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Abstract

The article presents the research into hygienizing process of chicken manure using calcium peroxide (CaO2) as an environmentally friendly biological deactivation agent. The influence of the addition of CaO2 to chicken manure on the bioavailability of phosphorus was also analyzed. The process of biological deactivation using CaO2, CaO and Ca(OH)2 agents was analyzed applying the disk diffusion method. To optimize the effect of the hygienizing parameters, (CaO2 concentration, pH, temperature and time) on the reduction of Enterobacteriaceae count the Taguchi method was applied. The content of bioavailable phosphorus was measured with the Egner-Riehm method and determined with spectrophotometry. The reduction in bacterial count followed an increase in the concentration of CaO2 in a sample. The optimal experimental conditions (CaO2=10.5 wt.%, pH=9.5, T=40°C, t=180 h) enabled a significant decrease in the Enterobacteriaceae count, from 107 cfu/g to 102 cfu/g. Analysis of the samples with Egner-Riehm method showed that the phosphorus content decreased with the addition of biocide CaO2: from 26.6 mg/l (for 3.5 wt.%) to 3.5 mg/l (for 10.5 wt.%). These values were slightly higher than the content of phosphorus deactivated with Ca(OH)2 i.e., from 11.25 mg/l (for 3.5 wt.%) to 4.49 mg/l (for 10.5 wt.%). The application of CaO2 for hygienizing chicken manure enables effective reduction of Enterobacteriaceae count to an acceptable level (below 1000 cfu/g). In comparison with the traditional techniques of hygienization, the application of CaO2 has a positive effect on the recovery of bioavailable phosphorus.

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Authors and Affiliations

Angelika Więckol-Ryk
1
Barbara Białecka
2
ORCID: ORCID
Maciej Thomas
3

  1. Central Mining Institute, Department of Risk Assessment and Industrial Safety, Poland
  2. Central Mining Institute, Department of Water Protection, Poland
  3. Chemiqua Water & Wastewater Company, Poland
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Abstract

The possibility of removing organic compounds from wastewater originating from the photochemical production of printed circuit boards by use of waste acidification and disposal of precipitated photopolymer in the first stage and the UV-Fenton method in a second stage has been presented. To optimize the process of advanced oxidation, the RSM (Response Surface Methodology) for three independent factors was applied, i.e. pH, the concentration of Fe(II) and H2O2 concentration. The use of optimized values of individual parameters in the process of wastewater treatment caused a decrease in the concentration of the organic compounds denoted as COD by approx. 87% in the first stage and approx. 98% after application of both processes. Precipitation and the decomposition of organic compounds was associated with a decrease of wastewater COD to below 100 mg O2/L whereas the initial value was 5550 mg O2/L. Decomposition of organic compounds and verification of the developed model of photopolymers removal was also carried out with use of alternative H2O2 sources i.e. CaO2, MgO2, and Na2CO3·1,5H2O2.

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Authors and Affiliations

Barbara Białecka
Maciej Thomas
Dariusz Zdebik
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Abstract

The possibility of Cu(II), Ni(II) and Sn(II) removal from model solutions and real wastewater from

the production of PCBs using Na2

CS3

for precipitation was presented in this paper. The testing was carried out

on a laboratory scale using model and real industrial wastewater containing additives in the form of complexing

compounds used in the production of PCBs (Na2

EDTA, NH3(aq), thiourea) and recommended by the USEPA

(Na3

MGDA, Na4

GLDA). Application of Na2

CS3

in optimal conditions of conducting precipitation process was

connected with obtaining wastewater containing low concentrations of metals (Cu 0.02 mg/L, Sn <0.01 mg/L, Ni

<0.005 mg/L at pH 9.39 and Cu 0.07 mg/L, Sn <0.01 mg/L, Ni 0.006 mg/L at pH 7.79). Controlled application of

Na2

CS3

by the use of a platinum redox electrode was also connected with obtaining treated wastewater containing

low concentrations of metals (Cu 0.019 mg/L, Sn <0.05 mg/L, Ni <0.0098 mg/L at pH 9–9.5 and E= -142 mV in the

laboratory scale and Cu 0.058 mg/L, Sn <0.005 mg/L, Ni 0.011 mg/L at pH 9.14 and E= +10 mV in the industrial

scale). Changing the value of redox potential of treated wastewater by dosing Na2

CS3

made it possible to control

the precipitation process on laboratory and industrial scale by the use of a platinum redox electrode. Controlled

application of Na2

CS3

can be used to remove Cu(II), Ni(II) and Sn(II) from industrial effl uent containing chelating

compounds like Na2

EDTA, NH3(aq), thiourea, Na3

MGDA and Na4

GLDA.

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Authors and Affiliations

Barbara Białecka
Maciej Thomas
Dariusz Zdebik

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