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The performance of modified anaerobic hybrid baffled (MAHB) bioreactor treating recycled paper mill effluent (RPME) was investigated at various organic loading rates (OLR) of 1, 2, 3 and 4 g COD/ L.day. The bioreactor was operated continuously at constant hydraulic retention time (HRT) of a day without effluent recycled and chemicals adjustment/addition. Throughout 70 days of operation, a maximum removal efficiency up to 97% of chemical oxygen demand (COD) and 98% of volatile fatty acid, biogas production of 12.51 L/day equivalent to methane (CH4) yield of 0.108L CH4/ g COD and a stable pH system between 6.6 to 7.2 were achieved. Additionally, alkalinity of the bioreactor system shows a stable profile that indicates the whole system was well buffered with a quit high degradation of volatile solid (VS) up to 18%. These results indicated that MAHB bioreactor has been successfully treated RPME at various OLR.

In this study, the response surface methodology (RSM) and artificial neural network (ANN) were employed to study the adsorption process of 2,4-dichlorophenoxyacetic acid (2,4-D) by using modified hydrogel, i.e., activated carbon poly(dimethylaminoethyl methacrylate) (AC/PDMAEMA hydrogel). The effect of pH, the initial concentration of 2,4-D and the activated carbon content on the removal of 2,4-D and adsorption capacity were investigated through the face-centered composite design (FCCD), optimal design and two-level factorial design. The response surface plot suggested that higher removal of 2,4-D and adsorption capacity could be achieved at the higher initial concentration of 2,4-D and lower pH and activated carbon content. The modeling and optimization for the adsorption process of 2,4-D were also carried out by different design methods of RSM and different training methods of ANN. It was found that among the three design methods of RSM, the optimal design has the highest accuracy for the prediction of 2,4-D removal and adsorption capacity (R2 = 0.9958 and R2 = 0.9998, respectively). The numerical optimization of the optimal design found that the maximum removal of 2,4-D and adsorption capacity of 65.01% and 65.29 mg/g, respectively, were obtained at a pH of 3, initial concentration of 2,4-D of 94.52 mg/L and 2.5 wt% of activated carbon. Apart from the optimization of process parameters, the neural network architecture was also optimized by trial and error with different numbers of hidden neurons in the layers to obtain the best performance of the response. The optimization of the neural network was performed with different training methods. It was found that among the three training methods of the ANN model, the Bayesian Regularization method had the highest R2 and lowest mean square error (MSE) with the optimum network architecture of 3:9:2. The optimum condition obtained from RSM was also simulated with the optimized neural network architecture to validate the responses and adequacy of the RSM model.

The microstructures and dielectric responses of calcium copper titanate (CCTO) ceramics with soda-lime glass addition was investigated. The addition of soda lime glass was varied from 0-5 wt.% by solid-state reaction. The dielectric properties of CCTO indicated that dielectric constant was increased while dielectric loss was decreased after glass addition. The SEM micrographs showed the grain size of CCTO was decreased while the grain boundaries area of CuO + glass were increased after the addition of soda-lime glass. Both XRD patterns of CCTO and CCTO-soda lime glass sintered samples showed the formation of CCTO phase with minor peaks of CuO phase, respectively. These results indicated that soda-lime glass addition gave a significant effect on the microstructural and dielectric responses of CCTO ceramics.

CCTO consist of huge dielectric constant up to 105 at temperature range -173 °C to 326 °C becomes an attraction to investigate the CCTO ceramics. The samples were tested using simultaneous thermogravimetry (TGA) and differential calorimetry (DSC) measurement in dual atmospheric gases condition by flowing nitrogen and oxygen gas. Phase changes of CCTO precursor were analyzed by X-ray diffraction machine. The samples CT900 and CT1000 occur both of mass loss and reabsorption due to the oxygen-rich environment. The mass loss for both samples CT900 and CT1000 has complete curves of CaCO3 decomposition. Sample CT900 shows incomplete of heat flow changes compare to samples CTNML and CT1000. The result shows that the formation of the CCTO phase structure does not depend on the oxygen gas environment but also requires specific heat of energy and temperature to changes the phase structure. DSC graph shows two magnitudes of heat flow changes for sample CT1000 that are an endothermic at temperature peak points 824 °C and 984 °C.

An improved lab-scale anaerobic baffled reactor was developed to treat recycled paper mill effluent (RPME). In this study, analysis of modified anaerobic baffled reactor (MABR) performance in RPME ...

The development of effective and simple methods for treating wastewater is a challenging task for environmental engineers. In this chapter, a novel modified anaerobic hybridized baffled (MAHB) bioreactor, which is a combination of regular suspended-growth and fixed biofilm systems together with the modification of baffled-reactor configurations, was proven to be a modest bioreactor for wastewater treatment rather than the commercial anaerobic baffled reactor (ABR). The significant advantages of this bioreactor were its ability to nearly realize the multi-stages anaerobic theory, allowing different bacterial groups to develop under more favourable conditions, reduced sludge bed expansion, no special gas or sludge separation required, and high stability to organic and toxic shock loads. The compartmentalization of this bioreactor results in a buffering zone between the primary acidification zone and active methanogenesis zone, and provided the strong ability to resist shock loads which broaden the usage of multi-phase anaerobic technology for industrial wastewater treatment.

The process kinetics of an anaerobic digestion process for treating recycled paper mill effluent (RPME) was investigated. A laboratory-scale modified anaerobic hybrid baffled reactor (MAHB) was operated at hydraulic retention times of 1, 3, 5, and 7 days, and the results were analyzed for the kinetic models. A kinetic study was conducted by examining the phase kinetics of the anaerobic digestion process, which were divided into three main stages: hydrolysis kinetics, acetogenesis kinetics, and methane production kinetics. The study demonstrated that hydrolysis was the rate-limiting step. The applied Monod and Contois kinetic models showed satisfactory prediction with μmax values of 1.476 and 0.6796 L day−1, respectively.

The startup and performance of 58 L modified anaerobic hybrid baffled (MAHB) reactor operated under mesophilic conditions (35˚C) were investigated. The performance data of MAHB reactor and its influence of seed loads and start up process with regards to chemical oxygen demand (COD) removal by using various seed arrangement are compared. Three different seed loads were evaluated. Similar start up strategies were adopted in all systems, using a constant hydraulic retention time (HRT) of 4 days and influent chemical oxygen demand (COD) concentration of 750 mg/L. This present study was done to compare the result for COD removal, pH, methane concentration, and solid content in terms of volatile suspended solids (VSS) at three different start up. Start up 3 shows better reactor performance with highest COD removal (87%), stable system pH, and higher methane content (> 65%). At the end of experiment, methanogen bacteria were observed in the MAHB reactor using autofluorescene microscope and scanning electron microscope (SEM) identification. Population of most probably Methanosarcina, Methanasaeta and Methanobacterium were present in the MAHB reactor which are responsible to produce methane in the system.

Recycled paper mill effluent (RPME) consists of various organic and inorganic compounds. In this study, modified anaerobic hybrid baffled (MAHB) bioreactor has been successfully used to anaerobically digest RPME. The anaerobic digestion was investigated in relation to methane production rate, lignin removal, and chemical oxygen demand (COD) removal, with respect to organic loading rate (OLR) and hydraulic retention time (HRT). The analysis using kinetic study was carried out under mesophilic conditions (37 ± 2 °C) and influent COD concentrations (1000-4000 mg L

Abundance of plastic by non-biodegradable petrochemical based plastic packaging materials has caused an interest in developing biodegradable plastic using waste derived polysaccharides or starch. Therefore, the aim of this study is to diminish the raw material from petroleum in plastic production besides mitigating the pollution due to the non-biodegradable petroleum based plastics. In this study, tapioca starch – nicotiana tabacum xylan composite films were successfully prepared. The influence of nicotiana tabacum-xylan content on the functional properties of tapioca starch film was studied. The result shows that the interaction between nicotiana tabacum-xylan and glycerol occurs between δC-C groups, while the other bonds are unaffected. This indicates that xylan act as filler loads which eventually increase the mechanical and strength of the composite films without affecting the major properties of the bioplastic based. This biocomposite film has high potential to be commercially used as natural biodegradable composite film replacing petrochemical based plastic.Abundance of plastic by non-biodegradable petrochemical based plastic packaging materials has caused an interest in developing biodegradable plastic using waste derived polysaccharides or starch. Therefore, the aim of this study is to diminish the raw material from petroleum in plastic production besides mitigating the pollution due to the non-biodegradable petroleum based plastics. In this study, tapioca starch – nicotiana tabacum xylan composite films were successfully prepared. The influence of nicotiana tabacum-xylan content on the functional properties of tapioca starch film was studied. The result shows that the interaction between nicotiana tabacum-xylan and glycerol occurs between δC-C groups, while the other bonds are unaffected. This indicates that xylan act as filler loads which eventually increase the mechanical and strength of the composite films without affecting the major properties of the bioplastic based. This biocomposite film has high potential to be commercially used as natural biodegr...

Organic Loading Rate (OLR) effect on the performance of Modified Anaerobic Hybrid Baffled (MAHB) bioreactor treating recycled paper mill effluent (RPME) was investigated in this present study. The MAHB reactor is operated with a range of OLR of 0.14–4.00 gm COD/lit/day by varying the influent Chemical Oxygen Demand (COD) concentration of 1000, 2000, 3000 and 4000 mg/lit and Hydraulic Retention Time (HRT) of 1, 3, 5 and 7 days. From the experiment, it was found that the reactor performance decrease when OLRs increase. Highest specific methane yield is 8.47 lit CH4/day with OLR of 1.33 gm COD/lit/day. The highest methane content achieved is 91.63 % from total of 6.43 lit biogas/day at a range pH of 6.6–7.5. Effluent Volatile Fatty Acid (VFA) was below 35 mg/lit HOAC throughout the experiment while alkalinity where fluctuated at low OLR and slightly stable as the OLR increases. Higher OLRs of 2.0 to 3.0 gm COD/lit/day results in addition of inorganics in the reactor causing destabilization of the reactor and process failure, and thereby significantly affect the reactor performance in terms of organic removal. The OLR of 1.33 gm COD/lit/day was found to be optimum for MAHB reactor for the effective treatment of RPME both in terms of specific methane yield and COD removals.

Anaerobic wastewater treatment is receiving renewed interest because it offers a means to treat wastewater with lower energy investment. Because the microorganisms involved grow more slowly, such systems require clever design so that the microbes have sufficient time with the substrate to complete treatment without requiring enormous reactor volumes. The anaerobic baffled reactor has inherent advantages over single compartment reactors due to its circulation pattern that approaches a plug flow reactor. The physical configuration of the anaerobic baffled reactor enables significant modifications to be made; resulting in a reactor which is proficient of treating complex wastewaters which presently require only one unit, ultimately significant reducing capital costs. This paper also concerns about mechanism, kinetic and hydrodynamic studies of anaerobic digestion for future application of the anaerobic baffled reactor for wastewater treatment.

Start-up period is considered to be the most unstable and difficult stage in anaerobic process and usually takes a long time due to slow-degree adaptation of anaerobic microorganisms. In order to achieve a shorter start-up period, a novel modified anaerobic baffled reactor (MABR) has been developed in this study, where each modified baffle has its own characteristics (form/shape) to facilitate a treatment ofrecycled paper mill effluent (RPME). The results ofphysico-chemical characteristics showed that effluent from recycled paper mill consisted of 4328mgL-1 chemical oxygen demand (COD), 669mg L-1 biochemical oxygen demand and 501mg L-1 volatile fatty acid. It also consisted of variety of heavy metals such as zinc, magnesium, iron and nickel at concentrations of 1.39, 12.19, 2.39 and 0.72 mgL-1, respectively. Performance of MABR during the start-up period showed that methane production reached 34.7% with COD removal of 85% at steady state. The result indicates that MABR was successfully operated during the start-up period in treating RPME within a period of less than 30 days.

The reduction of the duration of start-up and the improvement of process control are important factors in order to increase the competitiveness of anaerobic baffled reactor systems. In this paper, the start-up performance of modified anaerobic baffled reactor (MABR) in treating recycled paper mill (RPM) wastewater at batch and continuous phases was investigated. In batch phase, about 3.5 L (10 d HRT) of RPM wastewater were added daily to the reactor for 9 days, while 7 L/day (5 d HRT) was pumped into the reactor during the continuous phase. During batch and continuous phase, it was found that methane yield increased significantly from 0.003 to 0.09 L CH4/g COD day. During the whole start-up operation, the system demonstrated a remarkable performance of high COD removal efficiency (up to 71%) on day 30. Nevertheless, the pH was slightly decreased (from 7.3 to 6.2) during the period of phase 1 (batch) and phase 2 (continuous).

The performance and operational characteristics of a laboratory scale modified anaerobic hybrid baffled (MAHB) reactor were studied using recycled paper mill effluent (RPME) wastewater. MAHB reactor was continuously operated at 35°C for 90 days with organic loading rate (OLR) increased from 0.14 to 0.57 g/L/dy. This present study demonstrated that the system was proficient in treating low strength RPME wastewater. Highest carbon oxygen demand (COD) removal were recorded up to 97% for an organic loading of 0.57 g /L/dy while effluent alkalinity assured that the system pH in the MAHB compartments were of great advantages to acidogens and methanogens respectively. Methane and biogas production rate shows increment as the load increases, which evidently indicated that the most significant approach to enhance gas production rates involves the increment of incoming substrate moderately. Variations of biogas and volatile fatty acid (VFA) in different compartments of MAHB reactor indicated the chronological degradation of substrate. The compartmental structure of MAHB reactor provided its strong ability to resist shock loads. From this present study, it shows the potential usage of MAHB reactor broadens the usage of multi-phase anaerobic technology for industrial wastewater treatment.