Heavy metals accumulation from industrial wastewater even at low concentrations can cause long term cumulative health effects. To overcome this problem, phytoremediation is an alternative method to treat industrial wastewater. In this study, Ipomoea aquatica and Centella asiatica were used as phytoremediation plants for removing aluminum (Al) and iron (Fe) from industrial wastewater. The results showed that the regression value (R²) for all metal concentrations (mg/L) over treatment day is positive and similar to R² = 1. This result indicated that the metal concentration exhibits a good relationship for reflecting the decrease in the metal concentration with the proportion of treatment day. It was found that I. aquatica accumulates higher Al and Fe contents than C. asiatica. The translocation factor of both plants was found to be greater than 1, implying that both plants can accumulate and extract heavy metals from industrial wastewater.

Optimization of Leachate Treatment with Granular Biomedia: Feldspar and Zeolite

Leachate is a form of pollution from landfills with pollutants in organic and inorganic forms. Stabilized leachate is characterized by the presence of organic materials with high ammoniacal nitrogen concentrations (>400mg/L), high chemical oxygen demand (COD) concentrations (<4000mg/L) and the ratio of BOD/COD is low (<0.1). In this study, struvite precipitation used to remove high ammonia content and coagulation-flocculation using poly-aluminium chloride (PAC) as coagulant agent and cationic polymer as flocculant agent used for COD and colour removal. Response surface methodology (RSM) is applied to determine the optimum parameters and interaction effects of the four main factors that influence the efficiency of treatment used; coagulant dosage, flocculant dosage, pH and Mg-N-P ratio on COD, NH₃-N and colour removal. Optimum parameters obtained from the study were the coagulant dosage of 2250 mg/L, flocculant dosage of 14 mg/L, pH 7, and Mg: N: P ratio 1.1. The combination of struvite precipitation and coagulation-flocculation method results a percentage of removal of COD 48.6%, NH3-N 92.8% and color 98.8%

Aim: Application of response surface methodology (RSM) to determine optimum parameters in the coagulation-flocculation process aided by curcumin for boron removal from aqueous solution was investigated. Methodology: Different parameters such as pH, coagulant dosage, and curcumin dosage that effect boron removal were tested. Application of central composite design in RSM was used to design the coagulation-flocculation experiment. Results: The results showed 75% of boron removal, while the optimum parameters for boron removal were observed at pH 2.8, 132.05 ppm poly aluminum chloride dose and 1161.4 ppm curcumin dose, respectively. Interpretation: Quadratic regression showed that the model was significant and lack of fit P value was 0.107 (p > 0.05), implying a significant model correlation between the variables and responses. The experimental data and predicted model proved that RSM is an appropriate approach for optimising the coagulation-flocculation process in removing boron from aqueous solution.