International Journal of Environmental Engineering (4 papers in press)
INVESTIGATING THE ANTIMICROBIAL AND COAGULATION PROPERTIES OF Chrysophyllum albidum SEEDS
by Ubong Idiok, Nkeiruka Enyinnaya Nwaiwu.
Abstract: In the present study, plant based coagulant namely the seed of the Chrysophyllum albidum was investigated for its coagulation and antimicrobial efficacy. The coagulation study was conducted on a turbid surface water sample obtained at the Ezu River in Anambra state, Nigeria. The highest coag-flocculation activity was recorded at dosage of 0.4g/400mL, pH of 3, coagulation rate constant K = 7.4733x10-4m3/kg.s, and coagulation period ? = 2.29 secs. The observed turbidity removal efficiency of over 75% proved that the natural coagulant improved the quality of the water sample. On disinfection, the results indicated that the C. albidum seed extracts showed varying degrees of growth inhibitions on both Gram positive and Gram negative organisms. The antimicrobial activity observed ranged from 0 to 10 mm at different concentrations. The study shows that the C. albidum seed extracts is therefore a potential bio-coagulant and disinfectant that requires further studies and development.
Keywords: Coagulation; Antimicrobial activity; C albidum,.
Synthesis and Application of Coagulant Derived from Durio Zibethinus (DSS) for Emerging Contaminants (EC) Removal from Landfill Leachate
by Mohamad Anuar Kamaruddin, Mohd Suffian Yusoff, Emmanuel Madu Ijanu, Mohd Hafiidz Jaafar, Rasyidah Alrozi, Khairunnisa Fakhriah Mohd Omar
Abstract: In the modern era of advanced treatment of wastewater, the application of coagulant based aluminum (AI) like poly-aluminum chloride (PACl) in treatment often results in potentially toxic Al residuals being discharged into the aquatic environment. However, it is still prominently used because of easy to obtain and favorable to the treatment process. As alternatives, starch-based coagulants have been synthesized from various precursors that contain high starch yield. In this work, Durio Zibethinus starch (DSS) was synthesized from discarded fruits. And studied for its potential as a natural coagulant and coagulant aid in the presence of PACl to remove chemical oxygen demand (COD), turbidity, color, iron, manganese, and zinc by using coagulation and flocculation process. Leachate sample was sampled from Larut Matang dumping site, Perak, Malaysia. Optimum pH for DSS was determined by studying its surface charge through Zeta Potential. The highest zeta potential (-33.2mV) at pH 9 was chosen. Results showed that at the optimum condition, 7.2 g/L PACl at pH 6 removed 27% COD, 55% turbidity and 86% color. For removal of iron, manganese and zinc, the optimum condition of PACl was accounted at 7.2 g/L at pH7.5 with the removal of 99 %, 3 l% and 28 % respectively. For DSS as a coagulant, the optimum dosage was 360 g/L at pH 9. The highest removal of COD, turbidity, color, iron, manganese and zinc using DSS was 9 %, 22 %, 59 %, 70 %, 60 % and 32 % respectively.
The addition of DSS as a coagulant aid improved the removal rate of color, turbidity and zinc. lt gives l3% COD, 93 % turbidity, 96 % color, 86 % iron and 96 % zinc removal. However, the addition of DSS as a coagulant aid increased the concentration of manganese by 15 %. lt was assumed that PACl was more superior than DSS for the removal of turbidity, color, COD and iron removal. In conclusion, DSS has the potential to be a coagulant aid in coagulation and flocculation based on their removal efficiency values.
Keywords: Durio Zibethinus starch; Coagulant; Landfill leachate; Mechanism.
Special Issue on: Sustainability of Environmental Engineering in the 21st Century
Performance Evaluation of Natural Coagulant for Removal of Turbidity and Optimization of Coagulation Process
by MADHUKAR JADHAV
Abstract: The experiments were performed using batch coagulation-flocculation tests in order to determine the effect of varying pH, settling time and coagulant dose of Eugenia Jambolana (Jambhul) seed powder on initial turbidity of 30 NTU and 95 NTU respectively. In the batch test, the optimum turbidity removal was observed at a dose of 8 mg/L and 20 mg/L for 30 NTU and 95 NTU turbidity respectively. In the case of varying pH, optimum turbidity removal was observed at pH 8.5 for both turbidity ranges. It is also observed that, as the settling time increases, the residual turbidity decreases for both the turbidity ranges for Eugenia Jambolana (Jambhul) seed powder. The optimization study was significant. The ANOVA analysis performed assures the reliability of models indicating the significance of results and actual turbidity removal was nearly the same as predicted turbidity removal.
Keywords: coagulant; eugenia jambolana (jambhul) seed powder; settling time; turbidity.
Sustainability Development in Geotechnical Conceptual Design
by N.U.R. IRFAH MOHD PAUZI, Zakaria Che Muda, Mohd Shahril Mat Radhi
Abstract: The sustainability development in geotechnical conceptual design is to be developed for future generation. A tool box which consist of materials selection for construction, cost factor, life cycle cost analysis, construction method, technical, time, safety and public health, societal, culture, legal, environmental control are developed for sustainability in geotechnical area. This concept is critical when planning for the sustainability in the geotechnical conceptual design. The geotechnical work is the first stage in construction that will determine the success of the project in preserving the environment. Geotechnical for the earthwork design will decide the appropriate platform levels and profiles for the construction site which to reduce the environmental impact. In conclusion, the sustainability of the geotechnical engineering must take into account the eco-centric, techno-centric and socio-centric aspect of its development. The development in construction usually consider the technology but impacting the environmental and societal requirement. For the future generation benefit, the present resources should be preserved from depleting to maintain the sustainability needs of the later generations.
Keywords: Sustainability development; environmental control; societal impact; geotechnical conceptual design.