Acid rain still poses a global problem today, exerting many adverse effects on man, animal, and materials. As its research question, the present study tries to find out whether or not acid rains exist in Akure, Nigeria. For so doing, it determines physico-chemical properties of rain water samples, namely pH, temp, Electrical Conductivity (EC), TDS, acidity, SO4-, NO2-, Cl-, and Free CO2. According to the results, the pH ranged between 6.0 and 7.8, never falling below 5.6 which is an indication of acid rain. Also, the minimum EC was 3µS/cm and the maximum, 201µS/cm. Moreover, TDS was between 1 and 100mg/L, while Free CO2 had a mean of 23.00 and Standard Deviation of 6.16. The dominant ion was SO4- (10-11%), followed by NO3-, and Cl-. Results from the first six months (July-December 2015) reveal slight correlations in the following: TDS with pH (0.532), EC and pH (0.501), Temp and Free CO2 (0.59), whereas strong correlations have been recorded in the following parameters: Acidity with pH (0.71) and Temperature (0.69), NO2- with pH (0.96) and acidity (0.96), SO4- with temp (0.68) and NO2- (0.83), and finally Cl-  with Free CO2 (0.61), NO2- (0.73), and Cl- (0.65). It can be concluded that in the environment under this study there have been no acid rain within the period.

The effluent treatment plant sludge is one of the major sources of contamination with toxic metals. Since the sludge contains heavy metals, it must be pretreated to reduce the contamination. The heavy metals from the sludge can be reduced/ separated by washing it with a suitable leaching solution. In the present study, the efficiencies of three leaching solutions to remove the contaminants from an industrial sludge were studied and the leaching process was modeled. The leaching solutions used are 0.1 N HCl, 0.1 N EDTA and 0.1 N FeCl3. The efficiencies of leaching solutions were assessed by conducting column leaching experiments on the sludge and the migration rates of heavy metal ions of Cu, Zn, Ni, Cd, Pb, Fe and Cr present in the sludge were estimated. These migration rates are useful to estimate the quantity of leaching solution required at the site to achieve the required levels of concentrations in the sludge.

Macrolitter, especially macroplastics, (> 0.5 cm) negatively impact freshwater ecosystems, where they can be retained along lake shores, riverbanks, floodplains or bed sediments. Long-term and large-scale assessments of macrolitter on riverbanks and lake shores provide an understanding of litter abundance, composition, and origin in freshwater systems. Combining macrolitter quantification with hydrometeorological variables allows further study of leakage, transport, and accumulation characteristics. Several studies have explored the role of hydrometeorological factors in influencing macrolitter distribution and found that river discharge, runoff, and wind only partially explains its distribution. Other factors, such as land-use features, have not yet been thoroughly investigated. In this study, we provide a country-scale assessment of land-use influence on macrolitter abundance in freshwater systems. We analyzed the composition of the most commonly found macrolitter items (referred to as ‘top items’, n = 42,565) sampled across lake shores and riverbanks in Switzerland between April 2020 and May 2021. We explored the relationship between eleven land-use features and macrolitter abundance at survey locations (n = 143). The land-use features included buildings, city centers, public infrastructure, recreational areas, forests, marshlands, vineyards, orchards, other land, and rivers and canals. The majority of top items are significantly and positively correlated with land-use features related to urban coverage, notably roads and buildings. Over 60% of top items were found to be correlated with either roads or buildings. Notably, tobacco, food and beverage-related products, as well as packaging and sanitary products, showed strong associations with these urban land-use features. Other types of items, however, did not exhibit a relationship with land-use features, such as industry and construction-related items. Ultimately, this highlights the need to combine measures at the local and regional/national scales for effective litter reduction.

Contracting Parties to the OSPAR Convention for the Protection of the Maine Environment of the North-East Atlantic are required to undertake monitoring and assessment of both inorganic and organic contaminants. There is a requirement to assess contaminants across different trophic levels on an ecosystem-specific basis. However, this is currently constrained by the availability of relevant samples to cover the full range of trophic levels. This study investigates the variability (inter- and intra-species variation) of the concentrations and distributions of thirty-two polychlorinated biphenyl (PCB) congeners and nine polybrominated diphenyl ether (PBDE) congeners in twenty-six species covering four trophic levels from different geographic locations around Scotland. Trophic magnification factors (TMFs) were calculated using a traditional method and a balanced method for both the ICES-7 PCBs and BDE47, to refine and improve the application of TMFs to assess and predict biomagnification risk to biota in the marine environment. There were clear differences in congener percentage distribution between sample categories and species, with differences influenced by physiological processes and eco-biological parameters. Trophic magnification was found to occur for the ICES-7 PCBs and BDE47 using the traditional method, with the highest degree of trophic magnification reported for CB52. An unbalanced dataset was found to influence the calculated TMF and in some cases, the overall conclusion of the trophic transfer of PCB and PBDE congeners. The balanced method is highly recommended for calculating TMFs to ensure that the TMF is a true indication of the biomagnification potential, particularly when conducting regional comparisons for which sampling requirements are difficult to achieve.

Although effluent from municipal wastewater treatment plants (WWTPs) is a major stressor in receiving environments, relatively few studies have addressed how its discharge affects natural fish communities. Here, we assessed fish community composition over three years along a gradient of effluent exposure from two distinct WWTPs within an International Joint Commission Area of Concern on the Great Lakes (Hamilton Harbour, Canada). We found that fish communities changed with distance from both WWTPs, and were highly dissimilar between sites that were closest to and furthest from the wastewater outfall. Despite differences in the size and treatment technology of the WWTPs and receiving habitats downstream, we found that the sites nearest the outfalls had the highest fish abundances and contained a common set of signature fish species (i.e., round goby Neogobius melanostomus, green sunfish Lepomis cyanellus). Non-native and stress tolerant species were also more abundant near one of the studied WWTPs when compared to the reference site, and the number of young-of-the-year fish collected did not vary along the effluent exposure gradients. Overall, we show that fish are attracted to wastewater outfalls raising the possibility that these sites may act as an ecological trap.

Increasing interest of seeking substitutable water resources accrues from shortage of freshwater. One of the options considered is reclaimed water (also designated as recycled water) that has been widely used in daily life. Although reclaimed water can serve as a feasible reliever of water pressure, attention about its technologies and potential risks is growing in the meantime. Most established wastewater treatment plants (WWTPs) predate many new contaminants, which means treatment processes cannot ensure to dislodge certain contaminants completely from origin water. Furthermore, a wide range of factors, such as seasons and influent variations, affect occurrence and concentration of reclaimed water-borne contaminants, making research about quality of reclaimed water especially significant. Many reclaimed water-borne contaminants, including biological and chemical contaminants, are toxic to human health, and complex wastewater matrix may aggravate water quality of concern. The widespread use of reclaimed water continues to be a concern on agriculture, ecological environment and human health. This study aims to: 1) provide a critical review about occurrence and profiles of diverse contaminants in the treated reclaimed water, 2) discuss the possibility to avoid the secondary pollution in reuse of reclaimed water, and 3) reveal the prospective consequences of using reclaimed water on agriculture, ecological environment and human health.