Acidification Degree Research Articles

A portable optical sensor combining smartphone with phycocyanin-based fluorescent test paper for rapid, visual and on-site detection of CO32–

With the development of global industry, carbon dioxide emissions surged. The conversion of carbon dioxide from the air results in some CO32−, which can exacerbate environmental disasters like ocean acidification. Therefore, the content of CO32− in seawater is an important indicator of the degree of ocean acidification. In this study, natural fluorescent protein phycocyanin (PC) was used as a fluorescent probe, and a fluorescence detection method was established for quantitative monitoring of CO32− with quick response time (within 50 s), high sensitivity, and selectivity. The fluorescence quenching phenomenon between PC and CO32− was mainly attributed to static quenching. The limit of detection (LOD) was 0.42 μM and the method was successfully applied to monitor CO32− in tap water and seawater, acquiring satisfactory recovery between 99.28 % and 106.40 %. More importantly, paper-based test strips were easily fabricated using PC, enabling the rapid, visual, and on-site detection of CO32− with the aid of a smartphone. The visual detection integrated with the smartphone was converted to data information (RGB value) through a Color Picker APP and successfully used for quantitative identification of CO32−. By capturing fluorescent images and analyzing the corresponding RGB value via a smartphone, the linear calibration ranged from 0.5 μM to 500.0 μM with LOD of 0.11 μM was obtained. Satisfactory recoveries were acquired in tap water (98.00 %-107.50 %) and seawater (97.30 %-101.74 %), respectively. Therefore, integrating the PC fluorescent paper with a smartphone realizes the rapid, visual, and on-site detection of CO32− in the water environment, which is expected to broaden application prospects of monitoring ocean acidification degree.

Bacterial Cellulose Incorporating Multicolor Fluorescent Probes for Visual Acidity Detection in Paper-Based Cultural Relics.

Paper-based cultural relics often undergo acidification and deterioration during long-term preservation. Accurate detection of paper acidity is of great significance to assess aging status and extend the preservation lifetime of paper-based cultural relics. Rapid identification of the acidification degree and acid distribution across multiple regions of paper is essential. Inspired by fluorescent sensing technology, pH-sensitive cadmium telluride (CdTe) quantum dots (QDs) and rhodamine B (RB) fluorescent probes are synthesized and incorporated onto the nanofibers of a bacterial cellulose (BC) membrane to enable visual acidity detection of paper. Due to the complementary pH detection range of CdTe QDs and RB probes, the composite BC membrane exhibits a clear pH response across an acidic to neutral range (pH 3.0-7.5). Notably, the contrasting fluorescent colors of the two probes within the BC membrane allow for easy visualization of paper pH and acidity distribution with the naked eyes. A distinct color transition from red to green was observed on the fluorescent BC membrane when it is applied to a model paper with a gradient pH distribution. The feasibility of this method was verified by using the flat-headed pH electrode method. Additionally, common metal ions in most paper fillers, inks, pigments, as well as some sugars and amino acids showed minimal interference with the pH response of the composite BC membrane, highlighting its potential and broad applicability for visual acidity detection in paper-based cultural relics.

Optimising butyric and lactic acid yield from xylose by adjusting pH

This work studies the pH effect in xylose mixed culture fermentation, focusing on lactic and butyric acid production. Batch tests showed a complete substrate consumption at slightly acidic (pH 6) and alkaline conditions (pH 8), but a great inhibition of xylose conversion was observed at pH 4. Acetic acid was the only product at pH 8, while at pH 6, butyric and propionic acids were quantified as well with a large proportion of unidentified compounds. Continuous reactor operation showed that changes within the acidic pH range (pH 4.5 to pH 6) affect the acidification degree but not the product distribution, reaching the maximum butyric acid yield (0.38 Cmol/Cmol-s) at pH 5, while lactic acid was only detected when xylose conversion or butyric acid concentration dropped. Batch tests demonstrated that butyric acid was not inhibitory for xylose or lactic acid conversion and that the main product of lactic acid fermentation was butyric acid. Although pH is an essential variable steering the fermentation yield and selectivity, this study demonstrates that it must be combined with other operational conditions in order to obtain a stable production of lactic and butyric acids.

The synergistic role of ozonation and hydrolysis acidification on the enhanced pre-treatment of high-strength refractory 2-butenal manufacture wastewater: Performance, metabolism, and mechanisms

Targeted removal of three key refractory toxic organic compounds (TOMs) in 2-butenal manufacturing wastewater (2-BMW) is critical for enhancing pre-treatment by hydrolysis acidification (HA). We investigated the pre-treatment of 2-BMW with HA, coupled with ozonation in this study. Our results indicated that the removal rate of these key TOMs and the detoxification rate reached almost 100% and 46.3%, respectively, by ozonation under only 0.099 mg O3/mg chemical oxygen demand (COD). The organic load rate (OLR) reached 10.25 ± 0.43 kg COD/m3·d, and the acidification degree (AD) and detoxification efficiency reached 56.0% and 98.3%, respectively, with enhancements of 35.1% and 55.2%, respectively, compared with HA alone. The removal rate of the three key TOMs was improved by > 75%. The degradation pathways of these key TOMs were ring cleavage and ester formation by ozonation, followed by fermentation and acid production by HA. Ultimately, the synergistic role of ozonation and HA was revealed. The preferential cleavage of these key TOMs by ozonation was achieved because of their high electron cloud density and multiple reaction sites, which generated more fermentation-friendly products. The fermentation and acid production reactions may be directly involved in these products. Functional bacteria and key metabolic pathways were also enhanced by ozonation.

Revealing the photochemical damage behavior of acidified Xuan paper based on the spectroscopic investigation and principal component analysis

In museums, there is a huge storage of Xuan paper cultural relics with profound historical and artistic significances. Exploring the photochemical damage behavior of Xuan paper that is generally in acidification, namely its damage mechanisms and laws, is crucial for the preventive lighting protection for paper cultural relics. In this study, the accelerated aging experiments in the range of visible light were conducted on Xuan paper samples with different degrees of acidification. The photochemical damage mechanisms of samples were traced, which is related with the synergistic effects of oxidation and hydrolysis reactions. It can be found that there is an effect of acidification, a long-standing material property of Xuan paper, on its damage, which further defines its preservation state in museums. On this basis, a spectral quantification method of infrared spectra combined with the principal component analysis was proposed to comprehensively analyze the photochemical damage law of Xuan paper in different preservation states. The analysis shows that the effect of acidification degree (pH values), spectra wavelength (λ), and their interaction on the damage to Xuan paper are statistically significant. Furthermore, the fitted mathematical function of pH values and λ is of great importance for evaluating photochemical damage, in order to further develop preventive lighting protection applications.

Soil potassium regulation by initial K level and acidification degree when subjected to liming: A meta-analysis and long-term field experiment

Potassium (K) is the most commonly neglected macronutrient in global change, especially in acidified areas. Lime is a typical management to eliminate soil acidification in agroecosystem soils; however, its impact on soil K dynamics remains inconsistent under different acidic environments. Here, we combine a meta-analysis based on 407 observations from 89 papers and a long-term experiment to investigate the effect and main driving factors of liming on soil K change. The meta-analysis showed that lime application significantly reduced topsoil exchangeable K (EK) content by an average of 4.8% globally. The decrease in topsoil EK content due to liming depended on various soil properties, crop types, fertilizer regimes, and experiment types. Boosted regression tree analysis showed that initial soil exchangeable K (IEK) and pH were the main factors affecting soil EK change under the lime application. The field experiment results further evidence that the decrease of soil EK after the lime application was mainly due to increased K uptake by the crop, and EK transformed to non-exchangeable K (NEK). The application of lime has a greater impact on reducing subsoil EK content at a higher IEK thresholds. Soil EK showed a significant negative relationship with exchangeable calcium (Ca) and a significant positive relationship with exchangeable aluminum (Al). Redundancy analysis revealed that K input (KI), IEK, lime, Ca, Al, pH, and exchangeable magnesium significantly affected the K in soil and crops. The partial least squares path model showed that lime application and IEK levels combined indirectly influence soil K (EK and NEK) by directly affecting soil Ca and Al, K uptake, and K balances. The findings highlight the importance of the lime effect on K management in globally adverse environmental agroecosystems and indicate the key role of initial soil EK levels and acidification degree for regulating crops to excavate the subsoil potassium when subjected to liming.

Study on the technology of kumquat grapefruit sour beer

A kumquat-grapefruit acid beer was brewed with Australian barley malt, lactobacillu, D17 yeast, Qingdao hop flower, kumquat concentrated juice and grapefruit concentrated juice as raw materials by using special mash and fermentation process. The effects of acidification degree, the addition amount of kumquat and grapefruit juice concentrate and the addition time on beer flavor were studied in this paper. The results showed that when the pH was adjusted to 3.5 by acidification, the sour beer produced by adding 6% kumquat concentrated juice and 4% grapefruit concentrated juice before the CO2 pressure of the tank rised, the beer has white and exquisite foam with prominent fruit aroma, especially those of kumquat and grapefruit. The beer body was clear and transparent, with about 5% residual sugar. The sweet and sour taste of the beer was balanced. The beer contained unique nutrients of kumquat and grapefruit also, and was especially suitable to drink for brewers and ladies.

Методология оптимизации режимов дистилляции на основе критериев оценки качества продукта

The range of high-quality alcoholic beverages could be expanded by unconventional raw materials, e.g., bakery waste. Any new technology requires optimization of operating parameters at each production stage. The sensory properties of an alcoholic drink depend on the distillation mode. However, food science knows no objective methods for optimizing distillation parameters based on the biochemical composition of the raw material. The research objective was to develop a new methodology for optimizing the distillation procedure for alcoholic drinks based on unconventional raw materials. 
 The research featured distillates obtained from industrial samples of bakery waste. The variable factors included the distillation rate, which ranged from 5 to 17 cm3/min, and the wort acidification degree, which was pH 6.0–2.0. The composition and mass concentration of the main volatile components were determined by gas chromatography using a Thermo Trace GC Ultra device (Thermo, USA) with a flame ionization detector. The sensory evaluation was performed by a panel of qualified experts. The single-factor experiment showed that the distillation rate and the wort acidification degree affected the concentration of each volatile component in the distillate. 
 Using the method of pairwise correlation coefficients, the authors identified the most significant parameters: mass concentration of 1-propanol, phenylethyl alcohol, ethyl lactate, total enanthic esters, total enanthic esters vs. total esters, concentration of ethyl lactate vs. total enanthic esters, isobutanol concentration vs.1-propanol concentration. The linear pair correlation coefficients were calculated for these selected indicators, and the effect of each parameter on the sensory profile was represented as a regression model. The optimal operating parameters were determined by extremization of a two-variable function: pH 4.4 ± 0.2, speed 9.5 ± 1.0 cm3/min. 
 The new methodology provided for the following sequence of operations: determining the significance of the variable factor; selecting the evaluation parameters based on a single-factor experiment; determining the interaction; developing a regression model. This method can be used to calculate the optimal technological distillation parameters for other raw materials.

Hydrophobic durability and anti-corrosion of plasma nitriding layer: Evolution mechanisms of corrosion behavior under variations in local hydrochemistry

Mechanisms for the effects of nitrogen on the durability of hydrophobic and corrosion resistance of modified layers prepared on the surface of AH32 steel by plasma nitriding have been investigated. It was found that plasma nitriding can significantly improve the hydrophobicity of AH32 steel. All the contact angles (CAs) of the AH32 steel with 1 h, 3 h and 5 h nitriding were higher than 120°, which had excellent hydrophobicity. The acidification degree of the solution within the nitriding layer’s micro-zone was effectively reduced due to the dissolution of nitrogen. The micro-nano structures of the nitriding layers corroded severely after 15 days of exposure to NaCl solution. When the nitriding time is extended to 5 h, the acidification degree of the solution was intensified due to the enhanced blocking effect, and the nitrogen in the nitriding layer saturated that cannot provide enough nitrogen ions to offset the acidification of the solution, so the durability decreased instead. In comparison, the modified layer with 3 h nitriding in this study had the best durability and long-term service protective effect on AH32 steel.

Micro-structure and morphology of tailings sand under different oxidation and acidification degree

The tailings pond is a dangerous source of man-made debris flow with high potential energy. The oxidative acidification of tailings may cause the instability of the pond and induce serious safety accidents. The influence of oxidation and acidification degree on macro mechanical properties of tailings is discussed from the aspects of mineral composition and microstructure. The results show that as the degree of oxidation and acidification of tailings sand increases, the overall structural performance and load-bearing capacity decrease, and its cohesion (c) and internal friction angle (φ) show a decreasing trend. In fact, the engineering properties of tailings with different oxidation and acidification degrees are dominated by the physicochemical composition and structural characteristics. On the one hand, as the degree of oxidation increases, acidic substance will neutralize with CaCO3 and CaMg(CO3)2, resulting in the loss of cemented substance and the decrease of cementation force between tailing sand particles as well as the gradual destruction of the integrity of tailing sand. On the other hand, the increase of oxidation and acidification degree of tailing sand leads to a gradual reduction of outline (2D) fractal dimension and gray surface (3D) fractal dimension of surface laminated structure as well as the obvious reduction of laminated structure and its roughness of tailings sand.

Влияние активной кислотности на качественные характеристики дистиллятов

The quality of distillates depends on the biochemical composition of the raw material, the operating parameters of the wort production and fermentation, and the methods and modes of distillation. The active acidity of the medium (pH) can affect wort fermentation and distillation processes. The research objective was to study the effect of the active acidity of bakery waste wort on fermentation and distillation processes. 
 The study featured fermented wort samples from wheat bread, a mix of wheat and rye-wheat bread, and distillate fractions obtained by a single fractionated distillation of fermented wort. The distillation occurred in laboratory conditions in a direct distillation unit (Kothe Destillationstechnik, Germany) with a 10 dm3 cube. The effect of the acidification degree of saccharified wort on the fermentation efficiency was determined by the strength of the fermented wort. The composition of volatile components in the distillates was defined by gas chromatography in a Thermo Trace GC Ultra chromatograph (Thermo, USA). 
 When the pH of saccharified wort fell from 5.5 to 4.5–3.5, the synthesis of higher alcohols and ethers of higher fatty acids decreased during fermentation, while the acetone mass concentration increased. The acidification of fermented wort to pH = 3.5–3.0 at the distillation stage had a positive effect on the distillates from recyclable baking waste. This technique increased the yield of the middle fraction (distillate) by reducing the loss of absolute alcohol with the head and tail fractions. The concentration of acetaldehyde and ethyl acetate in the middle fraction decreased by 1.5 times while the content of enanthic ether components increased by more than 75%. As a result, the sensory profile increased by 0.4–0.5 points. The distillates from the mix of wheat and rye-wheat bread were superior to distillates from wheat bread. The statistical analysis provided the following criteria for a qualitative assessment of the distillates from recyclable baking waste: the mass concentration of acetaldehyde and the ratio of alcohols C5 to the sum of alcohols C3 and C4.
 Pre-fermentation oxidation of saccharified wort proved impractical for bakery waste recycling, whereas acidification of fermented wort before distillation increased the distillate yield and improved its sensory profile.

Effects of Chemical Fertilizer Reduction Combined with Straw Application on Diazotrophic Communities in a Double Rice Cropping System

Based on a three-year field experiment, the effects of reduced chemical fertilizer combined with straw application on paddy yield, soil fertility properties, and community structure of diazotrophs in a double-rice cropping field three years after straw application were examined. Three treatments were applied:conventional fertilizer application (CF), chemical fertilizer reduction combined with a low straw application rate (CFLS, 3 t·hm-2), and a high straw application rate (CFHS, 6 t·hm-2). The results showed that CFLS and CFHS did not significantly reduce rice grain yield (P>0.05); significantly neutralized soil acidification; increased soil microbial biomass carbon and nitrogen, dissolved organic carbon, and organic carbon content (P<0.05); and significantly reduced soil redox potential, ammonium nitrogen, and nitrate nitrogen contents (P<0.05). This was more conducive to improve soil nitrogen use efficiency. Compared with those under the CF treatment, the natural nitrogen fixation functional communities of CFLS and CFHS increased the Shannon, PD, and Evenness indexes (P<0.05) due to the improvement of conditions such as the increase in soil carbon storage and the decrease in acidification degree. The relative abundance of microbial communities with nitrogen fixation, carbon fixation, and plant growth promotion functions such as Ferrigenium, Sulfurivermis, Methylomonas, Methylovulum, Ectothiorhodospira, and Nostoc increased significantly (P<0.05). In conclusion, the reduction in chemical fertilizer combined with 3 t·hm-2 and 6 t·hm-2 straw application was an effective measure to improve the community structure of soil diazotrophs and the potential of soil nitrogen fixation.

Enzymatic Potential of Filamentous Fungi as a Biological Pretreatment for Acidogenic Fermentation of Coffee Waste.

Spent coffee grounds (SCGs) are a promising substrate that can be valorized by biotechnological processes, such as for short-chain organic acid (SCOA) production, but their complex structure implies the application of a pretreatment step to increase their biodegradability. Physicochemical pretreatments are widely studied but have multiple drawbacks. An alternative is the application of biological pretreatments that include using fungi Trametes versicolor and Paecilomyces variotii that naturally can degrade complex substrates such as SCGs. This study intended to compare acidic and basic hydrolysis and supercritical CO2 extraction with the application of these fungi. The highest concentration of SCOAs, 2.52 gCOD/L, was achieved after the acidification of SCGs pretreated with acid hydrolysis, but a very similar result, 2.44 gCOD/L, was obtained after submerged fermentation of SCGs by T. versicolor. This pretreatment also resulted in the best acidification degree, 48%, a very promising result compared to the 13% obtained with the control, untreated SCGs, highlighting the potential of biological pretreatments.

Continuous Production of Volatile Fatty Acids (VFAs) from Swine Manure: Determination of Process Conditions, VFAs Composition Distribution and Fermentation Broth Availability Analysis

For pollution control and waste utilization, a promising future direction is to obtain high-value carbon sources from organic waste. In this experiment, swine manure was efficiently converted into high concentration volatile fatty acids through continuous hydrolysis-acidification bioreactors. This study determined the process conditions, the composition distribution of volatile fatty acids and the availability of fermentation broth. The results showed that the reactor with a hydraulic retention time of 1.5 days had the optimal production performance of volatile fatty acids. The highest hydrolysis degree (62.2%) and acidification degree (42.5%) were realized in this reactor at the influent soluble chemical oxygen demand of 5460 mg/L. Furthermore, when the influent soluble chemical oxygen demand was 7660 mg/L, volatile fatty acids of 6065 mg-COD/L could be produced stably, and the proportion of volatile fatty acids in soluble chemical oxygen demand was the largest (75%). Additionally, the fermentation broth rich in volatile fatty acids could be applied to deep nitrogen and phosphorus removal. This work provides a productive approach to resource recovery from swine manure.

Experimental Simulation Study of Mine Water Acidification under the Action of Pyrite

The discharge of acidic water has become an environmental issue of great concern worldwide. In order to investigate the characteristics and mechanism of acidic water induced by pyrite in sulfur-rich mines, indoor static precipitation and dynamic leaching simulation experiments were carried out under the conditions of pyrite content, rock particle size, media combination, and ambient temperature. At the same time, this paper used the gray correlation method to quantitatively analyze the influencing factors. The results showed that the degree of groundwater acidification was negatively correlated with the rock particle size and temperature and positively correlated with the pyrite content. The quantitative analysis of the effect of each factor on acid mine drainage pH was pyrite content &gt; temperature &gt; rock size. When considering different media conditions, the combined effect of the three media on reducing the acidification degree of mine water was limestone &gt; gangue &gt; coal. In addition, dynamic leaching and static soaking have different effects on the acidification of the mine water, with the latter acidifying more rapidly. It is also concluded that although pyrite enrichment was the main controlling factor affecting the acidification of mine water in nature, complexation of trivalent iron ions adsorbed in the formation was more likely to be the main causal mechanism for the rapid acidification of mine water in coal mining areas.

GIS as a tool for Classification Lake’s acidification- and eutrophication degree

GIS (Geographic information system) was used as a tool to classify 50 lakes according to acidification- and eutrophication degrees. Both water pH and alkalinity showed similar trends of distribution whether they were used alone or together as determining criteria for acidification degree. Where as variables that was used for the determination of eutrophication degree revealed more or less different patterns. Therefore, one must be careful in determining which variable or variables that could be used in classification of lakes according to their eutrophication degree. Moreover, GIS can be used in documentation, analyzing, and prediction the possible future changes in Iraqi aquatic ecosystems.&#x0D; &#x0D;

Understanding the effect of trace elements supplementation on volatile fatty acids production from proteins

This investigation studies the impact of trace elements supplementation on protein anaerobic conversion into volatile fatty acids (VFAs). Two continuous reactors were operated with two model substrates, casein and gelatin, at acid (pH 5) and neutral (pH 7) conditions, with the addition of macro and micronutrients. Micronutrients increased the acidification degree of both proteins from 40% to 50% to more than 60% only at pH 7, which was consistent with a greater amino acid consumption at neutral conditions. Furthermore, trace elements modified the process selectivity, promoting valeric acids production and other variations dependant on protein composition. Isomerisation and chain elongation processes were identified as a consequence of the observed deviations between amino acid consumption and VFA production. Overall, this study demonstrated that the supplementation of micronutrients can be useful to enhance and steer the anaerobic fermentation of protein-rich streams.

High negative surface charge increases the acidification risk of purple soil in China

Purple soils, developing from rapid physical weathering of nutrient rich sedimentary rock and classified as Inceptisols or Entisols in United States Department of Agriculture (USDA) Taxonomy, are the most important agricultural soils in the Sichuan basin of southwestern China. A portion of purple soils has been acidified and the acidification risk of these soils need further understanding. Here, electrodialysis (ED) was used to simulate the process of natural acidification of soils. We investigated the acidification risk of purple soils by ED treatments and compared its acidification characteristics with that of variable charge soils (Oxisol and Alfisol). Our results showed that the degree of acidification of purple soils after ED treatments was much higher than that of variable charge soils, although the purple soils contained more exchangeable base cations. There was no significant correlation between the purple soil acidity before and after ED treatments, however, the pH of purple soils after the ED treatments had a significant negative correlation (r = −0.680, P < 0.01) with the soil cation exchange capacity (CEC). We concluded that CEC (i.e., effective negative surface charges) played a decisive role in determining the acidification potential of purple soils. High content of clay minerals and low content of Fe/Al oxides in the purple soils lead to the higher amount of effective negative surface charge than that of variable charge soils, which induced the rise in the amount of H+ and Al3+ absorbed on the surface of purple soils and increased the acidification degree of purple soils remarkably. Therefore, compared to the variable charge soils, the purple soils had a higher acidification risk. These findings will provide a useful reference for the understanding of the acidification characteristics of purple soils.

Response of soil fertility and Cu and Cd availability to biochar application on paddy soils with different acidification levels

The activation of toxic heavy metals caused by soil acidification has shown detrimental effect on rice safety and quality in paddy soil of southern China. Previous reports have shown that biochar had great potential in controlling heavy metal pollution in soil, but the effect of biochar on soil fertility and heavy metal availability in different soil acidity levels remains unknown. In our study, rice straw (RSBC) and rice husk (RHBC) were selected to produce biochar. An incubation experiment with three biochar application rates, namely 0 (CK), 20 g kg−1 (C1), and 50 g kg−1 (C2) combined with four soil acidification levels, pH value 4.09 (L1), 4.48 (L2), 4.68 (L3), and 5.04 (L4), was conducted in this study. The soil pH, total nitrogen (N), soil organic matter (SOM), available phosphorus (P), available potassium (K), available Cu and Cd concentrations were determined after incubation for 60 days. Results showed that the RSBC is greater in improving the pH and nutrients in acidified soil than RHBC, and the increase depends on biochar dosage. Compared with RHBC, the RSBC showed greater performance in decreasing the availability of Cu and Cd in four soil acidity levels (L1, L2, L3, and L4); the available Cu reduced by 41.32, 25.09, 21.42, and 5.80%, and available Cd by 15.69, 13.73, 17.65, and 17.65%, respectively. In addition, higher soil acidification degree induced smaller increase range of soil pH and available P concentration by biochar. We suggest that biochar can be applied in acidified paddy field to remediate heavy metal pollution in Southern China rice production. At the same time, we need to further ascertain the impact of these two biochars on the bioavailability of heavy metals in different soil acidity levels.

Red mud-based inorganic polymer spheres: Innovative and environmentally friendly anaerobic digestion enhancers

Red mud-based inorganic polymer spheres were used as alternative pH regulators and process enhancers in sequencing batch anaerobic reactors treating cheese whey. This byproduct tends to quickly acidify under anaerobic conditions, and the common route to control pH and ensure suitable conditions for methane production involves the use of commercial alkaline raw materials. The spheres were synthesized using significant amounts of hazardous and toxic waste, red mud (50 wt% of solid components), whose recycling is challenging. The inorganic polymeric spheres, when compared to virgin alkaline raw materials, improved organic matter removal by 44%, prevented VFA accumulation (acidification degree less than 20%), maintained pH values in a range (6.5–7.2) to ensure maximum methanogenic activity by archaea microorganisms, and boosted the methane volume by ~90%. These promising results demonstrate the feasibility and performance advantages of using these innovative spheres instead of virgin raw materials, which is an important tool towards sustainable development.