Stabilization of Soft Soil by Incinerated Sewage Sludge Ash from Municipal Wastewater Treatment Plant for Engineering Construction

Effective Management of Municipal Solid Waste cannot be achieved without involving wastewater treatment plants as they generate sludge that must be disposed of in an environmentally friendly manner. Therefore, recycling or reusing them are the preferred options for sustainable development. The study presented the use of incinerated sewage sludge ash (ISSA) as a soil stabilizing agent. Oxide compositions were determined by the X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD) and Toxicity Characteristic Leaching Procedure (TCLP). Result showed that ISSA contains Silicon oxide, SiO2 (61.42 %), Aluminum oxide Al2O3 (23.51 %) and Iron oxide, Fe2O3 (4.24 %) in high proportion. Clay soil with low to medium plasticity (CL) from an A-7-6 group was replaced with 0 % 3 %, 5 %, 7 % and 10 % ISSA. Test such as California Bearing Ratio (CBR), Unconfined Compressive Strength (UCS), Compaction and Atterberg limit were conducted. Soil obtained lowest OMC and highest MDD values both at 7% ash content. PI dramatically reduced at short extension of curing age from 21 % to 7 % at 10 % ISSA content thereby improving it from category A7 to A2. With 2.25 % at 3 days realized as the maximum value for resistance to loss in strength, durability requirement is satisfied. ISSA effectively raised CBR values of soil from 15.6 % to 19.5 %, 32.6 %, 47.9 % and 46.4 % respectively with 7 % ISSA additive yielding best result. Therefore, the study concludes that 7 % ISSA additive effectively enhance the strength of soft soils

Multi-criteria performance evaluation of gridded precipitation and temperature products in data sparse region

Inadequate climate data stations often make hydrologic modelling process quite a challenging task in data-sparse regions. Gridded climate data is being used as an alternative, however their accuracy to replicate the climatology of the region of interest with low level of uncertainty is important to water resource planning. This study utilized several performance metrics and multi-criteria decision to assess the skill of the widely used gridded precipitation and temperature data against quality controlled observed station record in Lake Chad basin. The study findings revealed that the products differ in their skills across the selected performance metrics, although promising especially with regards to temperature. However, there are some inherent weaknesses in replicating the observed station data. Princeton University Global Meteorological Forcing precipitation showed the worst skill with Kling Gupta Efficiency of (0.13 – 0.50), mean modified index of agreement of 0.68, and similarity coefficient (SU = 0.365), relative to other products with satisfactory skill across all stations. There are varying degree of mismatch in unidirectional precipitation and temperature trends, although satisfactory in replicating the hydro-climatic information with low level of uncertainty. Assessment based on multi-criteria decision revealed that Climate Research Unit, Global Precipitation Climatology Centre and Climate Prediction Centre precipitation and Climate Research Unit and Princeton University Global Meteorological Forcing temperature data exhibit better skill in terms similarity and are recommended for application in hydrologic impact studies, especially in the quantification of projected climate hazards and vulnerabilities for better water policy decision making in Lake Chad Basin

Waste derived biocomposite for simultaneous biosorption of organic matter and nutrients from green straw biorefinery effluent in continuous mode activated sludge systems

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

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

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

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

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

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

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

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