A new approach using coagulation rate constant for evaluation of turbidity removal

Abstract

Coagulation-flocculation-sedimentation processes for treating three levels of bentonite synthetic turbid water using date seeds (DS) and alum (A) coagulants were investigated in the previous research work. In the current research, the same experimental results were used to adopt a new approach on a basis of using coagulation rate constant as an investigating parameter to identify optimum doses of these coagulants. Moreover, the performance of these coagulants to meet (WHO) turbidity standard was assessed by introducing a new evaluating criterion in terms of critical coagulation rate constant (k c). Coagulation rate constants (k 2) were mathematically calculated in second order form of coagulation process for each coagulant. The maximum (k 2) values corresponded to doses, which were obviously to be considered as optimum doses. The proposed criterion to assess the performance of coagulation process of these coagulants was based on the mathematical representation of (WHO) turbidity guidelines in second order form of coagulation process stated that (k 2) for each coagulant should be C (k c) for each level of synthetic turbid water. For all tested turbid water, DS coagulant could not satisfy it. While, A coagulant could satisfy it. The results obtained in the present research are exactly in agreement with the previous published results in terms of finding optimum doses for each coagulant and assessing their performances. On the whole, it is recommended considering coagulation rate constant to be a new approach as an indicator for investigating optimum doses and critical coagulation rate constant to be a new evaluating criterion to assess coagulants' performance.

Removal of leachate pollutants using flocculation method at simultaneous factors of optimum pH and Tacca leontopetaloides biopolymer flocculant (TBPF) dosage via face‐centred central composite design

“…The first‐ and second‐order reaction equations for the flocculation process by TBPF are shown in Equations () and (), respectively. This kinetic reaction was in agreement with previous studies (Al‐Sameraiy, 2017; Holthoff et al, 1997; Menkiti & Ejimofor, 2016). The k (9 × 10 −6 L/mg/min) in Table 7 was obtained from the slope of 1/Ct against time (min), which represented the rate of flocculation constant for reaction order, α = 2.…”

Development of bio-based material from the Moringa oleifera and its bio-coagulation kinetic modeling–A sustainable approach to treat the wastewater

“…The performance of each bio-coagulant (MOSP) over sewage water was assessed in terms of kc as per Eq. (12) with the performance criterion being k2≥ k c for the sewage water ( Al-Sameraiy, 2017 ). The sewage wastewater had a kc value of 0.024 (1/NTU min), lower than the k2 value for municipal sewage water.…”

Coagulation/flocculation process for marble processing plant effluent: Modelling and optimization through response surface methodology

“…Both of the coagulation and flocculation techniques imply the aggregation of suspended colloidal particles in water, their mechanism, and inducing agents are completely different. In the coagulation process, the hydrolyzable inorganic counterions are used, for example, aluminum, calcium, and iron. When the electrostatic repulsion between the colloidal particles are eliminated via adsorption and charge neutralization mechanism, the solid particles settle down and form a sludge blanket at the bottom of the system.…”

“…In the coagulation process, the hydrolyzable inorganic counterions are used, for example, aluminum, calcium, and iron. When the electrostatic repulsion between the colloidal particles are eliminated via adsorption and charge neutralization mechanism, the solid particles settle down and form a sludge blanket at the bottom of the system. On the other hand, the high molecular weight polymeric flocculants are used in the flocculation instead of the coagulants .…”