Pollution
Volume:8 Issue: 2, Spring 2022

This research evaluates dibenzothiophene (DBT) adsorptive removal from the liquid stream on the graphitic carbon nitride (GCN) as a synthesized adsorbent at 25 0C with 3 g for 600 min. The morphological properties of GCN have been investigated by Brunauer–Emmett–Teller (BET), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), and X-ray Diffraction (XRD). The study of the characteristic properties of nano adsorbent proves the suitability of the synthesized GCN in mercaptan adsorption process with the obtained data showing a good agreement with Freundlich model. The equilibrium capacity of DBT adsorption has been calculated at about 39.1 mg/g. This has also been 25.8 mg/g for TBM (tertiary butyl mercaptan). The adsorption capacity has increased by adding to the adsorbent dosage. Thermodynamic studies expose the negative values for ΔS0 (-8.99 kJ/mol. K), ΔH0 (-21.05 kJ/mol), and ΔG0 (8.91 kJ/mol), which demonstrate that DBT adsorption has been a natural exothermic process. In addition, this experiment verifies that the substitution of N into the carbon structure improves the DBT removal efficiency in comparison with pristine CNT as an adsorbent. The removal efficiency of DBT onto GCN has been approximately 80%, i.e. 20% higher than that of pure CNT. Results show that the adsorption capacity of DBT as a cyclic source of mercaptan has been higher than Tertiary butyl mercaptan (TBM) as a liner one. The DBT adsorption mechanism is done by π–π electron interactions between the aromatic structures of DBT, lone-pair electrons of the S atoms, and the pyridinic GCN planes band.

The use of constructed wetland (CW) is a natural way of treating wastewater sustainably and economically. However, the implementation of these systems in freezing conditions is still a matter of research and development. The treatment capacity of CWs relies largely on the biological and biochemical processes which further depends on physical conditions such as temperature, solar radiations, etc. Application of wetland systems for treating wastewater faces many challenges in regions with cold climates, resolving which this review has been made. This paper presents a thorough understanding of the components of CWs and their role in contaminant removal. A comprehensive review of the different types of CWs has been done describing the treatment efficiency achieved by its implementation in the cold climate. Furthermore, various technologies which can be clubbed with CWs have also been listed along with the treatment efficiencies obtained. Literature survey indicates that the extent of removing organics (COD and BOD5) and total phosphorous (TP) are not likely to be affected, but total nitrogen (TN) removal appears to slow down at low temperatures. Despite several advantages of CW technology, further research is required to select suitable macrophytes and optimum design parameters to compensate for frigid conditions.

Iron removal from aqueous solution via ultrasound-assisted adsorption using Typha australis leaves as low cost adsorbent had been studied. The effects of various experimental parameters like mass of the Typha australis adsorbent and contact time have been investigated using a batch experiment. The adsorption kinetic data were analyzed using the Pseudo First Order (PFO) and Pseudo Second Order (PSO) models. The adsorption modeling was carried out using the Langmuir, Freundlich and Redlich-Peterson adsorption models. For kinetic study, the adsorption process fitted the PSO model and agreed with chemisorption. Both the Langmuir and Redlich–Peterson models were found to fit the adsorption isotherm data well, but the Redlich– Peterson model was better. The maximum adsorption capacity from the Langmuir model (qmax) was 0.84 mg/g. The results of the present work showed that the Typha australis leaf, without any treatment has a good potential for iron removal from aqueous solutions via ultrasound-assisted adsorption.

A monthly temporal monitoring of the physico-chemical parameters of the leachate from the Greater Casablanca “Mediouna” open-air landfill in Morocco over a period of 13 months was carried out to show their variability over time. This monitoring also highlights the effect of rainfall on leachate quality through fluctuations observed in wet and dry periods. Indeed, the leachate was sampled from a collector that drains a mixture of young and mature leachate. Several physico-chemical parameters were studied: pH, temperature, conductivity, organic matter (BOD5 and COD), total matter (TS, TVS), nitrogen (N-NO2-, N-NO3-, N-NH4+, TKN), total phosphorus (Tp), salts (Cl-, SO42-) and metals (Cd, Co, Cr, Ca, Cu, Fe, K, Mg, Mn, Ni, Pb, Zn). As a result, significant concentrations were recorded throughout the monitoring for the majority of the parameters, showing a high aggressiveness of the leachate. Also, statistically significant relationships were observed between the different parameters. On the other hand, the leachate pollution index (LPI) was calculated to determine the overall potential of leachate pollution. The identification and study of the behaviour of the physico-chemical parameters is very useful for the design of an adequate leachate treatment plant for the Greater Casablanca landfill "Mediouna", taking into consideration the extreme values recorded during the monitoring period, in order to avoid any malfunctioning due to an underestimation of the pollution.

The problem of pollution of aquatic ecosystems with microplastics has been actively studied by the world scientific community. Most of this research has been devoted to marine ecosystems, whereas scant research has been conducted on fresh water bodies. Lake Baikal (Russia) is a unique natural reservoir. Previous studies devoted to the amount of microplastics in the waters of Lake Baikal were carried out singularly and were not of a systemic character; therefore, previously obtained data does not reflect a complete picture of the state of the lake. Within the framework of this study, our goal was to study the composition and morphological structure of microplastic particles in the ice of Lake Baikal at different distances from the coastline. To do this, a number of ice samples were taken from the upper and lower sides at five different points in South Baikal opposite the village of Bolshiye Koty. Later these samples were analyzed for the types of microplastics and their amount. In the samples taken, two types of microplastics were found—fragments and fibers—with fibers being predominant. The median values of the number of microplastics particles are higher in samples taken at the interface between water and ice, compared to samples taken from the ice surface. Presumably, main part of microplastic fibers found opposite the village of Bolshiye Koty were brought in by a constant circular current from the opposite east coast. In turn, the low number of fragments in the samples may be due to the freezing of the coastline.

Sustainable urbanization under sustainable development goals requires quantitative information on urban landscape. Despite having the fastest growth of urban area and poor air quality, Faridabad, a constituent district of National Capital Region, fails to gain much research attention.  Present study based on multi-temporal; freely available satellite image has indicated 3% increase in the built-up against 2% decrease arable land from 2008 to 2018. Further, spatial metrics (Shanon’s entropy, class area (CA), number of patches (NP), largest patch index (LPI)) has indicated scattered development of built-up. Increase CA (11470 ha in 2008 and 13806 ha in 2018) and NP (221 in 2008 and 476 in 2018) have indicated isolated development of built-up with small area coverage. Increase in LPI (12.5% in 2008 and 13.5% in 2018) of built up indicated compact growth of dense built-up in the southern and eastern side leading to the vertical expansion of the city area. Linear expansion of the residential built-up, industrial, and commercial area along the highways, roads and railways and vehicular emission has contributed to the high aerosol concentration. While, in the rural region the high aerosol loading has also been observed because of the extensive use of fertilizer and stubble burning. Present research on land-use land cover changes and its impact on air quality could be contributed significantly in urban policy making for climate change adaptation and mitigation strategies.

The study was conducted to assess surface water quality in Ca Mau peninsula using multivariate statistical analysis. Fifty-one water samples with the parameters of pH, dissolved oxygen (DO), total suspended solids (TSS), biochemical oxygen demand (BOD5), chemical oxygen demand (COD), ammonium (N-NH4+), orthophosphate (P-PO43-) and total coliform were used in the evaluation. Water quality is assessed using national standard and water quality index (WQI). The methods of cluster (CA), discriminant (DA), principal component analysis (PCA) were used to analyze the variation patterns of water quality. The surface water was contaminated with organic matters, suspended solids, nutrients, and microorganisms. DA revealed that DO, TSS, BOD5 and pH contributed 76.91% to the seasonal variation of water quality. Water quality is classified from bad to heavily polluted. CA grouped water quality into 7 clusters and DO, TSS, BOD5, COD and coliform of the clusters 1-3 were significantly higher than those of the clusters 4-7. PCA presented that PC1-PC3 was the main sources affecting water quality, explaining 85.45% of the variation in water quality. The sources of pollution can be human (domestic wastewater, waste from agriculture, fisheries, industry, landfills), natural (hydrological regime, rainwater overflow, river bank erosion). pH, DO, BOD5, COD, TSS, N-NH4+, P-PO43- and coliform have an impact on water quality and need to be continuously monitored. However, for the multivariate statistical method to be more effective, an initial data set with several water quality parameters sampling locations is needed. The current results provide scientific information and support local water quality monitoring activities.

This study carries the evaluation of tolerance of sixteen plants against pollution. These plants have been selected and assessed for several phyto-socio-economic (tree height, canopy, type of tree, laminar structure, hardiness and economic value) and biochemical qualities (pH, Relative water content (R), Ascorbic acid (AA), Chlorophyll a (Chl a), (Chl b), Carotenoids (Car) and total Chlorophyll (TC)) and tested for Air pollution tolerance index (APTI) and Expected performance Index (EPI) and then EPI score used as grades of plants (Not Recommended, Very poor, Poor, Moderate, Good, Very good, Excellent and Best Plus Plant). Statistical analysis tool like correlation matrix among plant parameters and ANNOA test has been applied to understand the relationship among plant parameters and plant species. The best EPI score means best suited plant for the area for plantation and green belt development while plant with lower EPI may be used as bioindicators for the pollution because they are very sensitive for the air pollution.

Chromium VI is a frequent pollutant of industrial liquid effluents. It is a substance classified as a carcinogen group I. In this study, a Cr VI sorption mechanism was developed by using nanocellulose spheroids (hydrogel) obtained from ivory nut. Cr VI was detected in water by a colorimetric method, using 1, 5-diphenylcarbazide at λ 540 nm. Then, the sorption capacity of nanocellulose spheroids was tested by varying the solution's pH and temperatures. The outcome of the experiment shows that the most efficient pollutant’s adsorption conditions are occur at pH 4 and 25 °C. Removal percentages of Cr VI reached 91.29% (+/-1.36) and 95.33% (+/- 0.86). Additionally, the sorption kinetics showed that the adsorption reaction on the material reaches its equilibrium 20 to 30 minutes after the reaction starts. Finally, an analysis of adsorption isotherms showed a high adjustment with the Langmuir and Freundlinch isotherms. In this frame, this work’s results show that nanocellulose beads are an interesting alternative to efficiently reduce Cr VI from industrial and drinking water.

Plastic pollution is a threat to the environment because of its slow degradation rate and high usage. The aim of this study is to isolate plastic degrading microorganisms from soils. The soil samples used for this study were collected from dumpsites filled with plastic and plastic materials and the effectiveness of the degradation of plastic materials was studied over a period of six (6) weeks in broth and agar culture under laboratory conditions by weight determination method. Physicochemical and microbiological analysis was carried out on the various soil samples using standard protocols. The biodegradation of polyvinylchloride (PVC) was done in-vitro using the microorganisms isolated from the soil. Microorganisms that were able to degrade a higher percentage of the plastic materials were; Staphylococcus aureus, Streptococcus sp, Bacillus sp, Escherichia coli Aspergillus niger, Aspergillus flavus and Trichoderma viridae. The total viable count for bacteria and fungi were within the range of 11.8x105 CFU/g to 2.0x1010 CFU/g and 3.3x105 CFU/g to 0.1x1011 CFU/g respectively. Staphylococcus aureus, Streptococcus sp, Bacillus sp, Micrococcus sp, Aspergillus niger, Aspergillus flavus, and Trichoderma viridae, degraded plastic up to 25%, 31.2%, 25% 31.2%, 12%, 10% and 10% respectively. These isolates may be used to actively degrade plastics, thereby reducing the rate of plastic pollution in our ecosystem.

Exposure to household dust is a common occurrence in all countries and causes various diseases. This study provided information on the number, shape, size distribution, and elemental composition of household dust particles collected in urban homes in Agadir city in Morocco. Moreover, a potential human health risk of exposure has been identified based on current research. Samples were analyzed using computer-controlled scanning electron microscopy and ImageJ image processing program. A total of 3296 particles were analyzed for their size, and 76 particles were classified according to their size and elemental composition. Household dust particles were classified in six types: micro-aggregates (31.6%), biogenic (5.3%), spherical (17.1%), subrounded (7.9%), subangular (11.8%), and angular (26.3%). These particles were determined to have originated from a distant source (Trask classification index between 1 and 2.5). They were large (Skewness asymmetry coefficient > 1), and ranged from 0.2 to 363 µm with an average value of 22.8 ± 0.6 µm in diameter. Dust particles with diameters of 5-10 µm and 10-20 µm were the most abundant, while dust diameters of 10-20 µm, 20-30 µm, and > 100 µm were the highest in volume. The domestic dust deposition rate was 19.8 ± 7.4 g/m2 per year. Household dust is one of the major sources of PM10 in the residential environment (44.6% of the total number of particles), and the studied properties of house dust are highly related to human health. Household dust is a critical element to be considered in the occurrence of respiratory and cardiovascular infections.

In advanced oxidation processes, the application of ozonation has been immensely used in recent years for the treatment of effluent water from pharmaceutical, textile and chemical industries. In this study, procian blue, a major and vastly used reactive dye in the textile industry was chosen for ozonation. This work investigated the effect of ozonation for the treatment of synthetic textile effluent water. The change of pH values of dye solutions from 2-12 had moderate effect on dye removal. The degradation rate was faster during the initial period of ozonation and reached highest dye removal around 90 minutes. The highest 87% removal of dye was observed for the case of 60 mg/L dye solution at pH 12. At higher pH, the dye degradation increased as the rate of formation of hydroxyl radical increased with pH. Factors influencing on dye degradation like concentration of dye, time of ozonation, and addition of H2O2 with ozone (combined treatment) were also evaluated. The combined treatment (5 g/L of hydrogen peroxide) increased the degradation of dye to 92% as compared to 85% for pure ozonation process of 60 mg/L dye solution of initial pH 10. The procian blue dye degradation followed pseudo-first order kinetics with a value of rate constant 2.48×10-2 /min.

Increasing plastic usage pose a significant threat to the marine environment. Many studies have been conducted to examine the amount and environmental impacts of plastic waste across the world. This study was carried out to investigate the density and quality of plastics on the sea surface and seabed of İskenderun Bay. 35 different seabed sampling and 25 different sea surface sampling were conducted by using İskenderun Technical University R/V ISTE-1 vessel. A total of 1 661 581 m2   and 465 511 m2 swept from the seabed and sea surface were scanned, respectively. As a result of these scans, the amount of plastic waste density per unit area of the seabed was found as  0.126 g / m2 ± 0.011 (p: 0.95), and the amount of plastic waste density per unit area of sea surface was calculated as 0.052 gr ± 0.011 (p: 0.95). Scuba dives conducted in river mouths showed plastic deposition pits at the seabed. Major surface current systems and dominant southern winds were found to be effective in the sea surface distribution of plastic materials.

Batch adsorption process was employed to remove copper(II) and cadmium(II) ions from contaminated water using dried orange peel powder as a cellulosic adsorbent, which supports circular economy and sustainability. Metal ion concentrations were determined using a flame atomic absorption spectroscopy (FAAS). Effects of pH, sorbate-sorbent contact time, metal ion concentration and adsorbent dose on the removal efficiency of the metal ions was investigated. The adsorption equilibrium was reached at 120 and 150 minutes for Cu(II) ions and Cd(II) ions, respectively. At optimized pH and biosorbent load, 10 mg L-1 of Cu(II) and Cd(II)  ions could be removed to the extent 96.9% and 98.1%, respectively, within 2 hrs. However, the percentage removal of metal ions decreased with increasing their initial concentrations. The observed adsorption data was also interpreted in terms of Langmuir and Freundlich adsorption isotherm models. The calculated equilibrium data fitted more adequately with Freundlich model (higher correlation coefficient, R2) than Langmuir model, indicating heterogeneity of adsorption sites due to different functional groups in cellulose. Cd(II) ions showed less binding affinity and less desorption than Cu(II) ions. The maximum adsorption capacity (qmax) of dried orange peel were 2.78 mg/g and 2.57 mg/g for copper(II) and cadmium(II) ions, respectively.

Consumption of polythene is unavoidable in this era and it is increasing day by day. Polythene’s hazardous waste is adversely effecting environment. In fact any form of polythene is a nuisance to the environment because of strong resistance against degradation thus; they remain in nature for a very long time. Biodegradation is the only promising solution to overcome this problem.  Fungi, a group of saprophytic organisms are evolved to adapt for almost every environment, specially marine and freshwater source. This property drives fungi to grown on polythene even in adverse environment. So, present study was planned to compare biological degradation of low density polythene [LDPE] and biodegradable polythene by potential fungus to find out an eco-friendly and economic solution of polythene waste. Ten fungal strains were isolated from rotting polythene debris those are Penicillium chrysogenum, Rhizopus nigricans, Chaetomium murorum, Memnoniella echinata, Aspergillus fumigatus, Stachybotrys chartarum, Aspergillus niger, Chaetomium globosum, Aspergillus flavus and Fusarium oxysporum, in which Penicillium chrysogenum, Rhizopus nigricans, Aspergillus fumigatus, Aspergillus niger and Aspergillus flavus showed greatest results in terms of degrading both Low density polythene and biodegradable polythene. These isolates also showed good enzymatic reaction and weight loss. SEM analysis of polythene surface was also in support of these findings.

The present work is aimed at decreasing pollutants emitted by diesel engine exhaust tailpipe and enhancing performance by incorporating cobalt oxide nanoparticles in water emulsified diesel. Water concentration of 5% and 10% is used to prepare various WD emulsion blends, with nano particle dosage levels of 50PPM and 100PPM. High speed homogenizer and ultrasonicator devices are used to disperse water droplets in diesel. Surfactant mixture of span80 and tween20 is used to achieve long term stability of emulsified fuel. The functional groups of emulsified fuel are analysed using FTIR spectroscopy. The characterization of cobalt oxide nanoparticles is carried using scanning electron microscope. Physiochemical properties such as calorific value, density, viscosity of emulsion blends and pure diesel are determined and compared. Experimental results reveal that addition of cobalt oxide nanoparticles in emulsified fuel with increased dosage of 100PPM shows 23%, 33.3%, 25%, and 44.6% reduction in NOX, HC, CO and smoke emission compared to pure diesel. The improvement in BTE and BSFC were observed for all emulsion blends.

The purpose of this study was to evaluate the concentrations of potentially toxic elements in the Suches river using standardized geochemical indices and to identify the main sources of contamination in the section from the Suches lagoon up to 33.8 km downstream of the effluent river, in the district of Cojata, Puno, Peru. The concentration of Al, Ba, Co, Fe, M, Ni, P, V and Zn in sediments of the Suches river was determined by means of mass spectrometry from October 2019 to February 2020. The values of Co, Fe, Mn, Ni, P and Zn exceeded the base values of contamination according to the general geological references while Al, Ba and V, did not surpass them. The contamination factor showed that the elements Co and Ni revealed a very high level of contamination, while the Zn, a considerable level. The area has an average pollution load index value of 2.24, indicating moderate general pollution. The elements Co, Ni, Al and Zn were within the moderate and extreme classification according to the pollution index. The Spearman's correlation analysis allowed determining the association between Al, Fe, Mn, P and V, which share a natural origin and the accumulation of these elements is due to the effects of weathering and soil erosion. The evaluation of the contamination indices and the correlation confirm that Cobalt, Nickel and Zinc are toxic elements associated with gold mining and agricultural activities.

Dairy industries generate enormous volumes of waste water which are significantly rich in organic compounds; contributing to high BOD, COD and sulfates. As a mandate to ‘treat’ effluents generated by different unit operations in a dairy industry, current treatment methods rely on physico-chemical, mechanical and conventional biological interventions. This approach remains unviable because of cost intensiveness and excessive energy usage. Additionally, the significant lowering of pollution indicators remains a daunting task with inlet and outlet parameters. With these identifiable gaps, our study was aimed to screen bio-efficacious, naturally attenuated fungal isolates to lower exceeding levels of sulfate in effluents released by dairy industry. Effluent samples were collected from Effluent Treatment Plant (ETP) of Jaipur Dairy, Rajasthan Dairy Co-operation Limited (RCDF), Jaipur. For mycological investigations, qualitative screening was carried out in Potato Dextrose Agar (PDA) supplemented with Calcium Sulfate (CaSo4) (0.1g/L). The most promising fungal isolates belonging to Aspergillus sp. was characterized based on its cultural and microscopic characteristics. Microcosm study was conducted by supplementing Aspergillus sp. in Untreated Dairy Effluent (UDE) for a period of 7 days at Room Temperature (RT) under static conditions. Following the incubation phase, mycelial mesh (plug) was indicative of exponential fungal growth. Effluent seeded with Aspergillus sp. and abiotic controls were spinned at 5000 rpm for 15 minutes to eliminate biomass. Sulfate estimation was carried out in Cell Free Extract (CFE) of both experimental and control group. A significant reduction of 67.3% was observed (p<0.05) with respect to positive control and 8.4% when contrasted with abiotic control.

This study utilized kinetic models to study the treatment efficiencies of a laboratory-scale up-flow biological aerated filters reactor (UBAF). The treatment efficiency of a model reactor was studied using different operating conditions of the hydraulic retention times, organic loading rates, and kinetic parameters. As a result of the calculations, the second-order and modified Stover/Kincannon models are appropriate. The substrate removal rate constant K2(S) was 1.7 per day for the reactor, with a correlation coefficient of 0.9979. Utilizing the modified Stover/Kincannon model, the coefficient of the determined concentration was 0.9987; 0.9265; and 0.9685 for Chemical oxygen demand (COD); ammonium nitrogen (NH4+-N); and Total Nitrogen (TN), respectively. The calculation of the saturation value constants and maximum utilization rate for Chemical oxygen demand (COD); ammonium nitrogen (NH4+-N); and Total Nitrogen (TN) was performed using the modified Stover-Kincannon model were 178.57 and 201.80 for COD; 1.876 and 4.6 for NH4 +-N; 3.823 and 6.644 for TN, respectively. It is possible to determine the kinetic parameter for removing COD, NH4+-N, and TN from wastewater by using the modified Stover-Kincannon model.

A simple and rapid method for the highly sensitive determination of polycyclic aromatic hydrocarbons (PAHs) from airborne fine particulate matter (PM2.5) in an urban environment of Delhi was developed. The target compounds were 10 of the 16 United States Environmental Protection Agency (US-EPA) priority PAHs: fluoranthene, pyrene, chrysene, benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo[a]pyrene, dibenzo(ah)anthracene, benzo(ghi)perylene, indeno(1,2,3-cd)pyrene. For collecting the samples, the following two locations in Delhi (India) were chosen: ITO and Okhla Industrial Area.  Two sets of samples at these locations of were collected for the purpose of investigation. The fine particulate matter samples were collected on glass fiber filter papers for 24h, from which the PAHs were extracted using dichloromethane (DCM) and hexane using ultrasonication method. Comparison of the characteristic emission of spectra of PAHs with standard spectra indicated the degree of condensation of aromatic compounds present in the investigated mixtures. However, this identification could be more effective with the use of the respective values of Δλ parameter for each particular component of the mixture. It has been found that the concentration of the PAHs is maximum during the winter season and minimum during the summer and monsoon seasons at both the locations.

Activated carbon was prepared from corn cob agricultural waste with different impregnation ratios and pyrolysis times. The optimal adsorbent prepared using at 4:1 ZnCl2:corn cob char ratio at a temperature of 800 °C for 180 min provided the maximum Brunauer-Emmett-Teller (BET) surface area, total pore volume and average pore width, with values of 912.47 m2/g, 0.52 cm3/g and 22.61 Å, respectively. ZnCl2 was effective in creating well-developed pores on the surface of the activated carbon. The removal efficiency and adsorption capacity of the colour and the chemical oxygen demand (COD) of the biologically pre-treated leachate were examined utilizing the best corn cob activated carbon (CCAC) with varying CCAC dosages, contact times and initial pH values. The greatest colour and COD removal effectiveness were 88.6±0.2% and 83.7±0.4%, respectively, at the optimum CCAC dosage of 12 g for 40 min with an initial pH value of 10. In addition, maximum adsorption capacities were achieved for colour and COD of 10.3±0.02 mg/g and 12.6±0.05 mg/g, respectively, under the same conditions. The kinetics of colour and COD adsorption fitted very well with pseudo-second-order kinetic model. The CCAC performs well as an adsorbent for removing colour and COD in biologically pre-treated leachate.

The induction of oxidative stress in plants grown on crude oil-contaminated soils was investigated using a diesel contaminated soils model. Twelve cassava stems were grown in four garden pots containing different amounts of diesel oil as contaminants: 150 ppm, 300 ppm, 600 ppm and control (0 ppm). The growth of the plants was monitored for 12 weeks, after which chlorophyll contents, total proteins, lipid peroxidation and activities of catalase, glutathione, and superoxide dismutase (antioxidant enzymes) were determined from the leaves. Significant decreases (p<0.05) were observed in the antioxidant enzymes (67-86%), total proteins (79%) and total chlorophyll content (67%) in the cassava grown on diesel contaminated soil (600 ppm) compared to the control. Consequently, there were significant increase (p<0.05) in the leaf ratio and malondialdehyde (a marker for lipid peroxidation) 0.1909 ± 04 and 1.77 ± 0.34, when compared to the control 0.1530 ± 08 sq.cm/g and 0.10±0.01 µmol/mg protein respectively. It was thus concluded that stunted growth of plants and their death in diesel or crude oil contaminated soil could be traced to oxidative stress.

Ologe Lagoon is one of Lagos, Nigeria’s five major lagoons, which provide essential ecosystem services such as agriculture, fishing, transportation, salt and sand mining, tourism, and industrial development. There are concerns, however, that the lagoon’s water may not be safe for the ecosystem functions it offers. As a result, the physicochemical properties, heavy metal concentrations, and microbial loads of water samples from the lagoon, as well as their health risks, were examined in this study. Physicochemical analysis showed that calcium, chloride, nitrates, sulphate, dissolved oxygen, acidity, alkalinity, total dissolved solid, and total suspended solid were present within the World Health Organization permissible limits, but not so for phosphate and temperature. The heavy metal analysis revealed that the water had non-permissible levels of iron, cadmium, chromium, nickel, manganese, and copper, but lead was normal. The microbiological examination showed abnormal bacteria counts, while coliform and fungus were not detected. The average daily oral and dermal exposure to cadmium, chromium, and nickel were higher than the recommended daily intake, but iron, lead, and copper were within the limits. The hazard quotient of oral and dermal exposure to cadmium, dermal exposure to chromium, and oral exposure to manganese were higher than the recommended limit (> 1). The carcinogenic risks of Cd, Cr, and Ni were also greater than the acceptable limit. The results obtained indicate that Ologe Lagoon’s water is unsafe for the lagoon’s ecosystem functions. Relevant agencies should ensure that waste is treated before being discharged into the lagoon.

The paper provides data on spatial distribution of petroleum hydrocarbons, heterotrophic and hydrocarbon-oxidizing bacteria in water and bottom sediments as well as on heavy metals in bottom sediments at different sites in the zone of fresh and saline water mixing, with the salinity range 1–18 ‰ during spring low water and high water. Physical and chemical characteristics of the bottom sediments are given. The highest hydrocarbon-oxidizing bacteria percentage of the heterotrophic bacterioplankton count in the indicated areas was found in April, with the maximum of 55 % determined in the transition zone waters. The share of hydrocarbon-oxidizing bacteria in the heterotrophic bacteria abundance in the water was larger than that in the bottom sediments. The highest concentrations of chloroform-extractable substances and petroleum hydrocarbons were detected in the marine zone bottom sediments, and their lowest concentrations were found in the river zone. During the period under study, the petroleum hydrocarbon input (in almost equal volumes) was constant, which is indicated by the hydrocarbon percentage of chloroform-extractable substances, which on average was 31 % for the marine zone, 29 % for the transitional zone, and 32 % for the river zone. In contrast to the river and transition zones, the concentration of chloroform-extractable substances observed in the marine zone bottom sediments was constant.

Kharg Island in the Persian Gulf is the place for the major oil export terminals of Iran and hosts several large oil related industries. Coastal environment of the Kharg Island is rich in coral reefs. This paper presents concentrations and sources of aliphatic and aromatic hydrocarbons in the sediments from the coastal area of the island. The concentration of hydrocarbons in 14 seabed sediment samples from water depths of 13-20 m around the island were measured by gas chromatography (GC). Total Petroleum Hydrocarbon (TPH) concentrations in sediment samples ranged from less than 1 to 133 μg/g indicating low to moderate levels of oil pollution. Spatial distributions of TPH concentrations indicated no oil pollution in the southern part of the island, higher oil pollution levels near oil terminals and correlation with fine particles. Total Polycyclic Aromatic Hydrocarbons (∑PAHs) concentrations in sediment samples ranged from near zero to 6210 ng/g, indicating non to highly, but mainly moderately polluted levels. SPAHs concentrations, except at one station, were all less than the NOAA sediment quality guideline value for the effects range low. Developed indices for pollutant origins showed that hydrocarbons in all sediment samples collected in the study area had petrogenic origin. The results also indicated that the emissions from gas flares in the island were the main source of aromatic compounds in the sediment samples.