Monthly Archives: April 2013

Water quality impacts reverse osmosis biofouling in desalination

Siqian Huanga, Nikolay Voutchkovb, Sunny C. Jianga. Investigation of environmental influences on membrane biofouling in a Southern California desalination pilot plant. Desalination, Volume 319, 14 June 2013, Pages 1–9.

One of the challenges the seawater desalination industry faces today is reverse osmosis (RO) membrane biofouling. Traditional water quality parameters such as SDI and the RO feed water turbidity are inadequate at protecting the membrane from biofouling. This research investigated the environmental and water quality parameters in a Southern California desalination plant in order to develop a set of seawater desalination RO membrane biofouling indicators. Statistical analysis was performed on data collected onsite over two years. The relationships between operation parameters, rain precipitations, TOC, UV254, chlorophyll fluorescence in raw seawater and the performance loss of the RO desalination process are presented. The environmental triggers for accelerated RO membrane biofouling was further investigated by developing membrane fouling simulators at the desalination pilot plant. Biofouling was confirmed by confocal laser scanning microscopy investigation of membrane biofilm and live and dead bacterial cell counts. The results of this study indicated that biofouling was significantly correlated with water quality changes. Thus, chlorophyll fluorescence measurements can be used as a precursor for desalination membrane biofouling.

Click here for full paper (fee).

Temperature drives atmospheric CO2 due to ocean outgassing

This paper demonstrates temperature drives CO2 levels due to ocean outgassing. Man-made CO2 does not drive temperature. Man is not the primary cause of the rise in CO2 levels.

Roger J. Francey, Cathy M. Trudinger, Marcel van der Schoot, Rachel M. Law, Paul B. Krummel, Ray L. Langenfelds, L. Paul Steele, Colin E. Allison, Ann R. Stavert, Robert J. Andres & Christian Rödenbeck. Atmospheric verification of anthropogenic CO2 emission trends. Nature Climate Change 3,520–524(2013)doi:10.1038/nclimate1817

International efforts to limit global warming and ocean acidification aim to slow the growth of atmospheric CO2, guided primarily by national and industry estimates of production and consumption of fossil fuels. Atmospheric verification of emissions is vital but present global inversion methods are inadequate for this purpose. We demonstrate a clear response in atmospheric CO2 coinciding with a sharp 2010 increase in Asian emissions but show persisting slowing mean CO2 growth from 2002/03. Growth and inter-hemispheric concentration difference during the onset and recovery of the Global Financial Crisis support a previous speculation that the reported 2000–2008 emissions surge is an artefact, most simply explained by a cumulative underestimation (~ 9 Pg C) of 1994–2007 emissions; in this case, post-2000 emissions would track mid-range of Intergovernmental Panel on Climate Change emission scenarios. An alternative explanation requires changes in the northern terrestrial land sink that offset anthropogenic emission changes. We suggest atmospheric methods to help resolve this ambiguity.

Click here for full paper (fee).

Yangtze River: source of life and prosperity for the Chinese people

Floehr T, Xiao H, Scholz-Starke B, Wu L, Hou J, Yin D, Zhang X, Ji R, Yuan X, Ottermanns R, Roß-Nickoll M, Schäffer A, Hollert H. Solution by dilution?-A review on the pollution status of the Yangtze River. Environ Sci Pollut Res Int. 2013 Apr 23.

The Yangtze River has been a source of life and prosperity for the Chinese people for centuries and is a habitat for a remarkable variety of aquatic species. But the river suffers from huge amounts of urban sewage, agricultural effluents, and industrial wastewater as well as ship navigation wastes along its course. With respect to the vast amounts of water and sediments discharged by the Yangtze River, it is reasonable to ask whether the pollution problem may be solved by simple dilution. This article reviews the past two decades of published research on organic pollutants in the Yangtze River and several adjacent water bodies connected to the main stream, according to a holistic approach. Organic pollutant levels and potential effects of water and sediments on wildlife and humans, measured in vitro, in vivo, and in situ, were critically reviewed. The contamination with organic pollutants, including polycyclic aromatic hydrocarbons, polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans, polybrominated diphenyl ethers (PBDEs), perfluorinated compounds (PFCs), and others, of water and sediment along the river was described. Especially Wuhan section and the Yangtze Estuary exhibited stronger pollution than other sections. Bioassays, displaying predominantly the endpoints mutagenicity and endocrine disruption, applied at sediments, drinking water, and surface water indicated a potential health risk in several areas. Aquatic organisms exhibited detectable concentrations of toxic compounds like PCBs, OCPs, PBDEs, and PFCs. Genotoxic effects could also be assessed in situ in fish. To summarize, it can be stated that dilution reduces the ecotoxicological risk in the Yangtze River, but does not eliminate it. Keeping in mind an approximately 14 times greater water discharge compared to the major European river Rhine, the absolute pollution mass transfer of the Yangtze River is of severe concern for the environmental quality of its estuary and the East China Sea. Based on the review, further research needs have been identified.

Click here for full paper (Open Source).

Solar influence on global temperature

“There is little need to ascribe a unique cause to late 20th-century global warming (such as elevated atmospheric CO2 concentrations), as this latest warming is merely a run-of-the-mill relative warming, sitting atop a solar-induced baseline warming that has been in progress for the past four centuries.”

Click image below for full report.

Pages from solar_influence SPPI

Accelerated sea level rise claim refuted…..again.

The claim of a recent acceleration in the rate of sea level rise cannot be validated by tide gauge records, either in Australia or globally. It is quite the contrary.

Nils-Axel Morner, Albert Parker. Present-to-future sea level changes: The Australian case. Environmental Science: An Indian Journal. ESAIJ, 8(2), 2013 [43-51]

We revisit available tide gauge data along the coasts of Australia, and we are able to demonstrate that the rate may vary between 0.1 and 1.5 mm/year, and that there is an absence of acceleration over the last decades. With a database of 16 stations covering only the last 17 years, the National Tidal Centre claims that sea level is rising at a rate of 5.4mm/year.We here analyse partly longer-term records from the same 16 sites as those used by the Australian Baseline Sea Level Monitoring Project (ABSLMP) and partly 70 other sites; i.e. a database of 86 stations covering a much longer time period. This database gives a mean trend in the order of 1.5 mm/year. Therefore, we challenge both the rate of sea level rise presented by the National Tidal Centre in Australia and the general claim of acceleration over the last decades.

Click here for the full paper.

Community-based oral health self-care intervention for Hispanic families

Hull PC, Reece MC, Patton M, Williams J, Beech BM, Canedo JR, Zoorob R. A community-based oral health self-care intervention for Hispanic families. Int J Public Health. 2013 Apr 24.

OBJECTIVES: A community-based intervention is described that targets oral health self-care practices among Hispanic children in the United States and is being tested in an ongoing trial. Descriptive results of baseline oral health variables are presented.

METHODS: As of January 2013, 284 Hispanic children of ages 5-7 enrolled in the Healthy Families Study in Nashville, TN, USA. Families are randomized to one of two culturally appropriate interventions.

RESULTS: At baseline, 69.6 % of children brushed at least twice daily, and 40.6 % brushed before bed daily. One-third of parents did not know if their children’s toothpaste contained fluoride.

CONCLUSIONS: This intervention fills the need for community-based interventions to improve oral health self-care practices that are culturally appropriate in Hispanic families.

Average global temperature metric of little practical use

Studies like this are akin to the school yard bullies ganging up to push everyone else around, like winning the popular vote. With 20 or more authors, the study is simply a synthesis of reconstructions with perhaps no relationship to reality. What do we learn from this effort that we do not already know? Very little, if anything. Temperatures can differ regionally as well as locally, making the metric of an average global temperature of little practical use, as I have argued in the past.

Ahmed, M. et al. Continental-scale temperture variability during the past 2 millennia. Nature Geoscience(2013)doi:10.1038/ngeo1797.

Past global climate changes had strong regional expression. To elucidate their spatio-temporal pattern, we reconstructed past temperatures for seven continental-scale regions during the past one to two millennia. The most coherent feature in nearly all of the regional temperature reconstructions is a long-term cooling trend, which ended late in the nineteenth century. At multi-decadal to centennial scales, temperature variability shows distinctly different regional patterns, with more similarity within each hemisphere than between them. There were no globally synchronous multi-decadal warm or cold intervals that define a worldwide Medieval Warm Period or Little Ice Age, but all reconstructions show generally cold conditions between ad 1580 and 1880, punctuated in some regions by warm decades during the eighteenth century. The transition to these colder conditions occurred earlier in the Arctic, Europe and Asia than in North America or the Southern Hemisphere regions. Recent warming reversed the long-term cooling; during the period ad 1971–2000, the area-weighted average reconstructed temperature was higher than any other time in nearly 1,400 years.

Click here for full paper (fee). For more discussion of this paper, click here.