Today, the problem of air pollution has been highlighted by rapid population growth and urbanisation, along with the development of industry. Over the last fifty years, much attention has been paid to the relationship between lichens and airborne particulate matter (especially heavy metals). The use of living organisms in air pollution studies is now widely accepted in many countries and the results of these biomonitoring studies are very important for future action. The goal of this study was to determine heavy metals in Kırşehir province using the bag technique, a biomonitoring approach, with Pseudevernia furfuracea (L.) Zopf lichen and to develop a pollution map of the city. In November 2002, lichen specimens were obtained from an unpolluted region in the Yapraklı Mountains, Çankırı, and transplanted to 4 distinct places in Kırşehir. After 3 and 6 months of exposure, they were collected in order to analyse heavy metals (Cu, Cd, Mn, Ni, Pb and Zn) with Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). In addition, chlorophyll-a and chlorophyll-b contents were determined by Dimethyl sulfoxide (DMSO) method. The findings revealed that the heavy metal contents in various stations are the result of industrial, traffic, and heating activities. As a result, P. furfuracea showed excellent bioindicator ability for detecting air pollution.

Environmental pollution has become and increasing concern due to growing risk to human health. Soil pollution is an aspect of environmental pollution that has received comparatively less attention than water pollution. However, considering direct effects of contaminants transmission through ingestion to the human body, it can lead to greater risks for human health. Arsenic is a highly prevalent environmental pollutant, and considerable number of people worldwide suffer from constant exposure to it. While there are several ways to manage and remediate contaminated soils, phytoremediation has been paid special attention due to its higher social acceptability and lower cost. Nevertheless, this approach faces challenges, including effectively handling significant quantities of contaminated biomass, managing it appropriately, and selecting suitable plant species for the remediation process. In this regard, numerous endeavors have been undertaken to tackle these obstacles like strategies encompass the utilization of amendments, adept management of biomass, and the implementation of hybrid remediation approaches. This study aims to review prior research on mechanisms, challenges, and enhanced phytoremediation of arsenic-contaminated soils, encompassing reduction of contaminated biomass after phytoremediation.

Heavy metals contamination of rainwater is a function of the adsorbed metals present in the particulates of the atmosphere in which the rain was formed from and rainwater chemistry is an alternative way of monitoring urban air pollution for predominant metal species. Three distinct sampling sites (residential, industrial and commercial) were investigated in the south western part of Nigeria for one year. After acid digestion, quantification was done using a double-beam Atomic Absorption Spectrophotometer (AAS). The obtained results showed that heavy metals were predominantly present as free metal ion in the commercial and industrial areas but Mn and As mainly occurred in the suspended fraction. Residential area presented major fractions as bound to organic complexes except Cu and Cd which were principally available as suspended fraction. The health risks associated with the intake of the studied rainwaters indicated susceptibility to possible carcinogens upon consumption due to total RI > 10-4. Ecological risk assessment equally shown a very high level of ecological risks related with the metals due to RI ˃ 600. Sequel upon this, there is need for better sensitization of the citizenry to the sources and control of these pollutants.

Two fly ashes from municipal solid waste incineration were selected to study their heavy metal leaching behavior. The main purpose of this research is to investigate the characteristics of fly ashes and compare the leaching of heavy metals in different leaching environment. pH and acid neutralization capacity analysis showed that fly ashes were highly alkaline. Fly ashes also contained a variety of heavy metals including Pb, Cu, Cr, Zn, Cd and Ni etc. Leaching studies showed that the alkalinity of fly ashes raised the pH of leaching solution from acidic to basic. Ni, Cu and Zn were strongly bound to ashes and manifested low leaching. In contrast, Cr and Cd had high mobility but their leaching was inhibited by the low solubility of carbonate Cr and Cd. Pb was highly leachable in the alkaline environment with concentration in the leaching solution reached as high as 9.74 mg/L. In addition, the presence of EDTA in the environment also increased leaching. Pb concentration was raised to 16.63 mg/L. This could be attributed to the chelating capacity of EDTA which means that the presence of organics in natural environment should be taken into consideration.

Laboratory wastewater is categorized as hazardous waste that should not be released into the environment since it poses a serious threat to environmental safety. In the present study, the use of Sulphate-Reducing Bacteria (SRB) colonies in an anaerobic reactor to treat heavy metals-containing laboratory wastewater was examined. SRB was initially cultivated with the treatment of fermented compost and Postgate's medium before being attached to the laboratory-size anaerobic reactor to treat laboratory waste containing heavy metal. Within the 15 days of initial incubation under the room temperature of 28 °C, we discovered that SRB optimally grew on the medium with the composition of 5% Postgate B solution, 30% fermented compost liquid, and 5% active suspension liquid, with a total population of cell colonies was 1.2 x 105 CFU/ml. After SRB colonies from the most optimum medium were affixed to the reactor, the reactor attained 89% of lead (Pb) removal, 69.78% of iron (Fe) removal, and 48.93% of copper (Cu) removal for 15 days treatment periods. On the 21st days of treatment time, the removal efficiency increased significantly to 91.57%, 78.09%, and 83.56% of Pb, Fe, and Cu removed, respectively.

In this study, the concentrations of heavy metals were studied using atomic absorption spectroscopy of samples from the sediments of the Tigris River within the boundaries of the city of Mosul, northern Iraq, and the environmental parameters of heavy metals were calculated. The results showed that the average concentrations of Co, Cu, Cd, Pb, Zn, and Ni in (ppm) were (8.78, 30.42, 0.179, 12.04, 75.53, and 144.75), respectively, where these results were higher than the international accepted average. It indicates that the main factor in the high concentrations of heavy metals in the environment of the Tigris River in the city of Mosul is the pollution caused by human activities. The results of the environmental treatments for the studied heavy metals showed that the values of the enrichment factor (EF) were moderately contaminated with Cu, Cd, Ni, and Zn and not contaminated with Co and Pb. The value of the contamination factor (CF) for the sediments of the Tigris River in the studied areas showed that the sediments of those areas are moderately polluted with Co, Ni, and Zn metals. The degree of contamination (Cdeg) for the sediments of the study area in general ranges from low - medium pollution, the pollution load index (PLI) average of (1.03) showed that the sediments of the study area were contaminated with heavy metals. Therefore, we conclude that the environment of the Tigris River is polluted with heavy metals, but it is not at the level that causes concern at present.

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.

This study aims to assess the pollution of honey by heavy metals based on the efforts of an urbanization gradient in the city of Annaba (Northeast Algeria) where the dosage of five heavy metals (Fe, Cr, Ni, Cu, Cd) was carried out in four sites.The level of heavy metals was determined by atomic absorption spectrophotometer. The results obtained indicated that even when all the samples were contaminated they were of good quality since the concentrations did not exceed the international standards.According to the results of heavy metal concentrations in the honeys studied, the most abundant element is Fe with an average concentration of 6.956 ± 2.045 (mg/kg), Cr 0.765 ± 0.197 (mg/kg), Ni 0.6005 ± 0.159 (mg/kg), Cu 0.21025 ± 0.065 (mg/kg) and Cd 0.01425 ± 0.005 (mg/kg).The heavy metals studied are present in all samples but trace amounts. Moreover, the comparison of the honey from the four sites indicates to us that the healthiest honey is that of the urban site.

In this research, the capability of vermiculite in arsenic extraction, associated with characterizing its main properties was evaluated. To address this purpose, vermiculite was artificially contaminated with arsenic at 7 and 28-day intervals. Then, arsenic was extracted from contaminated soils by different extractants. Various physical and mechanical tests were performed to investigate the effect of arsenic as an anionic contaminant on the properties of the vermiculite, as well as to evaluate how the properties of the contaminated soil were altered by the extraction process. The carbonate bonding phase was probably mainly responsible for the adsorption and fixation of arsenic with more than 50% portion among measured fractions at different curing times. Based on the vermiculite condition, hydrochloric acid was the best extractant for removing arsenic in all studied samples (around 3 -18 % more than other extractants). The clay soil demonstrated few changes due to arsenic contamination and modification. In general, the most promising characteristics of vermiculite as clay liner are its stability after contamination due to high CEC and SSA; however, its workability and strength (UCS between 110 to 220 kPa at different soil conditions) is a challenge and must be improved by adding coarser fractions like silt particles. In general, the results of this study regarding the effects of arsenic contamination and extraction onto vermiculite’s physical properties can provide appropriate information for researchers and geo-environmental engineers.

The present study attempts to investigate some blood parameters of Otolithes ruber during different seasons in terms of both temperature and pollution. For so doing it uses 10 specimens, for each station and season, collected from 5 polluted stations, including Petrochemical, Ghanam, Zangi, Douragh, Patil, and Sajafi as the control group, away from pollution in Musa Creek. The fish are anesthetized with 1ml of clove extract per liter. Their blood samples are taken immediately from the caudal vein, using a heparinized syringe. Afterwards, the serum is separated in a centrifuge with a speed of 6000 rpm for 2 minutes. The desired factors are measured by the Mindray BS200 auto-analyzer and the total protein level, by Bradford's usual laboratory methods. Results show that AST, ALT, ALP, Glucose, and Triglycerides have increased in more polluted stations (P≤0.05). In sheer contrast, total protein and Albumin have decreased as pollution grows (P≥0.05). According to this study, environmental water pollution of the fish has a large impact on the concentration of measured blood parameters, whereas the influence of seasonal changes on most of them is low.