8/9/2019 Bioaccumulation of Arsenic in Chlorella vulgaris (Chlorophyta: Chlorellaceae) in effluent from industrial park Rio Sec…

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Bioaccumulation of Arsenic in Chlorel la vulgar is (Chlorophyta:Chlorellaceae) in effluent from industrial park Rio Seco andacute toxicity on Daphn ia magna  (Crustacea: Daphniidae),Arequipa, PeruRonald E. Huarachi Olivera1; Alex Dueñas Gonza1; Ursulo Yapo Pari1 ; Percy Apfata1;Norbert Tejada Rivera1; Dennis Manuel Cristóbal1 & Rosaura Gonzalez Juarez1

Contact¹Laboratory of Aquatic Biology, Academic Department of Biology,

National University of Saint Augustine (UNSA), Av. Alcides Carrión s/n, Arequipa, PeruvianE-mail: biologiaacuaticaunsa@gmail.com

*Corresponding author: A. Wolf • cel.: 5154958006028 · http://ecotoxicologia-bioensayos.blogspot.com 

Study AreaProblemScope

Arsenic in Chlorel la : experimental setup Acute toxicity in Daphnia : experimentalsetup

First results First results

- Plant of treatment Chilpina,Arequipa, PeruChlorella vulgaris (Chlorophyta:Chlorellaceae)71°32´15,93” LO;

16°26´50,76” LS;2293 m.s.n.m 

- INDUSTRIAL PARK RÍOSECO (IPRS)Northeast of the center of thecity of Arequipa; District CerroColorado, Province Arequipa,Peru.71°35’59´´ LO; 16°21’22´´ LS;2250 m.s.n.m. 

System of flow by gravity at different speedsof flow with Chlorella vulgaris. a) initialcultivation of 1.5 L of C. vulgaris by tray.b) effluent from the IPRS treated in thesystem of flow by gravity to 20 mL/min.c) 40 mL/min. d) 80 mL/min.

Determination of thecapacity of bioaccumulationof As in industrial effluentsof the IPRS 

Gravity flow system 

- 20 mL/min 

- 40 mL/min 

- 80 mL/min 

Samples were taken everyfour days for a period of 20days 

- Chlorophyll “a” 

- Residual concentrationof As 

Growth of Chlorella

vulgar is at differentconcentrations of As III(Na2HAsO3) 

T=Negative control

T1= 1.6 mg/L

T2= 3.2 mg/L 

T3= 6.4 mg/L 

Samples were taken every five days for a period of 20 days  

Evaluation of counting Chamber of Neubauer  

The effluent from the IPRS treated with lower residual As concentration, having gone throughthe modified system of flow by gravity. 

 Acute toxicity of industrial effluents of the IPRS treated with Chlorella vulgaris, inDaphnia magna. 

Count of neonates from 0 to 24 h:  LC50 (Median Lethal Concentration) 

 Negative control 

- 250 mL reconstituted water  

25% Effluent 

- 185 mL reconstituted water - 62.5 mL Effluent PIRS 

50% Effluent 

- 125 mL reconstituted water   - 125 mL Effluent PIRS 

 75% Effluent 

- 62.5 mL reconstituted water   - 187.5 mL Effluent PIRS 

Arsenic (As): Metalloid 

- Very Toxic Element 

- Damages on human health 

Environmental Protection Agency (EPA 1986) 

- Allowable limit of arsenic (As) in natural waters: 0.05 mg/L 

Microbial bioremediation of arsenic: Interesting option- High efficiency 

- Low-cost 

  Microbial activity:- Detoxify- Mobilize or immobilize the arsenic

Oxidation reductionBiomethylation 

Complexation processes 

Discharges to the environment

- INDUSTRIAL PARK RÍO SECO (IPRS):  Liquid waste

Big impact on air, water and soil pollution 

The growth of Chlorella vulgaris  accordingto concentrations of As III shows anincrease in the number of cells until the 4thassessment , (6.4 mg/L) 71333.34 org/mL. 

Shows the presence of two groups (a andb) according to the test of multiplecomparison of Tukey, the T3 treatment(6.4 mg/L) which presented higher growthof Chlorella vulgaris, followed bytreatments T1 and T2, being the controlgroup which presented lower averagegrowth. 

The concentration of chlorophyll "a" in asystem of flow by gravity withChlorella vulgaris shows the presence ofthree groups (a, b and c) according to thetest of multiple comparison of Tukey. 

The residual concentration of industrialeffluents of the IPRS As (Industrial Park RioSeco) through a system of flow by gravity withChlorella vulgaris shows the presence of twogroups (a and b) according to the Tukeymultiple comparison test. 

Industrial effluents of theIPRS As removal (IndustrialPark Río Seco) through thesystem of flow by gravitywith Chlorella vulgaris

shows bioaccumulation of As effluent to 20 mL/minwith 60.05%, followed by23.72% decrease retrieved40 mL/min, while thesmaller decline wasobtained to 80 mL/min at6.94% As present in theeffluents of the IPRS. Alsothe model describing thepercent decrease Asindicates that if the flowvelocity increases by 1mL/min As decreases in0.82%. 

 Acute toxicity of the IPRS treated with

Chlorella vulgaris, in Daphnia magnamodel mathematician Probit shown theLC50-48h = 3.25 mg/L effluent treated in thesystem of flow by gravity to 20 mL/min. 

General Scheme of heavy metal detoxification mechanism mediated by class III metallothineins (MtIII) in microalgae.Abbreviations: MeL) ,metal complex in solution, (Men+) free heavy metal ion, (X) biotic exocellular ligand, (E) glutamic acid, (C)cysteine, (G) glycine, (γEC) Gammaglutamylcysteine, (γECG)Glutathione, ([γEC]2G) Metallothionein n=2, (LMW) low molecularweight, (HMW) high molecular weigth, (γECS) Gamma glutamylcysteine synthetase, (PCS) phytochelatin synthetase, (HMT1)vacuolar ABC transporter. * when this step is repeated MtIII of longer chain can be synthesized, · MtIII is disassociated whenreleased to medium (Perales et., al. 2006) 

Conclusions

- Maximum growth of Chlorella vulgaris is present in the 4th assessment withT3 = 6.4 mg/L As III.

- The capacity of bioaccumulation of As with Chlorella vulgaris in effluents ofthe IPRS, was measured by indicator of biomass as the concentration ofchlorophyll "a" decreases as speed increases in the system of flow by gravitywith removal of the 60.05% As in 20 mL/min.

- The bioassay of toxicity with Daphnia magna indicates that the (LC50) was3.25 mg/L at 48 h evaluation.