Runoff characteristics in forest plots before and after wood ash fertilization

Spreading wood ash on forest and agricultural lands has been used for years to correct pH in acid soils and as a source of plant nutrients. However, it is necessary to enhance the knowledge of potential hazards derived from such a practise. Surface runoff pollution is one of these possible hazards. In this work we studied the quality of runoff water collected in two sloped forest plots before and after wood ash spreading, with the aim of checking potential undesirable effects of ash use. We have not found environmental pollution problems in runoff derived from the ash application zones. These results encourage further research and use of wood ash as an amendment in acid sloped forest soils.S

The effect of aging on element plant availability and bacterial counts of mixtures of wood ash and sewage sludge

This study investigated the chemical composition of a mixture of 70% wood ashes (a by-product of timber-industry) and 30% sewage sludge (% dry weight), immediately after preparation and after storage (42 days). The mixture had higher Mehlich 3 extractable Ca, Mg and K concentrations than either component alone, and low plant-available heavy metal concentrations, both immediately after mixing and after storage for up to 6 weeks. The results support the view that mixtures of this type may be useful for liming and fertilizing, given their neutralizing capacity and phyto nutrient concentrations. Furthermore, we compared the survival of Escherichia coli in a wood ash and sewage sludge mixture with their survival in mixtures ofsewage sludge and two levels of quicklime. The time needed to eliminate most bacteria was 29 days in the ash-sludge combination, while nine days were required for one of the quicklime-sludge mixtures, and counts were minimal for the quicklime-sludge mixture with a pH>12.We thank the support of Xunta de Galicia's I+D Plan (R+D Plan, Government of Galicia, Spain)S

Runoff characteristics in forest plots before and after wood ash fertilization

Spreading wood ash on forest and agricultural lands has been used for years to correct pH in acid soils and as a source of plant nutrients. However, it is necessary to enhance the knowledge of potential hazards derived from such a practise. Surface runoff pollution is one of these possible hazards. In this work we studied the quality of runoff water collected in two sloped forest plots before and after wood ash spreading, with the aim of checking potential undesirable effects of ash use. We have not found environmental pollution problems in runoff derived from the ash application zones. These results encourage further research and use of wood ash as an amendment in acid sloped forest soils

Control of sunroof buffeting noise by optimizing the flow field characteristics of a commercial vehicle

When a commercial vehicle is driving with the sunroof open, it is easy for the problem of sunroof buffeting noise to occur. This paper establishes the basis for the design of a commercial vehicle model that solves the problem of sunroof buffeting noise, which is based on computational fluid dynamics (CFD) numerical simulation technology. The large eddy simulation (LES) method was used to analyze the characteristics of the buffeting noise with different speed conditions while the sunroof was open. The simulation results showed that the small vortex generated in the cab forehead merges into a large vortex during the backward movement, and the turbulent vortex causes a resonance response in the cab cavity as the turbulent vortex moves above the sunroof and falls into the cab. Improving the flow field characteristics above the cab can reduce the sunroof buffeting noise. Focusing on the buffeting noise of commercial vehicles, it is proposed that the existing accessories, including sun visors and roof domes, are optimized to deal with the problem of sunroof buffeting noise. The sound pressure level of the sunroof buffeting noise was reduced by 6.7 dB after optimization. At the same time, the local pressure drag of the commercial vehicle was reduced, and the wind resistance coefficient was reduced by 1.55% compared to the original commercial vehicle. These results can be considered as relevant, with high potential applicability, within this field of researchThis work was supported by the National Natural Science Foundation of China (No. 52065013), the Guangxi Youth Science Fund Project (2018GXNSFBA281012), the Innovation-Driven Development Special Fund Project of Guangxi (Guike AA19182004), and the Liuzhou Scientific Research and Planning Development Project (2018AA20301)S

Cattle manure compost and biochar supplementation improve growth of Onobrychis viciifolia in coal - mined spoils under water stress conditions

Surface mining is a critical anthropogenic activity that significantly alters the ecosystem, while the use of appropriate revegetation techniques can be considered an important and feasible strategy in the way to improve the ecosystem services of degraded land. In the present study, we carried out a pot experiment to investigate the effects of three different variables on morpho-physiological and biochemical parameters of Onobrychis viciifolia to assess the capability of this species to be used for restoration purposes. Specifically, the variables studied were: (a) water (W) regime, working at five values as regards field capacity (FC) (i.e., 80% FC = highest, 72% FC = high, 60% FC = moderate, 48% FC = low, and 40% FC = very-low dose); and (b) rates of cattle manure compost (CMC) and wood biochar (BC) (weight/weight ratio), working at five rates (i.e., 4.0% = highest, 3.2% = high, 2.0% = moderate, 0.8% = low, and 0% = either no-CMC or no-BC dose). In addition, soil physical-chemical properties and enzyme activities were also investigated at the end of the experimental period. It was found that morphological growth attributes such as plant height, maximum root length, and dry biomass significantly increased with W, CMC and BC applications. Compared to control, moderate-to-high W, CMC and BC doses (W80CMC2BC2) increased net photosynthesis rate (by 42%), stomatal conductance (by 50%), transpiration rate (by 29%), water use efficiency (by 10%), chlorophyll contents (by 73%), carotenoid content (by 81%), leaf relative water content (by 33%) and leaf membrane stability index (by 30%). Under low-W content, the application of CMC and BC enhanced osmotic adjustments by increasing the content of soluble sugar and the activities of superoxide dismutase, catalase, peroxidase and ascorbate peroxidase, decreasing the oxidative stress, as verified by low levels of hydrogen peroxide, superoxide anion, malondialdehyde and proline contents in leaf tissues. Moreover, application of W, CMC and BC significantly improved soil water holding capacity, available nitrogen, phosphorus and potassium, urease and catalase activities, which facilitate plant growth. These results would aid in designing an appropriate strategy for achieving a successful revegetation of O. viciifolia, providing optimum doses of W (64% field capacity), CMC (2.4%) and BC (1.7%), with the final aim of reaching ecological restoration in arid degraded lands

The effect of aging on element plant availability and bacterial counts of mixtures of wood ash and sewage sludge

This study investigated the chemical composition of a mixture of 70% wood ashes (a by-product of timber-industry) and 30% sewage sludge (% dry weight), immediately after preparation and after storage (42 days). The mixture had higher Mehlich 3 extractable Ca, Mg and K concentrations than either component alone, and low plant-available heavy metal concentrations, both immediately after mixing and after storage for up to 6 weeks. The results support the view that mixtures of this type may be useful for liming and fertilizing, given their neutralizing capacity and phyto nutrient concentrations. Furthermore, we compared the survival of Escherichia coli in a wood ash and sewage sludge mixture with their survival in mixtures of sewage sludge and two levels of quicklime. The time needed to eliminate most bacteria was 29 days in the ash-sludge combination, while nine days were required for one of the quicklime-sludge mixtures, and counts were minimal for the quicklime-sludge mixture with a pH>12

Nitrogen, phosphorus, potassium, calcium and magnesium releasefrom two compressed fertilizers: column experiments

The objective of this work was to study nutrients release from two compressed nitrogen–potassium–phosphorous (NPK) fertilizers. In the Lourizán Forest Center, tablet-type controlled-release fertilizers (CRF) were prepared by compressing various mixtures of fertilizers without covers or binders. We used soil columns (50 cm long and 7.3 cm inner diameter) that were filled with soil from the surface layer (0–20 cm) of an A horizon corresponding to a Cambic Umbrisol. Tablets of two slow-release NPK fertilizers (11–18–11 or 8–8–16) were placed into the soil (within the first 3 cm), and then water was percolated through the columns in a saturated regime for 80 days. Percolates were analyzed for N, P, K+, Ca2+ and Mg2+. These elements were also determined in soil and fertilizer tablets at the end of the trials. Nutrient concentrations were high in the first leachates and reached a steady state when 1426 mm of water had been percolated, which is equivalent to approximately 1.5 years of rainfall in this geographic area. In the whole trial, both tablets lost more than 80% of their initial N, P and K contents. However, K+, Ca2+ and Mg2+ were the most leached, whereas N and P were lost in leachates to a lesser extent. Nutrient release was slower from the tablet with a composition of 8–8–16 than from the 11–18–11 fertilizer. In view of that, the 8–8–16 tablet can be considered more adequate for crops with a nutrient demand sustained over time. At the end of the trial, the effects of these fertilizers on soil chemical parameters were still evident, with a significant increase of pH, available Ca2+, Mg2+, K+, P and effective cation exchange capacity (eCEC) in the fertilized columns, as well as a significant decrease in exchangeable Al3+, reaching values < 0.08 cmol (+) kg−1.S

The Toxicity Exerted by the Antibiotic Sulfadiazine on the Growth of Soil Bacterial Communities May Increase over Time

The toxicity exerted by the antibiotic sulfadiazine on the growth of soil bacterial communities was studied in two agricultural soils for a period of 100 days. In the short-term (2 days of incubation), the effect of sulfadiazine on bacterial growth was low (no inhibition or inhibition <32% for a dose of 2000 mg·kg−1). However, sulfadiazine toxicity increased with time, achieving values of 40% inhibition, affecting bacterial growth in both soils after 100 days of incubation. These results, which were here observed for the first time for any antibiotic in soil samples, suggest that long-term experiments would be required for performing an adequate antibiotics risk assessment, as short-term experiments may underestimate toxicity effectsThis study has been funded by the Spanish Ministry of Economy and Competitiveness through the projects CGL2015-67333-C2-1-R and -2-R (FEDER Funds), and by Xunta de Galicia via CITACA Strategic Partnership (ED431E 2018/07) and BV1 research group (ED431C 2017/62-GRC). David Fernández Calviño holds a Ramón y Cajal contract (RYC-2016-20411) financed by the Spanish Ministry of Economy Industry and Competitiveness. Vanesa Santás Miguel holds a pre-doctoral fellowship founded by the University of VigoS

Photodegradation of ciprofloxacin, clarithromycin and trimethoprim: influence of pH and humic acids

In view of the rising relevance of emerging pollutants in the environment, this work studies the photodegradation of three antibiotics, evaluating the effects of the pH of the medium and the concentration of dissolved organic matter. Simulated light (with a spectrum similar to that of natural sunlight) was applied to the antibiotics Ciprofloxacin (Cip), Clarithromycin (Cla) and Trimethoprim (Tri), at three different pH, and in the presence of different concentrations of humic acids. The sensitivity to light followed the sequence: Cip > Cla > Tri, which was inverse for the half-life (Tri > Cla > Cip). As the pH increased, the half-life generally decreased, except for Cla. Regarding the kinetic constant k, in the case of Cip and Tri it increased with the rise of pH, while decreased for Cla. The results corresponding to total organic carbon (TOC) indicate that the complete mineralization of the antibiotics was not achieved. The effect of humic acids was not marked, slightly increasing the degradation of Cip, and slightly decreasing it for Tri, while no effect was detected for Cla. These results may be relevant in terms of understanding the evolution of these antibiotics, especially when they reach different environmental compartments and receive sunlight radiation.Ministerio de Ciencia, Innovación y Universidades | Ref. RTI2018-099574-B-C21Ministerio de Ciencia, Innovación y Universidades | Ref. RTI2018-099574-B-C2

Evaluation of Toxicity on Ctenopharyngodon idella Due to Tannery Effluent Remediated by Constructed Wetland Technology

Aquatic pollution caused by industrial effluents is an environmental issue, imposing deleterious impacts on the overall environment, specifically, on humans, by disrupting the balance of the ecosystem. Among all the industries, tanneries are considered some of the most polluting due to heavy use of toxic organic and inorganic compounds during leather processing, most of which find their way into rivers, lakes, and streams, thus exerting adverse effects on aquatic life, particularly on fish. Considering the huge concentrations of pollutants present in tannery effluents, toxicity evaluation is of prime importance. Therefore, bioassays are usually employed to assess the acute toxicity of industrial effluents and efficiency of effluent clean-up technologies as they provide a thorough response of test species to the substances present in the tested media. In the present study, the toxic effects of tannery effluent on common grass carp (Ctenopharyngodon idella) were studied for 96 h in laboratory conditions. The effluent was added at different concentrations, before and after treatment by constructed wetlands (CWs). During this period, mortality data was collected to calculate the 96 h-LC50 (lethal concentration inducing 50% mortality) and acute toxicity of C. idella. In addition to this, observations on change in morphological, physiological, and behavioural patterns were also made every 24 h. The present toxicity assay revealed that the raw tannery effluent changed the morphology, physiology, and behavioural response of fish. Moreover, fish exposure to raw/untreated effluent caused high acute toxicity and 100% mortality, due to the presence of high concentrations of salts and chromium (Cr) metal. While treatment of tannery effluent by CWs vegetated with different plants (B. mutica, L. fusca, and T. domingensis) significantly reduced its toxicity and fish mortality as well, and inoculation of salt and Cr-tolerant endophytic bacteria (Enterobacter sp. HU38, Microbacterium arborescens HU33, and Pantoea stewartii ASI11) further reduced (up to 90%) its toxicity level. Hence, the use of CWs for tannery effluent treatment can be recommended to favour public health and promote the overall safety of the environmentThis research was conducted under the grant number, No. 20-3854/R&D/HEC/14., of the Higher Education Commission (HEC), PakistanS