International Journal of Environmental Engineering (10 papers in press)
ASSESSING THE METHANE PRODUCTION FROM LEACHATE AND DEODORIZER BY USING A BATCH TEST OF ANAEROBIC DIGESTION
by Siti Amirah Mohd Tohir, Lee Dong Yeol, Marfiah Ab. Wahid, Norashikin Ahmad Kamal
Abstract: Anaerobic treatability of municipal landfill leachate was evaluated using lab-scale anaerobic batch reactors. The batch reactor contained two columns. Column 1 consisted of 3 litres of raw leachate and artificial substrate. Column 2 consisted of 3 litres of raw leachate, artificial substrate (mixture of wheat flour and water), and 600 g of deodoriser from the extraction of lemongrass. Before anaerobic digestion occurred, the characteristics parameter of the leachate sample was identified. Then, the process began by adding the artificial substrate into both columns and deodoriser into the column 2. After the anaerobic digestion happened, the biogas was produced. Next, the parameters of the sample were tested again to compare with the initial sample. Data showed that anaerobic digestion could treat the leachate sample and produced the biogas (column 1: 7,550 mg/L and column 2: 7,100 mg/L). The performance of biogas production shows the significant result with present of deodoriser.
Keywords: Anaerobic digestion; deodorizer; batch test.
Modifications of coconut waste as an adsorbent for the removal of heavy metals and dyes from wastewater
by Buddhima Siriweera, Sanuja Jayathilake
Abstract: Heavy metals, dyes, organic compounds and other pollutants released to the water ways without proper pre-treatment process has become a major hazard to the environment. Adsorption could be introduced as one of the most cost-effective and reliable treatment methods for the treatment of these effluents. Adsorbents play a vital role in the adsorption process and there is an increasing trend towards utilization of the low-cost adsorbents. Among the low-cost adsorbents, coconut-based adsorbents including coconut husk, coconut shell fibre and coconut coir pith have proven to be significantly effective with the provision of satisfactory adsorption capacities for the removal of pollutants from wastewater. Although, raw, coconut-based adsorbents have been utilized in some of the adsorption experiments, research works have been conducted to investigate the modification methods for these adsorbents for achieving the optimum pollutant removal capacities from the wastewater. These modification processes include acid and alkali treatments, modification with surfactants, polymerization and treatment with metal/metal chlorides as well as thermal treatments. The purpose of this review paper is to discuss the recent modification methods that have been applied for the coconut-based adsorbents and their effectiveness for the removal of contaminants from wastewater. Furthermore, suggestions for the improvement of these modification methods are provided.
Keywords: Adsorption; Adsorbents; Coir pith; Modification Methods; Acid and Alakli; Surfactants; Polymerization; Thermal.
Heavy Metal Removal from Industrial Wastewater and Runoff Discharge Using Modified Diatomite as Filtration Medium
by Faegheh Moazeni, Laura Nell, Tatiana Dominguez, Shirley Clark
Abstract: The adsorption of copper and zinc ions onto the modified diatomite with sodium hydroxide and manganese oxide (Mn-DM) was studied in isotherm batch solutions. The analysis of Cu (II) and Zn (II) results showed the effect of contact time and adsorbent dosage on the adsorption process performed in solutions with individual and combined metal ions, allowing observations of the selectivity and preference of modified diatomite in capturing Cu (II) and Zn (II). The paper also analyzed the effect of supplementing peat on the adsorption process, at various ratios to the modified diatomite, to obtain the optimized filter composition with highest adsorption efficiency. The obtained data was used to model the kinetics of the adsorption processes for both metal ions.
Keywords: Industrial Runoff; Adsorption; Modified Diatomite; Heavy metal; Peat; Natural sorbent; Kinetic Studies; Industrial wastewater; Zinc; Copper.
Performance of electroflotation on the treatment of landfill leachate and combined with other methods: recent studies
by Abdubaki Mohamed Hussen Shadi, Mohamad Anuar Kamaruddin, Madu Ijanu Emmanuel, Noorzalila Muhammad Niza
Abstract: Through the years, modern municipal solid waste (MSW) has mainly been dealt with via sanitary landfills. For a long period, this was the method of choice due to the simplicity and economical cost of landfilling. However, as more and more landfill leachates have been studied, there is no doubt that the management of landfill leachate (LFL) needs to be one of the priorities of any government to rapidly reduce further contamination to the environment that have recently been witnessed, especially on ground and surface marine life. Hence, in the last decade, more stringent rules and regulations have come up with the aim to reduce and combat the issue of environmental pollution. This paper is aimed at observing leachate composition, various LFL treatments specifically electrocoagulation, electroflotation, and electrocoagulation-electroflotation combined methods. A summary of their advantages and drawbacks in LFL pollution reduction is provided. By understanding how these methods aid in reducing contamination levels of leachates and some factors that affect their efficiency, it is hoped that a newer and more effective, as well as economical, method will be studied and pursued to control LFL pollution once and for all.
Keywords: Landfill; Leachate; LFL; Electrocoagulation Electroflotation EC/EF; ammonia nitrogen (AN).
Integration of photocatalysis with biological processes for removal of tetracycline from water
by Lamia Khenniche
Abstract: A combined process coupling photocatalysis and biological treatment were investigated for the removal of an antibiotic, tetracycline (TC). Photocatalytic degradation experiments of TC were carried out in a reactor operating in batch mode with internal UV irradiation. TiO2 (PC500) was tested and the antibiotic degradation was studied for different initial pollutant concentrations (10 100 mg.L-1. It was found that the degradation process is efficient at low concentrations (C0 ? 40 mg.L-1) and the kinetic degradation of TC in the presence of PC500 exhibited pseudo-second-order kinetics. The change in initial pH of TC solutions did not affect the photocatalytic degradation of the antibiotic and the optimal values of the UV intensity radiation and the concentration of PC500 were 25 W.m-2 and 1 g.L-1, respectively. The biodegradability study of the photocatalysed TC solutions based on the evaluation of BOD5, COD, TOC, BOD5/COD ratio and AOS showed a biodegradability of the obtained by-products for initial TC concentrations in the range 20 to 60 mg.L-1. Therefore, the coupling of photocatalysis and biological treatment is possible for the degradation of tetracycline.
Keywords: photocatalysis; antibiotic; modelling; kinetics; mineralization; biodegradability; PC500.
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,.
A Theoretical and Experimental Study on Removal of Nickel, Lead, and Zinc Metals from Wastewater Using Chlorella vulgaris Microalgae
by Abooali Golzary, Abdolreza Karbassi, Faezeh Manzoor
Abstract: Among various pollutants, heavy metals are highly regarded because of various harmful and sometimes irreparable effects. The effects of initial concentration of metal, pH and temperature on the efficiency of heavy metals of lead, zinc and nickel removal was investigated through culture of Chlorella vulgaris microalgae. The studies showed that the highest percentages of removal of lead, zinc and nickel metals were 93.2%, 95.6% and 94.2% respectively at initial concentration of 1 ppm, pH = 6 and 30°C for all three metals. At the removal efficiency of 90%, the optimal values of the three parameters were determined for each of the three metals. The optimal conditions were as follows: maximum initial concentration (Cimax) of 35 ppm, pH = 6 and temperature of 26°C for lead metal; Cimax = 50 ppm, pH = 6.3 and temperature of 27°C for zinc metal, and Cimax =25 ppm, pH = 6.6 and temperature of 26°C for nickel metal.
Keywords: Microalgae; Chlorella vulgaris; Heavy metal removal; Wastewater treatment; Response surface methodology (RSM).
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.