Bench-Scale Fixed-Bed Column Study for the Removal of Dye-Contaminated Effluent Using Sewage-Sludge-Based Biochar
25 May 2022-Sustainability-Vol. 14, Iss: 11, pp 6484-6484
TL;DR: In this paper , the effect of varying bed depth and flow rate over time on the removal efficiency of color from batik industrial effluent (BIE) was analyzed, and the results of FTIR showed that some functional groups such as CO and OH were hosted on the surface of the biochar.
Abstract: Batik industrial effluent wastewater (BIE) contains toxic dyes that, if directly channeled into receiving water bodies without proper treatment, could pollute the aquatic ecosystem and, detrimentally, affect the health of people. This study is aimed at assessing the adsorptive efficacy of a novel low-cost sewage-sludge-based biochar (SSB), in removing color from batik industrial effluent (BIE). Sewage-sludge-based biochar (SSB) was synthesized through two stages, the first is raw-material gathering and preparation. The second stage is carbonization, in a muffle furnace, at 700 °C for 60 min. To investigate the changes introduced by the preparation process, the raw sewage sludge (RS) and SSB were characterized by the Brunauer–Emmett–Teller (BET) method, Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy. The surface area of biochar was found to be 117.7 m2/g. The results of FTIR showed that some functional groups, such as CO and OH, were hosted on the surface of the biochar. Continuous fixed-bed column studies were conducted, by using SSB as an adsorbent. A glass column with a diameter of 20 mm was packed with SSB, to depths of 5 cm, 8 cm, and 12 cm. The volumes of BIE passing through the column were 384 mL/d, 864 mL/d, and 1680 mL/d, at a flow rate of 16 mL/h, 36 mL/h, and 70 mL/h, respectively. The initial color concentration in the batik sample was 234 Pt-Co, and the pH was kept in the range of 3–5. The effect of varying bed depth and flow rate over time on the removal efficiency of color was analyzed. It was observed that the breakthrough time differed according to the depth of the bed and changes in the flow rates. The longest time, where breakthrough and exhausting points occurred, was recorded at the highest bed and slowest flowrate. However, the increase in flow rate and decrease in bed depth made the breakthrough curves steeper. The maximum bed capacity of 42.30 mg/g was achieved at a 16 mL/h flowrate and 12 cm bed height. Thomas and Bohart–Adams mathematical models were applied, to analyze the adsorption data and the interaction between the adsorption variables. For both models, the correlation coefficient (R2) was more than 0.9, which signifies that the experimental data are well fitted. Furthermore, the adsorption behavior is best explained by the Thomas model, as it covers the whole range of breakthrough curves.
TL;DR: In this paper , a polypyrrole-polyethyleneimine (PPy-PEI) nano-adsorbent was successfully synthesized for the removal of methylene blue (MB) from an aqueous solution.
Abstract: In this work, a polypyrrole-polyethyleneimine (PPy-PEI) nano-adsorbent was successfully synthesized for the removal of methylene blue (MB) from an aqueous solution. Synthetic dyes are among the most prevalent environmental contaminants. A new conducting polymer-based adsorbent called (PPy-PEI) was successfully produced using ammonium persulfate as an oxidant. The PEI hyper-branched polymer with terminal amino groups was added to the PPy adsorbent to provide more effective chelating sites for dyes. An efficient dye removal from an aqueous solution was demonstrated using a batch equilibrium technique that included a polyethyleneimine nano-adsorbent (PPy-PEI). The best adsorption parameters were measured at a 0.35 g dosage of adsorbent at a pH of 6.2 and a contact period of 40 min at room temperature. The produced PPy-PEI nano-adsorbent has an average particle size of 25–60 nm and a BET surface area of 17 m2/g. The results revealed that PPy-PEI nano-composite was synthesized, and adsorption was accomplished in the minimum amount of time. The maximum monolayer power, qmax, for MB was calculated using the isothermal adsorption data, which matched the Langmuir isotherm model, and the kinetic adsorption data, which more closely fitted the Langmuir pseudo-second-order kinetic model. The Langmuir model was used to calculate the maximum monolayer capacity, or qmax, for MB, which was found to be 183.3 mg g−1. The as-prepared PPy-PEI nano-adsorbent totally removes the cationic dyes from the aqueous solution.
TL;DR: In this paper , the performance of the activated sludge bioreactor system (ASBS) for the treatment of pulp and paper industry wastewater (PPIW) was characterized.
Abstract: The pulp and paper industry has been recognized as one of the largest users of water worldwide. Water is used in nearly every step of the manufacturing process. It generates significant amounts of wastewater and leftover sludge, creating several problems for wastewater treatment, discharge, and sludge disposal. Adopting the most effective and economical treatment techniques before discharging wastewater is therefore crucial. Thus, this study aims to evaluate the performance of the activated sludge bioreactor system (ASBS) for the treatment of pulp and paper industry wastewater (PPIW). The PPIW was characterized. During the experiment, the domestic and PPIW wastewater were run at a fixed HRT of 1 day. Subsequently, the ASBS was evaluated by varying the HRT and OLR. The HRT was varied in the range of 3, 2, and 1 day. At a fixed HRT of 2 days, the maximum and minimum COD removal were 88.4 and 63.2%. Throughout the study, the ASBS demonstrated higher treatment efficiency in terms of COD removal. First order, Grau second order, and modified Stover Kincannon biokinetic models were applied for the study. The biokinetic investigation shows that the modified stover kinetic model was more appropriate for the description of the experimental data in terms of microbial growth parameters. Thus, the kinetic coefficients obtained in this study could be used for the bioreactor scale-up. The study has also proven that the biosorbent made from biomass waste can potentially help preserve non-renewable resources and promote zero-waste attainment and principles of a circular bioeconomy.
TL;DR: In this article , the effectiveness of a continuous flow bioreactor system (CFBS) in the treatment of agro-industrial effluent using hybrid waste sludge biochar (HWSB) was investigated.
Abstract: Agro-waste management processes are evolving through the development of novel experimental approaches to understand the mechanisms in reducing their pollution levels efficiently and economically from industrial effluents. Agro-industrial effluent (AIE) from biorefineries that contain high concentrations of COD and color are discharged into the ecosystem. Thus, the AIE from these biorefineries requires treatment prior to discharge. Therefore, the effectiveness of a continuous flow bioreactor system (CFBS) in the treatment of AIE using hybrid waste sludge biochar (HWSB) was investigated. The use of a bioreactor with hydraulic retention time (HRT) of 1–3 days and AIE concentrations of 10–50% was used in experiments based on a statistical design. AIE concentration and HRT were optimized using response surface methodology (RSM) as the process variables. The performance of CFBS was analyzed in terms of COD and color removal. Findings indicated 76.52% and 66.97% reduction in COD and color, respectively. During biokinetic studies, the modified Stover models were found to be perfectly suited for the observed measurements with R2 values 0.9741 attained for COD. Maximum contaminants elimination was attained at 30% AIE and 2-day HRT. Thus, this study proves that the HWSB made from biomass waste can potentially help preserve nonrenewable resources and promote zero-waste attainment and principles of circular economy.
TL;DR: In this paper , the authors adopted the systematic review to discuss the waste to resource potential applications of Petroleum Industry Sludge (PIS) for reusability in sustainable construction, wastewater treatment applications, and gas generation.
Abstract: The petroleum industry activities unavoidably generate a large quantity of sludge named Petroleum industry sludge (PIS). The generation rate has been increasing because of the ascending energy demand. It is a potential energy resource. PIS has been shown to contain hazardous constituents that may have negative consequences on the environment and public health. Thus, the treatment and disposal of this waste is a global issue. Numerous treatment methods have been demonstrated to reduce sludge volume and toxicity and recover petroleum components. The sludge qualities affect how effective they are. These treatment strategies can reduce the toxic substances in sludge and reduce their detrimental effects on human health and the environment. However, because of the sludge's tenacious character, only a few technologies can meet strict environmental laws while using a sizable amount of water, electricity, and chemicals. PIS treatment methods that are both waste-free and cost-effective are currently unavailable. In terms of environmental engineering significance, this study adopted the systematic review to discuss the waste to resource potential applications of PIS for reusability in sustainable construction, wastewater treatment applications, and gas generation. PIS application ineffective microorganism biofertilizer production, levan production, rubber tires manufacturing, metal catalysts synthesis, carbon–clay composites for use in sensors and electronic devices were also discussed. That is not enough, this review also found that the adoption of the circular economy that represents a new direction to create value and prosperity by elongating product lifespan and moving the waste from the end of the supply chain to the outset is very important. Thus, the circular economy potential of PIS to achieve self-cycle operation through the concept of “wastes-treat-wastes” in the petroleum industry was extensively discussed.
TL;DR: In this paper , the effectiveness of the continuous mode activated sludge (CMAS) system and the biocomposite-based-continuous mode activated Sludge (SB-CMAS)-based system in the treatment of green straw biorefinery effluent (GSBE) was investigated.
Abstract: The conventional disposal of green straws through burning can be eliminated in a biorefinery that converts them into a range of sustainable commercial products. However, this leads to the generation of green straw biorefinery effluent (GSBE). Green straw biorefineries discharge wastewater into the ecosystem that contains high concentrations of COD and NH4+−N. It is one of the most notable sources of visual pollution and disruption of aquatic life as well as public health that requires treatment prior to discharge. To improve the GSBE quality for environmental sustainability, the attainment of sustainable development goals 6, 9, and 14, “clean water and sanitation”, “inorganic and organic waste utilization for added values from material”, and “life below water” is very important. Therefore, the effectiveness of the continuous mode activated sludge (CMAS) system and the biocomposite-based–continuous mode activated sludge (SB-CMAS) system in the treatment of GSBE was investigated in this study. Response surface methodology (RSM) was used to optimize the process variables. At their optimized conditions, the performances of CMAS and SB-CMAS were analyzed in terms of COD and NH4+−N. Findings showed 81.21% and 95.50% COD and 78.31% and 87.34% NH4+−N reduction in concentration for CMAS and SB-CMAS, respectively. The high COD and NH4+−N removal efficiencies indicate the better performance of CMAS and SB-CMAS. The first- and second-order models and the modified Stover–Kincannon biokinetic models were utilized to analyze substrate removal rates. It was discovered that the modified Stover models were ideal for the measured data with R2 values 0.99646 and 0.91236 attained for COD and NH4+−N, respectively, in CMAS. The SB-CMAS had 0.99932 and 0.99533 for COD and NH4+−N, respectively. Maximum contaminant elimination was attained at 60% GSBE and 2-day HRT. Thus, to achieve the UN SDGs for 2030, findings from this study have the potential to answer goals 6, 9, and 14.
TL;DR: In this paper, the influence of carbonization and activating reagent on the pore structure of the activated carbon was investigated, and it was found that the maximum surface area were obtained at the carbonization temperature of 600°C in both ZnCl2 and H3PO4 activation, and that the surface areas were as large as those of the commercial activated carbons.
Abstract: Activated carbons were prepared from lignin by chemical activation with ZnCl2, H3PO4 and some alkali metal compounds. The influence of carbonization and activating reagent on the pore structure of the activated carbon was investigated. It was found that the maximum surface areas were obtained at the carbonization temperature of 600°C in both ZnCl2 and H3PO4 activation, and that the surface areas were as large as those of the commercial activated carbons. On the other hand, in alkali metal activation it was found that the maximum surface areas were obtained at the carbonization temperature of 800°C. Except for Na2CO3 maximum surface areas were much larger than those of the commercial activated carbons. The activated carbon prepared by K2CO3 activation showed a surface area of nearly 2000 m2/g. It was shown that ZnCl2 works effectively as dehydration reagent below 600°C. On the other hand, K2CO3 works effectively in two temperature ranges, below 500°C and above 600°C. Below 500°C, the carbonization behavior was modified by impregnation with K2CO3, but the pore structure changes little. Above 600°C, carbon was consumed by K2CO3 reduction and then the surface area was increased.
TL;DR: It is evident from the literature survey that decolorization by the adsorption shows a great promise for the removal of color from dyehouse effluent and if biomasses want to compete with the established ion-exchange resins and activated carbon, their dye binding capacity will need to be substantially improved.
Abstract: The effluent discharged by the textile dyehouses has a seriously detrimental effect on the aquatic environment. Some dyestuffs produce toxic decomposition products and the metal complex dyes release toxic heavy metals to watercourses. Of the dyes used in the textile industry, effluents containing reactive dyes are the most difficult to treat because of their high water-solubility and poor absorption into the fibers. A range of treatments has been investigated for the decolorization of textile effluent and the adsorption seems to be one of the cheapest, effective and convenient treatments. In this review, the adsorbents investigated in the last decade for the treatment of textile effluent containing reactive dyes including modified clays, biomasses, chitin and its derivatives, and magnetic ion-exchanging particles have been critically reviewed and their reactive dye binding capacities have been compiled and compared. Moreover, the dye binding mechanism, dye sorption isotherm models and also the merits/demerits of various adsorbents are discussed. This review also includes the current challenges and the future directions for the development of adsorbents that meet these challenges. The adsorption capacities of adsorbents depend on various factors, such as the chemical structures of dyes, the ionic property, surface area, porosity of the adsorbents, and the operating conditions. It is evident from the literature survey that decolorization by the adsorption shows a great promise for the removal of color from dyehouse effluent. If biomasses want to compete with the established ion-exchange resins and activated carbon, their dye binding capacity will need to be substantially improved.
TL;DR: The MCS column study states the value of the excellent adsorption capacity for the removal of Cr(VI) from aqueous solution that is useful for process design.
Abstract: Continuous fixed-bed column studies were carried out by using modified corn stalk (MCS) as an adsorbent for the removal of Cr(VI) from aqueous solution. The effect of various parameters like bed depths (1.4, 2.2 and 2.9 cm), flow rate (5, 10 and 15 mL/min), influent Cr(VI) concentrations (100, 200 and 300 mg/L) and influent solution pH (2.66, 4.91 and 5.66) was investigated. The exhaustion time increased with increase of bed depth, decrease of flow rate and influent concentration. The Adams–Bohart, Thomas and Yoon–Nelson models were applied to the adsorption under varying experimental conditions to predict the breakthrough curves and to evaluate the model parameters of the fixed-bed column that are useful for process design. The Thomas and Yoon–Nelson models were in good agreement with the experimental data. The MCS column study states the value of the excellent adsorption capacity for the removal of Cr(VI) from aqueous solution.
TL;DR: In this article, the characteristics of sewage sludge are discussed in terms of composition and the current options for its treatment with the associated environmental impacts, and a critical comparison is made of the drying techniques, co-feedstocks and catalytic processes, reaction kinetics, reactor technologies, operating conditions to be optimized, removal of impurities, fuel properties, their constraints and required improvements.
Abstract: The increasing levels of sewage sludge production demands research and development to introduce more commercially feasible options for reducing socio-economic and environmental problems associated with its current treatment. Sewage sludge may be processed to produce useful products or as a feedstock for energy generation. Initially, the characteristics of sewage sludge are discussed in terms of composition and the current options for its treatment with the associated environmental impacts. Processes to valorize sewage sludge are discussed, including heavy metal removal from sewage sludge, production of bio-char, production and use of activated carbon and use of sewage sludge combustion ash in cement and concrete. Thermochemical processes i.e., pyrolysis, co-pyrolysis and catalytic pyrolysis, also gasification and combustion for process intensification, energy and resource recovery from sewage sludge are then critically reviewed in detail. The pyrolysis of sewage sludge to produce a bio-oil is covered in relation to product bio-oil composition, reactor type and the use of catalysts. Gasification of sewage sludge focusses on the characteristics of the different available reactor types and the influence of a range of process parameters and catalysts on gas yield and composition. The selection and design of catalysts are of vital importance to enhance the selectivity of the selected thermochemical pyrolysis or gasification process. The catalysts used for sewage sludge treatment need more research to enable selectivity towards the targeted desired end-products along with optimization of parametric conditions and development of innovative reactor technologies. The combustion of sewage sludge is reviewed in terms of reactor technologies, flue gas cleaning systems and pollutant emissions. In addition, reactor technologies in terms of technological strength and market competitiveness with the particular application to sewage sludge are compared for the first time for thermochemical conversion. A critical comparison is made of the drying techniques, co-feedstocks and catalytic processes, reaction kinetics, reactor technologies, operating conditions to be optimized, removal of impurities, fuel properties, their constraints and required improvements. The emphasis of this review is to promote environmental sustainability for process intensification, energy and resource recovery from pyrolysis, gasification and combustion involving the use of catalysts.
TL;DR: The continuous column method was used in order to evaluate the feasibility to use the clay in wastewater purification systems and it is possible to conclude that the vermiculite has good potentialities for cost-effective treatments of metal-contaminated wastewaters.
Abstract: The sorption behaviour of vermiculite has been studied with respect to cadmium, copper, lead, manganese, nickel, and zinc as a function of pH and in the presence of different ligands. The continuous column method was used in order to evaluate the feasibility to use the clay in wastewater purification systems. The total capacity of vermiculite was found to decrease in the following order: Mn > Ni > Zn > Cd > Cu > Pb. The adsorption of metal ions on vermiculite decreases with decreasing pH and increasing ionic strength. In general, the metal uptake on the clay was hindered by the presence of strong complexing agents in solution and it decreases with increasing of the complexation constants of the ligands with exception of cysteine and tiron. It is necessary, hence, to consider all these factors to effectively predict the uptake efficiency of this sorbent. However, it is possible to conclude that the vermiculite has good potentialities for cost-effective treatments of metal-contaminated wastewaters.