Publications by authors named "Helge Liltved"
Article Synopsis
- - This study analyzes the impact of road construction on water quality, focusing on the E18 Arendal-Tvedestrand highway in Norway, by using Remote Sensing data from Sentinel-1 and Sentinel-2 to monitor water turbidity from 2017 to 2021.
- - Sentinel-2's Top of Atmosphere data, corrected using the MAIN algorithm, was found to be effective in estimating water turbidity levels, with findings showing a significant correlation between the corrected data and ground-based observations.
- - Results show that road construction activities can lead to increased turbidity in nearby water bodies, highlighting the potential of Remote Sensing tools in cloud platforms like Google Earth Engine for managing water quality during such projects.
Characterization and treatment of tunneling wastewater using natural and chemical coagulants.
Water Sci Technol
November 2023
Particles are a concern regarding tunneling wastewater, but gaps remain in understanding metal(loid)s content and coagulation efficiency. In this research, characterization of the wastewaters before and after treatment was investigated by chemical analysis and various techniques for particle characterization. Then, laboratory work was conducted to evaluate effectiveness of sedimentation and use of coagulants to remove particles and particle-associated contaminants.
View Article and Find Full Text PDFA method for reclaiming nutrients from aquacultural waste for use in soilless growth systems.
Water Sci Technol
January 2020
Article Synopsis
- The study aimed to create a method for recovering nutrients from aquaculture sludge, helping to solve disposal issues and the potential shortage of fertilizers.
- The process involves two main steps: aerobic digestion to mobilize nutrients and chitosan flocculation to remove solids and turbidity.
- Results showed a significant increase in soluble nitrogen and phosphorus during digestion, with chitosan reducing turbidity by 96% and allowing for the recovery of 80% of the sludge as a nutrient-rich liquid.
Article Synopsis
- Since 2005, NIVA has tested five chlorination-based ballast water management systems (BWMSs) under IMO guidelines, revealing that 25% and over 50% of discharge samples caused acute and chronic toxicity to algae, respectively.
- Most of this toxicity was linked to high levels of free residual oxidants (FRO) exceeding 0.08 mg Cl/l.
- While 22 disinfection by-products (DBPs) were identified, only four were found in potentially harmful concentrations, with no clear connection to algal toxicity, although using methylcellulose in tests appeared to reduce DBP formation compared to lignin.
Article Synopsis
- The study tested how different water treatment methods (filtration, UV, chlorine, ozone) affect the growth of Vibrio cholerae and Vibrio parahaemolyticus bacteria in seawater used for ballast tanks.
- After treatment, the bacteria were added to the water and incubated, revealing that they generally survived better in treated water compared to untreated.
- Notably, the presence of ozone led to the highest bacterial growth, while natural microorganisms added to the water actually reduced the growth of both V. cholerae and V. parahaemolyticus.
The BIOZO process--a biofilm system combined with ozonation: occurrence of xenobiotic organic micro-pollutants in and removal of polycyclic aromatic hydrocarbons and nitrogen from landfill leachate.
Water Sci Technol
September 2010
We present an assessment of xenobiotic organic micro-pollutants (XOM) occurrence and removal of polycyclic aromatic hydrocarbons (PAHs) in a novel biofilm system combined with ozonation, the BIOZO concept, treating partly stabilised landfill leachate. A novel, staged moving-bed biofilm reactor (SMBBR) design was implemented in laboratory- and pilot-scale, and the PAHs removal efficiency of controlled ozonation was assessed installing the ozonation step in the nitrate recirculation line (Position 1) or between the pre-anoxic and aerobic zones (Position 2). COD removal in a laboratory- and in a pilot-scale SMBBR system with and without ozonation is additionally addressed.
View Article and Find Full Text PDFWe present an assessment of the dynamics in the influent concentration of hormones (estrone, estriol) and antibiotics (trimethoprim, sulfamethoxazole, tetracycline, ciprofloxacin) in the liquid phase including the efficiency of biological municipal wastewater treatment. The concentration of estradiol, 17-alpha-ethinylestradiol, doxycycline, oxytetracycline, demeclocycline, chlortetracycline, cefuroxime, cyclophosphamide, and ifosfamide were below the limit of detection in all of the sewage samples collected within this study. Two different types of diurnal variation pattern were identified in the influent mass loads of selected antibiotics and hormones that effectively correlate with daily drug administration patterns and with the expected maximum human hormone release, respectively.
View Article and Find Full Text PDFClimate change impacts on activated sludge wastewater treatment: a case study from Norway.
Water Sci Technol
October 2009
Article Synopsis
- The study investigates how climate change impacts wastewater treatment systems, particularly in Oslo, Norway, focusing on winter operations.
- Findings reveal that when average daily temperatures rise above -1.5°C, there are significant increases in wastewater influent flow rates due to temporary snow melting.
- The research indicates that these temperature fluctuations and melting events create shock-conditions that disrupt key wastewater treatment processes, showing a need for improved modeling to predict these effects.
In Norway the combined hydraulic capacity of all domestic wastewater treatment plants is relatively equally distributed between three major treatment plant types; mechanical, chemical, and combined chemical and biological. The Western coast from Lindesnes in the south to the Russian boarder in the North is dominated by mechanical treatment plants, constituting approximately 68% of the treatment capacity in that area. In the present study we report concentrations and removal efficiencies of polycyclic aromatic hydrocarbons (PAHs), nonylphenols, phthalates, polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) found in five Norwegian wastewater treatment plants (WWTPs) applying different levels of treatment.
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