Mixture Of Sludge Research Articles

Hydrogen production from energetic poplar and waste sludge by electrohydrogenesis using membraneless microbial electrolysis cells

Membraneless microbial electrolysis cells (MECs) are potentially considered to produce biohydrogen (bioH2) in a green manner and simultaneously minimize agricultural and wastewater facility wastes. However, effective, sustainable, and cost-effective system configuration and improvement of operating variables, working at ambient conditions, are needed to make the MEC a sustainable process. Therefore, this study investigates the bioH2 production from poplar leaves and anaerobic sludge mixture by incorporating nanomaterials comprising Al2O3, MgO, and Fe2O3 metal oxides at various dosages. Moreover, the effects of applied cell voltage (0.5–1.5 V) and inoculum amount (20–40 mL) on bioH2 production and organic matter removal performance are evaluated. The maximum bioH2 production value is 417 mL at an applied voltage of 1.5 V with a chemical oxygen demand (COD) removal efficiency of 37.6 % under operating times of 5 min using 40 ml of inoculum. The bioH2 production of the MEC system is reduced with the decrease in inoculum amount. The highest bioH2 production of 828 mL is obtained at improved conditions in the presence of 1 g of Fe2O3 metal oxide. Overall, this study provides the potentiality of simultaneous waste minimization and bioH2 production under ambient conditions that highlight the waste-to-energy pathway for membraneless and green bioelectrochemical process.

High temperature pyrolysis of sewage sludge: Synergistic effects of co-pyrolysis with rice straw and composite plastics wastes

The synergistic effect of co-pyrolysis for the mixtures of sewage sludge (SS), rice straw (RS) and composite plastic wastes (PE&PP) has been investigated with the aim of high gas yields and hydrogen generation. In this context, the applicability of high temperature pyrolysis technology was evaluated at both rotary type batch reactor and rotating screw type continuous reactor operating under the industrially relevant conditions. Gas yields have been improved at increasing the operating temperatures up to 850 °C. The gas yield of 75.06 % with its H2 portion of 32.35 % has been achieved as the best results for continuous pyrolysis unit at pilot scale. Secondary reactions such as steam de-alkylation, steam cracking, water gas shift and so on were regarded as being responsible for the high gas yields when the primary products of pyrolysis, i.e. condensable vapors, were much exposed to the hot zones inside the reactor. The dehydration of organic components involving the loss of water may supply steam to create a reactive pyrolysis atmosphere. While the pyrolysis of sewage sludge and rice straw favors CO and CO2 formation due to the high oxygen contents of these feedstocks, more methane and light olefins were produced when the plastics were added to the feedstock blends. This was ascribed to the initially generated radicals from the decomposition of sewage sludge and/or rice straw that might promote the scission reactions of plastics towards volatiles. It was shown that high temperature pyrolysis can be applied to a variety of organic wastes such as rice straw, sewage sludge and waste plastics. Conversion of wastes to hydrogen fosters the circular economy by putting the disposal costs down and creates a new route on renewable hydrogen generation.

Physical and Numerical Modeling of a Flow Control Layer Made with a Sludge and Slag Mixture for Use in Waste Rock Pile Reclamation

Physical and Numerical Modeling of a Flow Control Layer Made with a Sludge and Slag Mixture for Use in Waste Rock Pile Reclamation

Combustion behavior of solid waste fuels in the vertical tube reactor under different oxy-fuel environments

Oxy-fuel combustion technology has been recognized as one of the promising ways for cost-effective CO2 capture. The co-combustion characteristics of flax straw biomass/bituminous coal mixture (FS/BC) and flax straw biomass/sewage sludge mixture (FS/SS) under air, oxy-fuel (21%/79% O2/CO2) and oxygen-enriched oxy-fuel (30%/70% and 40%/60% O2/CO2) conditions were investigated in the vertical tube reactor. In particular, the study focused on the burning characteristics, the effect of blending ratio, and flue gas emissions. The findings indicated that flax straw biomass exhibited superior ignition performance compared to its blends with sewage sludge and bituminous coal. A higher O2 concentration from 21% to 40 led to a reduction in ignition delay time by 4s at 850 ℃ and by up to 10s at 950 ℃. Moreover, char combustion time was reduced by 50% for FS/SS blends due to the lower fixed carbon content compared to FS/BC blends. Additionally, increasing the O2 concentration resulted in lower emissions of CO by ∽40% and N2O by ∽45% for both blends. However, this also led to a slight increase in SO2 and NO emissions by ∽15% and ∽26%, respectively. The optimal conditions for the tested samples in oxy-fuel environment were found to be 30% O2/70 CO2, which enhanced combustion performance while lowering flue gas emissions.

Essential Quality Attributes of Culture Media Used as Substrates in the Sustainable Production of Pre-Basic Potato Seeds

The sustainability of the primary sector is closely linked to meeting the demand for seeds using agro-industrial waste and bioresidues. Sustainability is a multidimensional concept focused on achieving environmental health, social justice, and economic viability. To this end, an experiment was designed based on a combination of biotechnological strategies accessible to many individuals. The first strategy involves the use of compost and vermicompost as cultivation substrates; the second is the in vitro acclimatization of potato plants to these substrates; and the third is the incorporation of Trichoderma asperellum into these substrates to determine the synergistic effect of both. The compost used in this work came from sewage sludge from an agri-food company (Cp); a dining room and pruning waste from a university campus (Cu); and vermicomposted coffee pulp waste (Cv). Each sample was mixed with coconut fiber (Fc) in proportions of 100, 75, 50, and 25%. In the resulting mixtures, María Bonita variety vitroplants were planted and placed in a greenhouse. The biometric response in the three cases indicated a dependence on the type of compost and the proportion of the coconut fiber mixture. The inoculation of Trichoderma asperellum with sewage sludge compost increased stem thickness (42.58%) and mini-tuber weight (6.74%). In contrast, uninoculated treatments showed the best performance in terms of the number of mini-tubers. A 50:50 mixture of sewage sludge compost with coconut fiber and without inoculation of Trichoderma asperellum was the best treatment for the production of pre-basic seeds of the María Bonita potato variety. The use of composted agricultural waste and bioresidues is shown as a valid and low-cost alternative for the sector, even independently of the incorporation of additional inoculants.

Sustainable Ceramic Glaze Development from Coal Power Plant Water Treatment Sludge: A Customer-Oriented Approach Using Delphi Method, QFD, and Mixture Design

This research delves into the sustainable utilization of waste materials, particularly chemical sludges from coal power plant water treatment processes, in ceramic glaze development. The study background underscores the growing interest in repurposing industrial waste for sustainability in the ceramics industry. To address this, this study employs innovative methods like the Delphi method and Quality Function Deployment (QFD) to understand customer needs and guide product development. The next step will be to design an experiment to find the optimization point of the mixture of chemical sludge, silica, and soda feldspar to obtain a prototype as desired from QFD. The experimental investigations in this study highlight that resistance to cracking is a crucial factor in glaze formulations. An analysis revealed that a formulation containing 15% sludge, 52% soda feldspar, and 22% silica emerged as the optimal combination for further development. The results indicate that the prototype holds promise for future development, as demonstrated by cracking tests accelerated in an autoclave and analyzed using image processing. These findings contribute to advancing sustainable practices in ceramics, aligning with broader goals of waste minimization, circular economy principles, and resource efficiency.

An Analysis of the Physicochemical and Energy Parameters of Briquettes Manufactured from Sewage Sludge Mixtures and Selected Organic Additives

An Analysis of the Physicochemical and Energy Parameters of Briquettes Manufactured from Sewage Sludge Mixtures and Selected Organic Additives

Impact of thermal hydrolysis on VFA-based carbon source production from fermentation of sludge and digestate for denitrification: experimentation and upscaling implications

Stricter nutrient discharge limits at wastewater treatment plants (WWTPs) are increasing the demand for external carbon sources for denitrification, especially at cold temperatures. Production of carbon sources at WWTP by fermentation of sewage sludge often results in low yields of soluble carbon and volatile fatty acids (VFA) and high biogas losses, limiting its feasibility for full-scale application. This study investigated the overall impact of thermal hydrolysis pre-treatment (THP) on the production of VFA for denitrification through the fermentation of municipal sludge and digestate. Fermentation products and yields, denitrification efficiency and potential impacts on methane yield in the downstream process after carbon source separation were evaluated. Fermentation of THP substrates resulted in 37–70 % higher soluble chemical oxygen demand (sCOD) concentrations than fermentation of untreated substrates but did not significantly affect VFA yield after fermentation. Nevertheless, THP had a positive impact on the denitrification rates and on the methane yields of the residual solid fraction in all experiments. Among the different carbon sources tested, the one produced from the fermentation of THP-digestate showed an overall better potential as a carbon source than other substrates (e.g. sludge). It obtained a relatively high carbon solubilisation degree (39 %) and higher concentrations of sCOD (19 g sCOD/L) and VFA (9.8 g VFACOD/L), which resulted in a higher denitrification rate (8.77 mg NOx-N/g VSS∙h). After the separation of the carbon source, the solid phase from this sample produced a methane yield of 101 mL CH4/g VS. Furthermore, fermentation of a 50:50 mixture of THP-substrate and raw sludge produced also resulted in a high VFA yield (283 g VFACOD/kg VSin) and denitrification rate of 8.74 mg NOx-N/g VSS∙h, indicating a potential for reduced treatment volumes. Calculations based on a full-scale WWTP (Käppala, Stockholm) demonstrated that the carbon sources produced could replace fossil-based methanol and meet the nitrogen effluent limit (6 mg/L) despite their ammonium content. Fermentation of 50–63 % of the available sludge at Käppala WWTP in 2028 could produce enough carbon source to replace methanol, with only an 8–20 % reduction in methane production, depending on the production process. Additionally, digestate production would be sufficient to generate 81 % of the required carbon source while also increasing methane production by 5 % if a portion of the solid residues were recirculated to the digester.

Evaluating environmental and economic benefits of using biochar in concrete: A life cycle assessment and multi-criteria decision-making framework

While several studies have assessed the applicability of using biochar in cement mortar and concrete preparation based on the best mechanical properties, this evaluation method should be improved to consider the techno-economic feasibility and the environmental impacts. To address this research gap, this study attempts to compare between the conventional concrete with 100 % cement as a control mixture (CM) and dumping of sludge into open sites (scenario_1), and biochar concrete using alum sludge biochar (ASB) as a partial cement replacement (scenario_2), regarding the project life cycle assessment (LCA) and economic feasibility. A multi-criteria decision-making (MCDM) framework was used to assign scores to the environmental LCA criteria, material functional performance tests, and cost considerations. The two scenarios were arranged in SimaPro LCA software, and then the different criteria were analyzed using the TOPSIS technique to choose the best alternative. The study demonstrated that the functional properties of the cement mixture containing 5 % of ASB were almost comparable to those of CM, owing to the presence of significant amounts of quartz (SiO2) that bonded strongly with cement molecules. This ASB mixture also enjoyed the least environmental impacts, reducing the global warming potential (GWP) by 32.2 % compared with the CM scenario. The scores of the “Cost” criterion, considering the price of raw materials, energy, production, and maintenance, for the two alternatives were almost comparable, depicting that scenario_2 achieved the highest closeness coefficient of 0.95 in the MCDM overall scoring. This study concluded that biochar could be incorporated into cementitious mixtures due to its lower impact on global warming to maintain a sustainable and economic concrete industrial strategy. Future studies should focus on studying the long-term durability of the biochar-based concrete mixtures and integrating into the MCDM strategy; in addition, determining the correlation between sustainable construction implementation and sustainable development goals achieved.

The Application of Converter Sludge and Slag to Produce Ecological Cement Mortars.

The paper presents an analysis of the effective use of a mixture of steel sludge (S1) and slag (S2) from the converter process of steel production for the production of cement mortars. Metallurgical waste used in the research, which is currently deposited in waste landfills and heaps near plants, posing a threat to groundwater (possibility of leaching metal ions present in the waste), was used as a substitute for natural sand in the range of 0-20% by weight of cement (each). The obtained test results and their numerical analysis made it possible to determine the conditions for replacing part of the sand in cement mortars with a mixture of sludge and slag from a basic oxygen furnace (BOF) and to determine the effects of such modification. For the numerical analysis, a full quadratic Response Surface Model (RSM) was utilized for two controlled factors. This model was subsequently optimized through backward stepwise regression, ensuring the inclusion of only statistically significant components and verifying the consistency of residual distribution with the normal distribution (tested via Ryan-Joiner's test, p > 0.1). The designated material models are helpful in designing ecological cement mortars using difficult-to-recycle waste (i.e., sludge and converter slag), which is important for a circular economy. Mortars modified with a mixture of metallurgical waste (up to 20% each) are characterized by a slightly lower consistency, compressive and flexural strength, and water absorption. However, they show a lower decrease in mechanical strength after the freezing-thawing process (frost resistance) compared to control mortars. Mortars modified with metallurgical waste do not have a negative impact on the environment in terms of leaching heavy metal ions. The use of a mixture of sludge and steel slag in the amount of 40% (slag/sludge in a 20/20 ratio) allows you to save 200 kg of sand when producing 1 m3 of cement mortar (cost reduction by approx. EUR 5.1/Mg) and will also reduce the costs of the environmental fee for depositing waste.

Life Cycle Assessment and Net Energy Analysis of an Integrated Hydrothermal Liquefaction-Anaerobic Digestion of Single and Mixed Beverage Waste and Sewage Sludge

The conversion of biomass to bioenergy is one of the approaches to creating a sustainable society. In this study, the life cycle assessment and the net energy analysis of converting mixed sewage sludge and beverage waste into bioenergy via a combined hydrothermal liquefaction-anaerobic digestion (HTL-AD) system was carried out. Primary sludge (PS), winery rose lees (RL), brewery Trub (BT), the mixture of brewery trub and primary sludge (BTPS) and the mixture of winery rose lees and primary sludge (RLPS) were the feedstocks considered. Efficient energy utilization [in form of net energy ratio (NER)], and environmental emissions were evaluated. The NER of BT (2.07) and RL (1.76) increased when mixed with PS (3.18) to produce BTPS (3.20) and RLPS (2.85). Also, the HTL phase of the combined HTL-AD system produced a greater NER than the AD phase in BT, BTPS, and PS and vice-versa in RL and RLPS. Six environmental impact categories were studied namely global warming, terrestrial acidification, ionizing radiation, terrestrial ecotoxicity, human carcinogenic toxicity, and human non-carcinogenic toxicity. RL produced the greatest environmental impact while BTPS produced the least impact, thus indicating the advantage of feedstock combination. This study shows that the combination of feedstocks for bioenergy production in an HTL-AD system does not only increase the quality and quantity of products but also increases the overall NER as well as reducting the environmental impacts. The study also proved that an integrated HTL-AD system is an energy efficient system with greater resource utilization and less environmental footprint than the constituent systems.

Investigating the utilization of oxidized textile residue as a strengthening substance in the composition of subgrade soil for pavement construction

<p>The textile industry, vital in the country's industrialization and playing a crucial role in the national economy, generates solid byproducts known as textile sludge. Integrating waste into stabilized soils, along with textile sludge (TS), fly ash (FA), and asphalt additives, offers scientific, economic and sustainability benefits. This study aimed to examine the subsurface solidification technique employing sludge and two supplement additives (asphalt and fly ash additive) implemented on pavement groundwork and supporting layers. The research involved characterization tests and physical soil stabilization with TS and stabilizers (fly ash, and asphalt) at proportions of 2.5%, 5%, 7.5%, 10%, 15%, and 20% as soil additives, which were carried out experimentally. The test results highlighted the potential application of soil-textile sludge mixtures in pavement strata (support and subgrade). The inclusion of fly ash has been proven to be the most effective method for chemically stabilizing the sludge. The maximum dry density was achieved with soil containing 10% textile sludge, supplemented with 15% fly ash. This resulted in a notable increase in UCS value from 235 kN/m2 to 242 kN/m2 and an improvement in CBR value from 4.1% to 9.12%. Furthermore, the addition of 5% bitumen further enhanced the UCS value, reaching 451 kN/m2 and significantly increased the CBR value to 21.6%. Stabilizing textile sludge offers significant environmental benefits by mitigating issues associated with improper waste disposal.</p>

Aquaculture sludge as feed for black soldier fly: Transfer of chemical and biological contaminants and nutrients

Aquaculture sludge (uneaten feed and faeces) is nutrient rich and has potential as feed for insects. The aim of this study was to investigate the transfer of chemical and biological contaminants, as well as nutrients, from aquaculture sludge to black soldier fly larvae. The larvae were reared on a sludge mixture made of different sludges collected from Norwegian freshwater salmonid facilities. The sludge was spiked with four common salmon pathogens: Infectious Pancreatic Necrosis Virus, Infectious Salmon Anemia virus, Yersinia ruckeri or Mycobacterium salmoniphilum. During the 15 days of growth on sludge, the black soldier fly larvae accumulated valuable nutrients including protein, fat, eicosapentaenoic acid, iron, manganese, zinc and selenium. The larvae also accumulated undesirable substances including cadmium, mercury, dioxins and polychlorinated biphenyls. The concentrations of dioxins exceeded the EU maximum level set for animal feed. None of the salmon pathogens that were spiked to the sludge were detected in the black soldier fly larvae. This study reports low risk of transfer of salmon pathogens from sludge to insect larvae, and showed that the transfer of heavy metals, minerals and metalloids are in accordance with earlier studies. The large variations in levels of heavy metals between batches of sludge can cause levels in BSF exceeding the EU maximum levels, and thus indicate a need for monitoring of the proposed value chain. The transfer of dioxins from sludge to insects, reported for the first time in this paper, would be of special interest for future research, with special focus on risk mitigation.

Mechanical and Microstructural Analysis of Lightweight Subgrade Bricks Synthesized from Mixtures of Coal Fly Ash and Sewage Sludge

Abstract The massive discharge of coal fly ash and sewage sludge has placed great pressure on the environment and society. This study proposes a feasible method for producing lightweight subgrade bricks from coal fly ash and sewage sludge. The results show that the lightweight subgrade bricks mainly consist of mullite (3Al2O3·2SiO2), hematite (Fe2O3), sillimanite (Al2SiO5), aluminum phosphate (AlPO4), and a small amount of cristobalite (SiO2). The formation of AlPO4 improved the sintering and mechanical properties of the sintered samples. The formation of voids and cracks in the sintered samples was primarily attributable to the combustion and sintering shrinkage of the organic matter in the mixture. The maximum compressive and flexural strengths were observed when the sewage sludge content was 40 wt. %, and the corresponding compressive strength and flexural strength were 19.86 and 8.57 MPa, respectively. An appropriate amount of sewage sludge improves the connections between coal fly ash particles and promotes the densification of the lightweight subgrade bricks. These results provide a direction for the development of applications for coal fly ash and sewage sludge in the field of building materials.

Intermittent anaerobic-aerobic biopiling for remediating energetic compound-contaminated soils

Demolishing obsolete ammunition and live fire training, along with other military activities, contaminated military sites with energetic compounds (ECs), are raising human concerns. Biopiling is a green and sustainable technology for soil remediation due to its low cost and minimal secondary pollution. This study investigated the effects of various bio-stimulants in enhancing intermittent anaerobic-aerobic biopiling for ECs degradation in soil. The results showed that intermittent anaerobic-aerobic biopiling with municipal sludge, livestock and poultry manure, and agricultural and forestry wastes degraded 93.7 % 2,4,6-trinitrotoluene (TNT), 79.5 % hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and 92.0 % octahydro-1,3,5,7-tetranitro −1,3,5,7-tetrazocine (HMX) in 15 days. Correlation analysis of the energetic compounds showed that the TNT concentration and its reduction products changed conversely under anaerobic conditions, indicating a faster TNT reduction. Analysis based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) database revealed an increase in the abundance of genes (nemA &porA) associated with nitrotoluene reduction. This study demonstrated that bio-stimulants composed of a mixture of municipal sludge, manure, and soil conditioner (SLA) could improve the physicochemical properties of the biopiling system and the microbial community structure, promoting the growth of Firmicutes that respond for the degradation of energetic compounds, including the influence of functional genes for TNT degradation.

Biomethane Production from the Two-Stage Anaerobic Co-Digestion of Cow Manure: Residual Edible Oil with Two Qualities of Waste-Activated Sludge

Wastewater treatment systems produce large volumes of sludge which is not used; its final disposal is in soil or landfill. This sludge represents a biomethane-energy alternative through anaerobic co-digestion, contributing to reducing the environmental impacts caused by their inadequate disposal. Biomethane production by the two-stage production method in batch digesters with pH and temperature control was evaluated by two qualities of waste-activated sludge (SLB50 and SLB90) and with a mixture of two co-substrates: cow manure (CEV50 and CEV90) and residual edible oil (CAV50 and CAV90). Bacteria in good-quality sludge (SLB90) showed a faster adaptation of 2 days than those in low-quality sludge (SLB50), with a 25-day lag phase. The highest CH4 production was for SLB90 (303.99 cm3 d−1) compared to SLB50 (4.33 cm3 d−1). However, the cow manure–sludge mixture (CEV90) contributed to the increased production of CH4 (42,422.8 cm3 d−1) compared to CEV50 (12,881.45 cm3 CH4 d−1); for CAV90 and CAV50, these were 767.32 cm3 d−1 and 211.42 cm3 d−1, respectively. The addition of sludge co-substrates improves the nutrient balance and C/N ratio; consequently, methane production improves. This methodology could be integrated into concepts of the circular economy.

Deep learning-based flocculation sensor for automatic control of flocculant dose in sludge dewatering processes during wastewater treatment

In sludge dewatering of most wastewater treatment plants (WWTPs), the dose of polymer flocculant is manually adjusted through direct visual inspection of the flocs without the aid of any instruments. Although there is a demand for the development of automatic control of flocculant dosing, this has been challenging owing to the lack of a reliable flocculation sensor. To address this issue, this study developed a novel image sensor for measuring the degree of flocculation (DF) based on deep learning. Two types of sludge samples were used in the laboratory-scale flocculation tests: excess sludge and mixtures of excess sludge and raw wastewater. To search for a deep learning regression model suitable for DF inference, ten models, including convolutional neural networks, vision transformers, and a multilayer perceptron MLP mixer, were comparatively analysed. The ConvNeXt and MLP mixer models showed the highest accuracies with coefficients of determination (R2) greater than 0.9. The region contributing to the DF inference in the flocculation images was visualised using a modulus-weighted, gradient-weighted regression activation map. A prototype of the flocculation sensor was constructed using an inexpensive EdgeAI device. This device comprises a single-board computer and an integrated graphical processing unit (GPU) and is equipped with a quantised ConvNeXt model. The maximum inference speed of the sensor was 12.8 frames per second (FPS). The flocculation control tests showed that the sensor could control the DF to the target value by adjusting the polymer flocculant dose. Therefore, the flocculation sensor can provide a data-driven approach to the management of the flocculation process, thereby facilitating the automation of WWTPs.

Degradation of carbamazepine and triclosan in sewage sludge mixtures used for fertilizing agricultural soils

Degradation of carbamazepine and triclosan in sewage sludge mixtures used for fertilizing agricultural soils

A kinetics study of microwave pyrolysis of sewage sludge and corn stalk mixture

AbstractFast pyrolysis of sewage sludge (SS), corn stalk (CS), and their mixture under both direct and indirect microwave heating was carried out in a prototype microwave thermogravimetric reactor at high heating rates, 179 and 203 K/min, respectively. It was found that the samples could be heated up rapidly by direct microwave heating, while there is a temperature lag of the sample to the heated reactor wall in indirect heating. The Flynn–Wall–Ozawa (FWO) and Kissinger–Akahira–Sunose (KAS) methods were used to analyze the thermogravimetric data of SS, CS, and their mixture under direct microwave heating. When the FWO method was used, the average activation energies of SS, CS, and their mixture were obtained as 6.0, 18.9, and 39.8 kJ/mol, respectively. When the KAS method was used, the average activation energies of CS and mixture were 12.6 and 31.6 kJ/mol, respectively. Those values are much lower than reported under conventional heating, and likely result from the interaction of microwave irradiation and the biomass samples. The reaction kinetics of directly microwave‐heated biomass pyrolysis from this study provide essential data for modelling, scaling, and designing the microwave‐assisted in‐situ catalytic pyrolysis reactors with mixed biomass and catalyst particles.

Effect of Biochar on Anaerobic Co-Digestion of Untreated Sewage Sludge with Municipal Organic Waste under Mesophilic Conditions

Anaerobic digestion (AD) is a biological process that occurs in the limited presence of oxygen. This process involves various difficulties during the operation, such as acidification and increased concentration of volatile fatty acids, which can inhibit methane production. Therefore, in this work, the impact of biochar on the co-digestion of untreated sludge and residual biomass under mesophilic conditions was studied. For the production of biochar, the gasification process was used at different temperatures: 759 °C (BL), 798 °C (BM), and 888 °C (BH). This biochar was added in concentrations of 0 g/L, 3.33 g/L, and 6.67 g/L at the beginning of the co-digestion process. The results showed that a concentration of 6.67 g/L with BH biochar increased the PBM by 18% compared to the control sample and reduced the chemical oxygen demand (COD) by 88%. In addition, there was a reduction of volatile fatty acids (VFA) of 42.75%. Furthermore, FTIR analysis demonstrated that biochar has appropriate functional groups for this process. These data suggest a good interaction of biochar with the mixture of sludge and municipal waste, indicating that biochar can improve the anaerobic co-digestion of untreated sludge and municipal waste.