The ability of biologically based wastewater treatment systems to remove emerging organic contaminants—a review

Biologically based wastewater treatment systems are considered a sustainable, cost-effective alternative to conventional wastewater treatment systems. These systems have been used and studied for the treatment of urban sewage from small communities, and recently, it has been reported that they can also effectively remove emerging organic contaminants (EOCs). EOCs are a new group of unregulated contaminants which include pharmaceutical and personal care products, some pesticides, veterinary products, and industrial compounds among others that are thought to have long-term adverse effects on human health and ecosystems. This review is focused on reporting the ability of biologically based wastewater treatment systems to remove EOCs and the main elimination mechanisms and degradation processes (i.e., biodegradation, photodegradation, phytoremediation, and sorption) taking place in constructed wetlands, ponds, and Daphnia and fungal reactors.     

Little Egret (Egretta garzetta) as a bioindicator of trace element pollution in Tunisian aquatic ecosystems

The Little Egret, Egretta garzetta, has breeding colonies in the island of Chikly (in the lake of Tunis) and in Thyna saltpans (in the gulf of Gabès), two important Tunisian wetlands that are strongly affected by anthropogenic activity. Here, we used E. garzetta chick feathers for environmental monitoring of breeding grounds of this species. Since trophic ecology is fundamental when interpreting contamination levels, our approach combined both trace-element (Hg, Pb, Cd, and Se) and stable-isotope analysis of ??¹³C, ??¹⁵N, and ??³⁴S. Hg, Se, and ??¹⁵N levels were higher in specimens collected on Chikly than in Thyna. These observations highlight the degree of eutrophication of the lake of Tunis. Yellow-legged gulls (Larus michahellis) breeding in the same areas also feeds in the lake and attains similar concentrations of Hg and Se. In Thyna, egrets and gulls exploit distinct foraging habitats, as demonstrated by stable isotope analysis. The highest Hg and Se concentrations were found in Thyna. This result is consistent with greater exploitation of marine resources from the gulf of Gabès.     

SEDIMENT AND NITROGEN TRANSPORT IN GRASS FILTER STRIPS1

ABSTRACT: An 18-month field experiment was conducted to evaluate the effectiveness of grass filter strips in removing sediment and various nitrogen species from runoff. Runoff was collected from six 3.7 m wide experimental plots with 24.7 m long runoff source areas. Two plots had 8.5 m filters, two plots had 4.3 m filters, and two plots had no filters. Runoff was analyzed for total suspended solids (TSS), total Kjeldahl nitrogen (TKN),. filtered TKN (FTKN), NH₄⁺-N, and NO₃-N. The Mann-Kendall nonparametric test for trend (changes in filter effectiveness over time) indicated that there were no trends in the yields and concentrations of TSS, NO₃^--N, NH₄-N, TKN, and FTKN for the 8.5 m filter over time. For the shorter 4.3 m filters, there were significant upward trends in TKN yield and downward trends in TSS, NH4-N, and FTKN concentrations, indicating that trapping efficiency may have started changing with time. The Kruskal-Wallis test indicated that the 8.5 m filters reduced median yields and concentrations of TSS and all N species, but the 4.3 m filters only reduced the median yields and concentrations of TSS, NH₄⁺-N, TKN, and the median concentration of FTKN. The 8.5 and 4.3 m filters reduced contaminate yields and concentrations from 42 to 90 percent and from 20 to 83 percent, respectively.     

Assessment of heat-inactivated marine Aspergillus flavus as a novel biosorbent for removal of Cd(II), Hg(II), and Pb(II) from water

Environmental Science and Pollution Research - A novel marine fungus was isolated and classified as Aspergillus flavus strain EGY11. The heat-inactivated form of isolated Aspergillus flavus was...     

Flocculation of metals during mixing of Siyahrud River water with Caspian Sea water

Flocculation of dissolved Cu, Mn, Ni, Zn, and Pb during mixing of Siyahrud River water with water sample of Caspian Sea at nine different salinity regimes was investigated. The maximum flocculation of elements occurs in the salinities 1.67‰ to 3.67‰ (except for Zn). The flocculation trend of Zn (80.9) >Mn (58.3) > Cu (30.5) > Ni (25.9) > Pb (19.5) indicates that flocculation of metals have nonlinear behavior towards salinity changes during estuarine mixing. Electrical conductivity shows a linear behavior in different proportions of salinity which is in contrast with the behavior of other studied parameters. Cluster analysis indicates that pH and NO(3) are governing factors in the flocculation of Cu, Mn, and Pb. The results of this research show that 80.9%, 19.5%, 25.9%, 30.5%, and 58.3% of dissolved Zn, Pb, Ni, Cu, and Mn flocculate during estuarine mixing. Total amount of studied dissolved element flowing in to the Caspian Sea would decrease from 5.62 to 2.76?t/year.     

Small scale farmers’ vulnerability to climatic changes in southern Benin: the importance of farmers’ perceptions of existing institutions

Farmers in rural Africa use a number of adaptive strategies to cope with observed climatic changes and their impacts on agriculture. Most studies on adaptive capacity focus on socio-economic parameters (such as poverty or education), and few provide detailed analysis on the role played by different institutions at local level, and the effects of how these institutions are perceived on farmers’ adaptation. Semi-structured interviews were conducted among 46 households from seven villages in southern Benin (West Africa), and among representatives of several institutions at the local level. Half the participants were involved in Non Governmental Organizations (NGOs) development projects and half were independent farmers. Results indicate that independent farmers mostly use non-agricultural coping strategies (loans, work in town) while project farmers mainly use agricultural adaptive strategies (improved seed varieties). Lack of adaptive capacity of independent farmers is linked to weak State institutions at the local level. Due to their lack of efficiency and high corruption rates, local State representatives are mistrusted. NGOs are trusted and seek for help, even by independent farmers. Even if NGOs do not have climate change adaptation in their agendas, they promote activities, which help reduce farmers’ vulnerability. Although our results are limited to south-western Benin, they question the way adaptation is promoted today, for instance through the United Nations Framework Convention for Climate Change (through the National Adaptation Programmes of Action).     

α-Amylase and α-glucosidase inhibitor effects and pancreatic response to diabetes mellitus on Wistar rats of Ephedra alata areal part decoction with immunohistochemical analyses

Ephedra alata, known as a medicinal plant in China, was used in this study as aqueous extract from aerial parts, for diabetes mellitus treatment. This study was carried out on two parts, in vitro, we tested the effect of the studied extract on the inhibition of α-glucosidase and α-amylase activities, and in vivo on Wistar male rats receiving alloxan intraperitoneally at a rate of 125 mg/kg. Extract (100, 200, and 300 mg/kg of body weight) was administrated for 28 days by oral gavage. Blood glucose, amylase, lipase, and lipid profile level were determined. Oxidative stress was evaluated by enzymatic activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), and by estimation of lipid peroxidation and protein carbonyl (PC) level. Histopathological changes in pancreas were investigated under photonic microscopy using immunohistochemical procedure. Our findings showed that aqueous extract inhibited in vitro both α-glucosidase and α-amylase activities and its use in vivo at 300 mg/kg of body weight restored pancreas weight and weight gain, ameliorated significantly (p ? 0.05) biochemical parameters; it prevented the increase in lipid and protein oxidation and the decrease in enzymatic and non-enzymatic defense system. Histological study of treated animals showed a comparable healed regeneration of beta cells.

     

Removal of phenol from aqueous solution by coupling alternating current with biosorption

Environmental Science and Pollution Research - The present research was devoted to water decontamination through the valorization of cellulosic fibers for the preparation of performing biosorbent,...