Final pH Research Articles

Performance and carcass characteristics of cattle with different castration practices

The aim of this research was to evaluate the performance and carcass characteristics of immunocastrated cattle, in comparison to castrated and non-castrated cattle supplemented on pasture. 36 bovines were used, distributed in a completely randomized design, in 3 treatments: non-castrated animals (ANC), animals castrated late by the surgical method (ACC) and immunocastrated animals (AIC), with 12 replicates each. Immunocastration was performed following the protocol of two doses of the immunocastrating vaccine, with an interval of 60 days, promoting a castrated effect of 120 days. The animals were kept on mixed pasture in an extensive rearing system using rotational grazing, they received mineral supplement in the first 3 months and specific feed for the fattening season in the subsequent 3 months, according to the property’s standards. The total experimental period was 180 days. Data were hidden from the normality test, analysis of variance and mean comparisons were performed using the Tukey test, except for the variable degree of finishing, which was maintained at the chi-square test, at 5%. Average daily weight and total weight gains, hot and cold carcass weights and hot and cold carcass yield did not show statistical differences (P>0.05) for animals submitted to different treatments. However, the cooling loss was lower in immunocastrated animals (P<0.05), followed by surgically castrated and non-castrated animals. Immunocastrated and surgically castrated animals showed better carcass finishing (P<0.05) than non-castrated animals. The initial temperature of the carcass was lower (P<0.05) in the immunocastrated group, while for the final temperature no statistical differences (P>0.05) were verified for the animals submitted to different treatments. Final carcass pH was higher (P<0.05) in immunocastrated than in surgically castrated animals, but did not differ (P>0.05) from non-castrated animals. Immunocastrated animals, in a grazing system receiving supplementation, showed similar gains in weight and carcass weight in relation to non-castrated and surgically castrated animals, however, with lower losses to carcass cooling.

Baseline investigation on enzyme induced calcium phosphate precipitation for solidification of sand

Introduction: Bio-cementation processes [namely, microbial induced carbonate precipitation (MICP) and enzyme induced carbonate precipitation (EICP)] have recently become promising techniques for solidifying loose sands. However, these methods release gaseous ammonia to the atmosphere, which is not desirable for real-scale applications. This study aims to propose an enzyme induced calcium phosphate precipitation (EICPP) method as a sustainable direction for the solidification of sand.Methods: Precipitation of calcium phosphate compound (CPC) was driven through pH-dependent mechanism regulated by enzymatic hydrolysis of urea. The baseline study was designed to consist of a series of precipitation tests and sand column tests, evaluating the influence of various recipes of cementation media (CM) on treatment efficiency. The evaluation program consisted of Unconfined compression tests, precipitation content measurement, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction.Results: The observations showed that the content of urea had an important role in proposed EICPP treatment, which determined the extent of the pH increase. This increase had a great influence on 1) utilization of soluble calcium, 2) precipitation content of calcium phosphate, and 3) the morphology of the precipitates. Results of sand column test suggested that injecting CM that consisted of acid-dissolved bone meal, urea and urease enzyme could result in the deposition of insoluble CPC that enabled the solidification of sand particles.Discussion: The precipitation quantity was found to increase with the increase in urea content; however, the treatment media with high urea content resulted amorphous-like crystals. The plate-like crystals were evidenced in CM with [Ca]/[urea] molar ratio between 1.5–2.0. X-ray Diffraction (XRD) analysis revealed that irrespective of the urea contents, the formed crystals were identified as brushite. Since the final pH of proposed EICPP method could be controllable within acidic-neutral conditions, the emission of ammonia gas would be eliminated.

The effects of stem bromelain on the gelation behavior of kappa carrageenan under linear and nonlinear rheological regimes

Carrageenans have shown a versatile and wide range of applications in the food and biomedical fields. To tune the rheological properties and improve the biological functions of carrageenan gels, the effect of stem bromelain (SBr) on the intermolecular interaction and rheological property of κ-carrageenan (κC) was investigated. The viscoelastic properties and gel network structure of pure SBr, κC, and SBr/κC mixtures were studied using dynamic rheology in the linear and nonlinear viscoelastic regimes. Different SBr/κC mixtures were prepared with varying final pH levels (pH 6.06, 6.95, and 8.08). The time series and frequency dependence of SBr/κC mixtures in the linear viscoelastic regime showed that the elastic modulus is (3–10 times) greater than the viscous modulus, indicating network structure formation. The temperature dependence of the viscoelastic moduli SBr/κC mixtures exhibited a significantly improved physical property than the pure SBr and κC, demonstrating synergistic relation between SBr and κC via enhanced electrostatic interaction. By increasing the pH level of the mixtures, a decrease in the shear moduli was observed attributed to the increasing repulsive interaction between SBr and κC. The observed nonlinear rheological responses suggest a transiently crosslinked network. Accordingly, with the gentle imposition of increasing stress levels, the nonlinear responses suggest that SBr/κC is a stress-mediated, highly entangled complex network with a pH-controlled dynamic viscoelastic property. Therefore, our results provide structural insights into the microscopic origins of the rheological behavior of SBr/κC mixtures as a basis for precise material design.

Preparation of pseudo-boehmite via carbonation of sodium aluminate lixivium extracted from coal fly ash

The hydrothermal process was employed to extract alumina from coal fly ash, resulting in the production of sodium aluminate lixivium. The lixivium exhibited a low concentration of Na2O and Al2O3, which was subjected to carbonation to synthesize pseudo-boehmite in this study. During carbonation, the pH of the lixivium was decreased as CO2 aeration, resulting in the formation of amorphous aluminum hydroxide, which subsequently transformed into pseudo-boehmite as the solution pH reached 10.0–10.5. Further decrease in solution pH below 9.5 caused the conversion of pseudo-boehmite into dawsonite. Monophase pseudo-boehmite was prepared from the lixivium after carbonation at 80–100 °C for 30–120 min with the final solution pH of 10.0–10.5. The resulting pseudo-boehmite exhibited a fibrous morphology and formed porous aggregations, which displayed a BET specific surface area of 445.48 m2/g, a cumulative pore volume of 0.76 cm3/g, with the majority of pores falling within the mesopore range of 2–50 nm. The pseudo-boehmite would dehydrate and transform into γ-Al2O3 while maintaining its original morphology after calcination at 450–700 °C, making the product promisingly use as a precursor for preparing mesopore γ-Al2O3 of widespread applications in industrial catalysis.

Ultrahigh-porosity Ranunculus-like MgO adsorbent coupled with predictive deep belief networks: A transformative method for phosphorus treatment

Phosphorus is a nonrenewable material with a finite supply on Earth; however, due to the rapid growth of the manufacturing industry, phosphorus contamination has become a global concern. Therefore, this study highlights the remarkable potential of ranunculus-like MgO (MO4–MO6) as superior adsorbents for phosphate removal and recovery. Furthermore, MO6 stands out with an impressive adsorption capacity of 596.88 mg/g and a high efficacy across a wide pH range (2–10) under varying coexisting ion concentrations. MO6 outperforms the top current adsorbents for phosphate removal. The process follows Pseudo-second-order and Langmuir models, indicating chemical interactions between the phosphate species and homogeneous MO6 monolayer. MO6 maintains 80 % removal and 96 % recovery after five cycles and adheres to the WHO and EUWFD regulations for residual elements in water. FT-IR and XPS analyses further reveal the underlying mechanisms, including ion exchange, electrostatic, and acid-base interactions. Ten machine learning (ML) models were applied to simultaneously predict multi-criteria (sorption capacity, removal efficiency, final pH, and Mg leakage) affected by 15 diverse environmental conditions. Traditional ML models and deep neural networks have poor accuracy, particularly for removal efficiency. However, a breakthrough was achieved by the developed deep belief network (DBN) with unparalleled performance (MAE = 1.3289, RMSE = 5.2552, R2 = 0.9926) across all output features, surpassing all current studies using thousands of data points for only one output factor. These captivating MO6 and DBN models also have immense potential for effectively applying in the real water test with error < 5 %, opening immense horizons for transformative methods, particularly in phosphate removal and recovery.

Screening of Eucalyptus camaldulensis clones for enhancing productivity and sustainability in problematic soils of Southern India

Among the various challenges faced by eucalyptus plantations in the Indian pulp industry, one of them is the development of resilient clones adaptable to saline soils. Large genetic diversity exists in E. camaldulensis because of high out-crossing rates and is expected to pass traits into the new developed clones. We used a salt injury score, survival percentage and proline content as a screening criterion to select new clones tolerant to high salt levels in soils. Proline has been identified as a beneficial solute in plants under stress caused by high salinity. Three months old clones of eleven new eucalyptus genotypes were transplanted in pots with free-draining coarse river sand. Four treatments comprising control, high Salt, High Salt + High pH and High pH were arranged in a randomised block design. Common salt (NaCl) was used for regulating salt concentrations while sodium bicarbonate (NaHCO3) was used for regulating the pH of the solutions. NaCl concentrations were increased every third day until the final concentration of 150 mM was reached. Similarly, pH of the solutions was also gradually increased till final pH of 10 was attained. Each treatment solution was delivered through automated drip delivery. Salt injury scores based on symptoms were positively correlated (0.812) with survival percentage and proline content. Eucalyptus genotypes were classified into five salt tolerant groups: tolerant (T), moderately tolerant (MT), moderately sensitive (MS), sensitive (S), and highly sensitive (HS). The mean values of proline content in leaves were different among the five groups, indicating that the proline content is a reliable marker for identifying salt tolerance. Proline contents in stressed seedlings were significantly different between the tolerant and highly sensitive groups, but the difference among the intermediate groups (MT, MS and S) was not significant. As the stress levels of salt and pH were increased, the sensitive hybrid clone tested showed very poor growth, which was also negatively correlated with the proline content in its leaves. Combination of high salt and high pH was also found to be correlated with reduced proline content, poor growth and survival among sensitive genotypes. In addition to the commonly used sodium and pH induced symptoms, proline content is suggested to be another useful criterion to differentiate salt-tolerant from salt-sensitive genotypes. This study helped in classification of genotypes with different levels of salt and pH tolerance, which may be used for deployment of genotypes according to changing edaphic conditions for sustainability of eucalyptus plantations.

Synthesis of Urea-Formaldehyde Fertilizers and Analysis of Factors Affecting These Processes

Urea formaldehyde slow-release fertilizers are efficient and environmentally friendly fertilizers. They have good slow-release properties and can significantly improve the utilization rate of fertilizers. However, problems remain regarding the synthesis of urea formaldehyde slow-release fertilizers, their characterization, and aspects of their performance. This study explores the effects of different reaction conditions on the quality of synthesized urea formaldehyde and establishes a response relationship between synthesis factors and sustained-release performance. Optimal conditions for urea formaldehyde synthesis included use of an ammonium chloride catalyst, pH 4 as the final pH condition, and a urea/formaldehyde molar ratio (U/F) of 1.3. Samples prepared in this study were characterized in terms of cold water-insoluble nitrogen, hot water-insoluble nitrogen, and soil-available nitrogen. The samples were also characterized by spectroscopic and instrumental methods to correlate the microscale behaviors of the urea formaldehyde particles with their performance as controlled-release fertilizers. This work is expected to provide a basis for the production of urea formaldehyde and to improve its performance as a slow-release fertilizer.

Characterization of Fermentations with Controlled Temperature with Three Varieties of Coffee (Coffea arabica L.)

Temperature control is the starting point for the development of controlled fermentation and improving coffee quality. The characteristics of coffee varieties can influence fermentation behavior. To evaluate the effect of the coffee variety on the behavior of controlled fermentation and on coffee quality, a completely randomized design was used with three varieties (Castillo, Cenicafé1 and Tabi) and two control temperatures (15 and 30 °C). Spontaneous fermentation was the control for each controlled process. The fermentation time, pH, glucose and lactic acid contents, as well as, the count of mesophiles, yeasts, lactic acid bacteria (LAB) and acetic acid bacteria (AAB), were assessed. The sensory quality of the coffee was classified as very good and excellent based on the variety, with averages above 82 Specialty Coffee Association (SCA) points. The highest values were for the Cenicafé1 variety. Fermentation behaviors were similar among varieties but not based on the given condition. Compared with spontaneous fermentation, the treatment at 15 °C prolonged the degradation of mucilage in more than 24 h; additionally, there were differences in the final pH values, less than 3.5 and close to 4.0, respectively. Quality was not significantly different between the controlled fermentation and the spontaneous fermentation (Wilcoxon test p &gt; 0.05) or between fermentation temperatures (Kruskal–Wallis test p &gt; 0.05).

Assessment of lamb meat quality in two cooking methods: Water bath versus oven cooking

This study investigated the influence of the cooking methods on lamb meat quality traits. Water bath (WB) vs. oven cooking (OC) was compared using commercial cuts known as T-bone and Leg steak (n = 20/treatment), sampled from feedlot-finished Corriedale lambs. All meat samples were analyzed for muscle area (MA) or cut size, final pH, color (L*, a*, b*), water-holding capacity (WHC), shear force (SF), cooking losses (evaporation (EL) and dripping (DL)), intramuscular lipid content (ILC), and myofibrillar fragmentation index (MFI). The associations between meat quality variables and cooking methods were studied by correlations, principal components (PCs), as well as factor analysis. There was no interaction between the cooking methods and the cuts (p > 0.05). Variables MFI and WHC were similar (p > 0.05); however, MA, L* , a* , pH, and SF were higher in Leg steak, whereas b* and ILC were higher in the T-bone cut (p < 0.05). Cooking loss variables (EL and DL) differed (p < 0.01) according to the cooking method. The multivariate approach showed that the first two PCs (PC1 and PC2) explained about 44% of the variability in lamb meat. Variables related to cut size (MA), tenderness (SF and MFI), and chemical composition (ILC) defined PC1 (24%), while variables EL and DL contributed to define PC2 (20%). The sum of EL and DL (total cooking losses – CL) was lower in the WB method for both cuts studied. Besides, EL was greater in OC, while DL was greater in WB, which may affect water loss and juiciness of lamb meat. Leg steak had higher MA, but lower ILC, and showed higher SF regardless of the cooking method used.

PSV-14 Effects of Forage or Coproduct-Based Transition Diets on the Rumen Microbiome and Ruminal Fermentation ex Vivo in Feedlot Steers

Abstract The objective was to determine the effect of replacing forage with coproducts in transition diets on rumen microbiome composition and ruminal fermentation ex vivo after steers consumed a common finishing diet. A random subset of 30 steers were selected from a larger, separate pen study. Steers were blocked by initial BW and allotted into 9 pens. Pens were then assigned to 1 of 3 dietary treatments for the 35 d adaptation period: a forage-based diet (FO; alfalfa and grass hay), a coproduct-based diet (CO; soybean hulls and modified wet distillers grains with solubles), and a coproduct-based diet pair-fed (CO-P) to isoenergetic levels of FO. Dry-rolled corn inclusion increased with either decreasing forage or coproduct inclusion. Both FO and CO were fed with slick bunk management. At d 35 and 63, rumen fluid was collected by esophageal tubing to determine differences in fermentation of the finishing diet as the substrate in an ex vivo model. Rumen fluid was also utilized for microbiome analysis using 16S rRNA sequencing on the Illumina MiSeq platform with 2 × 300 bp paired-end sequencing. Sequencing reads were analyzed within QIIME2. Statistical analyses were conducted using SAS 9.4. Fermentation data were analyzed using the MIXED procedure, while bacterial relative abundance data were analyzed in the GLIMMIX procedure. Correlations were analyzed using the CORR procedure. A treatment × sampling day interaction (P = 0.02) was observed for in vitro dry matter disappearance; on d 35, it was greater in steers fed CO compared with CO-P (58 vs. 53%, respectively), but no differences were observed on d 63. Within the rumen microbiome, there was a tendency (P = 0.06) for alpha diversity to have a treatment × day interaction. Specifically, CO steers had the greatest decrease in alpha diversity from d 35 to 63, but there was no change in alpha diversity in FO steers and CO-P steers over time. Final pH in from the ex vivo model was positively correlated (r = 0.32) with Bacteroidetes relative abundance but negatively correlated (r = -0.25) with Proteobacteria (P ≤ 0.05). In vitro dry matter disappearance was positively correlated (r = 0.38) with relative abundance of Firmicutes, but negatively correlated (r = -0.43) with Proteobacteria (P &amp;lt; 0.01). Dietary treatment did not affect (P ≥ 0.21) richness within the rumen microbiome. Rumen microbiome composition and ex vivo fermentation results suggest all treatments were adapted for the finishing diet at the conclusion of the 35-d adaptation period.

Biorefinery Approach for H2 and Acids Production Based on Uncontrolled pH Fermentation of an Industrial Effluent

In this work, the feasibility of uncontrolled pH acidogenic fermentation of industrial organic effluent from corn-bioethanol production was studied and modelled by using a Monod-based mathematical model. In order to do that, several tests were carried out at different initial pH values, ranging from 4 to 6. The experimental data showed a pH reduction during the fermentation process due to the generation of short-chain acids. When starting at initial pH of 5.0 and 6.0, the substrates were fully fermented reaching final pH s over 4 units in both cases and a final undissociated fatty acid concentration of about 80 (mmol·L−1) in both cases. Regarding fermentation at an initial pH of 4, the pH decreased to 3.5 units, and the organic substrates were not fully fermented due to the stoppage of the fermentation. The stoppage was caused by the very acidic pH conditions. The biomass showed an uncoupled growth as the operating conditions became more acidic, and, finally, the biomass growth was zero. Regarding the generation of fermentation products, in general terms, the highest economical value of products was obtained when fermenting at an initial pH of 5. More specifically, acetic acid was the acid that presented the highest yield at an initial pH value of 4. Butyric yield showed the highest values at initial pH values of 5 and 6. The highest H2 yield (1.1 mol H2·mol−1 dextrose) was achieved at an initial pH value of 5. Finally, the experimental data were modelled using a Monod-based model. From this model, the value of the main kinetics and stoichiometric parameters were determined.

LP309 a new strain of Lactiplantibacillus pentosus that improves the lactic fermentation of Spanish-style table olives.

Different varieties of table olives have suitable morphological characteristics that allow them to be processed as Spanish-style green table olives. However, the Campiñesa cultivar presents difficulties when submitted to a lactic fermentation, in spite of being inoculated with dedicated starter cultures such as OleicaStarter. The strategy followed in this study to facilitate the start of lactic fermentation was to reinforce the OleicaStarter culture with the use of the Lactoplantibacillus pentosus Lp309 a strain that enhanced the survival of lactic acid bacteria (LAB) at the beginning of fermentation, reaching final pH values (4.08±0.01), free acidity (1.00±0.01g/100mL of brine), LAB population (6.17±0.09 logCFU/mL), nutrient depletion (0.80±0.09g/kg of pulp), and lactic acid production (11.85±0.72g/L). These values allowed stabilization of the final product, thus complying with the quality and food safety standards established by the Codex Alimentarius for table olives.

Iron electrocoagulation activated peracetic acid for efficient degradation of sulfamethoxazole

Activation of peracetic acid (PAA) by Fe species is the attractive advanced oxidation processes for the removal of antibiotics. However, achieving optimal performance in many of these processes often requires acidic pH conditions, which impedes practical application. In this study, an iron electrocoagulation (EC) system was devised to for activate PAA and oxidate sulfamethoxazole (SMX). Under optimal conditions, the degradation of SMX by the EC/PAA system reached 96.2% within 15 min, with a pseudo-first order reaction constant of 0.241 min−1, but only consuming 0.044 kW·h/m3. Interestingly, the EC/PAA system showed a high buffering capacity in the initial pH range of 4–8 to maintain the final pH of around 7. The quenching experiments revealed both free radical and non-free radical pathways involved in the oxidation of SMX in the EC/PAA system. Specifically, the active species, including •OH, organic radicals (CH3COO• and CH3COOO•) and 1O2, contribute 86.77%, 5.53% and 7.70%, respectively. These findings suggest that the EC/PAA system has unique advantages and potential for the degradation of antibiotic organics such as SMX in aquatic environments due to its strong oxidative capacity, wide pH range and high buffering capacity.

Production of Eudrilus eugenia and Compost From Breeding Manure (Cattle, Cavies, Rabbits, And Poultry) In South Of Côte D’ivoire

Developing countries must, in order to support agriculture, integrate available natural resources and promote management of livestock waste. Therefore, the potential of earthworms to decompose organic waste must be exploit : vermicomposting. Thus earthworm Eudrilus eugeniae was cultured in 4 simples treatments and 6 mixed manure treatments. These treatments are combination or not of manure of cattle, cavies, rabbit and poultry. Each treatment has undergone 3 repetitions. The experiment lasted 12 weeks. pH, numerical productivity of E. eugeniae and biomass of E. eugenia have been determined. The results showed that all treatments containing rabbit manure have a final pH close to 7 (neutral pH) with the exception of MG +MR treatment. Those based on poultry or guinea-pig manure and the control range between 5 and 6.5 and are therefore more acidic. The average density and the earthworm biomass of the MC + MR treatment respectively 2889 ± 333 ind./ m2 and 397.22 ± 234.44 g / m2 are different from other treatments. the manure mixture is a privileged environment for Eudrilus eugeniae. It provides a significant biomass of earthworms that can be used in fish farming or in the diet of monogastric animal feed.&#x0D; &#x0D;

Microbial ecology and metabolite dynamics of backslopped triticale sourdough productions and the impact of scale

Triticale (X Triticosecale Wittmack) is a hybrid of wheat (Triticum aestivum L.) and rye (Secale cereale L.), combining the positive attributes of both cereals. However, it has not been exploited for sourdough production yet. Further, the effect of scale on sourdough production has not been investigated systematically up to now. The aims of the present study were to assess the microbial ecology and metabolomic output of eleven spontaneously fermented, backslopped sourdough productions made with triticale flour on a scale of 100, 200, 500, and 1000 g. The acidification profile [pH and total titratable acidity (TTA)], microbial diversity (culture-dependent and culture-independent), metabolite dynamics, and appropriate correlations were determined. After ten fermentation steps, different species of Lactobacillaceae were prevalent in the mature sourdoughs, in particular Latilactobacillus curvatus, Limosilactobacillus fermentum, and Pediococcus pentosaceus. The microbial diversity could be traced back to the grains and was also present in the milling fractions (flour, bran, and shorts). Furthermore, thanks to the use of Illumina-based high-throughput sequencing and an amplicon sequence variant (ASV) approach, the presence of undesirable bacterial groups (bacilli, clostridia, and enterobacteria) during the initial steps of the backslopping cycle was revealed, as well as a finetuned taxonomic diversity of the LAB genera involved. Small sourdough productions (100 and 200 g) selected for a lower species diversity and reached a stable consortium faster than large ones (500 and 1000 g). Although a comparable final pH of 3.6–4.0 was obtained, the TTA of small sourdoughs was lower than that of large ones. Regarding the metabolic output, the simultaneous production of mannitol and erythritol, beyond ethanol and glycerol, could be linked to sourdoughs in which Liml. fermentum was the sole LAB species present. Further, the use of the arginine deiminase pathway by P. pentosaceus and Liml. fermentum was obvious. An appropriate extraction method followed by liquid injection gas chromatography coupled to triple quadrupole tandem mass spectrometry allowed the quantification of interesting volatile organic compounds, such as ethyl lactate. These findings support the inclusion of triticale as a viable alternative to wheat or rye for the production of sourdoughs that can be integrated into bread-making production schemes.

Buffering Capacity Comparison of Tris Phosphate Carbonate and Buffered Peptone Water Salmonella Pre-Enrichments for Manufactured Feed and Feed Ingredients.

Various culture-based methods to detect Salmonella in animal feed have been developed due to the impact of this bacterium on public and animal health. For this project, tris phosphate carbonate (TPC) and buffered peptone water (BPW) buffering capacities were compared as pre-enrichment mediums for the detection of Salmonella in feed ingredients. A total of 269 samples were collected from 6 feed mills and mixed with the pre-enrichments; pH was measured before and after a 24 h incubation. Differences were observed when comparing pH values by sample type; DDGS and poultry by-product meal presented lower initial pH values for TPC and BPW compared to the other samples. For both TPC and BPW, meat and bone meal presented higher final pH values, while soybean meal and peanut meal had lower final pH values. Furthermore, for BPW, post cooling, pellet loadout, and wheat middlings reported lower final pH values. Additionally, most feed ingredients presented significant differences in pH change after 24 h of incubation, except DDGS. From meat and bone meal samples, four Salmonella isolates were recovered and identified: three using BPW and one using TPC. TPC provided greater buffer capacity towards neutral pH compared to BPW, but BPW was more effective at recovering Salmonella.

Removal of Remazol Black B dye using recirculation batch electrocoagulation

Textile industry wastewater mainly contains high concentration of organic matter including the active dye of Remazol Black B. This wastewater effluent needs to be properly treated before discharge into water bodies. Electrocoagulation is one of physico-chemical methods that can be used as an alternative of wastewater treatment in the textile industries because it has a good efficiency in removing colour. A wide range of pH measured in the textile industry wastewater (i.e., 3.9-14) may affect the effectiveness of electrocoagulation process. Other factors that affect electrocoagulation process were current intensity and wastewater flow. This study aims to determine the optimum of electrocoagulation process in the recirculation batch method using recirculation batch reactor. The applied current tested were 10 A, 15 A and 20 A, with flow rate of 2 L/min, 3 L/min, and 4 L/min. A synthetic textile wastewater was prepared with a Remazol Black B dye colour concentration of 10 ppm, 3 g/L of NaCl, and pH of 11. The parameters tested periodically in this study were pH, TDS and removal of colour and COD. Result of this study showed that by increasing the electric current strength and decreasing the flowrate, efficiency of pollutants removal was increased. Highest removal percentage of COD and colour were 100% and 88,78%% with current strength of 20 A, and flow rate of 2 L/min, the final pH was 11,4, whereas total dissolved solid fluctuated (i.e., 1785 mg/L– 1902 mg/L).

Leaching behavior of germanium presented in different phases from zinc oxide dust under atmospheric acid leaching conditions

Abstract Recovering germanium from zinc oxide dust (ZOD) produced from Pb–Zn smelter is an important pathway to extract germanium. However, the leaching efficiency of industrial germanium production is not satisfactory (usually less than 75 %). Therefore, the leaching behavior of Ge in different phases was discovered in this work. Ge in the ZOD mainly occurs in oxide, sulfide, silicate, and solid insoluble. The potential decides the oxidative dissolution of sulfide. The leaching recovery of zinc and germanium were 90 % and 80 % with oxidant, and 78 % and 80 % without oxidant, respectively. The effect sequence of oxidant type on the Zn leaching efficiency was MnO2 &gt; H2O2 ≈ oxygen &gt; air, but the type and addition of oxidant had no obvious effect on the leaching recovery of germanium. The final pH of leaching slurry limits the dissolution of oxide and hydrolysis-polymerization of impurity ions (such as Fe(III) and Si). Decreasing the final pH is beneficial to the leaching reaction of Zn and Ge. The germanium presented in oxide and sulfide is easy to leach, while the leaching of germanium existed in silicate and solid insoluble is relatively difficult. The structure of aluminate can be destroyed effectively using a 40 g/L HF solution. When the leaching percent of SiO2 is 86.82 %, the leaching recovery of Ge is 96.57 %. For the ZOD with higher content of Fe and Si, germanium leaching is negatively correlated with the content of Fe and Si in the ZOD. The results provide a scientific basis for improving the leaching recovery of germanium.

Performance Assessment of Wood Ash and Bone Char for Manganese Treatment in Acid Mine Drainage

Developing efficient methods for Mn separation is the most challenging in exploring innovative and sustainable acid mine drainage (AMD) treatments. The availability and capacity of certain waste materials for Mn removal warrant further exploration of their performance regarding the effect of process factors. This study addressed the influence of AMD chemistry (initial pH and concentrations of Mn, sulfate, and Fe), the solid/solution ratio, and the contact time on Mn separation by wood ash (WA) and bone char (BC). At an equivalent dose, WA displayed higher neutralization and Mn removal capacity over the initial pH range of 2.5–6.0 due to lime, dicalcium silicate, and fairchildite dissolution. On the other hand, at optimal doses, Mn separation by BC was faster, it was less affected by coexisting sulfate and Fe(II) species, and the carbonated hydroxyapatite structure of BC remained preserved. Efficient removal of Mn was feasible only at final pH values ≥ 9.0 in all systems with WA and at pH 6.0–6.4 using BC. These conclusions were confirmed by treating actual AMD with variable doses of both materials. The water-leaching potential of toxic elements from the AMD/BC treatment residue complied with the limits for inert waste. In contrast, the residue of AMD/WA treatment leached non-toxic quantities of Cr and substantial amounts of Al due to high residual alkalinity. To minimize the amount of secondary waste generated by BC application, its use emerges particularly beneficial after AMD neutralization in the finishing step intended for Mn removal.

A-103 Stability Study of the Biogenic Amines 5-Hydroxyindoleacetic Acid (5-HIAA), Vanillylmandelic Acid (VMA), and Homovanillic Acid (HVA) in Acidified Vs Non-acidified Human Urine Samples

Abstract Background Carcinoid tumors and neuroblastomas are disorders in which some neurotransmitters are produced. The first one is characterized by the overproduction of serotonin, which the main metabolite is 5-Hydroxyindoleacetic acid (5-HIAA). In neuroblastomas, approximately 90% of the tumors produce catecholamines, wherein Vanillylmandelic acid (VMA) and Homovanillic acid (HVA) are the main final products of catecholamine metabolism. Due to the great clinical importance of these disorders, our group previously developed a very sensitive method to identify and quantify VMA, HVA, and 5-HIAA by LC-MS/MS. Thus, was performed a study of sample stability to identify the impact of no-acidification of the samples and the optimal storage temperature to perform a high accuracy analysis. The study aimed to evaluate stability of acidified and non-acidified urine samples under refrigerated and frozen conditions to identify and quantify VMA, HVA and 5-HIAA compounds. Methods Isolated urine samples were collected from 24 volunteers. For each compound, the stability of non-acidified samples was compared with HCl acidified samples, aiming for a final pH among 1 and 4. Independent aliquots of the samples were made to obtain the following cohort: Baseline (day of collection acidification), 24 h post-collection acidification, 4 days, 8 days and 15 days acidification. Those samples were divided into 4 groups: A—refrigerated storage and non-acidified; B—frozen and non-acidified; C—refrigerated and acidified (default) and D—frozen and acidified. The quantification of the analytes was performed by a previously validated method that employ a simple dilution of the samples followed by the LC-MS/MS analysis. Chromatographic separation and detection were performed on the Waters ACQUITY UPLC system equipped with RP-C18 column and gradient separation and on a Waters XEVO TQ-S Micro mass spectrometer and electrospray ionization (ESI+), respectively. Results The comparison between the basal groups (collection day) was identical for the 3 compounds, in the non-acidified groups (A and B) and also in the acidified group (C and D). Pearson’s Correlation was 0.995, 0.993 and 0.995 (P &amp;lt; 0.0001) for VMA,HVA and 5 -HIAA, respectively. Stability for refrigerated samples has been confirmed for up to 7 days and 15 days for compound 5-HIAA. For 15-day samples, one of the differences exceeded the total allowed error (31.3%-Westgard). Frozen samples (non-acidified or acidified) reverse percentage differences when compared to the standard group. In addition, for group B (frozen and non-acidified) the differences exceeded the total allowed error. However, comparing those days after collection and basal groups, it was calculated that the maximum acceptable period to maintain the stability of the samples was up to 7 days in refrigerated condition. Conclusion The stability for the urinary measurement of VMA, ,HVA and 5-HIAA was considered acceptable in this study. The maximum period allowed for acceptable stability is up to 7 days in the refrigerated condition.