Efficacy of natural biocide on control of microbial induced corrosion in oil pipelines mediated by Desulfovibrio vulgaris and Desulfovibrio gigas

We compared the efficacy of a natural biocide with four chemical tetrakishydroxymethyl phosphonium sulfonate, benzyl trimethyl ammonium chloride, and formaldehyde, glutaraldehyde, to control microbial induced corrosion in oil pipelines. The efficacy of biocides were monitored against Desulfovibrio vulgaris and Desulfovibrio gigas in experimental pipes by measuring cell counts, H2S production, Fe(II) production, production of extracellular polymeric substances and structure of biofilm. The treatment with cow urine had minimum planktonic cell counts of 3 102 CFU/mL as well as biofilm cell counts of 9 101 CFU/mL as compared with tetrakishydroxyl methyl phosphonium sulfonate, benzyl trimethyl ammonium chloride, formaldehyde and glutaraldehyde. Sulfide production was the lowest with cow urine (0.08 mmol/L), followed by tetrakishydroxymethyl phosphonium sulfonate 0.72 mmol/L. On day 90 of treatment, Fe(II) production was also found to be the lowest with cow urine. The scanning electron microscopic studies indicated that the biofilm bacteria were killed by cow urine. These results demonstrate the cow urine mediated control of microbially induced corrosion, and this is indicative of its potential as a viable substitute of toxic biocides. To the best of our knowledge, this seems to be the first report which screens possible biocidal activity by cow urine as compared to the most common biocides which oil industry is currently using.     

Impact of Fly Ash from Coal-Fired Power Stations in Delhi, with Particular Reference to Metal Contamination

Indraprastha Power Station (IPP Stn) and Rajghat Power House (RPH), owned by Delhi Electric Supply Undertaking, are both coal-fired power stations located on Ring Road in New Delhi. Ash content of the coal used ranges between 38–47%. The ash is collected in electrostatic precipitators which have an efficiency of 99.3% (IPP station), and 99.7% (RPH). There are instances of major dust pollution around the power stations from fly ash dispersal. The main method of disposal of fly ash from the power stations is by mixing with water, the resultant slurry is pumped through pipes to ash disposal ponds. The supernatant from these ponds is discharged into River Yamuna. Field studies have revealed large quantities of fly ash being deposited into the river. Local populations of Eichhornia crassipes have reduced dramatically between 1987–1995, with a marked reduction in the year 1994–1995. Field studies, conducted in January, 1995 have investigated the impact of fly ash dispersal in the Delhi region with particular reference to metal contamination. Elemental concentrations for a range of elements are determined by ICP-AES in fly ash and top soils along four transects from the power stations up to a distance of 8 km. The effects of fly ash leachates from the ash settling ponds on the river are determined by analyzing river overbank soils and vegetation for their elemental contents. It is concluded that fly ash dispersal from the stacks are a source of alkali, alkaline-earth and to some extent heavy metals in soils in the vicinity of the power stations, and enrichment of elements in river overbank soils are a result of discharge of fly ash leachates from ash disposal ponds. However, the impact from both these sources of metal contamination is not large enough to give cause for concern. Marked reduction in populations of Eichhornia crassipes downstream of the river where it receives leachates from the ash disposal ponds are attributed to turbidity of the ash pond leachates and metal toxicity. Elemental enrichment in the floodplain soils, as a result of fly ash particle deposition during monsoons, may enhance the horticultural value of these soils as is shown by a healthy cultivated crop of Brassica juncea.     

226Ra, 232Th and 40K analysis in soil samples from some areas of Malwa region, Punjab, India using gamma ray spectrometry

The activity concentrations of soil samples collected from thirty different locations of Malwa region of Punjab were determined by using HPGe detector based on high-resolution gamma spectrometry system. The range of activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K in the soil from the studied areas varies from 18.37 Bq kg⁻¹ (Sangrur) to 53.11 Bq kg⁻¹ (Sitoguno), 57.28 Bq kg⁻¹ (Dhanola) to 148.28 Bq kg⁻¹ (Sitoguno) and 211.13 Bq kg⁻¹ (Sunam) to 413.27 Bq kg⁻¹ (Virk Khera) with overall mean values of 35 Bq kg⁻¹, 80 Bq kg⁻¹and 317 Bq kg⁻¹ respectively. The absorbed dose rate calculated from activity concentration of ²²⁶Ra, ²³²Th and ⁴⁰K ranges between 8.47 and 24.48, 35.68 and 92.38, and 8.74 and 17.11 nGy h⁻¹, respectively. The total absorbed dose in the study area ranges from 58.08 nGy h⁻¹ to 130.85 nGy h⁻¹ with an average value of 79.11 nGy h⁻¹. The calculated values of external hazard index (H_ex) for the soil samples of the study area range from 0.35 to 0.79. Since these values are lower than unity, therefore, according to the Radiation Protection 112 (European Commission. Radiation Protection 112 1999) report, soil from these regions is safe and can be used as a construction material without posing any significant radiological threat to population.     

Glutathione as a matrix for the synthesis of CdS nanocrystallites

GSH-capped CdS nanocrystallites were synthesized by reacting Cd(II)-GSH with aqueous sodium sulfide using specific initial sulfide/Cd(II) ratios. Spectroscopic analyses of fractions obtained from a size exclusion column showed varying absorption spectra indicating a significant dispersion in size-distribution of nanocrystallites at lower sulfide/Cd(II) ratios. However, size distribution of the nanocrystallites was narrower at initial sulfide/Cd(II) ratios that exceeded 1.0. An ethanol precipitation procedure was used to remove free Cd(II)-GSH complexes and selectively isolate GSH-capped nanocrystallites in a very narrow size range. Size exclusion chromatography indicated similar chemical compositions and overlapping spectral profiles of ethanol-precipitated samples suggesting apparent uniformity in both the size and the cap content. All of the GSH-capped CdS nanocrystallites with varying cap contents degraded p-nitrophenol upon irradiation at 366 nm. However, photocatalytic degradation of p-nitrophenol was significantly higher in samples with higher sulfide/Cd ratio and less capping material. The addition of H2O2 enhanced levels of photo-oxidation of p-nitrophenol.     

Audience perceptions of high-status ties and network advantage: The market for coaching jobs in the National Collegiate Athletic Association (2000–2011)

Social ties with high-status others can be a potent signal of an individual's underlying quality and future promise. Individuals in competitive markets, therefore, have an incentive to publicly claim connections to high-status others. However, cognitive limitations and biases can make social network connections difficult for observers to reliably discern, and claims to high-status ties can go unrecognized by the audience. Our core contention is that claims to high-status affiliation are advantageous only when the audience recognizes the claim—unrecognized claims, like unreliable signals, do not deliver advantage and can backfire. Further, we draw on the literature on imprinting and develop arguments for why some people are more likely to make claims to high-status ties and why some claims to high-status ties are more likely than others to be recognized by the audience. We test our arguments with data from the market for head coaching jobs in NCAA basketball (2000–2011). Our study contributes to the sparse literature on how social network ties that exist in the minds of third-party observers influence individual attainment in market settings; and it offers new insights into how imprinting processes shape the perception and use of high-status network ties.     

A review on ex situ mineral carbonation

The increased CO₂ quantities in the environment have led to many harmful effects. Therefore, it is very important to decrease the CO₂ levels in the environment. CO₂ capture along with safe and permanent storage using mineral CO₂ sequestration method can play an important role to reduce carbon emissions into the environment. Mineral sequestration is a stable storage method that provides long-term storage and an appropriate substitute for the more popular geological storage method. The process is most suited for places where there is a lack of underground cavities for underground geological storage. Minerals rich in Ca and Mg are used predominantly in carbonation reactions. In addition, those alkaline wastes that are rich in Mg and Ca such as cement waste, steel slag and many process ashes can also be employed in CO₂ sequestration. Mineral carbonation could be used for the sequestration of billions of tonnes of CO₂ every year. However, various drawbacks related to mineral carbonation still need to be addressed, such as resolving the slow rate of reactions, necessity of large amounts of feedstock, decreasing the high overall cost of CO₂ sequestration and reducing the huge energy requirements to accelerate the carbonation reaction. This study explores a number of carbonation methods, parameters that control the process and future potential applications of carbonated products.

     

Spatial analysis of soil resources in the Mewat district in the semiarid regions of Haryana,India

The soil characteristics are critical for crop health and its yield and therefore for agriculture. The soil properties are spatially variable and therefore soil resources should be managed as per location-specific requirements. An integrated spatial analysis of the soil resources of Mewat district was conducted to identify the soil resource management zones to develop site-specific soil management plan which might lead to sustained and enhanced crop yield. Spatial analysis of soil resources was conducted by modeling soil fertility and erosion which determines the crop productivity in the region. Soil fertility of the region was modeled using weighted overlay approach using 10 soil parameters, namely nitrogen, phosphorus, potassium, sulfur, iron, zinc, manganese, organic carbon, electrical conductivity, and pH. Each parameter was assigned weights based on their relative importance to agricultural productivity. The modeled soil fertility was classified into three fertility zones, low, medium, and high. Soil fertility was found to be low to moderate in 65% of the area, largely because of the low nitrogen, soil organic carbon, phosphorus concentration, and excessive salinity. Soil erosion was modeled using the universal soil loss equation (USLE) model by estimating rainfall erosivity factor (R), the soil erodibility factor (K), the topographic factors (L and S), cropping factor (C), and the conservation practice factor (P). Soil erosion problems were limited to areas having high elevation with barren land and areas with minimal management practices. The severity of soil erosion was found high in 15% of the region, while the remaining 85% showed low to moderate erosion. Soil fertility and erosion were integrated using the multivariate clustering method to identify soil management zones. The region was delineated into three soil management zones. Zone I (29%) which covers majorly Tarou block, was characterized by high soil fertility and low soil erosion. Zone II (18%) with medium soil fertility and high erosion covers villages of Taoru, Nuh, Nagina, FP Jhirka, and Punhana, which are located in the foothills of Aravalli ranges. Zone III represents the major part of the region, covering Nuh, Nagina, and FP Jhirka blocks (54%) with low soil fertility and erosion conditions. Thus, within the study area, the soil management domains are spatially variable in terms of fertility and soil erosion, and thus zone-specific soil management measures are required to improve the soil condition in order to sustain and improve agriculture production. The study would help the policy makers to design site-specific planning for identified soil resource management zones.     

Olivine dissolution from Indian dunite in saline water

The rate and mechanism of olivine dissolution was studied using naturally weathered dunite FO_98.21(Mg_1.884Fe_0.391SiO₄) from an Indian source, that also contains serpentine mineral lizardite. A series of batch dissolution experiments were carried out to check the influence of temperature (30–75 ^°C), initial dunite concentration (0.5 and 20 g/L), and salinity (0–35 g/L NaCl) under fixed head space CO₂ pressure (P\(_{\text {CO}_{2}}\) = 1 barg) on dunite dissolution. Dissolved Mg, Si, and Fe concentrations were determined by inductive coupled plasma atomic emission spectroscopy. End-product solids were characterized by scanning electron microscopy and X-ray diffraction. Initially, rates of dissolution of Si and Mg were observed to be in stoichiometric proportion. After 8 h, the dissolution rate was observed to decline. At the end of the experiment (504 h), an amorphous silica-rich layer was observed over the dunite surface. This results in decay of the dissolution rate. The operating conditions (i.e., salinity, temperature, and mineral loading) affect the dissolution kinetics in a very complex manner because of which the observed experimental trends do not exhibit a direct trend.     

Mechanisms of copper tolerance by Armeria maritima in Dolfrwyong Bog,north Wales--initial studies

Preliminary field studies were carried out at Dolfrwynog Bog in July 2000. Replicate samples of water, Armeria maritima plants and the soils adhering to its roots were collected and analysed for copper. Concentrations of up to 6486 mg kg^–1 of copper in the soils were recorded. Accumulation of copper by the plant as expressed by concentration factors (CF) show that it is acting mainly as a copper excluder. Of the copper that is taken up, most of it is retained within the roots with very little being transported to the shoots of the plant. Moreover, a further possible mechanism of tolerance is exhibited by the excretion of copper through its decaying leaves. Towards the use of in vitro cultures to study the copper tolerance mechanisms in A. maritima a micropropagation protocol has been developed. The ex vitro plants have been rooted and established in compost.     

Biodegradation of wastewater of Najafgarh drain,Delhi using autochthonous microbial consortia : a laboratory study

There are seventeen drains, which discharge their untreated urban and industrial wastewaters into the Delhi segment of river Yamuna. The Najafgarh drain is the first and the largest drain, and it alone contributes 1667.84 mld i.e. 60% of the total wastewater discharge into the river Yamuna and as such add 81.36 tons of BOD load per day. As per the available data approximately 95% of the wastewater of this drain is biodegradable. In the present study, an attempt has been made to reduce the BOD load and COD levels of wastewater of Najafgarh drain using autochthonous microbial consortium. During this study the raw wastewater samples were treated for 6 h time interval with different concentration of consortium. It was observed that by increasing the existing microbial population in the wastewater sample by 150-200% there is a significant decrease in BOD and COD levels. Finally, BOD/COD ratios before and after biotreatment have been analyzed to assess the efficacy of the natural consortium.