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CONTENTS
Volume 7, Number 3, September 2018
 
All Articleed are Open Access

Abstract
Krishna River is significantly affected due to Srisailam dam from past 30 years. The impact of this hydraulic structure drastically reduced the minimum flow regime on the downstream, which made the river nearing to decaying stage. In the present paper, Environmental Flow called minimum flow values released for the dam are estimated with the help of three hydrological methods viz., Range of variability Approach (RVA), Desktop Reserve Model (DRM), and Global Environmental Flow Calculator (GEFC). DRM method suggested considering the intermediate values obtained from among the three methods to preserve the ecosystem on the downstream of the river, which amounts to an average annual allocation of 9378 Million Cubic Meter (MCM) which is equal to 23.11% of mean annual flow (MAF).In this regard GEFC and RVA methods accounted for 22 % and 31.04% of MAF respectively. The results indicate that current reservoir operation policy is causing a severe hydrological alteration in the high flow season especially in the month of July. The study concluded that in the case of non-availability of environmental information, hydrological indicators can be used to provide the basic assessment of environmental flow requirements. It is inferred from the results obtained from the study, that the new reservoir operations can fulfil human water needs without disturbing Environmental Flow Requirements.

Key Words
environmental flow; hydrological alteration; reservoir operations; ecosystem

Address
A. Uday Kumar and K.V. Jayakumar: Department of Civil Engineering, National Institute of Technology, Warangal, Telangana, India

Abstract
Sixteen USEPA priority polycyclic aromatic hydrocarbons (PAHs) in the surface water from the coastal areas of Bangladesh were analyzed by GC-MS/MS. Samples were collected in winter and summer, 2015. The total concentration of PAHs (sigma PAHs) showed a slight variation in the two seasons, which varied from 855.4 to 9653.7 ng/L in winter and 679.4 to 12639.3 ng/L in summer, respectively. The levels of sigma PAHs were comparable to or relatively higher than other coastal areas around the world. The areas with recent urbanization and industrialization (Chittagong, Cox\'s Bazar and Sundarbans) were more contaminated with PAHs than the unindustrialized area (Meghna Estuary). Generally, 2–3-ring PAHs were the dominant compounds. Molecular ratios suggested that PAHs in the study areas could be originated from both pyrogenic and petrogenic sources. The risk assessment revealed the extremely high ecological risk of PAHs, indicating an intense attention should be paid to PAHs pollution in the coastal areas of Bangladesh.

Key Words
polycyclic aromatic hydrocarbons (PAHs); surface water; risk assessment; coastal area; Bangladesh

Address
Md. Habibullah-Al-Mamun: 1.) Graduate School of Environment and Information Sciences, Yokohama National University, 79-9 Tokiwadai Hodogaya, Yokohama, Kanagawa 240-8501 Japan
2.) Department of Fisheries, University of Dhaka, Dhaka 1000, Bangladesh

Md. K. Ahmed: Department of Oceanography, Earth & Environmental Science Faculty, University of Dhaka,
Dhaka 1000, Bangladesh

Shigeki Masunaga: Faculty of Environment and Information Sciences, Yokohama National University, 79-9 Tokiwadai Hodogaya, Yokohama, Kanagawa 240-8501 Japan


Abstract
In this study, conditions of solid phase extraction (SPE) for determination of some antibiotics such as trimethoprim, oxytetracycline, erythromycin, clarithromycin, azythromycin, doxycycline, sulfamethazine, ciprofloxacin, chlortetracycline, sulfamethoxazole in wastewaters were optimized. After the optimum volume and pH of the sample were determined, the effect of the concentration of the compounds and matrix were investigated. The highest recovery rates for antibiotic compounds were determined between 82% and 105% in 200 mL sample volume and pH 2.5. Then, antibiotic compounds were investigated in influent and effluent samples taken from Konya Urban Wastewater Treatment Plant. The concentration of the antibiotics was detected range of 0.11-101 ng/L in influent waters and less than dl-288 ng/L in effluent samples in wastewater treatment plant. Hazard quotients (HQs) of antibiotic compounds determined in WWTP effluents to evaluate the risk towards different aquatic organisms (algae, Daphnia magna and fish) were determined. Azythromycin for fish and erythromycin, sulfamethoxazole, ciprofloxacin, clarithromycin for algae posed a moderate risk while azythromycin, ciprofloxacin, clarithromycin, oxytetracycline posed a high risk for algae in the receiving environment.

Key Words
antibiotic; LC-MS/MS; risk assessment; SPE, wastewater

Address
Senar Aydin, Arzu Ulvi and Havva Kilic: Department of Environmental Engineering, Faculty of Engineering and Architecture, Necmettin Erbakan University, 42140 Konya-Turkey

Mehmet E. Aydin: Department of Civil Engineering, Faculty of Engineering and Architecture, Necmettin Erbakan University, 42140 Konya-Turkey


Abstract
Continuous input into the aquatic ecosystem and persistent structures have created concern of antibiotics, primarily due to the potential for the development of antimicrobial resistance. Degradation kinetics and mineralization of vancomycin B (VAN-B) by photocatalysis using TiO2 and ZnO nanoparticles was monitored at natural pH conditions. Photocatalysis (PC) efficiency was followed by means of UV absorbance, total organic carbon (TOC), and HPLC results to better monitor degradation of VAN-B itself. Experiments were run for two initial VAN-B concentrations (20–50 mgL-1) and using two catalysts TiO2 and ZnO at different concentrations (0.1 and 0.5 gL-1) in a multi-lamp batch reactor system (200 mL water volume). Furthermore, a set of toxicity tests with Daphnia magna was performed to evaluate the potential toxicity of oxidation by-products of VAN-B. Formation of intermediates such as chlorides and nitrates were monitored. A rapid VAN-B degradation was observed in ZnO-PC system (85 % to 70 % at 10 min), while total mineralization was observed to be relatively slower than TiO2-PC system (59 % to 73 % at 90min). Treatment efficiency and mechanism of degradation directly affected the rate of transformation and by-products formation that gave rise to toxicity in the treated samples.

Key Words
photocatalysis; vancomycin B; degradation; mineralization; ecotoxicity; transformation by-products; TiO2; ZnO

Address
Giusy Lofrano and Maurizio Carotenuto: Department of Chemistry and Biology- University of Salerno- via Giovanni Paolo II, 132- 8484 Fisciano (SA), Italy

Can Burak Özkal and Süreyya Meriç: Tekirdağ Namik Kemal University Environmental Engineering Department Çorlu, Tekirdağ, Turkey

Abstract
The sorption of metal ions with low-cost adsorbents plays an important role in sustainable development. In the present study, the efficacy of sugarcane bagasse, rain tree fruits (samaneasaman), banana stem and their mixtures, used as bio-sorbents, in the removal of Cu(II) and Pb(II) ions from aqueous solution is evaluated. Batch studies are conducted, and residual ions were measured using Inductively Coupled Plasma (ICP)-atomic spectrometer. Effect of pH, initial metal ion concentration, reaction time and adsorbent dosage are studied. The Pb(II) removal efficiency was observed to be 97.88%, 98.60% and 91.74% for rain tree fruits, banana stem and a mixture of adsorbents respectively. The highest Cu(II) ion removal was observed for sugarcane bagasse sorbent with an efficiency of 82.10% with a pH of 4.5 and a reaction time of 90 min. Finally, desorption studies were carried out to study the leaching potential of adsorbent, and it was found that the adsorbent is stable in water than the other leaching agents such as HCl, ammonium acetate, Sodium EDTA. Hence, these adsorbents can be effectively used for the removal of these heavy metals.

Key Words
low-cost adsorbents; heavy metal; lead; copper; banana stem; raintree fruit

Address
Narayana Harish: Department of Civil Engineering, Ramaiah Institute of Technology, MSRIT Post, MSR Nagar, Bengaluru,560054, Karnataka, India

Prashanth Janardhan: Department of Civil Engineering, National Institute of Technology Silchar, Cachar, 788010, Assam, India

Sanjeev Sangami: Department of Civil Engineering, Jain College of Engineering, Belagavvi, 590014, Karnataka, India


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