Removal performance for thermotolerant coliforms and fecal streptococci from dairy effluents by Kenadsa’s natural green clay (Bechar-Algeria) in a fixed-bed column

• Published in: Applied water science 2021-06, Vol.11 (6), p.1-15, Article 106
• Main Authors: Nabbou, Nouria, Benyagoub, Elhassan, Belhachemi, Meriem, Boumelik, Mustapha, Benyahia, Moncef
• Format: Article
• Language: English
• Subjects: Adsorbents; Adsorption; Agricultural wastes; Aluminium; Aluminum; Aluminum oxide; Analytical methods; Antiinfectives and antibacterials; Aquatic Pollution; Bacteria; Breakthrough time; Clay; Clay characterizations; Clay minerals; Clean technology; Coliforms; Comparative Law; Contaminants; Contamination; Dairy effluents; Discharge; Disinfection; Earth and Environmental Science; Earth Sciences; Efficiency; Effluent treatment; Effluents; Fecal coliforms; Fecal streptococci; Ferric oxide; Fixed beds; Fixed-bed adsorption process; Flow rates; Flow velocity; Fluorescence; Fourier analysis; Fourier transforms; Height; Hydrogeology; Illite; Illites; Impaired water use; Industrial and Production Engineering; Infrared analysis; Infrared spectroscopy; International & Foreign Law; International regulations; Iron constituents; Magnesium; Minerals; Nanotechnology; Optimization; Original Article; Parameters; Particle size distribution; Private International Law; Regulations; Removal; Service life; Silica; Silicon dioxide; Size distribution; Spectrometry; Superconductors (materials); Thermotolerant coliforms; Waste Water Technology; Wastewater irrigation; Wastewater treatment; Water Industry/Water Technologies; Water Management; Water Pollution Control; X-ray diffraction
• ISSN: 2190-5487; 2190-5495
• DOI: 10.1007/s13201-021-01441-1

This present work is a part of the liquid discharges treatment topic by studying the removal performance for thermotolerant coliforms (FC) and fecal streptococci (F.Strep) by a local natural light green clay from Kenadsa (Bechar-Algeria) under continuous adsorption processes in a fixed-bed column. The study estimated the clay adsorbing efficiency by the adsorption technique for bacteria contaminating the dairy effluent by determining the bacterial load before and after treatment. The mean log counts per 100 ml for FC and F.Strep were assessed by MPN method on liquid medium. The clay material characterizations were made through X-ray diffraction, X fluorescence spectrometry and Fourier transform infrared spectroscopy analysis. Besides, some parameters were estimated such as the breakthrough time t b (clay filter breakdown); the amount of the contaminating bacteria that was removed at the breakthrough time X b and the exhaustion of disinfection capacity X e ; the total amount of contaminating bacteria flowing through the column X total ; and the total removal efficiency (Y). According to the XRD, XRF and FTIR results, the predominant mineral constituents were silicon dioxide, aluminum oxide, ferric oxide and magnesium oxide with rates of 59,44; 18,09; 7,79; and 3,87%, respectively, and hence, their classification among non-swelling clay minerals, illite is the major mineral group of this material. The results of the bacteriological analysis of raw dairy effluents showed an average bacterial load of 3,88 Log 10 and 4,1 Log 10 CFU/100 mL for FC and F.Strep, respectively, exceeding the thresholds set by the national and the international regulations. The results of the dairy effluents treated by the tested material have shown that the used clay has a relatively high adsorption property for the clay fixed-bed system (3 cm of bed height), expressed by a total removed efficiency Y (%) of FC and F.Strep used to evaluate the column performance ranging from 55 to 84%. It gives a higher log removal for FC and F.Strep (0.98–1.65 Log 10 ) reported from the first adsorption process, and a breakthrough time ranged from 100 to 250 min, which was inversely proportional to the initial bacterial load of discharges and also linked to the nature of the bacterial contaminants. When the breakthrough occurs earlier, the column service life will be shortened. For the studied parameters, the results of treated effluent complied with national and WHO regulations for unrestricted agri