Environments

Open AccessArticle

Recycling of Cement Kiln Dust as a Raw Material for Cement

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Environments 2019, 6(10), 113; https://doi.org/10.3390/environments6100113 - 17 Oct 2019

Cited by 25 | Viewed by 5441

Abstract

Cement kiln dust (CKD) is a major by-product of cement manufacturing and has the potential to be recycled as a raw material if the high concentrations of chlorine and potassium are removed. This study tested four leaching solutions (distilled water and three organic [...] Read more.

Cement kiln dust (CKD) is a major by-product of cement manufacturing and has the potential to be recycled as a raw material if the high concentrations of chlorine and potassium are removed. This study tested four leaching solutions (distilled water and three organic acids) and determined the optimum reaction conditions. At a liquid/solid (L/S ratio) of 10, the removal efficiency of formic, citric, and oxalic acid was higher than that of distilled water, but at L/S 20, distilled water also achieved a high removal efficiency of Cl (≥90%) and K (≥70%). In addition, to minimize the discharge of wastewater after leaching, the efficiency of ion-exchange resins for the recovery of leaching solution was tested. When the cation- and anion-exchange resins were arranged together, more than 95% of both Cl and K contained in the leaching solution could be removed. Leaching solution without Cl and K was found to have a high leaching efficiency even after being recycled three times, resulting in a significant reduction in wastewater emissions. Full article

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Open AccessEditorial

Preface: Special Issue on Environmental Impact of Nature-Based Tourism

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Ronda J. Green

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David B. Croft

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Isabelle D. Wolf

Environments 2019, 6(10), 112; https://doi.org/10.3390/environments6100112 - 15 Oct 2019

Cited by 1 | Viewed by 4103

Abstract

Tourism is growing rapidly throughout the world, including nature-based tourism, but natural habitats are shrinking [...] Full article

(This article belongs to the Special Issue Environmental Impact of Nature-Based Tourism)

Open AccessEditor’s ChoiceArticle

Impact of Zirconium on Freshwater Periphytic Microorganisms

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Environments 2019, 6(10), 111; https://doi.org/10.3390/environments6100111 - 01 Oct 2019

Cited by 3 | Viewed by 4989

Abstract

The majority of studies on biofilms have focused on autotrophic and bacterial taxa, without considering the potential effects on biofilm grazers. In this work, we investigated the effects of realistic environmental concentrations of zirconium (Zr) on periphyton algal growth and micromeiofauna biodiversity. Glass [...] Read more.

The majority of studies on biofilms have focused on autotrophic and bacterial taxa, without considering the potential effects on biofilm grazers. In this work, we investigated the effects of realistic environmental concentrations of zirconium (Zr) on periphyton algal growth and micromeiofauna biodiversity. Glass slides were submerged in a pond for four weeks to colonize biofilms and exposed for four weeks in aquaria to targeted Zr concentrations of 0, 1, and 10 nM, which were monitored over time (average measured concentrations were 0.2 ± 0.1, 0.5 ± 0.3, and 2.9 ± 0.3 nM Zr). The four-week exposure to the highest concentration (3 nM) affected the micromeiofauna structure of biofilms and modified the autotrophic biofilm structure by increasing the proportion of green algae and decreasing the abundance of cyanobacteria and brown algae. Rotifers and the ciliate Aspidisca cicada appeared to be the most sensitive organisms among the observed micromeiofauna. A toxic effect of Zr on rotifers could explain such results. Indirect effects, such as reduced food availability given the reduced algal growth in the presence of Zr, could also play a role in the changes of micromeiofauna community structure. These results are among the few published data on the effects of Zr. Full article

(This article belongs to the Special Issue New Insights into Impacts of Toxic Metals in Aquatic Environments)

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Open AccessEditorial

Preface: Special Issue on Air Quality Assessment for Environmental Policy Support: Sources, Emissions, Exposures, and Health Impacts

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Andrea Spinazzè

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Domenico Maria Cavallo

Environments 2019, 6(10), 110; https://doi.org/10.3390/environments6100110 - 30 Sep 2019

Viewed by 4037

Abstract

The increased occurrence of serious health effects, mortality, and morbidity, as well as shortened life expectancy have been related to exposure to ambient air pollution [...] Full article

(This article belongs to the Special Issue Air Quality Assessment for Environmental Policy Support: Sources, Emissions, Exposures and Health Impacts)

Open AccessCorrection

Correction: Ducey et al. Differences in Microbial Communities and Pathogen Survival Between a Covered and Uncovered Anaerobic Lagoon. Environments, 2019, 6, 91

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Thomas F. Ducey

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Diana M. C. Rashash

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Ariel A. Szogi

Environments 2019, 6(10), 109; https://doi.org/10.3390/environments6100109 - 24 Sep 2019

Viewed by 3389

Abstract

The authors would like to correct the published article [...] Full article

(This article belongs to the Special Issue Innovative Animal Manure Management for Environmental Protection, Improved Soil Fertility and Crop Production)

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Open AccessArticle

Ammonia, Hydrogen Sulfide, and Greenhouse Gas Emissions from Lab-Scaled Manure Bedpacks with and without Aluminum Sulfate Additions

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Mindy J. Spiehs

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Bryan L. Woodbury

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David B. Parker

Environments 2019, 6(10), 108; https://doi.org/10.3390/environments6100108 - 20 Sep 2019

Cited by 4 | Viewed by 5365

Abstract

The poultry industry has successfully used aluminum sulfate (alum) as a litter amendment to reduce NH₃ emissions from poultry barns, but alum has not been evaluated for similar uses in cattle facilities. A study was conducted to measure ammonia (NH₃), [...] Read more.

The poultry industry has successfully used aluminum sulfate (alum) as a litter amendment to reduce NH₃ emissions from poultry barns, but alum has not been evaluated for similar uses in cattle facilities. A study was conducted to measure ammonia (NH₃), greenhouse gases (GHG), and hydrogen sulfide (H₂S) emissions from lab-scaled bedded manure packs over a 42-day period. Two frequencies of application (once or weekly) and four concentrations of alum (0, 2.5, 5, and 10% by mass) were evaluated. Frequency of alum application was either the entire treatment of alum applied on Day 0 (once) or 16.6% of the total alum mass applied each week for six weeks. Ammonia emissions were reduced when 10% alum was used, but H₂S emissions increased as the concentration of alum increased in the bedded packs. Nitrous oxide emissions were not affected by alum treatment. Methane emissions increased as the concentration of alum increased in the bedded packs. Carbon dioxide emissions were highest when 5% alum was applied and lowest when 0% alum was used. Results of this study indicate that 10% alum is needed to effectively reduce NH₃ emissions, but H₂S and methane emissions may increase when this concentration of alum is used. Full article

(This article belongs to the Special Issue Innovative Animal Manure Management for Environmental Protection, Improved Soil Fertility and Crop Production)

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Environments, Volume 6, Issue 10 (October 2019) – 6 articles

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