Monitoring and assessment of heavy metal/metalloid concentration by inductively coupled plasma mass spectroscopy (ICP-MS) method in Gonyeli Lake,Cyprus

The presence of heavy metals/metalloids in the ecosystem has been an increasing ecological and global public health concern due to their potential to cause adverse health effects. For this reason, the accumulation of some heavy metals such as Cr, Mn, Ni, Cu, As, Cd, Pb was assessed by way of ICP-MS in water, sediment and fish (Cyprinus carpio) sampled from Gonyeli Lake, North Cyprus. The results showed that these metals/metalloids are found widespread throughout the study area. In water, most concentrated element was manganese with 92.1 ppb and least concentrated was lead with 0.914 ppb. In sediment, copper had the highest concentration with 613 ppm, and cadmium the lowest with 1.57 ppm. In fish tissues (muscle and gills), the most concentrated element was manganese with 12.5 ppm and the least concentrated cadmium with 0.017 ppm. These results indicate that future remediation efforts are indispensable for the rehabilitation of the lake.     

Monitoring bacterial contamination of piped water supply in rural coastal Bangladesh

Safe drinking water is scarce in southwest coastal Bangladesh because of unavailability of fresh water. Given the high salinity of both groundwater and surface water in this area, harvested rainwater and rain-fed pond water became the main sources of drinking water. Both the government and non-government organizations have recently introduced pipe water supply in the rural coastal areas to ensure safe drinking water. We assessed the bacteriological quality of water at different points along the piped water distribution system (i.e., the source, treatment plant, household taps, street hydrants, and household storage containers) of Mongla municipality under Mongla Upazila in Bagerhat district. Water samples were collected at 2-month interval from May 2014 to March 2015. Median E. coli and total coliform counts at source, treatment plant, household taps, street hydrants, and household storage containers were respectively 225, 4, 7, 7, and 15 cfu/100 ml and 42,000, 545, 5000, 6150, and 18,800 cfu/100 ml. Concentrations of both of the indicator bacteria reduced after treatment, although it did not satisfy the WHO drinking water standards. However, re-contamination in distribution systems and household storage containers indicate improper maintenance of distribution system and lack of personal hygiene.     

Effects of multi-metal toxicity on the performance of sewage treatment system during the festival of colors (Holi) in India

The present study investigated the effects of heavy metals (Ni, Zn, Cd, Cu, and Pb) toxicity on the performance of 18 MLD activated sludge process-based sewage treatment plant (STP) during celebration of Holi (festival of colors in India). The composite sampling (n?=?32) was carried out during the entire study period. The findings show a significant decrease in chemical oxygen demand removal efficiency (20%) of activated sludge system, after receiving the heavy metals laden wastewater. A significant reduction of 40% and 60% were observed in MLVSS/MLSS ratio and specific oxygen uptake rate, which eventually led to a substantial decrease in biomass growth yield (from 0.54 to 0.17). The toxic effect of metals ions was also observed on protozoan population. Out of the 12 mixed liquor species recorded, only two ciliates species of Vorticella and Epistylis exhibited the greater tolerance against heavy metals toxicity. Furthermore, activated sludge shows the highest metal adsorption affinity for Cu, followed by Zn, Pb, Ni, and Cd (Cu?>?Zn?>?Pb?>?Ni?>?Cd). Finally, this study proves the robustness of activated sludge system against the sudden increase in heavy metal toxicity since it recovered the earlier good quality performance within 5?days.     

The Influence of Temperature on Chemical Fluid-Rock Reactions in Geological CO2 Sequestration

For a Bunter formation in the German Federal State of North Rhine Westphalia, we use numerical models to consider reactions between the supercritical, aqueous, and solid phases. These reactions may occur in a CO₂-water system representing a saline aquifer CO₂ storage scenario. Thus, the models are used for determining the extent of fluid–rock reactions during mineral dissolution or precipitation. In particular, we study the effect of temperature by comparing results for our system set at 100 °C and at 58 °C. Results show that the abundance of dissolved ions changes as a result of elevated temperature. For the entire 10,000-year simulation period, the overall geochemical behavior of the Bunter reservoir rock at the Minden site is explained in terms of different mineral transformations, although some of them are not changed significantly. This mainly comprises the alteration of carbonate minerals such as calcite, and aluminium silicates such as oligoclase, chlorite, illite, albite, kaolinite, and Na-smectite. Another chemical behavior derives from the generation and consumption of new secondary minerals such as dawsonite, pyrite, and Ca-smectite. In contrast to a system temperature of 58 °C, the mineralogical transformations of other minerals such as siderite, ankerite, dolomite, and magnesite are not observed at 100 °C. Also, the numerical simulation results show that at elevated temperature, the dominant role played by hydrodynamic mechanism dwarfs the role of other trapping mechanisms including dissolution and mineralization. Results also demonstrate how geological, petrophysical, and geochemical data can be integrated to estimate quantitatively the magnitude of the fluid–rock reactions. These reactions may entail new geotechnical problems, such as rock self-fracturing which ultimately decreases the CO₂ sequestration projects security.     

Mineral contents of the head, caudal, central fleshy part, and spinal columns of some fishes

In the experiment, mineral contents of the head, caudal, central fleshy part, and spinal columns of fishes were determined by inductively coupled plasma atomic emission spectrometry. The Ca content of base fleshy part ranged from 1,682 to 5,505 mg/kg. The Ca contents of central fleshy part were found between 104 and 428 mg/kg. This value was found between 5,582 and 7,368 in the spinal column parts. The K content in general ranged from 2,411 (Carassius gibellio) and 4,419 mg/kg (Scomber scombrus). The highest potassium was found on the central fleshy part and ranged between 3,214 and 4,419. The P content was found mostly on the bones and it range between 28,833 and 34,726. The least phosphor amount was found on the central fleshy part. While the Cd content ranges between 0.019 ppm and 0.104 mg/kg, Cr content changed between 1.32 and 4.20 ppm.     

Arsenic concentration variability, health risk assessment, and source identification using multivariate analysis in selected villages of public water system, Lahore, Pakistan

This paper reports high levels and variability in arsenic (As) levels at locations identified as one of the highest As-contaminated locations in Pakistan. Groundwater pollution related to arsenic has been reported since many years in the areas lying in outskirts of District Lahore, Pakistan. A comparative study is done to determine temporal variations of As from three villages, i.e., Kalalanwala (KLW), Manga Mandi (MM), and Shamki Bhattian (SKB). Seventy-three percent of the 30 investigated samples ranging in depth from 20 to 200 m, show an increasing trend in variations of As concentration over a time span of 4 years and 87 % of samples exceeded the WHO standard of 10 μg/L for As while 77 % of samples have As concentration >50 μg/L (national standard). Further results indicate that high levels of As is accompanied with increase pH (r?=?0.8) favoring desorption of As from minerals at higher pH under oxidizing conditions. For health risk assessment of arsenic, the average daily dose, hazard quotient (HQ), and cancer risk were calculated. The residents of the studied areas had toxic risk index in the order of SKB>KLW>MM, with 87 % of samples exceeding the typical toxic risk index 1.00 (ranging from 2.3–48.6) which was 83 % (ranging from 0.3–41) 4 years before. The results of the present study therefore indicate that arsenic concentrations are increasing in the area, which needs an immediate attention to provide alternate sources of water to save people at risk.     

Determination of heavy metal contents in some freshwater fishes

The concentrations of heavy metals in tench, pike-perch, and common carp fish caught in four different seasons from Damsa dam lake (Nev?ehir) were determined. Heavy metal contents of fishes changed depending on seasons. The highest Al (20.894 mg/kg) in tench was established in winter, and the lowest Al (1.605 mg/kg) was determined in summer. Fe content of tench fish changed between 112.906 mg/kg (autumn) and 31.207 mg/kg (spring). In addition, Zn contents of tench were found between 36.0323 mg/kg (summer) and 430.586 mg/kg (winter). The results indicate that concentrations of Cu of tench varied from 0.1934 mg/kg (winter) to 15.422 mg/kg (autumn). Results indicate that concentrations varied from 2.923 mg/kg (autumn) to 32.078 mg/kg (summer) with a mean of 11.1893 mg/kg for Al; 0.2483 mg/kg (spring) to 3.3088 mg/kg (autumn) with a mean of 1.6189 mg/kg for Ni; 0.5325 mg/kg (spring) to 0.845 mg/kg (autumn) with a mean of 0.7234 for Pb; and 7.0464 mg/kg (winter) to 253.686 mg/kg (summer) with a mean of 133.6348 for Zn. In common carp, Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn, Se, Ga, and Te contents were determined as 3.9623 mg/kg; 0.1293, 0.2336, 0.0526, 0.1543, 4.2406, 0.726, 1.797, 0.6216, 6.8536, 0.1783, 0.7876, and 0.371 mg/kg in autumn, respectively.     

Optimal water and waste-load allocations in rivers using a fuzzy transformation technique: a case study

In this paper, a new methodology is developed for integrated allocation of water and waste-loads in river basins utilizing a fuzzy transformation method (FTM). The fuzzy transformation method is used to incorporate the existing uncertainties in model inputs. In the proposed methodology, the FTM, as a simulation model, is utilized in an optimization framework for constructing a fuzzy water and waste-loads allocation model. In addition, economic as well as environmental impacts of water allocation to different water users are considered. For equitable water and waste load allocation, all possible coalition of water users are considered and total benefit of each coalition, which is a fuzzy number, is reallocated to water users who are participating in the coalition. The fuzzy cost savings are reallocated using a fuzzy nucleolus cooperative game and the FTM. As a case study, the Dez River system in south-west of Iran is modeled and analyzed using the methodology developed here. The results show the effectiveness of the methodology in optimal water and waste-loads allocations under uncertainty.