scholarly journals Are Rural and Small Community Aerated Wastewater Stabilization Ponds a Neglected Source of Microplastic Pollution?

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2833
Author(s):  
Zhiqiang Gao ◽  
James V. Cizdziel ◽  
Kendall Wontor ◽  
Haitao Lu
Keyword(s):  
Lemna Minor ◽  
Terrestrial Ecosystems ◽  
Dry Weight ◽  
Point Sources ◽  
Small Community ◽  
Small Communities ◽  
Stabilization Ponds ◽  
Potential Sources ◽  
Wastewater Treatment Systems ◽  
Wastewater Stabilization Ponds

Wastewater treatment systems collect and treat sewage that includes microplastics (MPs). However, we are not aware of any studies on the occurrence and distribution of MPs in wastewater stabilization ponds (WSPs), which serve small communities worldwide. Here, we characterized MPs (~45 µm–5 mm) in an aerated WSP serving ~500 houses and an adjacent lake. Putative MPs were most abundant in duckweed (Lemna minor) and sludge (75 ± 22 and 12.8 ± 3.1 particles/g, respectively: ±1 standard deviation (SD), n = 6, dry weight). In the water, average concentrations (particles/L ± 1 SD, n = 6) were highest in the pond (4.1 ± 0.6), followed by effluent (3.9 ± 0.5) and the lake (2.6 ± 0.6). Over 20 types of MPs were identified in each different compartment, with the distribution varying somewhat between the water, sludge, and duckweed. Polyester and polyethylene were the predominant types, followed by polyethylene terephthalate, polyacrylate, polyvinyl chloride, polystyrene, and others. Morphologies consisted of fibers (62–71%), fragments (28–37%), and beads (1–6%). High-density polymers were more frequently found in sludge. Potential sources of the MPs include synthetic textiles from laundry and other plastics washed down household drains. Overall, with ~786,000 MPs/day released in the pond effluent and with duckweed a source of food for waterfowl, we demonstrate that WSPs can be point sources of MPs to both aquatic and terrestrial ecosystems and thus deserve further scrutiny.

Nitrification in bulk water and biofilms of algae wastewater stabilization ponds

2007 ◽  
Vol 55 (11) ◽  
pp. 93-101 ◽  
Author(s):  
M.A. Babu ◽  
M.M. Mushi ◽  
N.P. van der Steen ◽  
C.M. Hooijmans ◽  
H.J. Gijzen
Keyword(s):  
Model Equation ◽  
Bulk Water ◽  
Balance Model ◽  
Nitrification Rate ◽  
Relative Contribution ◽  
Activity Test ◽  
Stabilization Ponds ◽  
Wide Range ◽  
Water Columns ◽  
Wastewater Stabilization Ponds

Nitrogen removal in wastewater stabilization ponds is poorly understood and effluent monitoring data show a wide range of differences in ammonium. For effluent discharge into the environment, low levels of nitrogen are recommended. Nitrification is limiting in facultative wastewater stabilization ponds. The reason why nitrification is considered to be limiting is attributed to low growth rate and wash out of the nitrifiers. Therefore to maintain a population, attached growth is required. The aim of this research is to study the relative contribution of bulk water and biofilms with respect to nitrification. The hypothesis is that nitrification can be enhanced in stabilization ponds by increasing the surface area for nitrifier attachment. In order to achieve this, transparent pond reactors representing water columns in algae WSP have been used. To discriminate between bulk and biofilm activity, 5-day batch activity tests were carried out with bulk water and biofilm sampled. The observed value for Rnitrbulk was 2.7 × 10−1 mg-N L−1 d−1 and for Rbiofilm was 1,495 mg-N m−2 d −1. During the 5 days of experiment with the biofilm, ammonia reduction was rapid on the first day. Therefore, a short-term biofilm activity test was performed to confirm this rapid decrease. Results revealed a nitrification rate, Rbiofilm, of 2,125 mg-N m−2 d−1 for the first 5 hours of the test, which is higher than the 1,495 mg-N m−2 d−1, observed on the first day of the 7-day biofilm activity test. Rbiofilm and Rnitrbulk values obtained in the batch activity tests were used as parameters in a mass balance model equation. The model was calibrated by adjusting the fraction of the pond volume and biofilm area that is active (i.e. aerobic). When assuming a depth of 0.08 m active upper layer, the model could describe well the measured effluent values for the pond reactors. The calibrated model was validated by predicting effluent Kjeldahl nitrogen of algae ponds in Palestine and Colombia. The model equation predicted well the effluent concentrations of ponds in Palestine.

scholarly journals Sulfur dioxide-enhanced Phytotoxicity of Ozone to Watermelon

1996 ◽  
Vol 121 (4) ◽  
pp. 716-721 ◽  
Author(s):  
Gwendolyn Eason ◽  
Richard A. Reinert ◽  
James E. Simon
Keyword(s):  
Sulfur Dioxide ◽  
Citrullus Lanatus ◽  
Dry Weight ◽  
Point Sources ◽  
Continuous Stirred Tank Reactor ◽  
Foliar Injury ◽  
Crop Species ◽  
Total Plant ◽  
Continuous Stirred Tank ◽  
The Impact

Three watermelon [Citrullus lanatus (Thunb.) Matsum & Nakai] cultivars with different ozone (O3) sensitivities were grown in a charcoal-filtered greenhouse and exposed in continuous-stirred tank reactor chambers to five levels (0, 100, 200, 300, or 400 nL·L-1) of sulfur dioxide (SO2) in the presence (80 nL·L-1) or absence (0 nL·L-1) of ozone (O3) for 4 hours/day, 5 days/week for 22 days. In the presence of O3, SO2 increased foliar injury in all three cultivars, but the impact was greatest for the most O3-sensitive cultivar, `Sugar Baby,' moderate for `Crimson Sweet,' and least for the least O3-sensitive cultivar, `Charleston Gray.' For all cultivars, SO2 intensified O3 suppression of leaf area for the first seven mainstem leaves and of dry weights for aboveground and total plant tissues. Root dry weight was independently suppressed by both pollutants, and the root: top ratio was linearly suppressed by SO2 alone. Sulfur dioxide combined with O3 can be detrimental to crop species such as watermelon. Thus, the potential for SO2 phytotoxicity should not be summarily dismissed, especially in the vicinity of SO2 point sources where O3 co-occurs.

scholarly journals Dziedzictwo kulturowe wspólnot lokalnych w tradycji ustnej

2020 ◽  
Vol 7 (1) ◽  
pp. 65-78
Author(s):  
Tadeusz Paleczny
Keyword(s):  
Cultural Identity ◽  
Cultural Heritage ◽  
Oral History ◽  
Social Memory ◽  
Social Bonds ◽  
Local Communities ◽  
Small Community ◽  
Small Communities ◽  
The Social

Cultural Heritage of Local Communities in Oral History. The Base of Constructing the Social Memory  Local communities construct their own cultural heritage on the base of speaking traditions means as oral history. Each small community protects its own set of symbols and elements of tradition, including belief, dialect and private stories and anecdotes. The oral history performs a function of a part of social memory and sustains close social bonds among members of small communities. The article concerns the oral history’s role in preserving the cultural identity of small local communities.

scholarly journals IceCube: An overview of physics results

2019 ◽  
Vol 207 ◽  
pp. 01002
Author(s):  
Ignacio Taboada
Keyword(s):  
Cosmic Rays ◽  
Real Time ◽  
Milky Way ◽  
Neutrino Flux ◽  
Point Sources ◽  
Neutrino Source ◽  
Potential Sources ◽  
Astrophysical Neutrinos ◽  
Astrophysical Neutrino

Cosmic rays and neutrinos are intimately related. And though TeVPeV astrophysical neutrinos have been observed, their sources and their relation to potential sources of cosmic rays remain unknown. Recently, the blazar TXS 0506+056 has been identified as a candidate neutrino source. In parallel, IceCube has conducted numerous searches for other potential neutrino neutrino sources. These proceedings are limited in scope, given the large breath of science results by IceCube: A description of the astrophysical neutrino flux; a review of the real-time program that enables multi-messenger follow-up of neutrinos; a summary of the observations of TXS 0506+056; a recap of the search for neutrino point sources with 7 years of IceCube data; an account of the tantalizing capabilities of IceCube and ANTARES to detect Milky Way neutrinos and a description of a method to identify Glashow resonance events.

Assessment of Contributing Factors to Air Service Loss in Small Communities

2019 ◽  
Vol 2673 (6) ◽  
pp. 598-606 ◽  
Author(s):  
Stephanie Atallah ◽  
Susan L. Hotle
Keyword(s):  
Fixed Effects ◽  
Market Competition ◽  
Conditional Logistic Regression ◽  
Small Region ◽  
Small Community ◽  
Contributing Factors ◽  
Small Communities ◽  
The Great Recession ◽  
Future Loss ◽  
The Impact

As indicated by current literature, service at small community airports was negatively affected by the Great Recession from 2007 to 2009 and recent changes in competition structure. Existing studies have looked at the recession’s lingering impact on small community airports (e.g., hub premiums, airport dominance, connectivity) and markets (e.g., market competition structure). However, to date it has been difficult to determine which factors contribute to a market’s potential future loss of service that serves a small community. In this study, we identified characteristics that could potentially contribute to a market’s loss or gain of service by incorporating different regional- and market-specific characteristics that have evolved over the years. This study used a fixed-effects conditional logistic regression and focused on region-to-region markets serving small communities that were in service at least once between 2007 and 2013. In total, the panel data included 1,367 markets departing from a small region and arriving at a small-, medium-, or large-sized region with 453 markets adding or losing service during that time. Fixed-effects were used to identify the impact of within-market variation on service loss over the years. Results showed that, first, markets affected by a merger were indeed at a higher risk of losing service. Second, markets operated by a fuel-intensive, small-aircraft fleet had a higher chance of being discontinued. Third, an increased number of competitors greatly reduced potential market service loss.

Agency and Communion in End-of-Life Decision-Making

2016 ◽  
Vol 25 (2) ◽  
pp. 87-106 ◽  
Author(s):  
Raymond C. Hawkins
Keyword(s):  
Decision Making ◽  
End Of Life ◽  
Assisted Suicide ◽  
Autonomous Agent ◽  
Life Transition ◽  
Small Community ◽  
Small Communities ◽  
Agency And Communion ◽  
End Of Life Decision ◽  
Life Decision

Both the assisted suicide and the hospice or palliative medicine movements are alike in that each weighs the wishes of the patient and family for end-of-life medical decisions. The balancing of agency and communion within small communities of support may provide the opportunity to inform end-of-life decision-making and acceptance of the dying process. In this sense, the spirit of “communitas” may instill faith that the ending of one’s life journey is both reasonable and meaningful. The role of the small community of support may be akin to that of the guide who assists the aging or dying person through the dialectic of being an autonomous agent and a communicant in the end-of-life transition.

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