Removal of glyphosate from water: applying coupled Sequencing Batch Reactor (SBR)-adsorption method

Wastewater discharged from Glyphosate manufacturing is a major environmental concern due to its complicated treatment process. In this study, the performance of a sequencing batch reactor (MSBR)-adsorption process treating Glyphosate wastewater was investigated. Operation results from SBR process showed that effluent's chemical oxygen demand (COD) removal efficiency, total suspended solids (TSS) and total phosphorus (TP) were 40 %, 105 mgL-1 and 55 mgL-1, respectively. However, the result of TP concentration did not meet the discharge limitation. The SBR effluent was then undergone an adsorption process using palm kernel shell-based activated carbon (PKS-AC). Minimum adsorbent dosage of 7 gL-1 was needed to further reduce TP concentration to discharge limitation of 2 mgL-1

Optimization of flocculation process for cut-stone wastewater: effect of rapid mix parameters

Wastewater produced from stone industry of Iran causes serious environmental problems associated with slurry disposal. In traditional method, many ponds are required for clarifying. The use of filtration and addition of chemicals enhance the efficiency of operation as well as saving laborer cost. The polymer bridging mechanism is responsible for flocculation of suspended particles. It was found that the increase of rapid mix velocity reduced the residual turbidity substantially except for the dosage of 0.2 mg of polymer. The addition of polymer was able to enhance flocs strength. For higher dosages of polymer, a direct relationship between increasing rapid mix velocity and reduction of turbidity was observed. The values of aggregation rate constant Kapp were calculated to evaluate the effects of rapid mix velocity and dosage of polymer on residual turbidity. The maximum value of Kapp = 7.2 x 10-3 was obtained for the rapid mix velocity 200 rpm and dosage of polymer 1 mg/l

Sorption kinetics for the removal of cadmium and zinc onto palm kernel shell based activated carbon

The kinetics and mechanism of cadmium and zinc adsorption on palm kernel shell based activated carbons (PKSAC) have been studied. A series of batch laboratory studies were conducted in order to investigate the suitability of palm kernel shell based activated carbon (PKSAC) for the removal of cadmium (cadmium ions) and zinc (zinc ions) from their aqueous solutions. All batch experiments were carried out at pH 7.0 and a constant temperature of 30+-1°C using an incubator shaker that operated at 150 rpm. The kinetics investigated includes the pseudo first order, the pseudo-second order and the intraparticle diffusion models. The pseudo-second order model correlate excellently the experimental data, suggesting that chemisorption processes could be the rate-limiting step

Comparative study of polypropylene composites reinforced with oil palm empty fruit bunch fiber and oil palm derived cellulose

In recent years, the race for producing biodegradable products has increase tremendously. Different approaches have been attempted to use biomass as natural biopolymer for production of biodegradable plastics. In this work, cellulose was derived from oil palm empty fruit bunch fiber (EFBF) by standard ASTM D1104 method. The cellulose and EFB fibers were blended in different ratios up to 50-wt.% with polypropylene (PP) using Brabender twin-screw compounder. Effects of cellulose and EFB fibers on the mechanical properties of PP were investigated. Studies on the morphological properties and the influence of fiber loading on the properties of PP-cellulose and PP-EFBF composites were also conducted. The PP-cellulose composite gave better results in comparison with PP-EFBF composite. The changes in mechanical and morphological properties with different cellulose and fiber loading were discussed

Use of Box-Behnken design in the preparation of mesoporous carbon coated monolith - BET surface area

Preparation of fiirfuryl alcohol based activated carbon monolith is reported. The effects of the preparation parameters like carbonization temperature, concentration of polyethylene glycol (PEG) and molecular weight of PEG on surface area are investigated. Based on Box-Behnken design, a quadratic model is developed to correlate the preparation parameters to surface area. From the analysis of variance. (ANOVA), carbonization temperature, concentration of polyethylene glycol (PEG) and molecular weight of PEG are identified the dominant parameters in controlling the surface area. The maximum surface area found from the liSM is 58'5.6m'Vg at carbonization temperature of 660°C and concentration of PEG of 31% vol. with molecular weight of PEG of 1000 g/mol

Optimisation of reactive dye removal by sequential electrocoagulation–flocculation method: comparing ANN and RSM prediction

The removal of Reactive Black 5 dye in an aqueous solution by electrocoagulation (EC) as well as addition of flocculant was investigated. The effect of operational parameters, i.e. current density, treatment time, solution conductivity and polymer dosage, was investigated. Two models, namely the artificial neural network (ANN) and the response surface method (RSM), were used to model the effect of independent variables on percentage of dye removal. The findings of this work showed that current density, treatment time and dosage of polymer had the most significant effect on percentage of dye removal (p0.8)

Equilibrium and kinetic study on reactive dyes adsorption by palm kernel shell-based activated carbon: in single and binary systems

The adsorption of two reactive dyes, Reactive Black 5 and Reactive Red E, onto palm kernel shell-activated carbon (PKSAC) was studied. The effect of the presence of more than one dye in solution on the equilibrium and kinetics of adsorption was investigated. Equilibrium isotherm models were applied to describe the adsorption capacities of single and binary systems. Adsorption of reactive dyes for single system can be represented by the Freundlich and the Redlich-Peterson models. For binary system, the equilibrium was described successfully by the modified extended Freundlich model. Experimental data showed that competitive adsorption for active sites on the carbon surface resulted in a reduction in the overall uptake capacity of the reactive dyes. The rates of adsorption in single system were found to agree well with the pseudosecond-order kinetic model. Finally, the chemical oxygen demand (COD) of the treated reactive dye solutions from single and binary systems showed that a minimum of 4 g/L dosage of PKSAC was needed to reduce the COD to an acceptable level according to the Water Quality Guidelines and the Pollutant Fact Sheets Guidelines

Dynamic optimization for controller tuning with embedded safety and response quality measures

Controller tuning is needed to select the optimum response for the controlled process. This work presents a new tuning procedure of PID controllers with safety and response quality measures on a non-linear process model by optimization procedure, with a demonstration of two tanks in series. The model was developed to include safety constraints in the form of path constraints. The model was then solved with a new optimization solver, NLPOPT1, which uses a primal-dual interior point method with a novel non-monotone line search procedure with discretized penalty parameters. This procedure generated a grid of optimal PID tuning parameters for various switching of steady-states to be used as a predictor of PID tunings for arbitrary transitions. The interpolation of tuning parameters between the available parameters was found to be capable to produce state profiles with no violation on the safety measures, while maintaining the quality of the solution with the final set points targeted achievable

Batch anaerobic treatment of fresh leachate from transfer station

Leachate from transfer station requires treatment before being discharged into the environment to avoid surface and underground water contamination. Various factors such as waste composition, availability of oxygen and moisture, designing and controlling of transfer station operations have been shown to affect the composition of the leachate. The high COD, BOD, ammonia nitrogen (NH3-N) and heavy metals contents of fresh leachate are the main problems faced by leachate treatment operators. The result of the present study indicated that this process reduced the COD content by 43%.The average removal efficiencies of BOD5, TS, TSS, and VSS were 80, 49, 37 and 39 %, respectively