RESUMEN
Domestic wastewaters causing pollution contain inorganic and/or organic materials. When the domestic wastewater outflows to the receiving waters, it causes physical, chemical, and biological pollution in them, and deteriorates the ecological balance of those waters. In the treatment of wastewater, various treatment methods are available depending on the pollution strength of the wastewater. Besides mechanical and biological methods, wastewater treatment with physicochemical methods is still one of the most effective and economical options. Particularly in wastewater with a high concentration of suspended solids, this method is very successful, and obtaining high suspended solids removal efficiencies is very possible. In this study, the effects of the use of coagulant and coagulant aid to be used in a treatment plant where domestic wastewater treatment is carried out are determined to increase the treatment efficiency of a biological treatment that comes later in the stages of the treatment. The effluent of the pre-settling tank may contain a lot of suspended solids. This presence of excess suspended solids decreases the efficiency at other levels of treatment and causes energy loss. In the experiments, the standard jar and inhibition tests are done as a method. As a result of the conducted studies, it is determined that the FeCl3, Synthetic coagulant LP 526, FeClSO4, and the combination of anionic polyelectrolyte yield the best results in the removal of the parameters of chemical oxygen demand (COD), total suspended solids (TSS), and volatile suspended solids (VSS). While FeCl3, APE 65, APE 85, Synthetic coagulant LP 526, and FeClSO4 did not show any inhibition effect in the sludge, APE 67, CPE 84, and (Al2(SO4)3 are found to cause inhibition in the sludge.
Asunto(s)
Eliminación de Residuos Líquidos , Aguas Residuales , Anaerobiosis , Análisis de la Demanda Biológica de Oxígeno , Reactores Biológicos , Aguas del AlcantarilladoRESUMEN
This study investigated the removal of Reactive Black 5 (RB5) textile dye from aqueous solutions using cotton (Gossypium hirsutum) seed shell (CSS) as low cost adsorbents. The data were described according to the Freundlich and Langmuir isotherm models. Of these, the Langmuir model provided the best fit for the experimental data. The highest measured adsorption density was 12.19 mg/g at pH 2. An equilibrium adsorption rate of RB5 by CSS (q(e) = 11.879 mg/g) was observed at 30 minutes. In order to evaluate the adsorption kinetic mechanisms, pseudo first and second order rate kinetic models and an intraparticle diffusion model were applied, with the pseudo second order model providing an excellent fit for the data.
Asunto(s)
Gossypium/química , Naftalenosulfonatos/aislamiento & purificación , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del Agua/métodos , Adsorción , Modelos Químicos , Estructura Molecular , Naftalenosulfonatos/química , Semillas/química , Soluciones , Contaminantes Químicos del Agua/químicaRESUMEN
A study on ion exchange kinetics and equilibrium isotherms of ammonium ion on natural Turkish clinoptilolite (zeolite) was conducted using a batch experiment technique. The effects of relevant parameters, such as temperature, contact time and initial ammonium (NH(4)(+)) concentration were examined, respectively. The pseudo first-order, pseudo second-order kinetic models and intraparticle diffusion model were used to describe the kinetic data. The pseudo second-order kinetic model provided excellent kinetic data fitting (R(2)>0.990) and intraparticle diffusion effects ammonium uptake. The Langmuir and Freundlich models were applied to describe the equilibrium isotherms for ammonium uptake and the Langmuir model agrees very well with experimental data. Thermodynamic parameters such as change in free energy (DeltaG(0)), enthalpy (DeltaH(0)) and entropy (DeltaS(0)) were also determined. An examination of the thermodynamic parameters shows that the exchange of ammonium ion by clinoptilolite is a process occurring spontaneously and physical in nature at ambient conditions (25 degrees C). The process is also found to be exothermic. The results indicate that there is a significant potential for the natural Turkish clinoptilolite as an adsorbent material for ammonium removal from aqueous solutions.
Asunto(s)
Compuestos de Amonio Cuaternario/aislamiento & purificación , Zeolitas/química , Cinética , Soluciones , Temperatura , Termodinámica , Turquía , AguaRESUMEN
The adsorption of reactive dyes on Gordes (Turkey) clinoptilolite was investigated by a series of batch and column adsorption experiments. Three reactive dyes (Everzol Black, Everzol Red, Everzol Yellow) were used in laboratory studies. Synthetic wastewaters were used and the ability of natural zeolite (clinoptilolite) and their modified form were examined. The adsorption results, in batch and column reactor, indicate that natural zeolite have limited adsorption capacities of the reactive dyes but are substantially improved upon modifying their surfaces with quaternary amines (HTAB). The degree of hydrophilicity is found to play an important role in the uptake of reactive dyes.
Asunto(s)
Colorantes/aislamiento & purificación , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del Agua/métodos , Zeolitas/química , Adsorción , Residuos Industriales , Industria Textil , Eliminación de Residuos LíquidosRESUMEN
Textile industry effluents exhibit large amounts of dye chemicals, which create severe water pollution. It is therefore important to reduce the dye concentration in the wastewater before discharging into the environment. In this study, the ability of sepiolite to uptake different reactive dyes is investigated. The dyes used in the experiments are Everzol Black B, Everzol Yellow 3RS H/C, and Everzol Red 3BS. A number of parameters on adsorption has been investigated in order to establish the adsorption pattern of sepiolite. The effect of conditioning time, solid/liquid ratio, pH, temperature, and dye concentrations on adsorption are studied. Adsorption isotherms for different reactive dyes have been obtained using both natural and modified sepiolites. The maximum capacity of natural sepiolite for the reactive dyes occurs at around 0.1-1 mg/g. Therefore, the natural sepiolite appears to have a little capacity for reactive dyes. The zeta potential profiles of natural and modified sepiolites against pH are also examined. The modified sepiolite exhibited ten times higher performance than the natural sepiolite.
Asunto(s)
Antiácidos/química , Colorantes/aislamiento & purificación , Silicatos de Magnesio/química , Industria Textil , Eliminación de Residuos Líquidos/métodos , Purificación del Agua/métodos , Adsorción , Concentración de Iones de Hidrógeno , Temperatura , Contaminantes Químicos del Agua/aislamiento & purificaciónRESUMEN
In this study, the adsorption mechanism of three reactive azo dyes (Everzol Black B, Everzol Red 3BS, Everzol Yellow 3RS H/C) on natural porous minerals, sepiolite and zeolite, have been examined in order to identify the ability of clay minerals on the removal of colored textile dyes from aqueous solutions. High ion exchange capacity, high surface areas and importantly their relatively cheap prices make them attractive adsorbents. For this purpose, series of batch adsorption tests were carried out as a function of solids concentration, time and dye concentration using natural and modified sepiolites and zeolites. Also, experiments were conducted to determine the amount of solid to be used in adsorption tests. An optimum solids concentration was selected as 0.05 g/mL (5%). Most of the adsorption was found to take place within the first 2h of mixing, taking into account the extreme changes like pH and concentration, the mixing period was selected as 4 h for further testing. The adsorption results indicate that both natural sepiolite and zeolite have limited adsorption capacities of the reactive dyes but are substantially improved by modifying their surfaces with quaternary amines. The mechanism of adsorption process is elucidated on the basis of experimental data.