Chemical oxygen demand, total organic carbon and colour reduction in slaughterhouse wastewater by unmodified and iron-modified clinoptilolite-rich tuff

Abstract

In this study, reduction of chemical oxygen demand (COD), colour, and total organic carbon in effluents from a slaughterhouse in central Mexico was performed using clinoptilolite-rich tuff. The experimental parameters considered were initial concentration of the adsorbate, pH, adsorbent dosage, and contact time. Surface morphology of the materials was tested by using scanning electron microscopy. Specific surface area was analysed by using Brunauer-Emmett-Teller (BET) and phase composition was analysed by using X-ray diffraction. The experimental adsorption data were fitted to the first- and pseudo-second-order kinetic models. The highest COD removal was observed in slightly acidic pH conditions. The maximum reduction efficiency of COD was accomplished with unmodified clinoptilolite-rich tuff at a contact time of 1440 min. In these conditions, the adsorbent was efficient for treating wastewater from a slaughterhouse. Moreover, after several regeneration cycles with Fenton reagent or hydrogen peroxide, the regenerated zeolite with H2O2 (3%) showed the best reduction efficiencies.

Bioremediation of piggery slaughterhouse wastewater using the marine protist, Thraustochytrium kinney VAL-B1

“…2 ) in media containing the residue at 100% of concentration, in which the highest biomass content was detected on the fifth day of cultivation. The initial COD measured in the residue was 9610 mg L −1 (data not shown), which is similar to those reported in the literature for SWW samples [38] , [39] . After 1 day of cultivation, COD levels in the medium supernatant increased, which could be due to the presence of organic matter from the residue-based medium and the inoculum medium, and the adaptation period of the microorganism, where THs are adjusting to their new conditions.…”

Aplicación de pretratamientos físicos y tratamientos biológicos al agua residual de rastro como estrategia para mejorar el rendimiento de metano

“…Las zeolitas son minerales de aluminosilicatos altamente porosos, con una red cargada negativamente y se caracterizan por su alta capacidad de intercambio iónico (Guaya et al, 2015;Gupta et al, 2015;Montalvo et al, 2012;Torres-Pérez et al, 2014). Tienen una combinación tetraédrica con una molécula de silicato o aluminio en el centro y cuatro átomos de oxígeno en los vértices (Jimenez-Cedillo, 2004; Wang y Peng, 2010).…”

“…La clinoptilolita es la zeolita natural más abundante y, por lo tanto, la más utilizada en el tratamiento de aguas industriales y agrícolas (Montalvo et al, 2012) así como en la eliminación de amonio y metales pesados (Torres- Pérez et al, 2014).…”

“…Estudios como los realizados por Torres- Pérez et al, (2014) y Zhang et al, (2019), han utilizado zeolita natural para la eliminación de amonio, fósforo, materia orgánica y color en aguas sintéticas que simulaban las concentraciones presentes en las aguas residuales de rastro, encontrando eficiencias de remoción del 50 %, 45 %, 30 % y 50 %, respectivamente, y señalando que la combinación de tratamientos biológicos con la adsorción en zeolita, es un método viable y prometedor para generar efluentes de mejor calidad.…”

“…Estos lotes de agua contenían gran cantidad de SV respecto a los ST, 76.1 %, 45.5 % y 61.4 % respectivamente, por lo que estos sólidos podrían ser de fácil degradación durante el proceso de digestión anaerobia (Lee et al, 2015;Torres-Pérez et al, 2014).…”