Pollution
Volume:6 Issue: 1, Winter 2020

Polycyclic aromatic hydrocarbons (PAHs), abundant in mixed contaminant sites, often coexist with heavy metals. The fate and remediation of PAHs depend heavily on the sorption and desorption behavior of these contaminants. The sorption behavior can in turn be highly affected by certain soil components and properties, such as soil organic matter (SOM) and the presence of heavy metals. Through review of the literature focused on research from 2006 to 2018, this paper discusses interactions, challenges, influencing factors and potential synergies in sorption/desorption of mixed PAHs and heavy metal contamination of soil. The presence of either natural organic matter or heavy metals can enhance the sorption capability of fine soil, retarding the PAHs in the solid matrix. The co-existence of SOM and heavy metals has been reported to have synergistic effect on PAHs sorption. Enhanced and surfactant desorption of PAHs are also affected by the presence of both SOM and metals. Remediation techniques for PAHs removal from soil, such as soil washing, soil flushing and electrokinetics, can be affected by the presence of SOM and heavy metals. More detailed studies on the simultaneous effects of soil components and properties on the sorption/desorption of PAHs are needed to enhance the effectiveness of PAHs remediation technologies.

The study investigates the effect of aluminium oxide nanoparticles as an additive to Madhuca Indica (mahua) methyl ester blends on performance, emission analysis of a single-cylinder direct injection diesel engine operated at a constant speed at different operating conditions. The test fuels are indicated as B10A0.2, B10A0.4, B20A0.2, B20A0.4 and diesel respectively. The results indicate that the brake thermal efficiency for aluminium oxide nanoparticles blended biodiesel increases slightly when compared to the mineral diesel. The carbon monoxide (CO), unburnt hydrocarbon (HC) and smoke emission marginally decrease as compared to mineral diesel. Oxides of nitrogen (NOx) emissions are minimum for the aluminium oxide nanoparticles blended mahua methyl esters. Higher cylinder gas pressure and heat release rate were observed for aluminium oxide nanoparticles blended mahua methyl ester. From the study, the blending of aluminium oxide nanoparticles in biodiesel blends produces a most promising results in engine performance and also reduces the harmful emission from the engines.

This study evaluated the responses of biochemical biomarkers in Astacus leptodactylus exposed to treated municipal effluents discharged into Keban Dam Lake, Elazığ Elazig, Turkey. A. leptodatyclus were exposed to treated municipal effluents and Catalase (CAT), Superoxide dismutase (SOD) activity and lipid peroxidation (TBARS), glutathione (GSH) levels were measured as oxidative stress biomarkers.  SOD activity was increased after exposing to treated municipal effluents for 24th and 96th h. CAT activities were decreased from 25.29 to 14.12 nmol/min/ml compared to control in the group exposed to treated municipal effluents for 24 h but it increased after 96 h exposure. GSH levels were decreased from 9.08 to 3.77 µM compared to control, but MDA levels were increased both at 24 th h and 96 th h after exposure to treated municipal effluents. CAT, SOD activities and MDA and GSH levels in the hepatopancreas of A. leptodactylus are sensitive and suitable biochemical biomarkers for evaluating the toxicity of the treated municipal effluent complex mixtures. Treated municipal effluents exposure was found to cause sub-lethal responses in A. leptodactylus suggesting oxidative stress.

Air quality prediction is highly important in view of the health impacts caused by exposure to air pollutants in urban air. This work has presented a model based on support vector machine (SVM) technique to predict daily average carbon monoxide (CO) concentrations in the atmosphere of Tehran. Two types of SVM regression models, i.e. -SVM and -SVM techniques, were used to predict average daily CO concentration as a function of 12 input variables. Then, forward selection (FS) technique was applied to reduce the number of input variables. After converting 12 input variables to 7 using the FS, they were fed to SVM models (FS-(-SVM) and FS-(-SVM)). Finally, a comparison among SVM models operation and previously developed techniques, i.e. classical regression model and artificial intelligent methods such as ANN and adaptive neuro-fuzzy inference system (ANFIS) was carried out. Determination of coefficient (R2) and mean absolute error (MAE) for -SVM (-SVM) were 0.87 (0.40) and 0.87 (0.41), respectively, while they were 0.90 (0.39) and 0.91 (0.35) for ANN and ANFIS, respectively. Results of developed SVM models indicated that both FS-(-SVM) and FS-(-SVM) regression techniques were superior. Furthermore, it was founded that the performance of FS-(-SVM) and FS-(-SVM) models were generally a bit better than the best FS-ANFIS and FS-ANN solutions for short term forecasting of CO concentrations.

Due to the fish are often at the top of the aquatic food chain and may accumulate large amounts of heavy metals from the water, this study was conducted to determine of Cd, Cr, Pb and Ni contents in the muscle of imported tilapia fish marketed in the city of Hamedan in 2017. In so doing, totally, 27 muscle samples from nine different brands of tilapia fish were randomly collected from the market basket of the study area. After preparation and processing the samples in the laboratory, the concentration of metals, was determined using inductively coupled plasma-optical emission spectrometer. The results showed that the mean concentrations (mg/kg) of Cd, Cr, Pb, and Ni in samples were 0.26 ± 0.09, 1.54 ± 0.15, 0.55 ± 0.11, and 0.67 ± 0.20 respectively. Also, the mean contents of Cd and Pb were higher than the maximum permissible levels (MPL) established by the World Health Organization (WHO). The computed health risk index values showed that no potential health risk for adults and children via consuming the muscle of tilapia fish at the current consumption rate for the study area. Based on the results, due to the mean contents of Cd and Pb in the muscle samples of tilapia fish were higher than the MPL, therefore, serious attention to the reduction of the discharge of hazardous substances in the aquatic ecosystems and also periodic monitoring of chemical residue particularly toxic heavy metals in the high-demand food is recommended.

The main objective of this study is to evaluate heavy metals contamination of highly consumed vegetables and hazardous effects of consuming these vegetables. The study was conducted in vegetable fields in three different regions according to the level of environmental pollutions, including "Isfahan", "Flavarjan" and "Faridan, Golpayegan and Natanz". Six types of vegetables in each field with three replicates in each region were selected in the summer of 2017 by the random sampling method from vegetable fields. The level of heavy metals (Pb, Cu, Co, Cd and Cr) in vegetables has been measured for each sample. The result showed that in the Isfahan region, the highest daily intake of Pb, Cu, Co, Cd and Cr for the consumption of all the vegetables was obtained in the recipients. The highest target hazard quotient for non-cancerous diseases of contaminated vegetables was 28.9 and 21.1 in "Isfahan" for children and adults, respectively. The target hazard quotient for vegetable consumption was greater than one and at high hazard for both age groups. The principal component analysis showed that the contamination by the heavy metals in the "Isfahan" and "Falavarjan" regions overlapped and the risk of contamination of heavy metals in urban vegetables in both regions increased the hazard of non-cancerous diseases. It is highly recommended that the quality standards of foods that are imposed on the production of food crops.

Microbial fuel cell represents an emerging technology to attain electrical energy from wastewater. There are several alternative methods available for wastewater treatment; Microbial fuel cell is one of them, which generates green energy from wastewater for making a contribution to renewable sources of energy. This study states the performance of microbial fuel cell with different parameters i.e., catholyte, electrodes, and initial COD concentration. Sodium chloride was used as catholyte and graphite rods were used as both electrodes. The sodium chloride concentrations in the cathode and initial chemical oxygen demand have also been optimized. The optimum sodium chloride of 70 mM in the cathode solution generates the maximum power density of 408.98μW/m2. As the sodium chloride concentration increases in catholyte, the capacity for power production also increases. The voltage output of Microbial fuel cell increases when the initial concentration of chemical oxygen demand increases to a peak value of 1500 mg/l and if the value exceeds this limit, the performance of Microbial fuel cell (in terms of voltage) starts decreasing. The chemical oxygen demand removal efficiency of a microbial fuel cell with simple graphite electrode and graphite electrodes with coated iron were 79% and 90% respectively.

Mathematical models for pollutant transport in semi-infinite aquifers are based on the advection-dispersion equation (ADE) and its variants. This study employs the ADE incorporating time-dependent dispersion and velocity and space-time dependent source and sink, expressed by one function. The dispersion theory allows mechanical dispersion to be directly proportional to seepage velocity. Initially the aquifer is assumed contaminant free and an additional source term is considered at the inlet boundary. A flux type boundary condition is considered in the semi-infinite part of the domain. Laplace transform technique (LTT) is then applied to obtain a closed form analytical solution. The effect of source/sink term as a function in the one-dimensional advection-dispersion equation is explained through the graphical representation for the set of input data based on similar data available in hydrological literature. Matlab software is used to obtain the graphical representation of the obtained solution. The obtained analytical solution of the proposed model may be helpful in the groundwater hydrology areas.

Emerging contaminants are distributed in to the environment from various anthropogenic activities. These Emerging contaminants (ECs) are mainly composed of products, such as pharmaceuticals, personal care products (PCPs), surfactants, plasticizers, pesticides etc. The present conventional system of waste treatment are not designed to treat these contaminants. Complex structure of these pollutants and their existence at low concentration makes them untraceable and hence found to be difficult in removal of these by present waste treatment. These chemicals are considered as threat to human health and environment. Therefore, disposal and treatment of these chemicals of emerging concern have been a key concern in the field of water treatment and its reuse. Biosensors can be used for biomonitoring of these contaminants with of biological system. Bioremediation plays an important role in the treatment of these pollutants of emerging concern. This review discusses about the sources, effects, and challenges in biomonitoring and bioremediation related to these emerging contaminants.

The human health impacts caused due to exposure to criteria outdoor air pollutants PM2.5, PM10 and NO2 were assessed in present study. The human health effects associated with exposure to atmospheric air pollution in NCT Delhi were estimated utilizing the AirQ+ v1.3 software tool integrated with Ri-MAP during the study period 2013-2018 considering 80% of the whole population subjected to air pollution exposure. Taking into account the World Health Organization (WHO) (2016) guidelines, the inter-annual average concentrations of PM2.5, PM10, and NO2, concentration response relationships and population attributable fraction (AF) or impact fraction (IF) concepts were adopted. The excess number of cases (ENCs) of Mortality (all) natural cases 30+ years, acute lower respiratory infection (ALRI), lung cancer (LC), ischaemic heart disease (IHD), stroke, incidence of chronic bronchitis in children, postneonatal infant mortality, chronic obstructive pulmonary disease (COPD), prevalence of bronchitis in children, incidence of asthma symptoms in asthmatic children in the year 2013 were 48332, 2729, 5645, 26853, 22737, 120754, 34510, 5125, 9813, 3054, 17203 and 682, respectively. Within half of a decade i.e. in year 2018, the ENCs of Mortality (all) natural cases 30+ years, ALRI, COPD, LC, IHD, stroke, incidence of chronic bronchitis in children, postneonatal infant mortality, prevalence of bronchitis in children, incidence of asthma symptoms in asthmatic children increased significantly and were 72254, 3471, 6547, 7568, 32358, 28233, 150110, 50810, 9019, 862, 29570 and 1189, respectively.

O-Anisidines (OAs) are extensively used as an intermediate for chemical reactions to produce various triphenylmethane and azo dyes, and also in manufacturing numerous pigments. They are found to be highly toxic and have carcinogenic properties, so it is imperative to treat OA solutions before disposal. In this study a promising approach to degrade OA solutions has been carried out using Fenton’s reagent. Oxidation trials were conducted for 24 hours and various parameters – OA removal, pH, effect of H2O2 and Fe2+, and COD removal – were analysed to understand the oxidative degradation of OA. For varying initial OA concentrations, the OA and COD removal efficiencies of 72 to 85% and 62 to 74%, respectively, were obtained at pH = 3, and at different optimum H2O2 and Fe2+ doses. Lower initial concentrations of OA showed better removal efficiencies. The reaction time was estimated to 360 minutes after which there was negligible degradation occurs.

With an increase in the global pollution, there is requirement for an alternative to the fossil fuels. Non-edible vegetable oils are highly promising for producing liquid fuels like diesel. Jatropha is a potential feedstock for biodiesel, currently utilized in India and many parts of the world. The optimization of reaction conditions such as temperature, time, catalyst and molar ratio for biodiesel production is important in reactor design. However, oils have characteristics reaction properties for optimum yield. Therefore, there is the need to identify such parameters in Jatropha oil ethyl esters production. Preparation of biodiesel from Jatropha oil ethyl esters using conventional homogeneous process. Optimization of Jatropha ethyl esters using Response surface methodology is done and data so obtained are fed to the design experiment software for analysis. The Jatropha ethyl esters yield was 92.62%. Maximum production of Jatropha oil ethyl ester was achieved with the process parameters viz molar ratio 8.5, reaction time 89.67min, reaction temperature 70.1°C and catalyst.0.62wt%.

The aim of this study was to compare the selected aquatic plants ability to remove nitrate from wastewater. Excess of these nutrients in water can directly affect human health (methemoglobinaemia) or indirectly through the products of secondary pollution include eutrophication. Negative impact of nutrients excess in surface water often causes the destruction of water ecosystems, and therefore, common substances of these elements must be monitored and managed. Spectrophotometric technique was commonly used for quick and simple analyses of nutrients in waste water. There are calibration curves for each nutrient and for the determination of their concentration. Phytotechnology is one of the biological wastewater treatment methods or processes to eliminate nitrate contaminant from aquatic system. So as to avoid the eutrophic formation of fresh water and to determine the efficiency of nitrate utilization by specific aquatic plants which include Utricularia aurea and Salvinia molesta were collected from a eutrophic lake at Theerthamkara, Kerala. The samples were allowed to grow in nitrate solution for about one month at different concentrations. The optical density (OD) of nitrate solution at 410 nm was measured on alternative days of the experiment by using UV spectrophotometer. After 33 days of treatment periods, the maximum amount of nitrate removed in terms of percentage was found to be 95% by Utricularia aurea and 92% by Salvinia molesta at 100 ppm nitrate concentration. The results revealed that the aquatic plant (carnivorous) based system of phytotechnology was productively removed the nitrate load from the synthetic wastewater containing nitrate.

In this research, a response surface methodology (RSM) was used to investigate the effects of independent parameters (pH, contact time, temperature, adsorbent dosage, and initial concentration of pollutant), their simultaneous interactions, and quadratic effects on crystal violet adsorption onto two starch based materials in the form of batch experiments. The characterizing results indicated that there is no significant difference between the potato starch and synthesized starch phosphate, as phosphorylation has not changed the crystalline structure of starch inside the granules. The maximum removal efficiency of crystal violet ions was obtained 99 % at the optimum adsorption conditions of initial concentration 213.54 mg/L, adsorbent dosage 0.25 g, contact time 14.99 min, temperature 15 °C, and initial pH of solution 9. RSM outputs showed that the maximum adsorption of crystal violet ions by could be achieved by raising pH and adsorbent dosage, and decreasing the initial crystal violet concentration. While temperature and contact time are not effective parameters in crystal violet removal from aqueous solutions using synthesized starch phosphate. Generally, the RSM model is suitable to optimize the experiments for dye elimination by adsorption, where the modified starch phosphate would be an effective adsorbent for treating crystal violet solution.

This study utilized Swietenia mahagoni bark–a wood processing industry waste, for the preparation of activated carbon, and then investigated for the removal of methyl orange (MO) dye by the Swietenia mahagoni bark activated carbon (SMBAC). The effect of pH (3–10), adsorbent dose (1–30 g/L), initial MO dye concentration (10–100 mg/L), and contact time (1–240 min) were evaluated. The surface morphology of the SMBAC was characterized by using fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Maximum removal efficiency of MO by SMBAC was 92%, when initial MO dye concentration was 10 mg/L, pH 3.0, adsorbent dose 10.0 g/L and 120 min equilibrium contact time. The adsorption data fitted well with the Freundlich (R2=0.997) and Halsey (R2=0.997) isotherm models than the Langmuir (R2=0.979) model, and express the multilayer adsorption on heterogeneous surface. The maximum adsorption capacity was 6.071 mg/g. The kinetics data were fitted well to pseudo-second order model (R2=0.999) and more than one process were involved during adsorption mechanism but film diffusion was the potential rate controlling step.  The study results showed that SMBAC adsorbed MO effectively, and could be used as a low cost potential bioadsorbent for the removal of anionic dyes in wastewater treatment.

The present study aims at investigation of the performance of nanofibrous filter, containing magnesium oxide (MgO) nanoparticles, for bioaerosols removal from the air stream. It synthesizes two types of polyacrylonitrile (PAN) and PAN/MgO nanofibers via electrospinning technique, and investigates the antibacterial properties of the produced nanofibers through disk diffusion. The air containing staphylococcus epidermidis is introduced into the filter test rig by a nebulizer and air sampling from the microorganisms takes place before and after the filters by means of a cascade impactor with blood agar culture medium, with the filters, themselves, examined at two states of UVC radiation and dark. The mean diameters of PAN/MgO and PAN are 221.38±65.56 nm and 320.25±87.35 nm, respectively, with the mean length of the inhibition zone for these nanofibers calculated as 0 (for PAN) and 2.8 mm (for PAN/MgO). It turns out that the mean percentage of filtration efficiency is higher in case of PAN/MgO than PAN nanofiber filter; however, the former displays higher mean pressure drop than the latter. For both types of nanofibers under UVC radiation, the mean percentage efficiency for bioaerosol removal is higher than in the dark.

Limited available water resources have rendered wastewater reuse an important issue to specialists in most developed countries, today. The current study works on membrane filtration for treatment of industrial wastewater. By comparing the two methods of membrane bioreactor (MBR) and hybrid membrane electro bioreactor (MEBR) processes, it finds that earlier fouling in the membrane occurs in the first method than the second one. In the membrane electro-bioreactor, in addition to membrane filtration and activated sludge process, the chemical process of electrical coagulation is performed concurrently, wherein the final product quality is improved and the fouling, reduced. In comparison to membrane bioreactor, this method is capable of removing higher percentage of chemical oxygen demand (COD) as an index of organic matters. Accordingly, it is recommended to use the membrane electro-bioreactor method as an alternative to membrane bioreactor for advanced wastewater treatment.

Formaldehyde has been documented to be naturally present in many common foods. There has been a big public concern over the use of formaldehyde in the preservation of food. Also, it is commonly used as a chemical substance, usually in the life and can interact with many bio-substance in the human body. The present study target to investigate the protective effects of  Cymbopogon schoenanthus (CS) extract against the reproductive and carcinogenic effects of formaldehyde on male rats. The Albino male rats were divided into equal six groups, first group: rendered as a control group; second group: received formalin (100 mg/kg bw) and third group and forth group: were received SC extract at (50 and 100 mg) respectively; fifth group and sixth group were received formalin (100mg /kg bw) + SC extract (50mg) and formalin (100mg /kg bw)+ SC extract (100 mg) respectively. At the end of the experiment the animals were scarified and blood samples were collected for measurement all tested parameters. The results showed that the oral exposure to formaldehyde at a dose of 100 mg/kg bw resulted in significant negative effects in all tested parameters, while the CS extract at tow doses (50 and 100 mg) alone or in combination with formalin restored the negative effects to normal levels compared with the untreated group. The histopathological examination was studied on testis tissues and the histopathological pictures showed the CS extract at tow mention doses had ameliorate the adverse effects that induced by formaldehyde hazards.