scholarly journals Non-Parametric Regression Analysis of Diuron and Gabapentin Degradation in Lake Constance Water by Ozonation and Their Toxicity Assessment

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 852
Author(s):  
Goswami ◽  
Jiang ◽  
Petri

Ozone possesses high selectivity in the oxidation of organic pollutants. It actively reacts with electron donating participants which contain π bonds and non-protonated amines groups. The removal efficiency of organic pollutants hugely depends upon the pollutants’ initial concentration and amount of ozone supplied. This study was conducted at Zweckverband Bodensee-Wasserversorgung (Lake Constance Water Supply), Germany. The prime objective of the research was to observe the performance of diuron and gabapentin ozonation for low ozone doses, therefore meeting the real application requirements of the water treatment plant. Thereby, 1 mg·L−1 of the given organic pollutants was chosen for the treatment. The ozone with a dosage of ≈0.68–1.01 mg·L−1 was generated and homogeneously mixed into Lake Constance water in a semi-batch reactor system. The adequate aliquots of diuron/gabapentin were spiked into the homogenous matrix to acquire the desired initial concentration. The effect of ozone dose and reaction time on the degradation of diuron and gabapentin was investigated. Low ozone doses were sufficient for the complete degradation of diuron and gabapentin, although satisfactory total organic carbon (TOC) reduction was not achieved. Nonetheless, the toxicity from ozone treated effluents can be avoided by adjusting treatment conditions. Due to that degradation data obtained did not follow normalization, the non-parametric (non-normalised) data were analysed with a generalised linear regression model for Gaussian and Poisson distribution. Statistical analysis showed that the ozonation treatment of diuron/gabapentin followed the Gaussian model distribution and the degradation data obtained was proven significant using the Kruskal–Wallis test.

2014 ◽  
Vol 1073-1076 ◽  
pp. 849-853
Author(s):  
Xiu Bin Lv ◽  
Zhi Hong Yang ◽  
Hai Zhao Zhao ◽  
Hong Ping Chen

A waste water treatment plant (WWTP) adopts sequencing batch reactor (SBR) process, which exist the problem of instable treatment effect on denitrification and dephosphorization. The total nitrogen (TN) and total phosphorus (TP) of the effluent could not reach the class A standard of discharge standard of pollutants for municipal wastewater treatment plant (GB18918-2002) (hereinafter referred to as the class A standard) as a result of different order in utilizing the carbon source between nitrification and denitrification. The step-feed procedure is used to improve the efficiency of denitrification and dephosphorization. Field experiments about the effects of the different influent distribution ratio (marked as λ) on denitrification and dephosphorization were carried out and the results showed that the effect of the effluent TN is the best and other indexes could also achieve class A standard when λ is 5:3.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Aderonke Adetutu Okoya ◽  
Olasunkanmi Olalekan Olaiya ◽  
Abimbola Bankole Akinyele ◽  
Nnenneh Oruada Ochor

Trihalomethanes (THMs) are formed when excess chlorine during chlorination of water reacts with organic material in water. They have mutagenic and carcinogenic properties. Moringa oleifera (MO) has found wide acceptance by many people in Nigeria who have used it for food for both humans and fauna, for health purposes, and as a coagulant for water treatment. However, the seed husks are currently discarded as waste and they have not been used as adsorbent to remove THMs from water. The physicochemical properties of both the treated and raw surface water were determined using standard methods, and the concentration of THMs was determined from the water treatment plant at different stages of treatment using gas chromatography with flame ionization detector (GC-FID). Recovery experiments were carried out to validate the procedure. The efficiencies of activated carbon of Moringa oleifera seed husk (MOSH) adsorbent for the removal of THMs in the water and as a coagulant for water treatment were also assessed. Batch adsorption experiments were carried out, and different parameters such as pH (5, 7, and 9), adsorbent dosage (0.2, 0.4, and 0.8 g), contact time (30, 60, and 90 minutes), and initial concentration (0.2, 0.4, and 0.6 mg/l) were optimized for the removal of trichloromethane and tribromomethane using the MOSH activated carbon. Experimental adsorption data from different initial concentrations of trichloromethane and tribromomethane were used to test conformity with Langmuir and Freundlich adsorption isotherms. The percentage recovery from our procedures ranged from 96.0 ± 1.41 to 100.0 ± 0.00 for trichloromethane while for tribromomethane the range was 60 ± 2.82 to 100.0 ± 0.00. The mean percentage adsorption efficiencies for the simulation experiment ranged from 34.365 ± 1.41 to 93.135 ± 0.57 and from 41.870 ± 0.27 to 94.655 ± 0.41 for trichloromethane and tribromomethane, respectively. The optimum conditions for both trichloromethane and tribromomethane were pH 9, 0.8 g adsorbent dosage, 60-minute contact time, and 0.6 mg/l initial concentration. The optimum values of these parameters used for the adsorption of the two THMs in the surface water serving the treatment plant gave an efficiency of 100.00 ± 0.00%. The turbidity values for the coagulation experiment reduced from 9.76 ± 0.03 NTU in the raw water before coagulation to 5.92 ± 0.13 NTU after coagulation while all other physicochemical parameters of the surface water decreased in value except conductivity and total dissolved solid which increased from 104.5 ± 3.54 to 108.0 ± 2.83 μS/cm and 63.00 ± 11.31 to 83.0 ± 8.49 mg/l, respectively. The experimental data best fit into Langmuir than Freundlich adsorption isotherm. The study concluded that MOSH activated carbon could serve as an adsorbent for the removal of THMs, calcium, and sulphur from water samples.


2002 ◽  
Vol 51 (4) ◽  
pp. 209-216 ◽  
Author(s):  
Lin Wang ◽  
Baozhen Wang ◽  
Dai Wang ◽  
Weijia Zhang ◽  
Yunan Yang ◽  
...  

2018 ◽  
Vol 147 ◽  
pp. 04006 ◽  
Author(s):  
Muhammad Yudha Ramdhani ◽  
M. Rangga Sururi ◽  
Siti Ainun

Leachate is the liquid waste from anaerobic decomposition in a landfill. The ozonation process can be used for leachate treatment. Sludge from sedimentation in water treatment plant contains 5.96% of Al and 9.35% of Si which can affect of its cation exchange capacity and affects the active site in the catalyst. This study aims to determine the effectivity of sludge in the ozonation process to treat leachate. A 1,5 L semi-batch reactor containing 1 L sample was used in this experiment with the rate of oxygen supply was at 4 L/min taken from ambient air. Two groups of sludge weighing 1.5 grams, 3.0 grams and 4.5 grams were used and activate with physically and chemically activated. The best result was obtained by the physically activated sludge with mass of 4.5 gram O3-L-4,5 AF. The differences of removal efficiency between O3-L-4,5 AF with the control (O3) for turbidity were respectively 13.02% and 7.81%, for EC were 10.57% and 8.29%, for COD were 49.44% and 37.50%, and for residual ozone concentration at the end of contact time were 7.6 mg/L and 9.7 mg/L. It can be concluded that activaed sludge and ozonation can be used as a catalyst in leachate treatment.


2018 ◽  
Vol 18 (3) ◽  
pp. 81-91 ◽  
Author(s):  
C. Lalhriatpuia

Nanopillars-TiO2 thin films was obtained on a borosilicate glass substrate with (S1) and without (S2) polyethylene glycol as template. The photocatalytic behaviour of S1 and S2 thin films was assessed inthe degradation of methylene blue (MB) dye from aqueous solution under batch reactor operations. The thin films were characterized by the SEM, XRD, FTIR and AFM analytical methods. BET specific surface area and pore sizes were also obtained. The XRD data confirmed that the TiO2 particles are in its anatase mineral phase. The SEM and AFM images indicated the catalyst is composed with nanosized pillars of TiO2, evenly distributed on the surface of the substrate. The BET specific surface area and pore sizes of S1 and S2 catalyst were found to be 5.217 and 1.420 m2/g and 7.77 and 4.16 nm respectively. The photocatalytic degradation of MB was well studied at wide range of physico-chemical parameters. The effect of solution pH (pH 4.0 to 10.0) and MB initial concentration (1.0 to 10.0 mg/L) was extensively studied and the effect of several interfering ions, i.e., cadmium nitrate, copper sulfate, zinc chloride, sodium chloride, sodium nitrate, sodium nitrite, glycine, oxalic acid and EDTA in the photocatalytic degradation of MB was demonstrated. The maximum percent removal of MB was observed at pH 8.0 beyond which it started decreasing and a low initial concentration of the pollutant highly favoured the photocatalytic degradation using thin films and the presence of several interfering ions diminished the photocatalytic activity of thin films to some extent. The overall photocatalytic activity was in the order: S2 > S1 > UV. The photocatalytic degradation of MB was followed the pseudo-first-order rate kinetics. The mineralization of MB was studied with total organic carbon measurement using the TOC (total organic carbon) analysis.


2018 ◽  
Vol 2 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Tee L. Guidotti

On 16 October 1996, a malfunction at the Swan Hills Special Waste Treatment Center (SHSWTC) in Alberta, Canada, released an undetermined quantity of persistent organic pollutants (POPs) into the atmosphere, including polychlorinated biphenyls, dioxins, and furans. The circumstances of exposure are detailed in Part 1, Background and Policy Issues. An ecologically based, staged health risk assessment was conducted in two parts with two levels of government as sponsors. The first, called the Swan Hills Study, is described in Part 2. A subsequent evaluation, described here in Part 3, was undertaken by Health Canada and focused exclusively on Aboriginal residents in three communities living near the lake, downwind, and downstream of the SHSWTC of the area. It was designed to isolate effects on members living a more traditional Aboriginal lifestyle. Aboriginal communities place great cultural emphasis on access to traditional lands and derive both cultural and health benefits from “country foods” such as venison (deer meat) and local fish. The suspicion of contamination of traditional lands and the food supply made risk management exceptionally difficult in this situation. The conclusion of both the Swan Hills and Lesser Slave Lake studies was that although POPs had entered the ecosystem, no effect could be demonstrated on human exposure or health outcome attributable to the incident. However, the value of this case study is in the detail of the process, not the ultimate dimensions of risk. The findings of the Lesser Slave Lake Study have not been published previously and are incomplete.


2019 ◽  
Vol 10 (1) ◽  
pp. 16
Author(s):  
V. MANE-DESHMUKH PRASHANT ◽  
B. MORE ASHWINI ◽  
B. P. LADGAOKAR ◽  
S. K. TILEKAR ◽  
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