Microplastics are widely used to manufacture diverse products such as textiles, skin care products, and household products such as detergents and soaps. However, microplastic pollution and its potential health risks are raising concerns worldwide. This study characterized and determined the safety of microplastics in water and sediments obtained from three locations, namely Ibeshe, Amuwo Odofin, and Ojo along Badagry lagoon, Lagos, Nigeria. The samples of the lagoon's surface water and sediments were treated and analyzed for the abundance of microplastics, as well as their shapes, sizes, and types of polymers. The risk index of the polymers in the microplastics was also estimated. Microplastics were found to be more abundant (p ≤ 0.05) in the sediments (283–315 particles/kg) than in the surface water (108–199 particles/L). In both the water and sediments at all the locations, the dominant shapes were fibers (52%–90%), followed by fragments (3%–32%) and films (1%–25%). In order of significance, the microplastic size range of 0-100µm and 100-500µm dominated the surface water, while the size range of 1000-5000µm and 500-1000µm dominated the sediments at all the locations. The dominant polymers in both the water and sediments at all the locations were polyethylene, polypropylene, and polyamide, while the least was polystyrene. In both the water and sediments at all the locations, the dominant risk score among the polymers is III (moderate risk). The results obtained suggest that microplastic pollution poses environmental and health risks to the lagoon, aquatic organisms, and humans. As such, the lagoon required microplastic remediation and control.

This study aimed at quantifying the heavy metal levels in soils and vegetables sampled from five suburban regions of Nairobi, Kenya. Using inductively coupled plasma- mass spectrometry (ICP-MS) the metals were quantified from the samples. The assayed heavy metals including Cd, Cr, Co. Cu, Fe, Hg, Mn, Ni, Pb, Zn and the metalloid arsenic were elevated beyond the reference values in both soils and vegetables. High pollutant levels in soils were affiliated to use of industrial and domestic wastewater for irrigation, application of heavy metal containing agrochemicals and geogenic sources of the pollutants. In collard leaves, the uptake of contaminated water via the roots and subsequent accumulation in the leaves was attributable to the observed results. The total hazard quotient (THQ) and hazard index (HI) as a result of arsenic and Hg was >1 in all sampled sites and >10, respectively for both indices and heavy metals. Similarly, the cancer risk (CR) and target cancer risk (TCR) from consumption of collard was greater than the recommended levels of 10-6 and 10-4, respectively with exception of Pb. The indices were indicative of negative non-carcinogenic and carcinogenic effects of consuming the vegetables to the community of the study area. The results of the study, though preliminary, suggest the need to safeguard the health of communities in the study area to ensure that they do not consume heavy metal contaminated vegetables due to the established health effects of such pollutants.

This research aims at developing a new relation to estimate the urban runoffwater quality through urban land use. According to the first phase of this research, sixurban characteristics and land use indices have been defined concerning all parameterswith either direct or indirect impacts on urban water quality: Population, land use type,meteorological factors, local physiographical parameters, urban patterns etc. have beenconsidered when developing the new indices. Three study areas, including different urbanland uses, have been selected in Tehran Metropolitan and urban drains maps andstructures have gone under study to determine the sampling points. Multi-statisticalanalysis, discriminate analysis, and multi-linear regression analysis have been applied forall water quality results and urban indices in each site, with the results revealing verystrong relations between urban land use and water quality variation. Temporarypopulation especially in downtown site has proved to be an effective temporal factor onhow even public transport could not have any significant effects, in case populationdensity has no significant influence on water quality, as all sanitary waste water inselected sites is collected through urban wastewater systems separately. General slop is asignificant factor in hydrocarbons and heavy metals, once they are not alongside thestreets route. All told, this paper recommends reusing urban drained runoff locally beforejoining other regions’ collectors. Here in urban drainage system, collection andaggregation of water could not be an appropriate factor in water quality managementunlike river systems. The model could be employed in urban local water consumptionmanagement in irrigation and public recovery.

In the present investigation, coagulation-flocculation and fenton process in conjunction with phytoremediation by water hyacinth (Eicchornia crassipes) were applied to treat the most frequently occurred contaminants in textile wastewater. The mean values of EC, TDS, turbidity, pH, DO, BOD, COD and TOC in the raw effluents were 2300 μSCm-1, 1260 mgL-1, 48.28 FTU, 10.5, 1.2 mgL-1, 265 mgL-1, 522 mgL-1 and 12.8 mgL-1, respectively whereas the average concentration of Cr, Pb, Mg, Cu, Ni and Zn was 0.86, 1.21, 10.97, 0.47, 2.85 and 0.52 mg/L, correspondingly which evidently indicated that the effluents were highly contaminated compared to Bangladeshi standard. The results demonstrated that the values of EC, TDS, turbidity, pH, BOD, COD and TOC reduced significantly compared to raw effluents by both coagulation-flocculation and fenton processes and meet the standards set by BDS-ECR except BOD and DO. After being treated the COD value reduced to 70 mg/L (86.56%) and 188 mg/L (63.985%) from its initial concentration by coagulation-flocculation and fenton process, respectively on the other hand TOC removal efficiency by coagulation- flocculation process was 97.8125%, significantly greater than fenton methods where removal efficiency was 63.9%. However, the BOD removal efficiency by both treatment processes was ~50% which was not satisfactory compared to local standard. Interestingly, the concentration of DO increased substantially by both coagulation-flocculation (1.2 to 4.4 mg/L) and fenton process (1.2 to 3.85 mg/L). In case of trace elements removal, the combination of coagulation-flocculation-water hyacinth and fenton-water hyacinth show promising results where the removal efficiency of coagulation-flocculation-water hyacinth and fenton-water hyacinth was 24%-76% and 17%-76.36%, respectively. Therefore, it can be concluded that coagulation-flocculation-water hyacinth combination is better than fenton-water hyacinth combination in terms of trace metals removal. Textile effluents treatment and management is considered as one of the most significant issues in Bangladesh herein based on the this study, combination of chemical and phytoremediation technologies could be a promising sustainable low cost alternative for Bangladesh’s textile industrial sector.

The advent of advanced features of soft computing can be used to solve complex problems which are more non-linear and messy. Many of the applications have been analysed and validated by the researchers through soft computing approach in the past.Neural Networks (NN) with appropriate selection of training parameters is implemented apart from conventional mathematical model. In this paper, analysis is made on the estimation of PM10 air quality in selected regions of Chennai district by wavelet approach with energy spectrograms. After analysing the results, NN of multilayer feed forward back propagation algorithm forecasts the air quality of selected regions. Discrepancies in selecting the training parameters of NN’s have been overcome by trial and error basis. This work will be helpful in proving the powerful tool of NN to forecast short term nonlinear parameters and the predicted results will give us the clear design of existing problem and thecontrol measures need to be implemented.

Significant attention has been given to nanotechnology as an emerging approach in water/wastewater treatment for heavy metals removal. Numerous research works on synthesizing, fabrication and upgrading nanoparticles have reported as an efficient adsorbent in removal of wide range of heavy metals from wastewater. This review intends to provide researchers with understanding and knowledge regarding the efficient nanoadsorbents, their adsorption mechanism towards selected heavy metals and fundamental principles of nanoadsorbent materials synthesis. In addition, further attention on the modification of nanoadsorbent and development of nanocomposites are highlighted in this paper as value added products to increase the adsorption capacity and enhance the heavy metals removal. Possible challenges and direction on utilization of nanocomposites for heavy metal removal in real wastewater effluent are discussed in view of their removal capability and cost efficiency. Future research works on developing a cost-effective way of nanocomposite production and toxicity testing of nanomaterials in wastewater applications are recommended. Further studies on the efficiency of the nanoadsorbents in pilot or industrial scale are highly needed to test the practicality of the nanoadsorbents for selected heavy metals removal from real wastewater.

The aim of this paper is to assess the radon concentration of surface and ground waters around Bismuth mining site located in Edu, Kwara State, Nigeria, in order to ascertain its radiological risk. Seventeen (17) water samples were collected and analyzed for radon concentration using a calibrated Rad7-Active Electronic Detector Durridge. The Radon concentration for surface water ranged from 16.23±3.45 Bq/l to 24.71±4.51 Bq/l with a mean of 19.14±3.98 Bq/l while that of ground water ranged from 21.59±3.29 to 27.93±5.74 Bq/l with a mean of 24.16±4.21 Bq/l. The concentration results were used to estimate the annual effective doses. The mean total annual effective dose obtained by summing the dose due to inhalation and ingestion for surface water samples were 187.97 μSvy-1, 257.84 μSvy-1 and 292.77 μSvy-1 for adult, children and infants respectively. Also, the mean effective doses for ground water samples were of 237.25 μSvy-1, 325.44 μSvy-1 and 369.53 μSvy-1 for adult, children and infants respectively. Both the radon concentration and the effective dose due to its inhalation and ingestion were higher than the recommended limit of 11.1 Bq/l and 100 μSvy-1 respectively for all samples. Therefore, consumption of the water in this area poses serious health risk as the water is not safe for all age groups considered. Therefore, it is advised that the water from both sources be treated before consumption.

This study aims at assessing the health-related risk of As, Co, Cr, Ni, and Cu in the soil around Angouran Mineral Processing Complex (AMPC), due to environmentally sensitive nature of the area, having agricultural activities, habitats of animal and plant species, and industrial activities integrated with each other. Soil samples have been collected from 74 points (0-20 cm) of the area and concentrations of heavy metals have been measured, using ICP-OES. The Geoaccumulation Index (Igeo), Enrichment Factor (EF), and Integrated Pollution Index (IPI) have been used to examine the pollution level. Moreover, hazard indices (HI), hazard quotient (HQ) and cancer risk (CR) have been utilized to assess the non-carcinogenic and carcinogenic health risks of heavy metals. The average concentration of heavy metals indicates that metals’ concentration in the soil have increased in the following order: Cr = Ni> As> Cu> Co. Results from Igeo, Ef, and IPI show that As and Ni are placed in the very high pollution category. The non-carcinogenic risk of dermal absorption (adults = 1.30 E + 00, children = 1.35 E + 00) of Cr and Co polluted particles turn out to be very high. In addition, the risk of cancer as a result of the ingestion of As- and Cr-contaminated soil particles is high in both of age groups, with children being 68% more likely to be at risk of cancer than adults. Therefore, actions such as soil remediation should be done to reduce the risk of exposure and protect the health of the residents, especially the farmers.

Energy recovery is a sustainable method of municipal solid waste (MSW) management. The co-incineration of refuse derived fuel (RDF) has shown several economic and environmental advantages. The objective of this research is to assess the impact of RDF recovery on leachate quality using leachate tests and calculation of greenhouse gases (GHG) reduction in the kilns of a cement plant. The qualitative results of the eluate show that there is an impact on leachate quality depending on the type of waste. The values of the chemical oxygen demand (COD), biological oxygen demand (BOD5), electrical conductivity and pH of the leachate from the raw waste after 120 hours of leaching are 29.33 gO2/kg DM, 14.00 g O2/kg DM, 4.27 ms/cm and 7.57. On the other hand, the values of the same quality parameters of the eluate generated by the waste without RDF are 19.33 g O2/kg DM, 20.67 g O2/kg DM, 2.77 ms/cm and 7.13; respectively. The calculation of GHG reduction shows that the substitution of 83,000 tonnes per year of petroleum coke by 15% of RDF (25,493 tonnes per year) can reduces 28,970 tCO2 eq.

In this study, efficiency of humic acids (HAs) derived from various sources to reduce CrVI in aqueous solutions was compared. HAs were extracted from leonardite, peat moss, peat, cocopeat, coal, common char, biochar, vermicompost and sewage sludge. Some chemical and spectral characteristics of the extracted HAs were measured. Then, the reducing efficiency of HAs was measured and its relationship with the determined properties was investigated. To measure the reducing efficiency of HAs, a concentration of 0.1 mM CrVI (as potassium dichromate) in a sodium nitrate solution (0.03M) with a pH of 2 and in the presence of 100 mg of HA per liter was used. The experiment was conducted in three ways (symbolized by E1, E2 and E3). They differ from each other with respect to the method of phosphate buffer addition to release CrVI ions adsorbed by HA. This buffer was added to an aliquot of final extract, to the whole volume of final suspension and to initial solution containing CrVI in experiments E1, E2 and E3, respectively. According to the results, the CrVI reducing efficiency depends not only on the nature of HA but on the method of experiment. The minimum reducing efficiency was observed for common char using experiment E2 and the maximum value was for biochar and cocopeat in all three experiments. The results showed that the two factors of ΔlogK and maximum reducing efficiency in the format of a multiple regression had a significant relationship with CrVI reducing efficiency of HAs.