Environments, Volume 7, Issue 9 (September 2020) – 9 articles

Reactive barriers, such as denitrifying bioreactors, have been identified as a clean-up option for nutrient-laden agriculture runoff. Here we tested a 20 m long, 3.75 m wide and 2.2 m deep woodchip bioreactor receiving tile drainage water from a 5.2 ha field site, aiming at testing the hydraulic functioning of a dual-inlet system and quantifying its impact on nutrient loads (nitrogen, reactive phosphorus, organic carbon) in a region with a drainage season taking place in the hydrological winter (November to April). The hydraulic conditions in the dual-inlet bioreactor system developed differently than expected; asymmetric flow rates led to long average hydraulic retention times and a highly dispersed residence time distribution, which was revealed by a bromide tracer test. With a nitrate load reduction of 51 to 90% over three drainage seasons, the woodchip bioreactor proved at the same time to be very effective under the winter conditions of northeastern Germany. The bioreactor turned from an orthophosphate source in the first year of operation into an orthophosphate sink in the second and third year, which was not expected because of anoxic conditions (favorable for denitrification) prevailing within the woodchips. Besides an efficient nutrient retention, the woodchip bioreactor contributed to the total organic carbon load of receiving waters, which impairs the overall positive role of bioreactors within intensively agriculturally used landscapes. We consider this promising low-maintenance biotechnology particularly suitable for single drainage pipes with high discharge and high nitrate concentrations. Full article

This article provides a sectoral innovation system perspective of the development of energy efficient and clean process technologies in the Swedish pulp and paper industry. Specifically, the analysis elaborates the importance of knowledge development, actor networks, and institutions (including policy) for progressing and diffusing novel technologies related to energy use. The empirical analysis also sheds light on how significant changes in the sectoral innovation system have influenced the relevant research, development and demonstration activities in the Swedish pulp and paper industry over the period 1970–2010. The results are based on various sources—e.g., industry magazines, reports from industrial consultants and associations, minutes from meetings—and illustrate the importance of well-functioning innovation systems for successful technological development and diffusion processes. They display, in particular, the importance of joint, industry-wide R&D activities, trust-based state—industry relationships, government R&D expenditures, and intense information sharing. One important implication is that the role of policy stretches beyond the funding of basic R&D. Policy also involves measures that strengthen existing actor networks, build competence, and secure the existence of research institutes that provide a bridge between basic knowledge generation (at the universities) on the one hand, and industrial application on the other. Full article

Gd³⁺ forms a strongly colored complex with 4-(2-pyridylazo)-resorcinol (PAR) in aqueous solutions. We characterized the Gd³⁺-PAR complex in order to use it as a probe of Gd³⁺ speciation in the presence of environmentally relevant ligands. The formation of the Gd³⁺-PAR complex was investigated from pH 5 to 8 in the presence of excess PAR. The absorbance of the Gd³⁺-PAR complex dramatically increased from pH 5 to 8 and application of the method of continuous variation indicates that the complex was primarily 1:2 Gd(PAR)₂ at pH 8. Stability constants for Gd³⁺ with other ligands can be quantified by competitive displacement of the PAR ligand. To establish the viability of this approach, we measured the stability constants between Gd³⁺ and several organic acids and carbonate. Our measurements show reasonable agreement with the literature values. We used the competitive displacement approach to establish that humic acids can competitively displace PAR from the Gd(PAR)₂ complex. Full article

Seaweed, a popular seafood in South Korea, has abundant dietary fiber and minerals. The toxicity of arsenic compounds is known to be related to their chemical speciation, and inorganic arsenic (iAs) is more detrimental than other species. Due to the different toxicities of the various chemical forms, speciation analysis is important for evaluating arsenic exposure. In this study, total arsenic (tAs) and six arsenic species (arsenite, arsenate, monomethylarsonic acid, dimethylarsinic acid, arsenobetaine, and arsenocholine) were analyzed in 180 seaweed samples. Although there were differences between seaweed species, the concentration of tAs was detected at levels ranging from 1 to 100 µg/g, and the distribution of six arsenic species differed depending on the seaweed species. No correlation between the concentration of iAs and tAs was found in most seaweed species. Through statistical clustering, hijiki and gulfweed were seen to be the seaweeds with the highest ratios of iAs to tAs. Using the iAs concentration data from the arsenic speciation analysis, a risk assessment of seaweed intake in South Korea was conducted. The margin of exposure values showed no meaningful risk for the general population, but low levels of risk were identified for seaweed consumers, with high intakes of gulfweed and hijiki. Full article

Although a growing body of research has debated the array of sustainability lessons of vernacular architecture, social sustainability discussions remain less advanced in comparison to the other pillars of sustainability. This has narrowed the plural lessons of vernacular architecture and limited the broad concept of sustainability to a partial one. Against this research gap, this study aims to conduct an assessment of the social sustainability of residential vernacular architecture through the application of a proposed Social Criteria of Green Building Assessment Tool (SCGBAT) assessment method. The SCGBAT proposes eight sets of social criteria categories namely; health and safety; participation and control; education; equity, accessibility and satisfaction; social cohesion; cultural values; physical resilience and also, 37 indicators for the evaluation of social sustainability. To empirically operationalize the proposed SCGBAT, this study utilizes the vernacular architecture typologies in the vernacular landscape of Louroujina village in Cyprus as a case study. Methods for data collection are desk review for secondary data while 135 close-ended questionnaires were used for primary data. The data are statistically presented based on Linkert scale and interpreted using both quantitative and descriptive analysis. The results demonstrated that the investigated vernacular architecture ranked lowly in Physical Resilience Indicator (PRI), Environmental Education Indicator (EEI), Accessibility and Satisfaction Indicator (ASI) but demonstrated sufficient lessons in the context of Health and Safety Indicator (HSI); Participation and Control Indicator (PCI); Social Equity Indicator (SEI); Social Cohesion Indicator (SCI); and Cultural Value Indicator (CVI). To this end, this paper contribute to the advancement of knowledge on the assessment of the social sustainability of vernacular architecture by innovatively applying a green building assessment approach and identifying the strengths and weaknesses of such approach in a vernacular setting. Full article

Foundries represent a significant part of the world’s economy and are a large consumer of energy and producer of solid waste. Sand-handling processes can use 5–10% of a foundry’s total energy. The goal of this research was to explore source reduction and waste minimization at a foundry, using both economic and Life Cycle Assessment (LCA) techniques to compare three secondary sand-reclamation options. LCA software modeled all sand processes at a mid-sized ferrous foundry in the USA. The LCA showed all secondary reclamation technologies, while more energy intensive at the foundry, lowered life cycle environmental impacts, including GHG emissions, ecotoxicity, and human health indicators, due primarily to source reduction and corresponding reduction in transportation both from the virgin sand source and to the landfill. Varying transportation distance had a large impact on LCA results to the point where the life cycle benefit of secondary reclamation became a liability in a zero distance scenario. Varying electricity generation to favor greener sources was also examined, but proved to have minimal impact on the LCA results. This research suggests that the greatest reduction of life cycle impacts in the sand-handling processes for a foundry is to find a geographically closer source for virgin sand. Full article

Other test method (OTM) 33A has been used to quantify emissions from natural gas sites since it was introduced by the Environmental Protection Agency (EPA). The method relies on point source Gaussian (PSG) assumptions to estimate emissions rates from a targeted site or source. However, the method often results in low accuracy (typically ±70%, even under conducive conditions). These accuracies were verified with controlled-release experiments. Typically, controlled releases were performed for short periods (15–20 min) under atmospheric conditions that were ideal for effective plume transport. We examined three methane release rates from three distances over various periods of time ranging from seven hours to seven days. Data were recorded continuously from a stationary tower. Atmospheric conditions were highly variable and not always conducive to conventional OTM 33A calculations. OTM 33A estimates were made for 20-min periods when the mean wind direction corresponded to ±90° of the direction from the controlled release to the tower. Further analyses were performed by varying the frequency of the data, the length of the individual OTM 33A periods and the size of the wind angle used to filter data. The results suggested that different (than conventionally used) period lengths, wind filters, data acquisition frequencies and data quality filters impacted the accuracy of OTM 33A when applied to long term measurements. Full article

This study applied a passive sampling approach using low-density polyethylene passive samplers to determine the treatment efficiency of the Kearl surface flow treatment wetland for polycyclic aromatic hydrocarbons (PAHs) in Oil Sands Process-affected Waters (OSPW). Treatment efficiency was measured as concentration-reduction and mass-removal from the OSPW. The results show that the wetland’s ability to remove individual PAHs from the influent varied substantially among the PAHs investigated. Treatment efficiencies of individual PAHs ranged between essentially 0% for certain methylated PAHs (e.g., 2,6-dimethylnaphthalene) to 95% for fluoranthene. Treatment in the Kearl wetland reduced the combined total mass of all detected PAHs by 54 to 83%. This corresponded to a reduction in the concentration of total PAHs in OSPW of 56 to 82% with inflow concentrations of total PAHs ranging from 7.5 to 19.4 ng/L. The concentration of pyrene in water fell below water quality targets in the Muskeg River Interim Management Framework as a result of wetland treatment. The application of the passive samplers for toxicity assessment showed that in this study PAHs in both the influent and effluent were not expected to cause acute toxicity. Passive sampling appeared to be a useful and cost-effective method for monitoring contaminants and for determining the treatment efficiency of contaminants in the treatment wetland. Full article

The main goal of this study was to identify the problems that are putting the viability of watering ponds at risk. For doing that, we have analyzed five different study cases: (I) livestock consumption, Mediterranean climate (rangelands of SW Spain), (II) multifunctional ponds (Arroyo de la Luz, Spain), (III) ecotourism (Valdepajares de Tajo, Spain), (IV) crop irrigation and fish farming, semi-arid climate (the wilaya of Ouargla, Algeria), and (V) livestock consumption, humid subtropical climate (Prudentópolis, Brazil). The identification of problems was made through surveys, personal interviews, local knowledge and literature review as well as through the analysis of water quality parameters such as the concentration of phosphates and fecal coliforms in some ponds. We have identified problems of water shortage (ca. 50% of rangeland farmers), pollution induced by agriculture (maximum values of phosphates = 1.33 mg L⁻¹) and livestock farming (maximum value of fecal coliforms ≈ 7000 cfu mL⁻¹), low potability for human consumption (score: 2.8/7.0), invasive species such as Azolla filiculoides (10 out of 17 watering ponds), high water temperature for aquaculture in summer (Algeria) and the increase of turbidity in nearby water courses due to the actions of free-fattening pigs (Brazil), among many other problems. We conclude an extra effort by stakeholders is still needed in order to agree mitigation strategies. Full article