Effect of hydraulic retention time on the treatment of pulp and paper industry wastewater by extended aeration activated sludge system

The pulp and paper industry produce dark-colored effluent with high levels of organic matter and nutrients. As a result, a biological treatment system consisting of an aeration tank containing 3.5-6 g/L starting biomass and a clarifier chamber was set up in this investigation. After acclimation, the reactor was driven at a flow rate of 5 L/day for a few weeks at 48h, 24h, and 12h HRT. All through the investigation, the concentrations of organic and nutrient parameters are measured in the influent and effluent samples and documented for data processing. The results reveal that ammonia has satisfactorily met the Standard 'A' standard limits of 10 mg/L after 24 hours of HRT. As a result, reduction efficiencies for nitrate and COD were 80.5% and 95%, respectively. Surprisingly, the majority of the effluent COD readings met the acceptable standard, so no additional testing is required. The mean BOD concentration in effluent was found to be 4.54 mg/L

Removal of nutrients from pulp and paper biorefinery effluent : operation, kinetic modelling and optimization by response surface methodology

This study investigated the effectiveness of extended aeration system (EAS) and rice straw activated carbon-extended aeration system (RAC-EAS) in the treatment of pulp and paper biorefinery effluent (PPBE). RAC-EAS focused on the efficient utilization of lignocellulosic biomass waste (rice straw) as a biosorbent in the treatment process. The experiment was designed by response surface methodology (RSM) and conducted using a bioreactor that operated at 1–3 days hydraulic retention times (HRT) with PPBE concentrations at 20, 60 and 100%. The bioreactor was fed with real PPBE having initial ammonia-N and total phosphorus (TP) concentrations that varied between 11.74 and 59.02 mg/L and 31–161 mg/L, respectively. Findings from the optimized approach by RSM indicated 84.51% and 91.71% ammonia-N and 77.62% and 84.64% total phosphorus reduction in concentration for EAS and RAC-EAS, respectively, with high nitrification rate observed in both bioreactors. Kinetic model optimization indicated that modified stover models was the best suited and were statistically significant (R 2 ≥ 0.98) in the analysis of substrate removal rates for ammonia-N and total phosphorus. Maximum nutrients elimination was attained at 60% PPBE and 48 h HRT. Therefore, the model can be utilized in the design and optimization of EAS and RAC-EAS systems and consequently in the prediction of bioreactor behavior

Diverse sustainable materials for the treatment of petroleum sludge and remediation of contaminated sites : a review

Activities in the petroleum industry unavoidably generates huge amount of petroleum sludge that contain hazardous constituents. Numerous treatment techniques are proven to reduce toxicity, sludge volume, and extract petroleum products. Their efficiency is determined by the sludge properties. These treatment technologies can lessen the hazardous elements in sludge and alleviate their negative environmental and human health impacts. However, only a few, can strike a compromise between meeting strict environmental regulations and consuming notable quantity of water, energy, and chemicals. Now, there are no waste-free and cost-effective technologies available for petroleum sludge treatment. Therefore, this review was designed to highlight the several waste, plants, and other materials that have been utilized during petroleum sludge or petroleum contaminated site treatment for resource recovery and to ensure environmental safety. The application of various additives to remediate petroleum sludge contaminated areas has been proven to be a practical and environmentally beneficial alternative. The review found that reusing remediated soils for bioremediation activity on soil contaminated with oil sludge was efficient. The review further revealed that phytoremediation by sowing plants in the soil can remarkably boost microorganism's growth and TPH elimination rate. Also, in planted treatments using Zea mays L., Secale cereale L., Festuca arundinacea, Onobrychis viciifolia, Vertiver zizanioide, Cajanus cajan, Medicago sativa, Lolium perenne, Ttrifolium pratense etc. the most probable number were significantly higher than in unplanted treatments. It was also discovered that there is a commercial potential for the use of plants as sources of biosurfactant for use in accelerated TPHs degradation. Biosurfactant supplementation in the phytoremediation of metals and petroleum hydrocarbons co-contaminated soil was effective. The review suggests the use of composite materials for petroleum sludge treatment

Bench-Scale Fixed-Bed Column Study for the Removal of Dye-Contaminated Effluent Using Sewage-Sludge-Based Biochar

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 (R 2 ) 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

Circular economy potential and contributions of petroleum industry sludge utilization to environmental sustainability through engineered processes - a review

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

Palm Oil Clinker as a Waste by-Product: Utilization and Circular Economy Potential

Conservation of natural resources to create ecological balance could be significantly improved by substituting them with waste by-products. Palm oil industry operations increases annually, thereby generating huge quantity of waste to be dumped into the landfill. Palm oil clinker (POC) is a solid waste by-product produced in one of the oil palm processing phases. This chapter is designed to highlight the generation, disposal problems, properties and composition of POC. The waste to resource potentials of POC would be greatly discussed in the chapter starting with the application of POC in conventional and geopolymer structural elements such as beams, slabs, columns made of either concrete, mortar or paste for coarse aggregates, sand and cement replacement. Aspects such as performance of POC in wastewater treatment processes, fine aggregate and cement replacement in asphaltic and bituminous mixtures during highway construction, a bio-filler in coatings for steel manufacturing processes and a catalyst during energy generation would also be discussed. Circular economy potentials, risk assessment and leaching behavior during POC utilization would be evaluated. The chapter also discusses the effectiveness of POC in soil stabilization and the effect of POC pretreatment for performance enhancement. Towards an efficient utilization, it is important to carry out technical and economic studies, as well as life cycle assessments, in order to compare all the POC areas of application described in the present review article. POC powder has proven to be pozzolanic with maximum values of 17, 53.7, 0.92, 3.87, 1.46, for CaO, SiO2, SO3, Fe2O3 and Al2O3. Therefore, the present chapter would inspire researchers to find research gaps that will aid the sustainable use of agroindustry wastes. The fundamental knowledge contained in the chapter could also serve as a wake-up call for researchers that will motivate them to explore the high potential of utilizing POC for greater environmental benefits associated with less cost when compared with conventional materials

TREATMENT OF SYNTHETIC WASTEWATER WITH 3D PRINTED BIO-CARRIER IN SUBMERGED ATTACHED GROWTH SYSTEM

The conventional wastewater treatment plant is still struggling to meet ammonia and nitrate discharge limits in Malaysia. In this study comparison of synthetic domestic wastewater treatment (DWW) was established between conventional activated sludge (CAS) and submerged attached growth activated sludge (SAGAS) systems to find appropriate solution. The submerged attached growth bio‒carrier (TAVID) was printed through vat polymerization of acrylate-based resin using stereo‒lithography (SLA) technology to utilize as submerged attached growth bio‒carrier. The specific surface area (SSA) of TAVID was 971 m2⁄m3, with density, zeta potential and contact angle of 1.15±0.05 g/cm3, -30.46 mV, and 43.6° ± 2.8° respectively, indicating high SSA and hydrophilic behaviour of bio‒carrier. The effects of cycle time (CT) and filling ratio (FR) were studied in sequential batch mode

Predicting the Influence of Pulverized Oil Palm Clinker as a Sustainable Modifier on Bituminous Concrete Fatigue Life: Advancing Sustainable Development Goals through Statistical and Predictive Analysis

Currently, the viscoelastic properties of conventional asphalt cement need to be improved to meet the increasing demands caused by larger traffic loads, increased stress, and changing environmental conditions. Thus, using modifiers is suggested. Furthermore, the Sustainable Development Goals (SDGs) promote using waste materials and new technologies in asphalt pavement technology. The present study aims to fill this gap by investigating the use of pulverized oil palm industry clinker (POPIC) as an asphalt–cement modifier to improve the fatigue life of bituminous concrete using an innovative prediction approach. Thus, this study proposes an approach that integrates statistically based machine learning approaches and investigates the effects of applied stress and temperature on the fatigue life of POPIC-modified bituminous concrete. POPIC-modified bituminous concrete (POPIC-MBC) is produced from a standard Marshall mix. The interactions between POPIC concentration, stress, and temperature were optimized using response surface methodology (RSM), resulting in 7.5% POPIC, 11.7 °C, and 0.2 MPa as the optimum parameters for fatigue life. To improve the prediction accuracy and robustness of the results, RSM and ANN models were used and analyzed using MATLAB and JMP Pro, respectively. The performance of the developed model was assessed using the coefficient of determination (R2), root mean square error (RMSE), and mean relative error (MRE). The study found that using RSM, MATLAB, and JMP Pro resulted in a comprehensive analysis. MATLAB achieved an R² value of 0.9844, RMSE of 3.094, and MRE of 312.427, and JMP Pro achieved an R² value of 0.998, RMSE of 1.245, and MRE of 126.243, demonstrating higher prediction accuracy and superior performance than RSM, which had an R² value of 0.979, RMSE of 3.757, and MRE of 357.846. Further validation with parity, Taylor, and violin plots demonstrates that both models have good prediction accuracy, with the JMP Pro ANN model outperforming in terms of accuracy and alignment. This demonstrates the machine learning approach’s efficiency in analyzing the fatigue life of POPIC-MBC, revealing it to be a useful tool for future research and practical applications. Furthermore, the study reveals that the innovative approach adopted and POPIC modifier, obtained from biomass waste, meets zero-waste and circular bioeconomy goals, contributing to the UN’s SDGs 9, 11, 12, and 13

Sequential batch reactors for aerobic and anaerobic dye removal : a mini-review

One of the most challenging aspects of environmental conservation is the treatment of dye wastewater. Thus, this mini-review discussed the issues and major advances in the application and performance assessment of the aerobic, anaerobic, anaerobic-aerobic, aerobic-anaerobic, and anoxic–aerobic REACT-operated SBR systems with regards to bio-decolorization and COD removal rates. In SBRs run in aerobic modes, it is possible to cultivate aerobic granular sludge for color removal. To be precise, SBR has a higher COD removal efficiency with a lower color removal efficiency. Under anaerobic conditions, lesser COD removal was observed for several dyes studied in this chapter. In an alternating anaerobic-aerobic SBR system, color removal tends to occur during the anaerobic phase, while the aerobic phase is required to further reduce the effluent COD concentration. However, molecular oxygen drastically reduced color removal in SBR during dye wastewater treatment. This chapter discusses the aerobic-SBR treatment process for dye removal. The discussion focused on dye wastewater treatment using aerobic granules, granular activated carbon, adsorbents, biocarrier white rot fungi, varying dye mixtures, dye concentrations and SBR operational parameters. Adsorbents, membranes, biocarriers, exported microbial cultures, and various operational conditions have also been used in sequential anaerobic/aerobic batch reactors to enhance system performance. This chapter assessed the different treatment mechanisms and dynamics and concluded that combining two treatment methods significantly yields better color, DOC, and BOD5 removal than a single biological or chemical treatment