Remediation of Polluted River Water by Biological, Chemical, Ecological and Engineering Processes

Selection of appropriate river water treatment methods is important for the restoration of river ecosystems. An in-depth review of different river water treatment technologies has been carried out in this study. Among the physical-engineering processes, aeration is an effective, sustainable and popular technique which increases microbial activity and degrades organic pollutants. Other engineering techniques (water diversion, mechanical algae removal, hydraulic structures and dredging) are effective as well, but they are cost intensive and detrimental to river ecosystems. Riverbank filtration is a natural, slow and self-sustainable process which does not pose any adverse effects. Chemical treatments are criticised for their short-term solution, high cost and potential for secondary pollution. Ecological engineering-based techniques are preferable due to their high economic, environmental and ecological benefits, their ease of maintenance and the fact that they are free from secondary pollution. Constructed wetlands, microbial dosing, ecological floating beds and biofilms technologies are the most widely applicable ecological techniques, although some variabilities are observed in their performances. Constructed wetlands perform well under low hydraulic and pollutant loads. Sequential constructed wetland floating bed systems can overcome this limitation. Ecological floating beds are highly recommended for their low cost, high effectiveness and optimum plant growth facilities

Decontamination of the passaic river sediments using ultrasound with ozone nano-bubbles

The Passaic River is 129km long and flows through the northern New Jersey. During the mid-twentieth century, the U.S. census indicated that there were approximately 2,900 industries along the river bank. The amount of industries established next to the river indicated the inevitable river pollution, which was compounded by lenient environmental protection laws. One of the major contributors of the river pollution was Diamond Alkali Co., which started production of chemicals around 1951 at the 4km marker in the Passaic River. In 1970, the United States Environmental Protection Agency (U.S. EPA) identified the Passaic River as the second most polluted river in the United States, where in 1983 a Diamond Alkali site investigation showed extremely high levels of hazardous chemicals. Contaminants in the river included PAHs, PCDD/F, PCBs, DDT, pesticides and their byproducts, and heavy metals including Hg, Cr, and Pb. This made the contaminated river eligible for cleanup funds under the federal Superfund program. Hence, the U.S. EPA initiated investigations to identify the severity of the river pollution. In 2016, the U.S. EPA proposed a cleanup program to mitigate the impact of the pollution in the river sediments. Scrutinizing the U.S. EPA remediation plan brings up concerns that will impact the current condition of the river. The dredging exposing the contaminated sediments to freshwater, capping to prevent future dredging, and others such as dewatering and the transportation of the dredged sediments impacting the community during the cleanup are some of the major concerns. Hence, identifying a better and complete technology to remediate the Passaic River\u27s contaminated sediments is a necessity. This remediation plan should have the capability to be carried out in-situ, where the negative impacts from the current plan can be mitigated. This research is on developing a novel in-situ technology to remediate the Passaic River sediments by using ultrasound and ozone nano-bubbles. The study identifies key parameters that will enhance the removal of organic and inorganic pollutants from the contaminated sediments. The key parameters that impact the proposed technology are temperature, pH level, ozone nano-bubble size, dissolved ozone concentration, ultrasound power, dwell time, and the duration of ultrasound treatment. Each parameter is varied while observing its impact on the removal efficiency of organic and inorganic contaminants in contaminated sediments. The solution temperature has a direct impact on Ozone levels in water, where organic material removal indicates high removal efficiencies at low temperatures. The maximum removal efficiencies of organics were 92%. The inorganic contaminant used during the investigation is chromium. The removal efficiency of the chromium does not show a significant impact due to temperature, where the study shows a 98% removal efficiency. The test results show that the combination of ozone, nano-bubbles, and ultrasound to treat contaminated sediments is a reliable and implementable technology. The data obtained from the laboratory experiments can be used to develop a pilot scale study for possible field application

Comparative Analysis of Treatment Technologies for PFAS in Water

Many per- and polyfluoroalkyl substances (PFAS), which are characterized by fluorinated carbon chains, have been identified as chemicals of concern due to their toxicity, widespread distribution, and persistence in the environment. This study analyzes the conventional and novel treatment technologies of activated carbon, anion exchange resin, high-pressure membranes, electrocoagulation, foam fraction, ozonation, molecular imprinted polymer adsorbents, bioremediation, electrolysis, photolysis, and sonochemical degradation in regard to PFAS removal. Further optimization of treatment technologies to remove PFAS from water is necessary. Future research will continue the development of treatment trains to enhance removal efficiency and cost-effectiveness

The reduction of petroleum hydrocarbons in soil under saline conditions using ultrasound.

Salts (i.e. NaCl) and hydrocarbons are common soil pollutants found at contaminated sites generated by the oil and gas industry, and such pollutants pose serious risks to the environment and human health. In this study, a series of laboratory experiments were conducted to identify the properties influencing interactions of crude oil, dissolved salt, and soil particles and to evaluate the effectiveness of ultrasonic technology as a useful remediation technique for treating mixed soil contaminants. A sample of soil (sand, clay and muskeg) equivalent to 30 ml volume was spike with 1 to 2% of crude oil (volume: volume). Two salinity categories (no salt and 0.14 M salt added) were selected and the soil slurry was irradiated for up to 40 minutes using a 20 kHz ultrasonic probe operating at an intensity of 400 W/m². The change in crude oil concentration was measured in treated samples by gas chromatograph. The results indicated that the application of ultrasound generally increased the removal of hydrocarbons by a maximum of approximately 50% observed in sand. In contrast, the presence of salt significantly reduced the removal of hydrocarbons.The original print copy of this thesis may be available here: http://wizard.unbc.ca/record=b143505

Evidence on public health interventions to prevent the negative health effects of climate change

Suggested Citation: Anderson H, Brown C, Cameron LL, Christenson M, Conlon KC, Dorevitch S, Dumas J, Eidson M, Ferguson A, Grossman E, Hanson A, Hess JJ, Hoppe B, Horton J, Jagger M, Krueger S, Largo TW, Losurdo GM, Mack SR, Moran C, Mutnansky C, Raab K, Saha S, Schramm PJ, Shipp-Hilts A, Smith SJ, Thelen M, Thie L, Walker R. BRACE Midwest and Southeast Community of Practice. 2017. Climate and Health Intervention Assessment: Evidence on Public Health Interventions to Prevent the Negative Health Effects of Climate Change. Climate and Health Technical Report Series. Climate and Health Program, Centers for Disease Control and Prevention.CS263538-AClimateAndHealthInterventionAssessment_508.pdf2017CDC cooperative agreement awards funded under CDC-RFA-EH13-1305 and CDC-RFA-EH12-1202961

GEOGRAPHIC INFORMATION SYSTEMS AND APPLIED ECONOMICS: AN INITIAL DISCUSSION OF POTENTIAL APPLICATIONS AND CONTRIBUTIONS

Geographic Information Systems (GIS) are becoming increasingly important to virtually all of the natural and social sciences. Applied economists will find that GIS can make valuable contributions to many of the problems with which they are concerned. Moreover, a great deal of the science behind GIS technology would benefit from the contributions of applied economists. This paper presents some initial suggestions for the ways in which GIS may be important to economics and the GIS related issues concerning which applied economists could provide useful insights.Research and Development/Tech Change/Emerging Technologies,

Study on the remediation of organic soil contaminated with polychlorinated biphenyls using a variable frequency microwave furnace

The development of new and innovative remediation technologies for soil contaminated with Polychlorinated Biphenyl (PCB) is necessary to fulfill the need of cleanup of contaminated sites. In the past eight years the Laboratory for Microwave treatment as Hazardous Substance Management Research Center has investigated the use of Microwave energy to remediate contaminated soils. A major drawback of using single frequencies of the microwave range is the non-uniformity of the electromagnetic field. In this thesis a Variable Frequency Microwave Furnace (operating between 2.40 and 7.50 GHz) is used to improve the uniformity of the field. A new method is used to map the field uniformity in a fixed and variable frequency furnace. Frequency ranges larger than 1 GHz lead to uniform field distribution. Soil with an organic content of 82% was contaminated with PCB congeners #53 and #65 to ca. 400 ppm, and subjected to microwave exposure. Extracts of blanks and treated samples were analyzed with GC/MS. No breakdown products were observed in any of the extracts. The reduction of PCB in the extract was not dependent on the length of exposure to microwave energy. Soil temperature had the greatest effect on the reduction efficiency in the extract: the reduction efficiency at 170°C averaged at 55%, at 100°C it was only 17% for PCB #53. In preliminary experiments no PCBs were detected in the offgas. Additional experiments have to investigate the fate of the PCB in the soil as the offgas

Photocatalytic degradation of organic contaminants by titania particles produced by flame spray pyrolysis

Advanced oxidation of organic pollutants with TiO2 photocatalysts is limited due to the wide bandgap of TiO2, 3.2 eV, which requires ultraviolet (UV) radiation. When nanosized TiO2 is modified by carbon doping, charge recombination is inhibited and the bandgap is narrowed, allowing for efficient photodegradation under visible light. Here, we propose a flame spray pyrolysis (FSP) technique to create TiO2. The facile process of FSP has been successful in preparing highly crystalline TiO2 nanoparticles. Using the same procedure to deposit TiO2 onto biochar, the photocatalyst was doped by the carbonaceous material. The morphology, crystalline and electronic structure of the FSP TiO2 and TiO2-decorated biochar (TiO2-BC) were characterized by SEM, XRD, TGA, DLS, and diffuse reflectance UV-vis spectroscopy. Photocatalytic performance of TiO2 and TiO2-BC was investigated for model organic contaminants in an aqueous solution under UV and visible light, which will be compared to that of Degussa P25 TiO2 as a control

Is the Hyporheic Zone Relevant beyond the Scientific Community?

Rivers are important ecosystems under continuous anthropogenic stresses. The hyporheic zone is a ubiquitous, reactive interface between the main channel and its surrounding sediments along the river network. We elaborate on the main physical, biological, and biogeochemical drivers and processes within the hyporheic zone that have been studied by multiple scientific disciplines for almost half a century. These previous efforts have shown that the hyporheic zone is a modulator for most metabolic stream processes and serves as a refuge and habitat for a diverse range of aquatic organisms. It also exerts a major control on river water quality by increasing the contact time with reactive environments, which in turn results in retention and transformation of nutrients, trace organic compounds, fine suspended particles, and microplastics, among others. The paper showcases the critical importance of hyporheic zones, both from a scientific and an applied perspective, and their role in ecosystem services to answer the question of the manuscript title. It identifies major research gaps in our understanding of hyporheic processes. In conclusion, we highlight the potential of hyporheic restoration to efficiently manage and reactivate ecosystem functions and services in river corridors. View Full-Tex