Purification of Forest Clear-Cut Runoff Water Using Biochar: A Meso-Scale Laboratory Column Experiment

Biochar can be an effective sorbent material for removal of nutrients from water due to its high specific surface area, porous structure, and high cation and anion exchange capacity. The aim of this study was to test a biochar reactor and to evaluate its efficiency in runoff water purification and consecutive nutrient recycling in clear-cut peatland forests. The goodness of the method was tested in a meso-scale (water volume thousands of liters) reactor experiment by circulating runoff water through wood biochar-filled columns and by determining water nutrient concentrations in the column inlet and outlet. The pseudo-first and second order kinetic models were fitted to the experimental data and the adsorption rate (Kad) and maximum adsorption capacity (Qmax) of the biochar reactor were quantified. The concentration of total nitrogen (TN) decreased by 58% during the 8-week experiment; the majority of TN adsorption occurred within the first 3 days. In addition, NO3-N and NH4-N concentrations decreased below the detection limit in 5 days after the beginning of the experiment. The maximum adsorption capacity of the biochar reactor varied between 0.03–0.04 mg g−1 biochar for NH4-N, and was equal to 0.02 mg g−1 biochar for TN. The results demonstrated that the biochar reactor was not able to adsorb TN when the water TN concentration was below 0.4 mg L−1. These results suggest that a biochar reactor can be a useful and effective method for runoff water purification in clear-cut forests and further development and testing is warranted. Unlike traditional water protection methods in peatland forestry, the biochar reactor can effectively remove NO3-N from water. This makes the biochar reactor a promising water protection tool to be tested in sites where there is the risk of a high rate of nutrient export after forest harvesting or drainage

Purification of Forest Clear-Cut Runoff Water Using Biochar: A Meso-Scale Laboratory Column Experiment

Biochar can be an effective sorbent material for removal of nutrients from water due to its high specific surface area, porous structure, and high cation and anion exchange capacity. The aim of this study was to test a biochar reactor and to evaluate its efficiency in runoff water purification and consecutive nutrient recycling in clear-cut peatland forests. The goodness of the method was tested in a meso-scale (water volume thousands of liters) reactor experiment by circulating runoff water through wood biochar-filled columns and by determining water nutrient concentrations in the column inlet and outlet. The pseudo-first and second order kinetic models were fitted to the experimental data and the adsorption rate (Kad) and maximum adsorption capacity (Qmax) of the biochar reactor were quantified. The concentration of total nitrogen (TN) decreased by 58% during the 8-week experiment; the majority of TN adsorption occurred within the first 3 days. In addition, NO3-N and NH4-N concentrations decreased below the detection limit in 5 days after the beginning of the experiment. The maximum adsorption capacity of the biochar reactor varied between 0.03–0.04 mg g−1 biochar for NH4-N, and was equal to 0.02 mg g−1 biochar for TN. The results demonstrated that the biochar reactor was not able to adsorb TN when the water TN concentration was below 0.4 mg L−1. These results suggest that a biochar reactor can be a useful and effective method for runoff water purification in clear-cut forests and further development and testing is warranted. Unlike traditional water protection methods in peatland forestry, the biochar reactor can effectively remove NO3-N from water. This makes the biochar reactor a promising water protection tool to be tested in sites where there is the risk of a high rate of nutrient export after forest harvesting or drainage

Biochar as adsorbent in purification of clear‑cut forest runoff water : adsorption rate and adsorption capacity

Peer reviewe

Nitrogen Recovery from Clear‑Cut Forest Runoff Using Biochar: Adsorption–Desorption Dynamics Affected by Water Nitrogen Concentration

Forest regeneration operations increase the concentration of nitrogen (N) in watercourses especially outside the growing season when traditional biological water protection methods are inefficient. Biochar adsorption-based water treatment could be a solution for nutrient retention. We studied the total nitrogen (TN) and nitrate-nitrogen (NO3--N) adsorption-desorption properties of spruce and birch biochar. The adsorption test was performed under four different initial concentrations of TN (1, 2, 3, and 4 mg L-1) using forest runoff water collected from ditch drains of boreal harvested peatland. The results showed that the TN adsorption amount increased linearly from the lowest to the highest concentration. The maximum adsorption capacity was 2.4 and 3.2 times greater in the highest concentration (4 mg L-1) compared to the lowest concentration (1 mg L-1) in spruce and birch biochar, respectively. The NO3--N adsorption amount of birch biochar increased linearly from 0 to 0.15 mg NO3--N g biochar(-1) when the initial concentration of NO3--N increased from 0.2 to 1.4 mg L-1. However, in spruce biochar, the initial concentration did not affect NO3--N adsorption amount. The results indicate that concentration significantly affects the biochar's capacity to adsorb N from water. The desorption test was performed by adding biochar extracted from the adsorption test into the forest runoff water with low TN concentration (0.2 or 0.35 mg L-1). The desorption results showed that desorption was negligibly small, and it was dependent on the TN concentration for birch biochar. Therefore, biochar can be a complementary method supporting water purification in peatland areas.Peer reviewe

CH4 oxidation in a boreal lake during the development of hypolimnetic hypoxia

Freshwater ecosystems represent a significant natural source of methane (CH4). CH4 produced through anaerobic decomposition of organic matter (OM) in lake sediment and water column can be either oxidized to carbon dioxide (CO2) by methanotrophic microbes or emitted to the atmosphere. While the role of CH4 oxidation as a CH4 sink is widely accepted, neither the magnitude nor the drivers behind CH4 oxidation are well constrained. In this study, we aimed to gain more specific insight into CH4 oxidation in the water column of a seasonally stratified, typical boreal lake, particularly under hypoxic conditions. We used (CH4)-C-13 incubations to determine the active CH4 oxidation sites and the potential CH4 oxidation rates in the water column, and we measured environmental variables that could explain CH4 oxidation in the water column. During hypolimnetic hypoxia, 91% of available CH4 was oxidized in the active CH4 oxidation zone, where the potential CH4 oxidation rates gradually increased from the oxycline to the hypolimnion. Our results showed that in warm springs, which become more frequent, early thermal stratification with cold well-oxygenated hypolimnion delays the period of hypolimnetic hypoxia and limits CH4 production. Thus, the delayed development of hypolimnetic hypoxia may partially counteract the expected increase in the lacustrine CH4 emissions caused by the increasing organic carbon load from forested catchments.Peer reviewe

Iäkkäiden asukkaiden ravitsemustila Helsingin pitkäaikaisen ympärivuorokautisen hoidon yksiköissä

Helsingissä vuosina 2003-2017 tehtyjen ravitsemustutkimusten tarkoituksena on ollut tutkia ympärivuorokautisessa hoidossa olevien vanhusten ravitsemustilaa. Tässä artikkelissa kuvataan ravitsemustilan ja -hoidon kehittymistä tehostetussa palveluasumisessa vuosina 2007, 2011 ja 2017 sekä laitoshoidossa (vanhainkodeissa) vuosina 2003, 2011 ja 2017 tehtyjen tutkimusten tulosten pohjalta. Helsingin ravitsemustutkimukset on toteutettu käyttäen samaa strukturoitua kyselylomaketta ja MNA-ravitsemusarviota (Mini Nutritional Assessment). Tässä artikkelissa esitetään tutkimuslomakkeiden muuttujia (ikä, sukupuoli, siviilisääty, koulutustaso, fyysinen ja kognitiivinen toimintakyky, sairaudet ja lääkitys) kuvaamaan asukasrakenteen eroja eri asumismuodoissa. Ravitsemukseen liittyvistä muuttujista esitetään välipalojen syömistä, täydennysravintovalmisteiden ja D-vitamiinivalmisteiden käyttöä sekä painon seurantaa ja painehaavoja. Tulosten mukaan asukkaiden toiminnanvajeet ja muistisairaiden osuus ovat merkittävästi lisääntyneet. Tästä huolimatta ravitsemustilan mukaan riski- tai virheravitsemustilassa olevien osuudessa ei ole tapahtunut lisäystä. Ravitsemushoitokäytännöt ovat parantuneet. Tässä artikkelissa raportoidaan keskeiset trenditiedot eri tutkimusvuosilta. Noin 15 vuotta kestänyt tutkimus- ja kehittämishanke on ollut hyödyllinen asukkaiden hyvinvoinnin kannalta. Hyvä ravitsemus on merkittävä tekijä ikääntyneiden hyvinvoinnissa.Peer reviewe

Arctic soil methane sink increases with drier conditions and higher ecosystem respiration

Arctic wetlands are known methane (CH4) emitters but recent studies suggest that the Arctic CH4 sink strength may be underestimated. Here we explore the capacity of well-drained Arctic soils to consume atmospheric CH4 using >40,000 hourly flux observations and spatially distributed flux measurements from 4 sites and 14 surface types. While consumption of atmospheric CH4 occurred at all sites at rates of 0.092 ± 0.011 mgCH4 m−2 h−1 (mean ± s.e.), CH4 uptake displayed distinct diel and seasonal patterns reflecting ecosystem respiration. Combining in situ flux data with laboratory investigations and a machine learning approach, we find biotic drivers to be highly important. Soil moisture outweighed temperature as an abiotic control and higher CH4 uptake was linked to increased availability of labile carbon. Our findings imply that soil drying and enhanced nutrient supply will promote CH4 uptake by Arctic soils, providing a negative feedback to global climate change

Terveydensuojelulain mukaisten asunnontarkastusten jälkivalvonta

Tämän opinnäytetyön tavoitteena oli tutkia asunnontarkastusten jälkivalvontaa ja kehittää toimintamalli jälkivalvontaa varten. Osana opinnäytetyötä lähetettiin terveydensuojeluviranomaisille jälkivalvonnan toteuttamista koskeva Webropol-kysely helmikuussa 2013. Opinnäytetyö ja siihen liittyvä kysely tehtiin yhteistyössä Kouvolan Ympäristöpalvelujen ja Etelä-Suomen aluehallintoviraston kanssa. Jälkivalvontakyselyyn vastattiin yhteensä 29 valvontayksiköstä eri puolelta Suomea. Kyselyn vastausprosentti oli noin 40 %. Vastauksista ilmeni, että ajanpuutteen takia toimenpidekehotusten jälkivalvonta jää usein suorittamatta. Sen sijaan korjausmääräyksen tai käyttökiellon saaneita kohteita valvotaan huomattavasti tehokkaammin ongelmien vakavuudesta johtuen. Jälkivalvontaa suoritetaan erityisesti asiakirjavalvonnan ja tarkastusten avulla, mutta myös erilaisia näytteenottoja ja mittauksia hyödynnetään jonkin verran tutkittaessa terveyshaitan poistumista. Jälkivalvonnan suurimmat ongelmat kohdistuvat puutteellisiin resursseihin ja tiedonkulkuun. Korjausten onnistumisen osoittamiseen varmuudella tarvitaan entistä pidempiä seurantajaksoja. Jälkivalvonta vaatii selkeää valtakunnallista ohjeistusta, jotta valvontayksiköiden menettely asunnontarkastusprosessissa olisi johdonmukaista ja tasapuolista.The purpose of this thesis was to investigate the methods of the subsequent control and thereby to develop an operating model. The thesis included a survey which was done in cooperation with Environmental Services of Kouvola and Southern Finland Regional State Administrative Agency. The survey was sent to the health inspectors working with housing health issues. The survey was answered by 29 health inspectors from different parts of Finland. The responses showed that the subsequent control of the repair requests is often left unattended, whereas the repair orders and housing bans are controlled more effectively due to their severity. The subsequent control is usually done by monitoring repair plans and performing a final inspection to the repaired house. Samplings and measurements are also used. Resources and poor communication are considered as a major problem of the subsequent control. The subsequent control requires a clear national directive so the housing inspection process would be coherent

Vertical stratification patterns of methanotrophs and their genetic controllers in water columns of oxygen-stratified boreal lakes

The vertical structuring of methanotrophic communities and its genetic controllers remain understudied in the water columns of oxygen-stratified lakes. Therefore, we used 16S rRNA gene sequencing to study the vertical stratification patterns of methanotrophs in two boreal lakes, Lake Kuivajarvi and Lake Lovojarvi. Furthermore, metagenomic analyses were performed to assess the genomic characteristics of methanotrophs in Lovojarvi and the previously studied Lake Alinen Mustajarvi. The methanotroph communities were vertically structured along the oxygen gradient. Alphaproteobacterial methanotrophs preferred oxic water layers, while Methylococcales methanotrophs, consisting of putative novel genera and species, thrived, especially at and below the oxic-anoxic interface and showed distinct depth variation patterns, which were not completely predictable by their taxonomic classification. Instead, genomic differences among Methylococcales methanotrophs explained their variable vertical depth patterns. Genes in clusters of orthologous groups (COG) categories L (replication, recombination and repair) and S (function unknown) were relatively high in metagenome-assembled genomes representing Methylococcales clearly thriving below the oxic-anoxic interface, suggesting genetic adaptations for increased stress tolerance enabling living in the hypoxic/anoxic conditions. By contrast, genes in COG category N (cell motility) were relatively high in metagenome-assembled genomes of Methylococcales thriving at the oxic-anoxic interface, which suggests genetic adaptations for increased motility at the vertically fluctuating oxic-anoxic interface.Peer reviewe