Treatment of real wastewater using co-culture of immobilized <i>Chlorella vulgaris</i> and suspended activated sludge

Mujtaba, Ghulam,Lee, Kisay Elsevier 2017 Water research Vol.120 No.-

<P><B>Abstract</B></P> <P>The use of algal-bacterial symbiotic association establishes a sustainable and cost-effective strategy in wastewater treatment. Using municipal wastewater, the removal performances of inorganic nutrients (nitrogen and phosphorus) and organic pollutants were investigated by the co-culture system having different inoculum ratios (R) of suspended activated sludge to alginate-immobilized microalgae <I>Chlorella vulgaris</I>. The co-culture reactors with lower R ratios obtained more removal of nitrogen than in pure culture of <I>C. vulgaris</I>. The reactor with R = 0.5 (sludge/microalgae) showed the highest performance representing 66% removal after 24 h and 95% removal after 84 h. Phosphorus was completely eliminated (100%) in the co-culture system with inoculum ratios of 0.5 and 1.0 after 24 h and in the pure <I>C. vulgaris</I> culture after 36 h. The COD level was greatly reduced in the activated sludge reactor, while, it was increasing in pure <I>C. vulgaris</I> culture after 24 h of incubation. However, COD was almost stabilized after 24 h in the reactors with high R ratios such as 2.0, 5.0, and 10 due to the higher concentration of activated sludge. The growth of <I>C. vulgaris</I> was promoted from 0.03 g/L/d to 0.05 g/L/d in the co-culture of low inoculum ratios such as R = 0.5, implying that there exist an optimum inoculum ratio in the co-culture system in order to achieve efficient removal of nutrients.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This paper highlights the use of co-culture system in municipal wastewater treatment. </LI> <LI> Removal of nutrients was significantly increased in properly inoculated co-culture system. </LI> <LI> Release of organic matter from <I>Chlorella</I> biomass decreased the COD removal performance. </LI> </UL> </P>

Removal of nutrients and COD from wastewater using symbiotic co-culture of bacterium Pseudomonas putida and immobilized microalga Chlorella vulgaris

Mujtaba, G.,Rizwan, M.,Lee, K. Korean Society of Industrial and Engineering Chemi 2017 Journal of industrial and engineering chemistry Vol.49 No.-

<P>Simultaneous removal of nutrients (ammonium and phosphate) and COD was investigated by the co-culture consortium of microalga Chlorella vulgaris and bacterium Pseudomonas putida. The co-culture system showed higher removal of both nutrients and COD than the each axenic culture, indicating that nutrients uptake capability of C vulgaris was enhanced in the presence of P. putida. The best performance in the removal of nitrogen, phosphorus, and COD was obtained through the co-culture with suspended P. putida and immobilized C vulgaris, demonstrating that the employment of immobilization of one species is more synergistic than suspended co-culture system in nutrients removal from wastewater. (C) 2017 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.</P>

Removal of nutrients and COD through co-culturing activated sludge and immobilized <i>Chlorella vulgaris</i>

Mujtaba, Ghulam,Rizwan, Muhammad,Kim, Garam,Lee, Kisay Elsevier 2018 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.343 No.-

<P><B>Abstract</B></P> <P>Simultaneous removal of inorganic nutrients (nitrogen and phosphorus) and organic carbon (glucose) was realized from synthetically-made municipal wastewater using co-culture of suspended activated sludge and immobilized <I>Chlorella vulgaris</I> in a single reactor. Use of immobilized microalgae and suspended activated sludge can help in separating microalgae biomass from the culture broth at the end of treatment. Efficient removal of nutrients and COD was achieved by the symbiotic co-culture than stand-alone cultures of <I>C. vulgaris</I> and activated sludge after 2-d of retention time. By decreasing inoculum ratio of suspended activated sludge to immobilized <I>Chlorella vulgaris</I> (from 5.0 to 0.2), the performance of nutrients removal was enhanced significantly, and the co-culture at 0.5 inoculum ratio accomplished highest removal of nitrogen (99.8%) and phosphorus (100%) within 2 days of incubation. In the case for the removal of COD, co-culture with different inoculum ratios demonstrated virtually similar performance (showing 90–95% removal after 2-d treatment) which is indicating that there was no robust association between carbon degradation and inoculum ratio. The maximum growth of microalgae (0.76 from initial 0.4 g L<SUP>−1</SUP>) was obtained from the co-culture having 0.5 inoculum ratio indicating significance of proper inoculation. Co-culture at 0.5 inoculum ratio of suspended activated sludge and immobilized <I>C. vulgaris</I> was advanced in the semi-continuous mode treatment. By repeating batch cycles for three times, the co-culture considerably eliminated 98–100% nitrogen, 92–100% phosphorus, and 94–96% COD and accumulated 2.2 g L<SUP>−1</SUP> of biomass production confirming the stability of the current co-culture system in municipal wastewater medium.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The current co-culture exhibited simultaneous removal of nutrients and COD in two days. </LI> <LI> Removal efficiency was increased by decreasing the inoculum ratio from 5.0 to 0.5. </LI> <LI> The co-culture system demonstrated stability up to three repeated batch operations. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Effects of post-cultural incubation conditions on microalgal lipid production

( Ghulam Mujtaba ),최욱진,유시리,이기세 한국공업화학회 2011 한국공업화학회 연구논문 초록집 Vol.2011 No.-

The applications of ozone-based advanced oxidation processes for wastewater treatment: A review

Hussain, Mujtaba,Mahtab, Mohd Salim,Farooqi, Izharul Haq Techno-Press 2020 Advances in environmental research Vol.9 No.3

The rise in population and industrialization accounts for the generation of a huge amount of wastewaters. The treatment of this wastewater is obligatory to safeguard the environment and various life forms. Conventional methods for high strength wastewater treatment coming out to be ineffective. Advanced oxidation processes (AOPs) for such wastewater treatment proved to be very effective particularly for the removal of various refractory compounds present in the wastewater. Ozone based AOPs with its high oxidizing power and excellent disinfectant properties is considered to be an attractive choice for the elimination of a large spectrum of refractory compounds. Furthermore, it enhances the biodegradability of wastewaters after treatment which favors subsequent biological treatments. In this review, a detailed overview of the AOPs (like the Fenton process, photocatalysis, Electrochemical oxidation, wet air oxidation, and Supercritical water oxidation process) has been discussed explicitly focusing on ozone-based AOPs (like O₃, O₃/H₂O₂, O₃/UV, Ozone/Activated carbon process, Ozone/Ultrasound process, O₃/UV/H₂O₂ process). This review also comprises the involved mechanisms and applications of various ozone-based AOPs for effective municipal/industrial wastewaters and landfill leachate treatment. Process limitations and rough economical analysis were also introduced. The conclusive remarks with future research directions also underlined. It was found that ozonation in combination with other effective AOPs and biological methods enhances treatment efficacies. This review will serve as a reference document for the researchers working in the AOPs field particularly focusing on ozone-based AOPs for wastewater treatment and management systems.

Client-driven Music Genre Classification Framework

Ghulam Mujtaba(굴람무즈타바),Eun-Soo Park(박은수),Seunghwan Kim(김승환),Eun-Seok Ryu(류은석) 한국방송·미디어공학회 2020 한국방송공학회 학술발표대회 논문집 Vol.2020 No.7

Analysis of Relationship between O3, NO, and NO2 in Riyadh, Saudi Arabia

Mohammed Mujtaba Shareef,Tahir Husain,Bader Alharbi 한국대기환경학회 2018 Asian Journal of Atmospheric Environment (AJAE) Vol.12 No.1

For the first time in the city of Riyadh, the formation of O3 and its relationship with NO and NO2 (NOx) was investigated. Throughout the summer O3, NO, and NO2 were collected from three locations: residential, industrial, and rural areas. During the sampling period O3 concentrations exceeded 1-hour local standards a few times yet remained consistent with the standards most of the time. The O3 concentrations were observed highest in the rural location and lowest in the industrial area. The diurnal variation of NO followed a double peak: one in the morning and the other in the evening, representing the traffic pattern. Early morning NO peaks were observed in the rural location, which were attributed to the movement of NO from other locations. The O3 concentrations depicted typical pattern, increasing after sunrise and reaching its maximum during midday. The highest O3 concentrations were observed in the rural location followed by the residential and industrial. NO2 photolysis rates were 3-4 times higher compared to other similar investigations, potentially due to intense solar radiation. A strong negative correlation was observed between NOx and O3 values in the industrial location indicating photochemical activities around the industrial area were higher, likely due to additional NOx emissions from industries. Regression analysis of NOx and OX (O3 +NO2) indicated that in residential and industrial locations at nighttime there were large NOx independent regional contributions which is attributed to VOCs. The Weekend Effect was observed in the city potentially due to the production of the OH radical and subsequent reactions with VOCs implying that the area is VOC-sensitive.

A comprehensive review of the Fenton-based approaches focusing on landfill leachate treatment

Hussain, Mujtaba,Mahtab, Mohd Salim,Farooqi, Izharul Haq Techno-Press 2021 Advances in environmental research Vol.10 No.1

Landfilling is the most commonly adopted method for a large quantity of waste disposal. But, the main concern related to landfills is the generation of leachate. The leachate is high strength wastewater that is usually characterized by the presence of high molecular recalcitrant organics. Several conventional methods are adopted for leachate treatment. However, these methods are only suitable for young leachate, having high biodegradability and low toxicity levels. The mature and stabilized leachate needs advanced technologies for its effective treatment. Advanced oxidation processes (AOPs) are very suitable for such complex wastewater treatment as reported in the literature. After going through the literature survey, it can be concluded that Fenton-based approaches are effective for the treatment of various high/low strength wastewaters treatment. The applications of the Fenton-based approaches are widely adopted and well recognized due to their simplicity, cost-effectiveness, and reliability for the reduction of high chemical oxygen demand (COD) as reported in several studies. Besides, the process is relatively economical due to fewer chemical, non-sophisticated instruments, and low energy requirements. In this review, the conventional and advanced Fenton's approaches are explained with their detailed reaction mechanisms and applications for landfill leachate treatment. The effect of influencing factors like pH, the dosage of chemicals, nature of reaction matrix, and reagent ratio on the treatment efficiencies are also emphasized. Furthermore, the discussion regarding the reduction of chemical oxygen demand (COD) and color, increase in biodegradability, removal of humic acids from leachate, combined processes, and the pre/post-treatment options are highlighted. The scope of future studies is summarized to attain sustainable solutions for restrictions associated with these methods for effective leachate treatment.

Simultaneous Removal of Inorganic Nutrients and Organic Carbon by Symbiotic Co-culture of Chlorella vulgaris and Pseudomonas putida

Ghulam Mujtaba,Muhammad Rizwan,이기세 한국생물공학회 2015 Biotechnology and Bioprocess Engineering Vol.20 No.6

The co-culture system of photosynthetic microalgae Chlorella vulgaris and aerobic heterotrophic bacteria Pseudomonas putida was investigated as a possible combination of symbiotic mixed culture for the simultaneous removal of nutrients (ammonium and phosphate) and organic contaminants. Using synthetic municipal wastewater, the co-culture system exhibited symbiotic enhancement in the removal of nutrients and organic carbon compared to each of axenic cultures. The co-culture system performed successfully in removing both of ammonium and chemical oxygen demand (COD), showing around 80% removal for 4 days. Strategies of nitrogen and phosphorous starvation in C. vulgaris for two days prior to main treatment did not increase the performance of nutrients removal, indicating that the nutrient starvation as a pretreatment is unnecessary. Without alkalinity (as bicarbonate), nutrients and COD were not removed significantly, implying that the existence of alkalinity is essential for symbiotic treatment of both nutrients and organics. Results demonstrated that coculture system composed of C. vulgaris and P. putida can be a potential candidate of mixed culture system for the simultaneous removal of nutrients and organic carbon in wastewater treatment using a single reactor.

Treating real municipal wastewater by immobilized C. vulgaris and suspended activated sludge

( Ghulam Mujtaba ),이기세 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.0

Using real municipal wastewater (RMW), simultaneous removal of inorganic nutrients (N and P) and organic contaminants was accomplished in a single reactor with co-culture of immobilized C. vulgaris and suspended activated sludge. Co-culture successfully reduced the significant amount of N (93% removal) after 2.5 d of retention time. Complete removal of P was achieved after 1-d treatment, but after that, co-culture excreted some stored P in the culture medium. The concentrations of Nand P in the effluent were less than 2 and 0.1 mg L-1, respectively.However, the performance of co-culture for COD reductions was not satisfactory (only 50% removal). The growth of C. vulgaris was enhanced in the co-culture system that indicates the importance of synergistic effect of activated sludge. The current co-culture system is proved to be a good candidate in treating the inorganic nutrients, still, further improvement is needed for the elimination of organics.