Treatment of sanitary sewer overflow with fixed media bioreactors

Fixed media bioreactors (biofilters) are a promising and proven technology used for wastewater treatment in unsewered rural areas. As an on-site treatment system, it cart potentially provide high treatment efficiency with a relatively low cost and maintenance. This research expanded the application of fixed media bioreactors and tested their feasibility in the treatment of sanitary sewer overflows (SSO) at high hydraulic loading of 0.2 m/h. Sand, peat, and textile (felt) were used as media to treat simulated 6-h peak flows for a 25-year SSO event in the city of Columbus, Ohio. The influent SSO was a mixture of primary sludge from a wastewater treatment plant diluted with tap water. The efficiency of treatment was measured as changes in the concentrations of biochemical oxygen demand (BOD5), chemical oxygen demand (COD), and total suspended solids (TSS). Sand as a filter medium had the best removal of organic matter with average 84% reduction of BOD5 and 90% of COD. The TSS removal was more than 90% in all media. Peat and felt were,somewhat more efficient than the sand in the TSS removal. The media type and influent BOD5 concentration were two major factors that impacted the treatment of BOD5 (p<0.007). For the treatment of COD, significant factors were media type, influent concentration, and time course of loading in each SSO event (ps <= 0.001)

Seikkailukasvatuksen vaikutukset luokan ryhmäilmiöihin

Tiivistelmä. Kandidaatintutkielmamme tarkastelee systemaattisen kirjallisuuskatsauksen muodossa kotimaista ja kansainvälistä tutkimuskirjallisuutta seikkailukasvatuksesta ja ryhmäilmiöistä. Tavoitteenamme on selvittää, millaisia vaikutuksia seikkailukasvatuksella on luokan ryhmäilmiöihin. Käsittelemme tutkimuksen aikana seikkailukasvatuksen käsitteellisiä ja historiallisia taustoja sekä siihen liitettyjä oppimiskäsityksiä. Lisäksi selvennämme seikkailukasvatuksen ja elämyspedagogiikan välistä käsitteellistä yhteneväisyyttä. Perehdymme myös ryhmäilmiöiden moniulotteiseen ja jatkuvasti muuttuvaan luonteeseen. Seikkailukasvatusta voidaan pitää vaihtoehtoisena toiminnallisena opetusmenetelmänä, jossa korostuu osallistujien aidot elämykset ja kokemukset. Perusopetuksen opetussuunnitelman (2014) ja seikkailukasvatuksen oppimiskäsitykset yhdistyvät toisiinsa. Seikkailukasvatusta voidaankin hyödyntää perustellusti koulun opetuksessa. Opettajan täytyy kuitenkin huomioida toimintaa järjestäessään turvallisuusnäkökulmat, jotta oppilaat kokisivat elämykset mielekkäiksi. Kasvatuksellisesta näkökulmasta matalankynnyksen seikkailukasvatustoiminta soveltuu parhaiten koulun tavoitteisiin. Tutkimuksen edetessä vertasimme ja arvioimme jatkuvasti tutkimuskirjallisuutta kriittisesti ja pyrimme liittämään tutkimuksen tulokset suomalaiseen yhteiskuntaan ja koulujärjestelmään. Havaitsimme tutkimuksen aikana, että luokka on ryhmänä jatkuvasti muutoksen kohteena. Siihen vaikuttavat samanaikaisesti fyysinen ympäristö, sosiaalinen ympäristö, yksilöiden ominaisuudet, ryhmäsuhteet ja ryhmäprosessit. Seikkailukasvatuksella voidaan kehittää luokan ryhmädynamiikkaa ja ryhmän kiinteyttä. Lisäksi pienryhmä soveltuu erityisen hyvin seikkailukasvatuksen välineeksi, koska pienryhmässä jäsenet pystyvät vaikuttamaan ryhmän toimintaan tehokkaammin. Pienryhmätoiminta tukee myös yksilön sosiaalisten taitojen kehittymistä

Identifying main uncertainties in estimating past and present radiative forcing of peatlands

ABSTRACT Reconstructions of past climate impact, i.e., radiative forcing (RF), of peatland carbon (C) dynamics show that immediately after peatland initiation the climate warming effect of CH4 emissions exceeds the cooling effect of CO2 uptake, but thereafter the net effect of most peatlands will move towards cooling, when RF switches from positive to negative. Reconstructing peatland C dynamics necessarily involves uncertainties related to basic assumptions on past CO2 flux, CH4 emission, and peatland expansion. We investigated the effect of these uncertainties on the RF of three peatlands, using either apparent C accumulation (aCAR), net C balance (NCB), or NCB plus C loss during fires as basis for CO2 uptake estimate; applying a plausible range for CH4 emission; and assuming linearly interpolated expansion between basal dates, or comparatively early or late expansion. When we factored that some C would only be stored temporarily (NCB and NCB+fire), the estimated past cooling effect of CO2 uptake increased but the present-day RF was affected little. Altering the assumptions behind the reconstructed CO2 flux or expansion patterns, caused the RF to peak earlier and advanced the switch from positive to negative RF by several thousand years. Compared to NCB, including fires had only small additional effect on RF lasting less than 1000 yr. The largest uncertainty in reconstructing peatland RF was associated with CH4 emissions. As shown by the consistently positive RF modelled for one site, and in some cases for the other two, peatlands with high CH4 emissions and low C accumulation rates may have remained climate warming agents since their initiation. Although uncertainties in present-day RF were mainly due to the assumed CH4 emission rates, the uncertainty in lateral expansion still had a significant effect on the present-day RF, highlighting the importance to consider uncertainties in the past peatland C balance in RF reconstructions.Reconstructions of past climate impact, that is, radiative forcing (RF), of peatland carbon (C) dynamics show that immediately after peatland initiation the climate warming effect of CH4 emissions exceeds the cooling effect of CO2 uptake, but thereafter the net effect of most peatlands will move toward cooling, when RF switches from positive to negative. Reconstructing peatland C dynamics necessarily involves uncertainties related to basic assumptions on past CO2 flux, CH4 emission and peatland expansion. We investigated the effect of these uncertainties on the RF of three peatlands, using either apparent C accumulation rates, net C balance (NCB) or NCB plus C loss during fires as basis for CO2 uptake estimate; applying a plausible range for CH4 emission; and assuming linearly interpolated expansion between basal dates or comparatively early or late expansion. When we factored that some C would only be stored temporarily (NCB and NCB+fire), the estimated past cooling effect of CO2 uptake increased, but the present-day RF was affected little. Altering the assumptions behind the reconstructed CO2 flux or expansion patterns caused the RF to peak earlier and advanced the switch from positive to negative RF by several thousand years. Compared with NCB, including fires had only small additional effect on RF lasting less than 1000 year. The largest uncertainty in reconstructing peatland RF was associated with CH4 emissions. As shown by the consistently positive RF modelled for one site, and in some cases for the other two, peatlands with high CH4 emissions and low C accumulation rates may have remained climate warming agents since their initiation. Although uncertainties in present-day RF were mainly due to the assumed CH4 emission rates, the uncertainty in lateral expansion still had a significant effect on the present-day RF, highlighting the importance to consider uncertainties in the past peatland C balance in RF reconstructions.Peer reviewe

Planck 2013 results. XI. All-sky model of thermal dust emission

Peer reviewe

Planck 2013 results. XX. Cosmology from Sunyaev-Zeldovich cluster counts

Peer reviewe

Carbon dioxide fluxes and carbon balance of an agricultural grassland in southern Finland

A significant proportion of the global carbon emissions to the atmosphere originate from agriculture. Therefore, continuous long-term monitoring of CO2 fluxes is essential to understand the carbon dynamics and balances of different agricultural sites. Here we present results from a new eddy covariance flux measurement site located in southern Finland. We measured CO2 and H2O fluxes at this agricultural grassland site for 2 years, from May 2018 to May 2020. In particular the first summer experienced prolonged dry periods, which affected the CO2 fluxes, and substantially larger fluxes were observed in the second summer. During the dry summer, leaf area index (LAI) was notably lower than in the second summer. Water use efficiency increased with LAI in a similar manner in both years, but photosynthetic capacity per leaf area was lower during the dry summer. The annual carbon balance was calculated based on the CO2 fluxes and management measures, which included input of carbon as organic fertilizers and output as yield. The carbon balance of the field was -57 +/- 10 and -86 +/- 12 g C m(-2) yr(-1) in the first and second study years, respectively.Peer reviewe

Planck 2013 results. XXII. Constraints on inflation

We analyse the implications of the Planck data for cosmic inflation. The Planck nominal mission temperature anisotropy measurements, combined with the WMAP large-angle polarization, constrain the scalar spectral index to be n(s) = 0.9603 +/- 0:0073, ruling out exact scale invariance at over 5 sigma Planck establishes an upper bound on the tensor-to-scalar ratio of r = 2 do not provide a good fit to the data. Planck does not find statistically significant running of the scalar spectral index, obtaining dn(s)/dln k = -0.0134 +/- 0.0090. We verify these conclusions through a numerical analysis, which makes no slowroll approximation, and carry out a Bayesian parameter estimation and model-selection analysis for a number of inflationary models including monomial, natural, and hilltop potentials. For each model, we present the Planck constraints on the parameters of the potential and explore several possibilities for the post-inflationary entropy generation epoch, thus obtaining nontrivial data-driven constraints. We also present a direct reconstruction of the observable range of the inflaton potential. Unless a quartic term is allowed in the potential, we find results consistent with second-order slow-roll predictions. We also investigate whether the primordial power spectrum contains any features. We find that models with a parameterized oscillatory feature improve the fit by delta 2 10; however, Bayesian evidence does not prefer these models. We constrain several single-field inflation models with generalized Lagrangians by combining power spectrum data with Planck bounds on fNL. Planck constrains with unprecedented accuracy the amplitude and possible correlation (with the adiabatic mode) of non-decaying isocurvature fluctuations. The fractional primordial contributions of cold dark matter (CDM) isocurvature modes of the types expected in the curvaton and axion scenarios have upper bounds of 0.25% and 3.9% (95% CL), respectively. In models with arbitrarily correlated CDM or neutrino isocurvature modes, an anticorrelated isocurvature component can improve the 2 by approximately 4 as a result of slightly lowering the theoretical prediction for the 40 multipoles relative to the higher multipoles. Nonetheless, the data are consistent with adiabatic initial conditions.Peer reviewe

Planck-LFI radiometers' spectral response

The Low Frequency Instrument (LFI) is an array of pseudo-correlation radiometers on board the Planck satellite, the ESA mission dedicated to precision measurements of the Cosmic Microwave Background. The LFI covers three bands centred at 30, 44 and 70 GHz, with a goal bandwidth of 20% of the central frequency. The characterization of the broadband frequency response of each radiometer is necessary to understand and correct for systematic effects, particularly those related to foreground residuals and polarization measurements. In this paper we present the measured band shape of all the LFI channels and discuss the methods adopted for their estimation. The spectral characterization of each radiometer was obtained by combining the measured spectral response of individual units through a dedicated RF model of the LFI receiver scheme. As a consistency check, we also attempted end-to-end spectral measurements of the integrated radiometer chain in a cryogenic chamber. However, due to systematic effects in the measurement setup, only qualitative results were obtained from these tests. The measured LFI bandpasses exhibit a moderate level of ripple, compatible with the instrument scientific requirements.Comment: 16 pages, 9 figures, this paper is part of the Prelaunch status LFI papers published on JINST: http://www.iop.org/EJ/journal/-page=extra.proc5/jins