The last decade witnessed a quantum increase in wind energy contribution to the U.S. renewable electricity mix. Although the overall environmental impact of wind energy is miniscule in comparison to fossil-fuel energy, the early stages of the wind energy life cycle have potential for a higher environmental impact. This study attempts to quantify the relative contribution of individual stages toward life cycle impacts by conducting a life cycle assessment with SimaPro^® and the Impact 2002+ impact assessment method. A comparative analysis of individual stages at three locations, onshore, shallow-water, and deep-water, in Texas and the gulf coast indicates that material extraction/processing would be the dominant stage with an average impact contribution of 72% for onshore, 58% for shallow-water, and 82% for deep-water across the 15 midpoint impact categories. The payback times for CO₂ and energy consumption range from 6 to 14 and 6 to 17 months, respectively, with onshore farms having shorter payback times. The greenhouse gas emissions (GHG) were in the range of 5–7 gCO₂eq/kWh for the onshore location, 6–9 CO₂eq/kWh for the shallow-water location, and 6–8 CO₂eq/kWh for the deep-water location. A sensitivity analysis of the material extraction/processing stage to the electricity sourcing stage indicates that replacement of lignite coal with natural gas or wind would lead to marginal improvements in midpoint impact categories.

Electricity generation from coal is one of the leading contributors to greenhouse gas emissions in the U.S. and has adverse effects on the environment. Biomass from forest residue can be co-fired with coal to reduce the impact of fossil-fuel power plants on the environment. W. A. Parish power plant (WAP, Richmond, TX, USA) located in the greater Houston area is the largest coal and natural gas-based power generation facility in Texas and is the subject of the current study. A life cycle assessment (LCA) study was performed with SimaPro^® and IMPACT 2002+ method, for the replacement of 5%, 10%, and 15% coal (energy-basis) with forest residue at the WAP power plant in Texas. Results from the LCA study indicate that life cycle air emissions of CO₂, CO, SO₂, PM_2.5, NO_X, and VOC could reduce by 13.5%, 6.4%, 9.5%, 9.2%, 11.6%, and 7.7% respectively when 15% of coal is replaced with forest residue. Potential life cycle impact decreased across 9 mid-point impact categories of, human/aquatic toxicity, respiratory organics/inorganics, global warming, non-renewable energy, mineral extraction, aquatic acidification, and terrestrial acidification/nitrification. The potential impact across damage/end-point categories of human health, ecosystem quality, climate change, and resources reduced by 8.7%, 3.8%, 13.2%, and 14.8% respectively for 15% co-firing ratio.

Advanced reduction processes (ARPs) are treatment processes that involve combining reducing reagents and activating tools to produce highly reactive reducing free radicals. The process has proven effective for treating oxidized contaminants, and the effects of process variables on the degradation kinetics of various target contaminants have been investigated in our previous studies. In natural environments, natural organic matter (NOM) is found in surface or ground water. NOM absorbs UV light and can react with photochemically produced radicals, thus affecting target contaminant photochemical reactions and further influencing the efficiency of ARP. This study examines the impact of humic acid (HA) and Suwanee River NOM on bromate reduction rates with UV irradiation using a low-pressure mercury UV lamp. The effects of the sulfite dose, solution pH, and light intensity are studied and the pseudo-first-order rate constants in the presence of HA (kobs,HA) are compared to those observed in the absence of HA (kobs). At low HA concentrations of 1 mg L−1, kobs,HA was larger than kobs; however, kobs,HA was less than kobs at higher HA concentrations. Furthermore, kobs,HA did not increase with increasing sulfite doses in the presence of HA, which is unlike the behavior of kobs.

Almond harvest accounts for substantial particulate matter less than 10 µm in aerodynamic diameter (PM10) emissions in California each harvest season. This paper addresses the reduction of harveste...