Nature Environment and Pollution Technology

Malay Chaudhuri ¹, Chan Xuan Hui ¹

Affiliations
1 Deptt. of Civil Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak Darul Ridzuan, MY

Abstract

A plant-based adsorbent was prepared from Neem (Azadirachta indica) leaf and adsorption of two textile acid azo dyes, Acid Red 18 and Acid Orange 7, from aqueous solution was examined. Batch adsorption test showed that extent of dye adsorption depended on contact time, pH and adsorbent dose. Equilibrium adsorption was attained in 5 h and maximum adsorption occurred at pH 2. Dye adsorption followed pseudo secondorder kinetics. Equilibrium adsorption data were described by the Langmuir and Freundlich adsorption isotherm models. Acid dye adsorption capacity of the Neem leaf powder was compared with that of other plant-based adsorbents and activated carbons. Neem leaf powder is effective in adsorptive removal of acid dyes from aqueous solution and textile dye waste.

Keywords

Neem Leaf Powder, Adsorption, Acid Azo Dyes, Freundlich Isotherm, Langmuir Isotherm.

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Augustine Chioma Affam ¹, Malay Chaudhuri ¹

Affiliations
1 Department of Civil Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak Darul Ridzuan, MY

Abstract

The study examined the effect of the operating conditions of the UV photo-Fenton process on COD and TOC removal, biodegradability improvement and mineralization of combined chlorpyrifos, cypermethrin and chlorothalonil pesticides in aqueous solution. The optimum operating conditions for treatment of an aqueous solution containing 100 mg/L of chlorpyrifos, 50 mg/L of cypermethrin and 250 mg/L of chlorothalonil were observed to be H₂O₂/COD molar ratio 2, H₂O₂/Fe²⁺ molar ratio 25 and pH 3. Under the optimum operating conditions, complete degradation of the pesticides occurred in 1 min. Biodegradability (BOD₅/COD ratio) increased from zero to 0.38 and COD and TOC removal were 78.56 and 63.76%, respectively in 60 min. The treatment resulted in release and mineralization of organic carbon and nitrogen from the pesticide molecules as evident from TOC degradation (removal), and decrease in NH₃-N from 22 to 3.9 mg/L and increase in NO₃-N from 0.7 to 19.3 mg/L in 60 min. The study shows that UV photo-Fenton process is effective in pretreatment of combined chlorpyrifos, cypermethrin and chlorothalonil pesticides aqueous solution for biological treatment.

Keywords

Pesticides, Chlorpyrifos, Cypermethrin, Chlorothalonil, UV Photo-Fenton Process.

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Taimur Khan ¹, Shahril Anwar Bin Ab Wahap ¹, Malay Chaudhuri ¹

Affiliations
1 Deptt. of Civil Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak Darul Ridzuan, MY

Abstract

Arsenic occurs in groundwater in two valence states, as trivalent arsenite [As(III)] and as pentavalent arsenate [As(V)]. As(III) is more toxic and more difficult to remove from water by adsorption on activated alumina. In this study the ability of rice husk silica to adsorb As(III) from water was examined. Silica was prepared by burning rice husk in a muffle furnace at 500°C. Batch adsorption tests showed that extent of As(III) adsorption depends on pH, initial As(III) concentration and the contact time. Equilibrium adsorption was attained within 180 min, with maximum adsorption occurring at a pH value of 7-8 which is in the pH range for groundwater. The adsorption of As(III) by rice husk silica followed pseudo second-order kinetics. Equilibrium adsorption data were well described by the Langmuir and Freundlich isotherm models. According to the Langmuir isotherm, As(III) adsorption capacity of rice husk silica is 1.897 mg/g which is 10.5x higher than that (0.180 mg/g) of activated alumina. Hence, rice husk silica would be an effective substitute for activated alumina in the removal of As(III) from groundwater at wells or in households.

Keywords

Rice Husk Silica, Adsorption, Arsenite.

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Gan Chin Heng ¹, Emad Soliman Elmolla ², Malay Chaudhuri ¹

Affiliations
1 Deptt. of Civil Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak, MY
2 Deptt. of Civil Engineering, Al-Azhar University, Cairo, EG

Abstract

Photo-Fenton treatment of a mature landfill leachate was optimized by using the response surface methodology (RSM). The optimum operating variables to achieve 70% removal of COD, 80% removal of colour and 80% removal of NH₃-N were: H₂O₂/COD molar ratio 3.75, H₂O₂/Fe²⁺ molar ratio 10.5 and irradiation time 1.5 h. There was good agreement (< 2% error) between experimental removal efficiency and model prediction. The characteristics of the photo-Fenton treated leachate were: NH₃-N 112 mg/L, colour 108 Pt-Co Unit, COD 350 mg/L, BOD₅ 116 mg/L and BOD₅/COD ratio 0.33, indicating that the treated leachate was amenable to biological treatment. The study has revealed that RSM is an effective tool to optimize the treatment process and photo-Fenton is an effective pretreatment of mature landfill leachate for biological treatment.

Keywords

Photo-Fenton, Mature Landfill Leachate, Response Surface Methodology (RSM).

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Malay Chaudhuri ¹, Emad S. Elmolla ², Rashidah Bt. Othman ¹

Affiliations
1 Deptt. of Civil Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak, MY
2 Deptt. of Civil Engineering, Al-Azhar University, Cairo, EG

Abstract

Activated carbon was prepared from coconut coir and adsorption of reactive dyes Remazol Red F-3B and Remazol Blue by the activated carbon was examined. Batch adsorption test showed that extent of dye adsorption was dependent on dye concentration, contact time, pH and carbon dose. Equilibrium adsorption was attained in 3 h and maximum adsorption occurred in the acidic pH range of 1 to 3. Adsorption capacity of the activated carbon for the dyes was evaluated by batch equilibrium test and compared with that of a commercial activated carbon. According to Langmuir and Freundlich adsorption isotherms, the coconut coir activated carbon showed higher capacity for adsorption of Remazol Red F-3B than that of the commercial activated carbon. For Remazol Blue, both the activated carbons showed comparable adsorption capacity. Coconut coir activated carbon is a suitable substitute for commercial activated carbon in the removal of reactive dyes from aqueous solution.

Keywords

Adsorption, Coconut Coir, Reactive Dyes, Activated Carbon, Langmuir and Freundlich, Isotherms.

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Emad S. Elmolla ¹, Malay Chaudhuri ¹

Affiliations
1 Department of Civil Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskander, 31750 Tronoh, Perak, MY

Abstract

The study examined photo-Fenton treatment of an antibiotic wastewater containing amoxicillin and cloxacillin, and evaluated the effect of operating conditions (H₂O₂/COD molar ratio and H₂O₂/Fe²⁺molar ratio) on biodegradability (BOD₅/COD ratio) improvement and mineralization. The optimum operating conditions for treatment of the antibiotic wastewater was observed to be H₂O₂/COD molar ratio 2.5 and H₂O₂/Fe²⁺ molar ratio 20 (COD/H₂O₂/Fe²⁺ molar ratio 1/2.5/0.125) at pH 3 and reaction time 30 min. Under optimum operating conditions, complete degradation of amoxicillin and cloxacillin occurred in one minute, biodegradability improved from 0.09 to 0.50 ± 0.01 in 30 min, and COD and DOC removal were 67 ± 1% and 51 ± 2%, respectively in 30 min. The study indicated that the photo-Fenton process can be used as pretreatment for antibiotic degradation and biodegradability improvement of antibiotic wastewater containing amoxicillin and cloxacillin.

Keywords

Antibiotic Wastewater, Amoxicillin, Biodegradability, Cloxacillin, Photo-Fenton Treatment.

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Malay Chaudhuri ¹, Shamsul Rahman Mohamed Kutty ¹, Siti Haida Yusop ¹

Affiliations
1 Department of Civil Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak Darul Ridzuan, MY

Abstract

The study examined adsorption of copper and cadmium by the activated carbon prepared from coconut coir. Batch adsorption test showed that extent of metal adsorption was dependent on metal concentration, contact time, pH and carbon dose. Adsorption was low at acidic pH and increased with increase in pH. Adsorption capacity of the activated carbon for copper and cadmium was evaluated by adsorption isotherm test and compared with that of a commercial activated carbon. The coconut coir activated carbon showed higher limiting capacity for adsorption of copper and cadmium (84.74 mg/g and 68.03 mg/g) than that of the commercial activated carbon (46.30 mg/g and 14.90 mg/g).

Keywords

Adsorption, Copper, Cadmium, Coconut Coir, Activated Carbon.

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Malay Chaudhuri ¹, Toh Yew Wei ¹

Affiliations
1 Department of Civil Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak Darul Ridzuan, MY

Abstract

In a laboratory study, decolourisation of four reactive dyes (Cibacron Yellow C5G, Remazol Blue RGP, Remazol Red RGP and Remazol Golden Yellow RGP) by modified photo-Fenton (UV-vis/ferrioxalate/H2O2) process under irradiation with sunlight was examined. Over 90% decolourisation occurred in 90-120 min for dye concentrations of 20, 50 and 100 mg/L, indicating the effectiveness of ferrioxalate complexes in decolourisation of even strongly coloured solutions. The study has demonstrated that modified photo-Fenton process is an effective process for decolourisation of reactive dyes. The process is useful for treatment of dyehouse waste in tropical and equatorial regions where sunlight is abundant.

Keywords

Reactive Dyes, Decolourisation of Dyes, Photocatalytic Degradation, Modified Photo-Fenton Process.

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Malay Chaudhuri ¹, Putri Sarah Aainaa Binti Khairuldin ²

Affiliations
1 Department of Civil Engineering, University Teknologi Petronas, Bandar Seri Iskandar, 31750 Tronoh, Perak Darul Ridzuan, MY
2 Department of Civil Engineering, Universiti Teknologi Petronas, Bandar Seri Iskandar, 31750 Tronoh, Perak Darul Ridzuan, MY

Abstract

Performance of Moringa oleifera seed extract as primary coagulant and as coagulant aid with alum in clarification of turbid coloured water was examined and compared with the performance of alum. M. oleifera seed extract is effective as prime coagulant and as coagulant aid with alum. Compared with alum (residual filtrate turbidity 2 NTU and residual colour 3 TCU), it produces water with slightly higher residual filtrate turbidity (4 and 3 NTU) and residual colour (15 and 13 TCU), but the residual turbidity and residual colour are within the WHO drinking water guideline values for turbidity (5 NTU) and colour (15 TCU).

Keywords

Coagulation-Clarification, Turbid Coloured Water, Natural Coagulant, Moringa oleifera, Seed Extract.

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S. K. Kohli ¹, Malay Chaudhuri ²

Affiliations
1 Army Headquarters, Kashmir House, New Delhi-110 011, IN
2 Civil Engineering Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar-31750, Tronoh, Perak, MY

Abstract

Lignite (raw or alum-treated) was found to possess about one-half the fluoride sorption capacity of commercial grade activated alumina. No significant difference in performance of raw and alum-treated lignite in five cycles of defluoridation column test at pH 5.0 ± 0.2, using hydrochloric acid as regenerant, was observed. Infrared spectra indicated interaction of fluoride with carbonyl and aromatic ring functional groups in lignite. The results call for long-duration column tests, employing fluoride-bearing groundwater of varied characteristics and at natural pH, to confirm suitability of lignite as a low-cost medium for home water defluoridation in rural areas of developing countries.

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