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Supplementary Treatment of Wastewater by Using Ecological Lime Derived from Eggshell Waste – A New Sustainable Strategy for Safe Reuse

Assal Aicha, Nasrellah Hamid, Aarfane Abdellatif, Bakasse Mina, El Mahi Mohammed, El Mostapha Lotfi

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 1

180--189

EN

Wastewater from wastewater treatment plants (WWTPs) often requires further treatment before it can be safely reused. Lime is a common and affordable material used for this purpose, but its production can generate significant environmental impacts. This study developed an eco-friendly and effective lime substitute from eggshell waste for wastewater treatment. First, pre-treated wastewater effluent from WWTP El Jadida, Morocco, was collected and characterized. It was found that COD, BOD5, and TSS values showed non-conformity from Moroccan discharge standards, as well as high concentrations of heavy metals such as cadmium (Cd), zinc (Zn), aluminum (Al), chromium (Cr), manganese (Mn), lead (Pb), silver (Ag), beryllium (Be), copper (Cu) and cobalt (Co). These pollutants represent a potential risk to human health and the environmental ecosystem. To reduce this pollution, the optimal mass of lime powder obtained by thermal treatment of eggshell waste was determined by testing a concentration series of 6, 12, 18, 24, 30, and 36 g·L-1. The findings confirmed that the addition of the optimal dose of prepared lime (24 g·L-1) resulted in a significant reduction in pollution parameters, with abatement rates of 77% for BOD5, 63% for COD and 66% for TSS, respectively. Furthermore, the eco-friendly lime substitute also showed promise in reducing the colorization rate for dyes by 84% and removing heavy metals through precipitation. However, the generated by-product loaded with toxic pollutants should be encapsulated in eco-materials to ensure safe operation and contribute to a sustainable management strategy for wastewater treatment.

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Zastosowanie promieniowania ultrafioletowego do rozkładu barwników w roztworach wodnych

Perkowski J., Szadkowska-Nicze M., Blus K., Wroński P.

Prace Instytutu Elektrotechniki

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2012

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Z. 255

93-107

PL

Przeprowadzono badania dekoloryzacji roztworów barwników azowych za pomocą wybranych procesów pogłębionego utleniania z udziałem promieniowania UV. Zastosowano fotoutlenianie w obecności tlenu, ozonu, nadtlenku wodoru, nadtlenku wodoru i ozonu, oraz fotokatalityczne utlenianie z udziałem ditlenku tytanu TiO2 P25 firmy Degussa. Doświadczenia wykonano w temperaturze pokojowej dla roztworów następujących barwników reaktywnych: żółtego BK-221, czerwonego BK-230, fioletowego BK-253 i czarnego RB5. Stosowano produkty komercyjne w stężeniach 100 i 200 mg/dm3. Jako źródła światła wykorzystano niskociśnieniową lampę rtęciową o mocy 15 W i średniociśnieniową o mocy 8 W. Proces dekoloryzacji analizowano spektrofotometrycznie w zakresie UV-VIS za pomocą spektrofotometru Perkin Elmer Lamda 750.

EN

Decoloration of azo dyes by selected advanced oxidation processes under UV irradiation was investigated. Photooxidation in the presence of oxygen, ozone, hydrogen peroxide, as well as hydrogen peroxide and ozone and photocatalytic oxidation with titanium dioxide TiO2 Degussa P25 was applied. Experiments were performed at room temperature, and the solutions of the following reactive dyes: yellow BK-221, red BK-230, purple BK-253 and black RB5 were investigated. The solutions of the commercial products with concentrations of 100 and 200 mg/dm3 were used. The low-pressure mercury lamp with power of 15 W and the medium-pressure Hg lamp with power of 8W were applied as the light sources. The decoloration process was analyzed spectrophotometrically in the UV-VIS range by a Perkin Elmer Lamda 750 spectrophotometer.

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Effect of gamma-irradiation on aqueous solutions of Apollofix dyes

Solpan D., Torun M., Güven O.

Nukleonika

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2007

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Vol. 52, nr 3

109-113

EN

Radiation processing has been considered as a promising process for the treatment of textile industry waste effluents. In this study, the possibility of using gamma-rays to degrade and decolorize Apollofix dyes in water has been investigated. Two different Apollofix dyes, Apollofix Red (AR) and Apollofix Yellow (AY) in aqueous solutions were irradiated in air with doses from 1.0 kGy to 8.0 kGy at a 0.14 kGy/h of dose rate. The change in absorption spectra, pH, chemical oxygen demand (COD), biological oxygen demand (BOD) and the degree of decoloration (percent reduction in optical density) were examined in the presence and absence of H2O2. The absorption bands at 534 nm and 420 nm for AR and AY were observed to decrease rapidly with increasing irradiation dose. The degree of decoloration of each dye solution with irradiation dose was estimated as 100 percent for the lower concentration (50 ppm) dye solutions. The complete decoloration was observed after 2.0 kGy and 1.0 kGy doses for AR and AY dyes. The COD and BOD reduction and the change of pH for all dye solutions on irradiation showed similar behavior.

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Decomposition of Anthraquinone Dye Acid Blue 62 by the Decoloration of Textile Wastewater by Advanced Oxidation Process

Perkowski J., Kos L., Ledakowicz S., Żyłła R.

Fibres & Textiles in Eastern Europe

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2003

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Vol. 11, no. 2 (41)

88--94

EN

The results of the decomposition of anthraquinone dye Acid Blue 62 are discussed in the paper. Different versions of the advanced oxidation process were used for decoloration of the aqueous solution of this dye. Such agents as ozone, hydrogen peroxide, UV and gamma radiation, as well as various combinations of those factors, were applied. The effectiveness of the decoloration reaction induced by the different process versions was compared. In all those processes, the main oxidising species was hydroxyl radical. Therefore, using pulse radiolysis, the rate constant of the primary reaction of hydroxyl radical with the anthraquinone dye Acid Blue 62 molecule was determined. Based on the results obtained, a mechanism of the primary decomposition reactions was proposed.

PL

Zbadano rozkład barwnika antrachinonowego Acid Blue 62. Do dekoloryzacji jego roztworów wodnych zastosowana różne wersje procesu pogłębionego utleniania i czynniki utleniające takie jak: ozon, nadtlenekwodoru, promieniowanie UV i gamma oraz różne ich kombinacje. Opierając się na uzyskanym stopniu dekoloryzacji roztworów, porównano efektywności różnych wersji procesu pogłębionego utleniania. We wszystkich zastosowanych procesach ważnym czynnikiem utleniającym jest rodnik hydroksylowy. Metodą radiolizy impulsowej wyznaczono stałą szybkości reakcji między rodnikiem a cząsteczką barwnika Acid Blue 62. Propozycje przebiegu tej reakcji oparto na danych z radiolizy impulsowej oraz wynikach odbarwiania roztworu w procesie inicjowanym rodnikami hydroksylowymi.