Kinetics of Nutrient Removal in an Integrated Suspended Growth Reactor

Wastewater effluent discharge in a large amount of ammonia, nitrate and phosphorus lead to eutrophication the river. Eutrophication is a serious environmental issue that threaten the fishes and aquatic plants. To prevent this from happening, ammonia produced in STP and raw wastewater removal is achieved during nitrification by having an extended aeration while nitrate removal is achieved during denitrification in anoxic tank. In this research study, a pilot plant of integrated suspended growth system (i-SGS) reactor was used to achieve simultaneous removal of ammonia and nitrate. The reactor has three main compartments which are anoxic chamber, aeration camber, and clarifier and operated at a constant flow rate of 720 L/d and fixed SRT of 40 days. The RAS time was set to once every 10 minutes for 5 minutes while the IR time is once every 16 minutes for 5 minutes. The wastewater quality parameters, namely chemical oxygen demand (COD), ammonia, and nitrate were measured to determine and evaluate the removal efficiency of them in i-SGS whereas phosphorus was measured to ensure the effluent standard meet the C:N:P ratio requirement. Samples from four sampling points were taken to conduct the laboratory experiment and three replication of the results for each parameter were measured. It was determined that i-SGS was able to eliminate average 72% of COD at 46 mg/L of clarifier effluent, and achieved 95% of ammonia removal at average 1.22 mg/L of the clarifier effluent concentration while obtained 43% of nitrate removal in the anoxic tank. Last but not least, the C:N:P ratio obtained was 100:14:8, denoted that i-SGS has ample of nutrients loading provided because it is more than the minimum nutrient requirements, 100:5:1. The removal was possible through the nitrification-denitrification process in the i-SGS pilot plant bioreactor. The operational SRT of 40 days have shown to be effective and stable for the COD but not for nitrifiers. The effluent discharge of COD, ammonia and nitrate in the pilot plant i-SGS has meet the standard requirement of DOE Malaysia, standard A and B respectively

Boron removal from produce water through adsorption

Boron (B) is essential for the development and functioning of organisms, involving their growth, health, and development of plants, animals, and humans. Nevertheless, the increasing use of boron in various applications has led to environmental problems and health issues. Several separation technologies have been employed to remove boron, and adsorption is one such technology that utilizes adsorbents to address solutions containing extremely low levels of boron. This finding investigates the residual boron from a synthesized solution through adsorption, using CRB05 as the adsorbent. The impact of adsorbent dosage, contact time, boron concentration, and pH on residual boron was examined. The findings indicate that the pH plays a substantial role impact on the residual boron efficiency from all adsorbents. The highest residual of boron was achieved at pH 4.5, adsorbent dosage 1125 mg/L, time 255 minutes, and concentration 1150 mg/L with 98% removal. Adsorption of boron using CRB05 proved to be an effective method for recovering boron from the synthesis solution. The findings of this study enhance our comprehension of the adsorption behavior of CRB05 and provide insights into the optimal operating conditions for efficient boron removal

Response Surface Methodology to Optimize Methane Production from Mesophilic Anaerobic Co-Digestion of Oily-Biological Sludge and Sugarcane Bagasse

Oily-biological sludge (OBS) generated from petroleum refineries has high toxicity. Therefore, it needs an appropriate disposal method to reduce the negative impacts on the environment. The anaerobic co-digestion process is an effective method that manages and converts organic waste to energy. For effective anaerobic digestion, a co-substrate would be required to provide a suitable environment for anaerobic bacteria. In oily-biological sludge, the carbon/nitrogen (C/N) ratio and volatile solids (VS) content are very low. Therefore, it needs to be digested with organic waste that has a high C/N ratio and high VS content. This study investigates the use of sugarcane bagasse (SB) as an effective co-substrate due to its high C/N ratio and high VS content to improve the anaerobic co-digestion process with oily-biological sludge. The sugarcane bagasse also helps to delay the toxicity effect of the methane bacteria. Batch anaerobic co-digestion of oily-biological sludge was conducted with sugarcane bagasse as a co-substrate in twelve reactors with two-liter capacity, each under mesophilic conditions. The interaction effect of a C/N ratio of 20-30 and a VS co-substrate/VS inoculum ratio of 0.06-0.18 on the methane yield (mL CH4/g VSremoved) was investigated. Before the anaerobic digestion, thermochemical pre-treatment of the inoculum and co-substrate was conducted using sodium hydroxide to balance their acidic nature and provide a suitable pH environment for methane bacteria. Design and optimization for the mixing ratios were carried out by central composite design-response surface methodology (CCD-RSM). The highest predicted methane yield was found to be 63.52 mL CH4/g VSremoved, under optimum conditions (C/N ratio of 30 and co-substrate/inoculum ratio of 0.18)

Lithium adsorption from aqueous solution using aluminum hydroxide: Characterization, optimization by response surface methodology, kinetic modelling, and isotherm studies

The growing need for Lithium (Li) chemicals for industrial application demands finding affordable and environmentally friendly ways of producing them beyond conventional land mining. Adsorption is a promising technique for Li recovery as it selectively extracts Li from aqueous resources at a low cost and with minimal energy requirements. The use of adsorption for Li recovery is important for promoting a circular economy and decreasing natural Li in the environment. Thus, this study aim to assess the efficiency of aluminum hydroxide (Al(OH)3) as an adsorbent for Li recovery from aqueous solution by adjusting the amount of adsorbent, time, Li concentration, and pH. The use of Al(OH)3 provides selective separation of Li ions and can be used as a simple and cost-effective method for purifying Li-containing solutions. The optimal conditions for the adsorption process were determined using the Box-Behnken in response surface methodology (RSM). The findings revealed that the highest removal was anticipated with a 1150 mg/L adsorbent dose, 4.5 pH, 1150 mg/L initial concentration, and 255 minutes contact time. The outcome of the finding supports the use of Al (OH)3 as a suitable choice for recovering Li due to its greater capacity for sorption and higher percentage of Li absorbed. The analysis of the isotherm and kinetic experiment results showed that the Temkin isotherm and the pseudo-first-order model were well-fitting, with R2 values of 0.998 and 0.999, respectively. This study emphasizes the effectiveness of Al(OH)3 in recovering Li and details the optimal adsorption process. As a result, Al(OH)3 has been presumed to be the most suitable choice for Li recovery because it outperforms other available adsorbents with high sorption ability

Boron removal from produce water through adsorption

Boron (B) is essential for the development and functioning of organisms, involving their growth, health, and development of plants, animals, and humans. Nevertheless, the increasing use of boron in various applications has led to environmental problems and health issues. Several separation technologies have been employed to remove boron, and adsorption is one such technology that utilizes adsorbents to address solutions containing extremely low levels of boron. This finding investigates the residual boron from a synthesized solution through adsorption, using CRB05 as the adsorbent. The impact of adsorbent dosage, contact time, boron concentration, and pH on residual boron was examined. The findings indicate that the pH plays a substantial role impact on the residual boron efficiency from all adsorbents. The highest residual of boron was achieved at pH 4.5, adsorbent dosage 1125 mg/L, time 255 minutes, and concentration 1150 mg/L with 98% removal. Adsorption of boron using CRB05 proved to be an effective method for recovering boron from the synthesis solution. The findings of this study enhance our comprehension of the adsorption behavior of CRB05 and provide insights into the optimal operating conditions for efficient boron removal

Parametric optimization of additive manufactured biocarrier submerged in sequencing batch reactor for domestic wastewater treatment

The high nutrient concentration in domestic wastewater effluent can endanger the aquatic life via eutrophication. Thus, research have been carried out to prevent harm to aquatic life. In regard biofilm reactors have been successful by far with few limitations. Bio-carrier fabrication of desired shape is one of the limitations. Recently, the invention of additive manufacturing (AM) of object made it feasible to fabricate the desired shape. In this study additive manufactured bio‒carrier (AMB) was printed using AM technique, with high surface area to volume ratio as well as density higher than water. The submerged attach growth sequencing batch biofilm reactor (SAGSBBR) for organic and nutrient removal from domestic wastewater (DWW) was conducted to determine the optimum bio‒carrier filling ratio (FR) and cycle time (CT) by using response surface methodology (RSM) with CT ranging between 12 h and 24 h and FR ranging between 0 and 20%. The maximum chemical oxygen demand (COD), ammonia-nitrogen (NH4+‒N), and total phosphorus (TP) removal was 96.8 mg/L, 93.32 mg/L, and 88.89 mg/L respectively, which was achieved in submerged attached growth sequential biofilm batch reactor with 10% FR (SAGSBBR‒10). The optimization study determined the optimal solution of CT and FR to be 17.07 h and 12.38% respectively, with desirability of 0.987. The predicted mean of responses for the optimal solution were 96.64%, 94.40% and 89.94% for COD removal, NH4+‒N removal and TP removal, respectively. The rate of biomass attachment at the first stage in SAGSBBR‒10 and SAGSBBR‒20 was about 11.39 mg/carrier.d and 8.64 mg/carrier.d, whereas the highest accumulation achieved was 98.27 mg/carrier and 80.15 mg/carrier respectively. Thus, this study can assist us to achieve sustainable development goal (SDG) 6

Trend and current practices of coagulation-based hybrid systems for pulp and paper mill effluent treatment : mechanisms, optimization techniques and performance evaluation

This paper presents an overview of pulp and paper mills (PPM) production processes, the resulting release of wastewater effluent loaded with wide range of pollutants and associated environmental impacts. The review highlighted the different types of functional materials and their modified forms employed as coagulants for pulp and paper mills industries effluent (PPME) treatment that have been intensively studied as a promising strategy for PPM to achieve cleaner and sustainable treatments in accordance with sustainable development goals (SDGs) “6-Clean water and sanitation”, “9-Industry, innovation, and infrastructure”, and “12-Responsible consumption and production”. Standalone coagulation treatment processes are inherently ineffective towards meeting the increasingly stringent discharge requirements, coupled with their higher energy demand, and increased operational and maintenance costs. Owing to the recalcitrant nature of PPME contaminants, this review explored the effectiveness of the coagulation processes for decontamination of PPME. Furthermore, the review provides a state-of-the-art coagulation-based hybrid systems employed for enhanced PPME treatment. The process limitations, influencing factors and optimization techniques are highlighted. The review also highlights how sustained research in the subject area impacts on achieving cleaner production. The review also discusses coagulant classifications and the synergistic, antagonistic and shock load toxic effects of hybrid coagulants on toxicant biodegradation and their associated system efficiency. Moreover, it offers a guide for the development and application of sustainable hybrid-based coagulants for PPME treatment. The findings presented herein provide a vital theoretical foundation for sustainable solutions to improve coagulation-based hybrid systems efficiency and their scale-up towards potential commercialization

Sugarcane Bagasse as a Co-Substrate with Oil-Refinery Biological Sludge for Biogas Production Using Batch Mesophilic Anaerobic Co-Digestion Technology: Effect of Carbon/Nitrogen Ratio

Man-made organic waste leads to the rapid proliferation of pollution around the globe. Effective bio-waste management can help to reduce the adverse effects of organic waste while contributing to the circular economy at the same time. The toxic oily-biological sludge generated from oil refineries’ wastewater treatment plants is a potential source for biogas energy recovery via anaerobic digestion. However, the oily-biological sludge’s carbon/nitrogen (C/N) ratio is lower than the ideal 20–30 ratio required by anaerobic digestion technology for biogas production. Sugarcane bagasse can be digested as a high C/N co-substrate while the oily-biological sludge acts as a substrate and inoculum to improve biogas production. In this study, the best C/N with co-substrate volatile solids (VS)/inoculum VS ratios for the co-digestion process of mixtures were determined empirically through batch experiments at temperatures of 35–37 °C, pH (6–8) and 60 rpm mixing. The raw materials were pre-treated mechanically and thermo-chemically to further enhance the digestibility. The best condition for the sugarcane bagasse delignification process was 1% (w/v) sodium hydroxide, 1:10 solid-liquid ratio, at 100 °C, and 150 rpm for 1 h. The results from a 33-day batch anaerobic digestion experiment indicate that the production of biogas and methane yield were concurrent with the increasing C/N and co-substrate VS/inoculum VS ratios. The total biogas yields from C/N 20.0 with co-substrate VS/inoculum VS 0.06 and C/N 30.0 with co-substrate VS/inoculum VS 0.18 ratios were 2777.0 and 9268.0 mL, respectively, including a methane yield of 980.0 and 3009.3 mL, respectively. The biogas and methane yield from C/N 30.0 were higher than the biogas and methane yields from C/N 20.0 by 70.04 and 67.44%, respectively. The highest biogas and methane yields corresponded with the highest C/N with co-substrate VS/inoculum VS ratios (30.0 and 0.18), being 200.6 mL/g VSremoved and 65.1 mL CH4/g VSremoved, respectively

Pretreated palm oil clinker as an attached growth media for organic matter removal from synthetic domestic wastewater in a sequencing batch reactor

Attached-growth systems are biological wastewater treatment processes with biomass attached to a media for organic matter and nutrient removal from wastewater. In this regard, bioreactors containing biocarriers have been successful by far with few limitations. The impact of bio-carrier materials type and properties on wastewater treatment is one important aspect that needs attention. Different synthetic materials have been utilized. However, this study utilized waste palm oil clinker (POC) as a biocarrier in a sequencing batch reactor (SBR) for syntheticdomestic wastewater treatment. This is to work in line with the attainment of sustainable development goals (SDGs). In this study, the POC was used as a biocarrier submerged in the aeration tank of bioreactor A of an attached growth system. Whereas the bioreactor B acts as a control. The overall working volume of the bioreactor systems was 10 L each. The treatment efficiency was measured by differing the hydraulic retention time (HRT) while organic contaminants were monitored. The HRT was varied at 6, 12, 24, 48, and 72 hours with the organic loading rate (OLR) kept constant at 550 mg/L.d. At all conditions of HRT (6–72 hours), minimum and maximum COD removals were up to 80% and 95.4% respectively. The influence of HRT was found to be more affected. Several biokinetic models, that includes the First order and Stover-Kincannon, were fitted to the steady-state data collected at different HRTs. The COD R2 values of 0.9096 and 0.9269 were obtained for reactors A and B, respectively. The maximum removal rate constant (μmax) and the saturation value constant (KB) for the Stover-Kincannon, were observed as 0.0005 g/L.d and 1 g/L.d, respectively for the bioreactor A. Throughout the study, POC incorporated SBR system demonstrated higher treatment efficiency compared to the control reactor in terms of COD removal. Thus, findings from this study have the potential to answer SDGs 6, 9, and 14