Combined treatment of domestic and pulp and paper industry wastewater in a rice straw embedded activated sludge bioreactor to achieve sustainable development goals

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

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

Agricultural wastewater treatment using oil palm waste activated hydrochar for reuse in plant irrigation : synthesis, characterization, and process optimization

The best possible use of natural resources and the large amounts of trash produced by industrial and human activity is necessary for sustainable development. Due to the threat of global climate change and other environmental challenges, waste management systems are changing, leading to more instances of water resource management. The waste generated must be controlled from a sustainability point of view. Typically, the conventional disposal of Agricultural Wastewater (AW) and biomass can be achieved by recycling, reusing, and converting them into a variety of green products. To improve the AW quality for the purposes of environmental sustainability, Sustainable Development Goals (SDGs) 6 and 14, dealing with clean water, sanitation, and life below water, are very important goals. Therefore, the present investigation evaluates the effectiveness of a Bench-scale Activated Sludge Reactor (BASR) system for AW treatment. The BASR was designed to focus on getting the maximum possible utilization out of a biosorbent derived from oil palm waste activated hydrochar (OPAH). This is in accordance with SDG 9, which targets inorganic and organic waste utilization for added value. An experiment was developed using the Response Surface Methodology (RSM). A Hydraulic Retention Time (HRT) of 1–3 days was used in the bioreactor’s setup and operation, and Mixed Liquor Suspended Solids (MLSS) concentrations of 4000–6000 mg/L were used. BASR was fed with AW with initial mean concentrations of 4486 ± 5.63 mg/L and 6649 ± 3.48 for the five-day Biochemical Oxygen Demand (BOD5) and Chemical Oxygen Demand (COD) experiments, respectively. The results obtained showed that maximum reductions of 84.66% and 72.07% were recorded for BOD5 and COD, respectively. Through RSM optimization, the greatest reductions in the amounts of organic materials were achieved with a 2-day HRT and an MLSS dosage of 5000 mg/L. Substrate elimination thresholds were assessed using the first-order, the Grau second-order, and the modified Stover–Kincannon models. The reported observations were found to be perfectly fit by the modified Stover–Kincannon model, with high R2 values of 0.9908 and 0.9931 for BOD5 and COD, respectively. As a result, the model may be used to design the BASR system and forecast how the reactor would behave. The findings from this study suggest that the developed OPAH has promising potential to be applied as eco-friendly material for the removal of BOD5 and COD from AW. Consequently, the study findings additionally possess the ability to address SDGs 6, 9, and 14, in order to fulfil the United Nations (UN) goals through 2030

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

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

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

Synthesis, characterization, and performance evaluation of hybrid waste sludge biochar for cod and color removal from agro-industrial effluent

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

A systematic literature review of biocarriers : central elements for biofilm formation, organic and nutrients removal in sequencing batch biofilm reactor

Over the past decades, several materials utilized as biocarriers for immobilization of microorganisms have been gaining popularity showing different degrees of effectiveness. However, information concerning their effects on sequencing batch biofilm reactors (SBBR) performance is still lacking. There is currently no single widely acceptable material documented for proper biofilm formation, as most materials cannot achieve satisfactory level. Problems of biocarrier also exists due to the emergence of newer and more complex pollutants. Therefore, resource-efficient and environmentally friendly biocarriers are a call of the hour. This article thus, presents a systematic literature review of existing research articles on the various advances made between 2005 and 2021 about biocarrier physical properties, and performances with specific focus on their contributions in biofilm formation, nutrients and organic matter removal. This is to establish their role as central elements in biofilm formation. The review further described the operational challenges, mass transfer considerations, and recommendations made during successful utilization of the biocarriers in SBBR systems. Future research areas that may ultimately lead to large-scale commercial application of this biocarriers and will result in sustainable and environmentally friendly solution to the problems created during wastewater treatment have also been identified. This paper suggests that future researchers investigate the efficiency of composite biocarriers. It is believed that information contained in this review will increase readers fundamental knowledge, guide future researchers and be incorporated into future works on experimentally-based studies on biocarriers in SBBR systems

Parametric optimization and kinetic modelling for organic matter removal from agro-waste derived paper packaging biorefinery wastewater

The state-of-the-art paper packaging biorefinery utilizes cellulose fibrous material from paddy straw and papaya latex to produce packaging products. This in turn generate wastewater with high organic matter content that if disposed without treatment will pollute water bodies and affect aquatic life below water. Therefore, to comply with "clean water and sanitation" (SDG 6) and "life below water" (SDG 14), this study assesses the efficacy of an extended aeration activated sludge (EAAS) in the treatment of paper packaging biorefinery wastewater (PPBW) by employing paddy straw-derived activated carbon as a biosorbent. Findings revealed that the system was able to achieve 95–98.2% and 90.62–94.96% biological oxygen demand (BOD 5 ) and chemical oxygen demand (COD) reduction, respectively. The maximum organic matter removals were achieved at 2-day hydraulic retention time (HRT) and 60% PPBW concentration. To evaluate substrate removal rates, the first-order, modified Stover–Kincannon and Grau second-order models were used. In the modified Stover–Kincannon model, high correlation coefficients values R2 of 0.99986 and 0.99991 were obtained for COD and BOD 5 , respectively. Twenty grams COD/L/day and 50 gBOD 5 /L/day were obtained as Umsr for COD and BOD 5 , respectively, and 20.402 g/L/day and 56.295 g/L/day as K V constants for COD and BOD 5 , respectively. The COD and BOD 5 biokinetic constant values for the Grau second-order organic matter removal rate constant kS were 36 day −1 and 0.78 day −1 , respectively. Here, 0.9989 and 0.99928 were the obtained R2 values for COD and BOD 5 , respectively. The EAAS bioreactor system described by modified Stover–Kincannon model was proven to best suit the experimental data. Therefore, the model can be used in designing an EAAS system and consequently predict the bioreactor behaviour. The result of this study provided a benchmark for the actual implementation of PSAC in PPBW treatment for COD and BOD 5 removal. It has been proven that PSAC biosorbent sourced from a natural agro-waste material is essential and could be used as an efficient substance for organic matter removal. Operating expenses and associated savings were such that PASC was more attractive in an economic analysis of wastewater treatment demands. It is environmentally benign and offers a green treatment option to the PPBW. It could be an alternative to chemical materials because it is harmless to human health and proffer sustainable solution to potable water production

Sources of water contamination by heavy metals

This chapter titled “Sources of Water Contamination by Heavy Metals” provides an extensive discussion of the various sources of heavy metals in water bodies. Heavy metals are defined and their properties and uses are outlined. The chapter examines the different sources of heavy metals, including natural, anthropogenic, and from diverse sources such as waste materials and industrial processes. The sources, characteristics, uses, and impacts of individual heavy metals including arsenic, nickel, zinc, lead, mercury, copper, chromium, and cadmium are also discussed in detail. Furthermore, the chapter evaluates the different indexing approaches for heavy metal pollution including the heavy metal pollution index (HPI), the contamination index (CI), the evaluation index of heavy metals (HEI), and the heavy metal index (HMI). The analytical methods for heavy metal detection are also discussed, including broad categories such as spectroscopic detection, electrochemical detection, and optical methods of detection. This chapter will be useful to researchers and professionals in the fields of environmental science, chemistry, engineering, and water resources management who are interested in understanding the sources and impacts of heavy metal contamination in water bodies. The information provided in this chapter will also be useful for the development of effective strategies for the prevention and mitigation of heavy metal pollution in water bodies