Hydromorphological and socio-cultural assessment of urban rivers to promote nature-based solutions in Jarabacoa,Dominican Republic

In Latin America and the Caribbean, river restoration projects are increasing, but many lack strategic planning and monitoring. We tested the applicability of a rapid visual social–ecological stream assessment method for restoration planning, complemented by a citizen survey on perceptions and uses of blue and green infrastructure. We applied the method at three urban streams in Jarabacoa (Dominican Republic) to identify and prioritize preferred areas for nature-based solutions. The method provides spatially explicit information for strategic river restoration planning, and its efficiency makes it suitable for use in data-poor contexts. It identifies well-preserved, moderately altered, and critically impaired areas regarding their hydromorphological and socio-cultural conditions, as well as demands on green and blue infrastructure. The transferability of the method can be improved by defining reference states for assessing the hydromorphology of tropical rivers, refining socio-cultural parameters to better address river services and widespread urban challenges, and balancing trade-offs between ecological and social restoration goals.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01565-3.     

Emissions of organic micropollutants from discontinuously operated municipal waste incinerators

The emission of particles and organic micropollutants (PAH, PCDD and PCDF) was measured from three intermittently operated municipal waste incinerators of medium size. The mutagenicity of the stack gas samples were measured as well. The results show a good agreement between the PAH emitted and the mutagenicity in the stack gases, but none of these parameters correlate with the PCDD/PCDF content.     

Preliminary correlation of organic molecular tracers in residential wood smoke with the source of fuel

Polar cyclic di- and triterpenoids were analyzed in the extracts of residential wood combustion aerosols collected in suburban sections of Eugene, Oakridge and Corvallis, Oregon. Additional samples collected included alder wood, smoke from two wood stoves burning only alder or pine as fuel, soot from a stove burning alder and a fireplace where oak was the predominant fuel. Due to the relatively cooler temperatures present under the smoldering conditions of residential wood combustion, as compared to the active burning of forest fires and slash burns, incomplete combustion resulted in the preservation of high levels of the natural products.There were three distinct signatures which could be used to trace relative input from coniferous, alder and oak combustion products, i.e. diterpenoids, lupane-derived triterpenoids and friedelin, respectively. Conifer combustion products dominated the suburban smoke aerosols.     

Rapid measurement of aerosol concentration in flue gas using an optical fiberscope

We succeeded in developing a new instrument for dust measurement, based on a study of existing methods. It is portable and gives a real-time response. it is based on the measurement of the scattering intensity of near-infrared radiation. Light from a semiconductor laser is transmitted to the detector unit through a heat-resistant fiberscope, and the infrared energy scattered by the aerosol is returned to a sensor in the same way. The detector is inserted directly into the measured gas stream, and can be moved to various points in the stream to obtain representative cross-sectional measurements. Aerosol measurements can be made over a concentration range of 0.01–1000 mg m⁻³. The response appears to be the same, based on mass concentration, for flyash, combustion smoke, and dust in a steel mill.     

Mechanism of spring high oxidant episode— A meteorological analysis in and around the Hokuriku district,Japan

In order to clarify the mechanism of spring surface level high oxidant episodes, both upper and surface level ozone observations were carried out from April to June 1983. The results were analyzed using aerological data and AMeDAS (Automated Meteorological Data Acquisition System) data.During the observation period, there were 11 days with high oxidant episodes which were defined as when the recorded ozone concentration exceeded 100 ppb at any of five stations. Meteorological conditions under which the surface episodes occurred were examined for three cases when upper level ozone distributions were observed, and the mechanism of the episode were investigated. In this paper, the analysis for one case is explained in detail. For this case: (i) the peak time of oxidant (ozone) concentration at each surface station was controlled by the transition pattern of photochemical oxidant under the local wind system and (ii) the stratospheric air with high concentrations of ozone intruded into the troposphere through the tropopause gap (tropopause folding) behind the cyclone and continued to descend gradually. In the lower troposphere, it descended further due to the influence of topography, and contributed to high surface oxidant episodes. The descent of stratospheric ozone was related to the position of both cyclones and anticyclones. The other two cases had similar upper meteorological conditions but different surface wind systems such as land and sea breeze.     

Simulated effects of tropospheric emissions on the global antimony cycle

A novel steady-state model, based on an eight-reservoir geochemical cycle, is presented for Sb. From this, the time-dependent effects of increasing industrial Sb emissions have been examined by computer simulation. Coal combustion has the largest impact, raising the tropospheric burden by 160% between 1800 AD and 2140 AD. However, the present-day Sb burden was not predicted by the simulations, suggesting that a large vapour-phase source, possibly from low-temperature mobilization, has not been identified experimentally. Small variations in the deposition velocity of pollutant Sb in the simulations had little effect on short-range transport, but a dramatic effect on the long-range transport of this element.     

Instrumentation and monitoring of a bentonite landfill liner

A landfill site in northern Wales which lies only a few metres above the local water table was lined with a mixture of locally available sand and imported bentonite. To test the permeability and leachate attenuation capacity of this liner special test chambers lined with high-density polyethylene (HDPE) were constructed underneath the sand-bentonite liner and instrumented to collect samples of any infiltrating water. Over an 18-month period there has been less than 1 mm of infiltration from a completed section of the landfill into the test chambers. No evidence of contamination of the groundwater by the landfill has been detected in test wells. The sampling continues.