyl phthalate under visible light.

Among the bismuth oxyhalides, bismuth oxide has the shortest band gap and high absorption power in the visible light region. Dimethyl phthalate (DMP) has been identified as endocrine-disrupting plasticizer and emerging pollutant, which was selected as the target pollutant to evaluate the efficacy of the studied catalytic process. In this work, Bi7O9I3/chitosan and BiOI/chitosan were efficaciously synthesized by the hydrothermal process method. Characterizing prepared photocatalysts was done by employing transmission electron microscopy, X-ray diffraction, scanning electron microscopy energy-dispersive spectroscopy, and diffuse reflectance spectroscopy. For this study, the test design was performed using the Box-Behnken Design (BBD) method in which the variables of pH, Bi7O9I3/chitosan dose, and dimethyl phthalate concentration were examined for the catalytic removal of dimethyl phthalate in the presence of visible light. Our detected results disclosed that the order of efficiency in DMP removal was as follows: Bi7O9I3/chitosan > BiOI/chitosan > Bi7O9I3 > BiOI. Also, the maximum pseudo-first-order kinetic coefficient for Bi7O9I3/chitosan was 0.021 (min)-1. When the synthesized catalysts were exposed to visible light irradiation, the predominant active species were O2- and h+ for degradation of DMP. The study on the reuse of Bi7O9I3/chitosan showed that this catalyst could be reused 5 times without significant reduction in efficiency, which indicates the cost-effectiveness and environmental friendliness of using this catalyst.

Acidic modification of natural stone for Remazol Black B dye adsorption from aqueous solution- central composite design (CCD) and response surface methodology (RSM).

This study investigated the adsorption capacity of Remazol Black B (RBB) from aqueous solutions using a pumice stone as a cheap, high-frequent, and available adsorbent. The raw pumice was modified using five acids: Acetic, Sulfuric, Phosphoric, Nitric, and Hydrochloric acid. Fourier transform infrared spectrograph (FTIR), x-ray fluorescence (XRF), and scanning electron microscopy (SEM) were used to analyze the morphological and chemical properties of raw and modified adsorbents. The adsorption capacity equilibrium was investigated using the Langmuir, Freundlich, Temkin, and Dubinin - Radushkevich isotherms. The results indicated that the data are well-fitted with Langmuir isotherm. The maximum adsorption capacity was observed when pumice modified with H2SO4 (qm = 10.00 mg/g) was used, and the RBB removal efficiency was higher than that for raw pumice (qm = 5.26 mg/g). Also, the results were best fitted with pseudo-second-order kinetic. The experiments indicated that increasing the RBB concentration reduces the efficiency of adsorbents while increasing the contact time and adsorbent doses improved the RBB removal efficiency. Accordingly, it can be concluded that pumice stone modified with various acids can be considered a cheap adsorbent with high efficiency in removing RBB from industry effluent.

Scallop shell coated Fe2O3 nanocomposite as an eco-friendly adsorbent for tetracycline removal.

ABSTRACTThe present study focused on the usability of scallop shell coated Fe2O3 nanoparticles as an eco-friendly new absorbent in the treatment of tetracycline (TC). The process performance in terms of TC removal was investigated at different operating conditions, i.e. at solution pH of 3-11, Fe2O3-scallop dosage of 0.4-2.4 g L-1, initial TC content of 20-120 mg L-1 and temperature of 25-55°C. Solution pH of 7 yielded the highest TC removal efficiency (99%). At this pH value, almost complete TC removal was achieved at a Fe2O3-scallop shell nanocomposite dose of 1.6 g L-1 and 25°C. The responsible TC removal mechanism is suggested as the non-electrical π-π dispersion interaction between the bulk π system on the absorbent surface and TC molecules bearing both benzene rings and double bonds at this solution pH. TC removal efficiency appreciably enhanced up to the Fe2O3-scallop dosage of 1.6 g L-1 being an optimum. Adsorption rate was found to be fast at lower initial TC concentrations than 40 mg L-1. The effect of temperature on TC removal efficiency was insignificant. Adsorption followed the pseudo-second-order kinetic model. Experimental data perfectly fitted by the Langmuir equation. The maximum adsorption capacity was calculated as 49.26 mg g-1. Thermodynamic analysis demonstrated that adsorption process was spontaneous process and endothermic. The results obtained from the present study proved the excellent performance of scallop shell coated Fe2O3 nanoparticles as an eco-friendly adsorbent in TC treatment.

Status of TNF-α and IL-6 as pro-inflammatory cytokines in exhaled breath condensate of late adolescents with asthma and healthy in the dust storm and non-dust storm conditions.

Exposure to airborne particulate matter (PM) can be considered as an important risk factor for human health. Some cytokines have been recognized as the biomarkers of exposure to air pollution. Experimental studies indicate that PM exposure could be associated with inflammation. Thus, the purpose of this study was to evaluate whether the exposure to air PM is associated with biomarkers of inflammation. The specific aim of this study was to determine the correlation between airborne PM levels and IL-6 and TNF-α as airway inflammation biomarkers among two groups of late adolescents in northwest of Iran. This study included 46 subjects, comprising 23 asthmatic subjects and 23 non-asthmatic persons. Environmental PM (PM10, PM2.5 and PM1) levels were measured in dust storm and non-dust storm days during both cold and warm seasons. Following the sampling of PM, Two pro-inflammatory cytokines of IL-6 and TNF-α in exhaled breath condensate (EBC) were also determined in the EBC samples via commercial ELISA kits. Daily mean ambient air PM10, PM2.5 and PM1 concentrations during the dust storm days was 221.79, 93.13 and 25.52 µg m-3 and in non-dusty days 48.37, 18.54 and 6.1 µg m-3, respectively. Biomarkers levels were significantly (p < 0.001) higher in asthmatic students compared to the non-asthmatic subjects. EBC cytokines levels were increased in dust storm days compared to the non-dusty days (p < 0.001) and were positively correlated with different size of ambient PM concentration. Dust storm conditions can increase the pro-inflammatory cytokines and cause adverse effects on pulmonary health and lung tissue damage.

Adsorption of 4-Nitrophenol on calcium alginate-multiwall carbon nanotube beads: Modeling, kinetics, equilibriums and reusability studies.

In this study calcium alginate-multiwall carbon nanotube (CA/MWCNTs) was synthesized using (CA) calcium alginate and multiwall carbon nanotube (MWCNTs), and its efficiency in adsorption of 4-Nitrophenol (4-NP) in aqueous solution was studied. The structure and properties of the synthesized adsorbent were investigated using scanning electron microscope (SEM), thermal gravimetric analysis (TGA), Fourier transform infrared (FTIR), and X-ray diffraction (XRD). The experimental design was performed using Box-Behnken design (BBD) in which variables pH, CA/MWCNTs, and temperature were examined. The results of the effect of temperature on the removal efficiency of 4-NP showed that the adsorption efficiency decreases with increasing temperature. The results of nonlinear isotherm and kinetics models showed that Langmuir and pseudo-second-order models were more consistent than other models. The maximum adsorption capacity of 4-NP in this study by CA, MWCNTs, and CA/MWCNTs was 136, 168.4, and 58.8 mg/g, respectively, which indicates that the use of MWCNTs on CA could increase the adsorption capacity. The results of reuse of the synthesized adsorbent at 4-NP removal also showed that after 5 reuse of the adsorbent, the removal of 4-NP using CA/MWCNTs is reduced by about 10%, which shows that the synthesized adsorbent can be used several times to adsorb contaminants without significant reduction in the efficiency.

Associations between short term exposure to ambient particulate matter from dust storm and anthropogenic sources and inflammatory biomarkers in healthy young adults.

This study examined the association between particulate matter from anthropogenic and natural sources and inflammatory biomarkers, including hs-CRP, IL-6, sTNF-RII, and WBCs, in two groups of healthy young subjects. We followed up subjects of two panels (16 to 22 years old), including 22 subjects selected from the urban area (Tehran city) with high-level pollution background and 22 subjects selected from the rural area (Ahmadabad) with low-level pollution background. In each group, we collected 4 times blood samples in various air pollution conditions, In the subjects of the urban group, there was a substantial difference (p < 0.05) between inversion days and cold season control days, and between dust storm days and warm season control days for concentrations of hs-CRP, IL-6, and WBCs biomarkers. In the subjects of the rural group, a significant difference could be detected in the concentration of hs-CRP, IL-6, and WBCs biomarkers (p < 0.05) between inversion days and cold season control days, and between dust storm and warm control days. We found that the difference in concentrations of hs-CRP, IL-6, and WBCs biomarkers between dust storm days and warm control conditions in the rural group were higher than the difference in inversion and cold control conditions, which can be attributed to low background air pollution in the rural area. In the urban area, the health effect of anthropogenic sources of PM is higher than the dust storm condition, which can be attributed to the stronger effect of anthropogenic pollution effect.

Effective adsorptive removal of reactive dyes by magnetic chitosan nanoparticles: Kinetic, isothermal studies and response surface methodology.

In the present study, magnetic chitosan (MC) was synthesized, characterized, and used as an efficient adsorbent for the removal of Reactive Red 141 (RR-141) and Reactive Yellow 14 (RY-14) dyes. Synthesized magnetic chitosan nanoparticles were used for characterization with the help of scanning electron microscope (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), and X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The effect of the pH, concentration of pollutants, and adsorbent dosage on the amount of adsorption was studied. Under optimum conditions, the removal rate of RR-141 and RY-14 was 99.5 and 92.7%, respectively. The maximum adsorption capacities were obtained 98.8 and 89.7 mg/g for the RR141 and RY-14, respectively. The results from isotherm models showed that the adsorption of dyes on magnetic chitosan nanocomposite correlated well with Freundlich model, whereas the kinetics studies revealed that the adsorption process was fitted by pseudo-first-order for both dyes. Results of the reusability tests confirmed the magnetic chitosan (MC) nanoparticles could be used for several times. Based on the experimental results obtained, the MC has adequate potential for the treatment of water contaminated with anionic dyes.

The acute effects of short term exposure to particulate matter from natural and anthropogenic sources on inflammation and coagulation markers in healthy young adults.

Airborne particulate matter is associated with increasing the risk of cardiovascular diseases. The purpose of this study was to investigate the association between air pollution conditions and MDA, vWF, and fibrinogen markers in the blood of two panels of healthy young individuals in an urban area in Tehran city with a high air pollution background and another group was living in a rural area (Ahmad Abad Mostofi), with a low air pollution background. In each group, 4 blood samples were taken as follows: one in inversion days, the second in winter, but during the existence of normal condition in terms of air pollution, the third sample in the spring during the normal condition in terms of air pollution and the fourth sample during the dust storm conditions. In the urban and rural groups, there was a significant difference between the concentration of MDA, vWF, fibrinogen between inversion and cold season control conditions, and between dust storm conditions and warm season control conditions (p < 0.05). The results showed that the association of dust storm condition on the measured biomarkers was stronger than the inversion condition, which health consideration in the dust conditions be taken into account similar to the inversion conditions.

Environmental exposure to endotoxin and its health outcomes: A systematic review.

Exposure to endotoxin occurs environmentally and occupationally. There are several differences between them in terms of the variety and severity of health outcomes, possible exposed groups and type and route of exposure. Occupational exposures caused adverse health outcomes in almost all cases, but there is disparity in the incidence of significant health outcomes due to environmental exposure to endotoxin. This study has therefore endeavoured to investigate health outcomes from environmental exposure to endotoxin. A systematic review was conducted of three databases and non-occupational studies reporting the environmental concentration of endotoxin, and observed health outcomes in exposed groups were included in the review (n = 27). The studies showed that first exposure to endotoxin occurs in infancy by the inhalation route. Inhalation is the only exposure route that can induce inflammation as the main symptom of exposure to endotoxin. The studies included were conducted using four approaches: molecular immunology, measurement of lung volumes, clinical sensitisation test and diagnosis of asthmatic and respiratory symptoms such as wheezing. By the immunological approach, all the included studies reported that environmental exposure to endotoxin, especially at a younger age, has a protective effect on the incidence of asthma in adolescence. The main disparity observed was in studies using the approach of diagnosed asthma. Overall, however, they confirm the protective effect of exposure to endotoxin although, in the case of children with non-atopic asthma, the results could be different.

Tetracycline removal from aqueous solutions using zeolitic imidazolate frameworks with different morphologies: A mathematical modeling.

Concerns about environment pollution by antibiotics raised notable attention. In this context, metal-organic frameworks (MOFs) can produce an excellent platform for toxicant removal from water environments. In the current investigation, eight MOFs (ZIF-67-NO3, ZIF-67-Cl, ZIF-67-SO4, ZIF-67-OAC, ZIF-8-Octahedron, ZIF-8-Leaf, ZIF-8-Cuboid, and ZIF-8-Cube) with different chemical and textural compositions were synthesized, and furthermore, the adsorption of Tetracycline (TC) by them was evaluated. Also, the key experimental conditions were modeled using response surface methodology (RSM). Among the prepared MOFs, the highest tendency for TC removal was nominated to ZIF-67- Acetate (ZIF-67-OAC). By model optimization approach, the optimum system conditions as contact time, adsorbent dosage, pH and adsorbed antibiotic concentration were reported as 26.8 min, 0.63 g/L, 5.9, and 74.6 mg/L, respectively. The proposed equilibrium model showed that the TC accumulated on ZIF-67-OAC surface is reversible in multilayer with the highest monolayer capacity of 446.9 mg/g. Furthermore, based on separation factor (KL), TC adsorption is more favorable at a higher amount of MOFs added. Moreover, according to the fitted kinetic model, the process was controlled by chemisorption. ZIF-67-OAC shows excellent structural stability during mechanical agitation in an aqueous environment, and the TC removal capacities of regenerated adsorbent did not change considerably at the end of cycle 4 compared to the first cycle. Considering the findings among the examined MOFs, the ZIF-67-OAC can be approached as a promising adsorbent for the removal of antibiotics from aqueous environments.

Optimization of heavy metal biosorption onto freshwater algae (Chlorella coloniales) using response surface methodology (RSM).

In this study, the interaction of the initial metal concentration, time of reaction and Chlorella coloniales algae dose were taken for the biosorption of Cr, Cd, Co, Fe and As from aqueous solutions using the Box-Behnken design. The regression equation coefficients were calculated and the data confirmed the validity of second-order polynomial equation for the removal of Cr, Cd, Co, Fe and As with Chlorella coloniales algae. Analysis of variance (ANOVA) showed a high coefficient of determination value (R2) for Cr, Cd, Co, Fe, and As, being respectively 0.998, 0.998, 0.995, 0.998 and 0.994. Heavy metal biosorption increased with the increase in time of reaction from 30 h to 100 h then smoothly steadily decreased. The biosorption capacity of Chlorella coloniales increased when initial Cd concentration was increased from 5 to 12 mg/L, and then no change was seen with further increasing in initial Cd concentration. At low concentrations of heavy metal, Chlorella coloniales showed its effectiveness for Cr, Co, Fe and As bioaccumulation, but at high concentrations of heavy metal bioaccumulation efficiency decreased Under optimal value of process parameters, maximum efficiencies for the removal of Cr, Cd, Co, Fe, and As were 97.8, 97.05, 95.15, 98.6 and 96.5% respectively. The results of the present study suggest that use of C. Coloniales algae can be a good alternative to the current expensive methods of removing heavy metals from aqueous solution.

The concentration data of heavy metals in vegetables of Guilan province, Iran.

Food safety is a major problem currently facing the world and food consumption has been identified as the major pathway for human exposure to hazardous pollutants such as heavy metals. These datasets include the concentration of heavy metals like Cd, Pb, Cu, Ba, Co and Sn in selected vegetables in Guilan province and estimate daily intake of metals. The results of this dataset showed that the average concentration of heavy metals including Cd, Pb, Cu, Ba, Co and Sn in total vegetables were 0.55, 1.098, 4.095, 5.98, 0.69, and 0.2 mg/kg, respectively. The mint showed higher levels of Pb, Cu and Co contamination compared to other vegetables. The estimated daily intakes of Cd, Pb, Cu, Ba, Co and Sn for children were 0.311, 0.622, 2.320, 3.388, 0.391, 0.119 µg/day, whereas for adults were 0.182, 0.363, 1.357, 1.98, 0.228, 0.069 mg/kg, respectively. The present data highlights that both adults and children consuming vegetables ingest significant amount of these metals.

Characterization, kinetic, thermodynamic and isotherm data for diclofenac removal from aqueous solution by activated carbon derived from pine tree.

The usage of low cost material as adsorbent would be admirable from environmental point of view. Thus, herein, this data set present a simple method for providing an adsorbent from activated carbon derived from pine tree. The prepared adsorbent was applied to remove diclofenac from aqueous solution. The characterization data of the adsorbent was analyzed using FTIR method. The FTIR test results showed that adsorbent has a functional group that is useful in adsorption process. It was conducted in laboratory scale and the adsorption technique was batch technique. The information regarding isotherms of diclofenac adsorption were listed. The Langmuir isotherm was suitable for correlation of equilibrium data with correlation coefficient value of 0.999. Adsorption of diclofenac by adsorbent from activated carbon follows pseudo second order model with correlation coefficient value (R2) of 0.9997. The data implied that the maximum adsorption capacity of adsorbent to uptake diclofenac from aqueous solution was obtained 54.67 mg/g. The acquired data indicated that the adsorption of diclofenac by the adsorbent prepared from activated carbon derived from pine tree is a promising technique for treating diclofenac bearing wastewaters.

Short-term effects of particle size fractions on lung function of late adolescents.

Although ambient air pollution has been linked to reduced lung function in healthy students, longitudinal studies that compare the response of asthmatic and healthy adolescents are lacking. To evaluate lung function responses to short-term ambient air particulate matter (PM10, PM2.5, and PM1) levels, we conducted a study on high school students aged 15-18 years. The aim of this study was to assess effects of acute exposure to ambient air particulate matter (PM) on lung function in healthy and asthmatic late adolescents. We examined associations of lung function indices and ambient PM levels in 23 asthmatic and 23 healthy students. Paired-samples T test was used to evaluate the association of exposure to airborne PM concentrations with lung function test results (FVC, FEV1, FEV1/FVC, and FEF25-75). We observed negative impact of exposure to an increased concentration of ambient air PM10, PM2.5, and PM1 on lung function parameters of asthmatic and healthy late adolescents. These findings are consistent with other similar short-term studies which have confirmed the adverse effect of PM air pollution. These associations were stronger in asthmatic subjects compared with those in healthy ones. There are significant adverse effects of ambient air PM on pulmonary function of adolescents, especially asthmatics.

Catalytic decomposition of 2-chlorophenol using an ultrasonic-assisted Fe3O4-TiO2@MWCNT system: Influence factors, pathway and mechanism study.

As a reusable sonocatalyst, magnetically separable Fe3O4-TiO2@MWCNT (FMT) was synthesized by an ultrasound-assisted wet impregnation method and was evaluated in the removal of 2-chlorophenol (2CP). Physical and chemical properties of the catalyst composite materials were investigated by all catalysts were systematically characterized using Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), Energy Dispersive X-ray Analysis (EDX), Dynamic light scattering (DLS), and N2-physisorption. The efficiency and kinetics of 2CP removal by FMT-assisted sonocatalysis (FMT-US) was systematically investigated under various operational parameters i.e. pH, FMT and 2CP concentration, temperature and ultrasonic power. The results indicated that 0.4gL-1 FMT dosage, pH 5, temperature of 35°C as well as 50 w ultrasound power are the most favorable conditions for the degradation of the 2CP. Furthermore, both of the superoxide and hydroxyl radicals were produced in the reaction, however, superoxide radicals were assumed to be the dominating reactive species for the 2CP degradation, according to the scavenging tests and electron paramagnetic resonance tests. Moreover, the FMT catalyst exhibited a high reusability and stability in the US/FMT system during the five repetitive experiments. The intermediate products were identified by GC-MS, thereby a possible degradation pathway is proposed. The chemical oxygen demand (COD) and corresponding total organic carbon (TOC) removal efficiencies were 64.9% and 56.7%, respectively. Finally, toxicity tests showed that the toxicity of the solution increased during the first 5min and then decreased significantly with the progress of the oxidation. The mechanisms of ultrasound irritation enhanced FMT activation were also proposed.

Data on pollutants content in the influent and effluent from wastewater treatment plant of Rasht in Guilan Province, Iran.

Data on this paper show the concentrations of COD, BOD5, TSS, K+, Ca2+, Na+, Cl-, [Formula: see text], [Formula: see text], Mn2+, Fe2+, Mg2+, Zn2+, Ni, Pb, Cu and Cd in the influent and effluent of wastewater, and also the nematode eggs, total and fecal coliform in effluents from wastewater treatment plant of Rasht, Guilan Province, in Iran. Measurements of pollutants in influent and effluent was measured according to standard methods (W.E. Federation and Association, A. P. H., 2005) [1]. Statistical analysis of the data was carried out using Special Package for Social Sciences (SPSS 16).

CFD modeling of incinerator to increase PCBs removal from outlet gas.

Incineration of persistent organic pollutants (POPs) is an important alternative way for disposal of this type of hazardous waste. PCBs are very stable compounds and do not decompose readily. Individuals can be exposed to PCBs through several ways and damaged by their effects. A well design of a waste incinerator will convert these components to unharmfull materials. In this paper we have studied the design parameters of an incinerator with numerical approaches. The CFD software Fluent 6.3 is used for modelling of an incinerator. The effects of several baffles inside the incinerator on flow distribution and heat is investigated. The results show that baffles can reduce eddy flows, increase retaining times, and efficiencies. The baffles reduced cool areas and increased efficiencies of heat as maximum temperature in two and three baffle embedded incinerator were 100 and 200 °C higher than the non-baffle case, respectively. Also the gas emission leaves the incinerator with a lower speed across a longer path and the turbulent flow in the incinerator is stronger.

Heavy metal contamination in street dusts with various land uses in Zahedan, Iran.

A total of 78 street dust samples (75 within city and 3 from suburban) were collected from different areas with various land use within the city of Zahedan in November 2013 at the end of a long dry period. After digestion, the concentrations of Cd, Cr, Cu, Ni, Pb, and Zn were measured by using ICP-OES. The degree of pollution by heavy metals was assessed with respect to the background concentration by calculation and comparison of the pollution index, integrated pollution index (IPI) and enrichment factor (EF). The mean IPI values (aggregate of six heavy metals) in commercial, high traffic, industrial, urban park, and residential were 3.65, 2.76, 1.68, 1.53 and 1.25, respectively. The results of EF analysis showed almost all sampled urban land use types to be enriched in heavy metals compared with sampled background levels, suggesting heavy metals contamination of street dust in the urban center is from anthropogenic sources.

Degradation and biodegradability improvement of the olive mill wastewater by peroxi-electrocoagulation/electrooxidation-electroflotation process with bipolar aluminum electrodes.

Olive mill wastewater is considered as one of the most polluting effluents of the food industry and constitutes a source of important environmental problems. In this study, the removal of pollutants (chemical oxygen demand (COD), biochemical oxygen demand (BOD5), polyphenols, turbidity, color, total suspended solids (TSS), and oil and grease) from olive oil mill processing wastewater by peroxi-electrocoagulation/electrooxidation-electroflotation process with bipolar aluminum electrodes was evaluated using a pilot continuous reactor. In the electrochemical unit, aluminum (Al), stainless steel, and RuO2/Ti plates were used. The effects of pH, hydrogen peroxide doses, current density, NaCl concentrations, and reaction times were studied. Under optimal conditions of pH 4, current density of 40 mA/m(2), 1000 mg/L H2O2, 1 g/L NaCl, and 30-min reaction time, the peroxi-electrochemical method yielded very effective removal of organic pollution from the olive mill wastewater diluted four times. The treatment process reduced COD by 96%, BOD5 by 93.6%, total, polyphenols by 94.4%, color by 91.4%, turbidity by 88.7, suspended solids by 97% and oil and grease by 97.1%. The biodegradability index (BOD5/COD) increased from 0.29 to 0.46. Therefore, the peroxi-electrocoagulation/electrooxidation-electroflotation process is considered as an effective and feasible process for pre-treating olive mill wastewater, making possible a post-treatment of the effluent in a biological system.