Potassium supplement enhanced cadmium removal in a Microcystis aeruginosa photobioreactor: evidence from actual and simulated wastewater

2021 ◽  
pp. 127719
Author(s):  
Mengzi Liu ◽  
Yanyan Wei ◽  
Muhammad Salam ◽  
Xiaobing Yuan ◽  
Bingsheng Liu ◽  
...  
2008 ◽  
Vol 99 (15) ◽  
pp. 7034-7040 ◽  
Author(s):  
Guiqiu Chen ◽  
Guangming Zeng ◽  
Lin Tang ◽  
Chunyan Du ◽  
Xiaoyun Jiang ◽  
...  

2020 ◽  
Vol 13 (2) ◽  
pp. 91-98
Author(s):  
Zahraa N. Abbas ◽  
Ali H. Abbar

A rotating tubular packed bed electrochemical reactor was used for the electrochemical removal of cadmium (Cd) from simulated wastewater. Impacts of electrolysis operating parameters: current (0.56–2.8 A), rotation speed (100–500 rpm), initial cadmium concentration (20–100 ppm), and pH (3-9) were investigated. Response surface methodology and Box-Behnken design were used for optimizing the process parameters where cadmium Removal Efficiency (RE %) was selected as a response function. Findings of the present work suggested that currently has a main impact on the removal efficiency of cadmium followed by rotation speed, then concentration and pH. The results of the regression analysis showed that experimental data could be fitted to a second-degree polynomial model with value of the determination coefficient (R2) equal to 91.8 %. Optimal conditions for process parameters based on the RSM model were initial Cd concentration of 32.0 ppm, current of 2.8 A, rotation speed of 371 rpm and pH = 3, where a final cadmium concentration less than 0.3 ppm was obtained after 30 min of electrolysis process (RE= 99.28% ).


2020 ◽  
Vol 85 ◽  
pp. 47-58
Author(s):  
Y Jiang ◽  
Y Liu

Various studies have observed that increased nutrient supply promotes the growth of bloom-forming cyanobacteria, but only a limited number of studies have investigated the influence of increased nutrient supply on bloom-forming cyanobacteria at the proteomic level. We investigated the cellular and proteomic responses of Microcystis aeruginosa to elevated nitrogen and phosphorus supply. Increased supply of both nutrients significantly promoted the growth of M. aeruginosa and the synthesis of chlorophyll a, protein, and microcystins. The release of microcystins and the synthesis of polysaccharides negatively correlated with the growth of M. aeruginosa under high nutrient levels. Overexpressed proteins related to photosynthesis, and amino acid synthesis, were responsible for the stimulatory effects of increased nutrient supply in M. aeruginosa. Increased nitrogen supply directly promoted cyanobacterial growth by inducing the overexpression of the cell division regulatory protein FtsZ. NtcA, that regulates gene transcription related to both nitrogen assimilation and microcystin synthesis, was overexpressed under the high nitrogen condition, which consequently induced overexpression of 2 microcystin synthetases (McyC and McyF) and promoted microcystin synthesis. Elevated nitrogen supply induced the overexpression of proteins involved in gas vesicle organization (GvpC and GvpW), which may increase the buoyancy of M. aeruginosa. Increased phosphorus level indirectly affected growth and the synthesis of cellular substances in M. aeruginosa through the mediation of differentially expressed proteins related to carbon and phosphorus metabolism. This study provides a comprehensive description of changes in the proteome of M. aeruginosa in response to an increased supply of 2 key nutrients.


2019 ◽  
Vol 46 (1) ◽  
pp. 73-84
Author(s):  
L. Zhou ◽  
S. Nakai ◽  
G. F. Chen ◽  
Q. Pan ◽  
N. X. Cui ◽  
...  

2018 ◽  
Vol 43 (2) ◽  
pp. 265-274 ◽  
Author(s):  
W.X. Hong ◽  
S.P. Zuo ◽  
L.T. Ye ◽  
B.Q. Qin

2016 ◽  
Vol 15 (8) ◽  
pp. 1689-1703 ◽  
Author(s):  
Ackmez Mudhoo ◽  
Manjeet Bansal ◽  
Vinod Kumar Garg ◽  
Diwan Singh

2020 ◽  
Vol 51 (4) ◽  
pp. 1231-1238
Author(s):  
Zeki & Ridha

This study was aimed to investigate the ability of N.oleander to remove Cadmium (Cd) from wastewater. A prolonged toxicity test was performed in a single exposure and run for 65 days with various concentrations of Cd. Plants were grown in sand medium and irrigated with simulated wastewater contaminated with Cd, using different concentrations (0, 10, 25, 50, 75 mg/L), which were chosen based on previous preliminary test. The results of physical observation of the plants didn’t show any withering symptoms. The Cd concentration in plants increased, while in water decreased. The results of plant analysis showed that Cd concentration in plant shoots (stems and leaves) was higher than that in roots for almost all exposure doses along the test duration. The concentration of Cd in water decreased significantly from the first week of the test and become (0 mg/l) on day-35 for 10 and 25 mg/l exposure doses, while exceeded the permissible limits for 50 and 75 mg/l exposure doses and were 0.14 and 0.91 mg/l, respectively. Wet weight and dry weight of Oleander decreased with increasing Cd concentration level except for 10 mg/l exposure dose where the plant wet weight and dry weight increased at the end of the test. Bioaccumulation factor (BAF) and Translocation Factor (TF) was found to be greater than 1, indicating that Oleander is a successful hyperaccumulator for Cd.


2020 ◽  
Vol 16 (4) ◽  
pp. 436-446
Author(s):  
Vallerie A. Muckoya ◽  
Philiswa N. Nomngongo ◽  
Jane C. Ngila

Background: Parabens are synthetic esters used extensively as preservatives and/or bactericides in personal care personal products. Objective: Development and validation of a novel robust chemometric assisted analytical technique with superior analytical performances for the determination of ethylparaben, methylparaben and propylparaben, using simulated wastewater matrix. Methods: An automated Solid Phase Extraction (SPE) method coupled with liquid chromatographymass spectrometry was applied in this study. A gradient elution programme comprising of 0.1% formic acid in deionised water (A) and 0.1% formic acid in Methanol (B) was employed on a 100 x 2.1 mm, 3.0 μm a particle size biphenyl column. Two-level (2k) full factorial design coupled with response surface methodology was used for optimisation and investigation of SPE experimental variables that had the most significant outcome of the analytical response. Results: According to the analysis of variance (ANOVA), sample pH and eluent volume were statistically the most significant parameters. The method developed was validated for accuracy, precision, Limits of Detection (LOD) and Limit of Quantification (LOQ) and linearity. The LOD and LOQ established under those optimised conditions varied between 0.04-0.12 μgL−1 and 0.14-0.40 μgL−1 respectively. The use of matrix-matched external calibration provided extraction recoveries between 78-128% with relative standard deviations at 2-11% for two spike levels (10 and 100 μgL-1) in three different water matrices (simulated wastewater, influent and effluent water). Conclusion: The newly developed method was applied successfully to the analyses of parabens in wastewater samples at different sampling points of a wastewater treatment plant, revealing concentrations of up to 3 μgL−1.


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