scholarly journals Comparison of Nitrogen Treatment by Four Onsite Wastewater Systems in Nutrient-Sensitive Watersheds of the North Carolina Coastal Plain

Nitrogen ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 268-286
Author(s):  
Charles P. Humphrey ◽  
Michael O’Driscoll ◽  
Guy Iverson
Keyword(s):  
North Carolina ◽  
Permeable Reactive Barriers ◽  
Wastewater Remediation ◽  
Treatment Efficiency ◽  
The North ◽  
Onsite Wastewater ◽  
Lack Of Information ◽  
Remediation Strategies ◽  
Wastewater Systems ◽  
N Treatment

Wastewater may be a source of nitrogen (N) to groundwater and surface waters if not effectively treated. In North Carolina, onsite wastewater systems (OWSs) are used by 50% of the population for wastewater treatment, but most OWSs are not routinely monitored. There is a lack of information regarding the N contributions from OWSs to water resources. Four sites with OWSs were instrumented with groundwater wells near their drainfield trenches to compare N concentrations in groundwater to concentrations in wastewater and to determine the N treatment efficiency of the systems. Two OWSs (Site 200 and 300) were less than 1 year old, and two (Site 100 and 400) were more than 10 years old at the start of the study. Two OWSs (Site 100 and 200) used pressure dosing, while two OWSs (Site 300 and 400) used gravity distribution. The mean N treatment efficiency of the four OWSs was 77%. The new OWSs were more efficient (92%) relative to the older OWSs (62%) at reducing N concentrations. Similar N treatment efficiencies were observed when pooling data for the pressure dosed (77%) and gravity (79%) OWSs. Each OWS influenced groundwater by causing increases in N concentrations. It is important that new OWSs are installed at a shallow depth and with sufficient separation to groundwater to promote the aerobic treatment of wastewater. Remediation strategies including the installation of permeable reactive barriers or the use of media filters may be needed in some areas to reduce N transport from existing OWS.

Phosphate treatment by onsite wastewater systems in nutrient-sensitive watersheds of North Carolina's Piedmont

2016 ◽  
Vol 74 (7) ◽  
pp. 1527-1538 ◽  
Author(s):  
Charles Humphrey ◽  
Brent Serozi ◽  
Guy Iverson ◽  
Jordan Jernigan ◽  
Sushama Pradhan ◽  
...  
Keyword(s):  
Surface Waters ◽  
Surface Water Quality ◽  
Environmental Parameters ◽  
Additional Treatment ◽  
Single Pass ◽  
The North ◽  
Onsite Wastewater ◽  
Mass Load ◽  
Wastewater Systems ◽  
Phosphate Treatment

The goal of this study was to gain a better understanding of the PO4-P treatment efficiency of onsite wastewater systems (OWS) installed in nutrient-sensitive watersheds of the North Carolina Piedmont. Four OWS including two conventional and two single-pass sand filter (SF) systems were evaluated at sites with clay-rich soils. Piezometers were installed near all of the OWS, and down-gradient from the conventional OWS for groundwater collection and characterization. Septic tanks, groundwater, SF effluent, and surface waters were sampled each season during 2015 (five times) and analyzed for PO4-P and Cl concentrations and for various environmental parameters. The conventional and SF OWS reduced PO4-P concentrations by an average of 99% and 90%, respectively, before discharge to surface waters. Mass-load reductions of PO4-P were also greater for the conventional OWS (mean 95%), relative to SF (83%) systems. The effluents discharged by SF OWS were influencing surface water quality. Additional treatment of the effluent from single-pass SF with reactive media is suggested, along with monitoring of the final effluent for PO4-P concentrations. This research provides important information that is absent from the published literature concerning PO4-P contributions to water resources from OWS in clay soils.

N, P and K Fertilizers Alter Plant Growth, Essential Oil Yield and Gender of Sweet Gale (Myrica gale L)

2014 ◽  
Vol 8 (1) ◽  
pp. 9-17
Author(s):  
X. Chang ◽  
P. Martin
Keyword(s):  
Plant Growth ◽  
Field Trials ◽  
Oil Yield ◽  
Oil Composition ◽  
Myrica Gale ◽  
The North ◽  
Oil Concentration ◽  
N Treatment ◽  
And Gender ◽  
Essential Oil Yield

To investigate whether the fertilizers N, P or K individually affect plant growth, oil content and the gender of sweet gale, two trials, pot and field trials, were carried out at Orkney College UHI in Scotland. A pot trial was established with eight soils which were collected from different sweet gale trial sites in the north of Scotland. Although neither shoot yield nor oil concentration in shoots was affected by soil, there were significant differences in shoot yields as a result of fertilizer treatments (nitrogen (N), phosphorus (P), potassium (K) or none (control)). The best yield was obtained from the N treatment which was double to that of the control and P treatments. N, P or K fertilizers did not consistently affect shoot oil concentration in two seasons; however, oil yield was significantly affected, and N treatment produced two-three fold oil yield increases compared with the control or P treatment. In the N treatment, the increase in shoot yield was positively correlated with total nitrogen or nitrate nitrogen in the soil, suggesting the occurrence of a nitrogen priming effect. Data suggested that as shoot yield increased the oil concentration in shoots decreased. Neither soil nor N, P or K fertilizers had a significant effect on oil composition. Amongst fertilizer treatments, P resulted in the largest number of plants changing gender from female to male. A field N trial confirmed that nitrogen significantly enhanced the shoot yield of young plants.

ZIRCON GEOCHRONOLOGY OF THE RALEIGH TERRANE IN THE NORTH CAROLINA EASTERN PIEDMONT

2017 ◽  
Author(s):  
Brandon Tyler Peach ◽  
◽  
David E. Blake ◽  
David E. Blake ◽  
Todd A. LaMaskin ◽  
...  
Keyword(s):  
North Carolina ◽  
Zircon Geochronology ◽  
The North
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