Aerobic composting of distilled grain waste eluted from a Chinese spirit-making process: The effects of initial pH adjustment

2017 ◽  
Vol 245 ◽  
pp. 778-785 ◽  
Author(s):  
Shi-Peng Wang ◽  
Xiao-Zhong Zhong ◽  
Ting-Ting Wang ◽  
Zhao-Yong Sun ◽  
Yue-Qin Tang ◽  
...  
Keyword(s):  
Aerobic Composting ◽  
Ph Adjustment ◽  
Initial Ph ◽  
Distilled Grain Waste

scholarly journals Silica Removal from a Paper Mill Effluent by Adsorption on Pseudoboehmite and γ-Al2O3

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2031
Author(s):  
Ruben Miranda ◽  
Isabel Latour ◽  
Angeles Blanco
Keyword(s):  
Paper Mill ◽  
Ph Adjustment ◽  
Paper Mill Effluent ◽  
Kinetics Studies ◽  
Silica Removal ◽  
Industrial Water Use ◽  
Optimum Ph ◽  
Initial Ph ◽  
Equilibrium And Kinetics ◽  
Kinetics Of

Effluent reuse is a common practice for sustainable industrial water use. Salt removal is usually carried out by a combination of membrane processes with a final reverse osmosis (RO). However, the presence of silica limits the RO efficiency due to its high scaling potential and the difficulty of cleaning the fouled membranes. Silica adsorption has many advantages compared to coagulation and precipitation at high pHs: pH adjustment is not necessary, the conductivity of treated waters is not increased, and there is no sludge generation. Therefore, this study investigates the feasibility of using pseudoboehmite and its calcination product (γ-Al2O3) for silica adsorption from a paper mill effluent. The effect of sorbent dosage, pH, and temperature, including both equilibrium and kinetics studies, were studied. γ-Al2O3 was clearly more efficient than pseudoboehmite, with optimal dosages around 2.5–5 g/L vs. 7.5–15 g/L. The optimum pH is around 8.5–10, which fits well with the initial pH of the effluent. The kinetics of silica adsorption is fast, especially at high dosages and temperatures: 80–90% of the removable silica is removed in 1 h. At these conditions, silica removal is around 75–85% (<50 mg/L SiO2 in the treated water).

scholarly journals Supported Nanosizedα-FeOOH Improves Efficiency of Photoelectro-Fenton Process with Reaction-Controlled pH Adjustment for Sustainable Water Treatment

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Chuan Wang ◽  
Hong Liu ◽  
Zhimin Sun ◽  
Jian Huang ◽  
Yang Liao
Keyword(s):  
Iron Oxide ◽  
Water Treatment ◽  
Fenton Reaction ◽  
Fenton Process ◽  
Major Step ◽  
Ph Adjustment ◽  
Extra Energy ◽  
Initial Ph ◽  
The Individual ◽  
20 Nm

The overall photoelectro-Fenton (PE-Fenton) process for water treatment with neutral initial pH includes three steps of pH reduction, PE-Fenton reaction, and pH elevation. Reaction-controlled pH adjustment (RCpA), which utilizes the intrinsic electrochemical reactions instead of chemical addition, has been employed to lower the pH, maintain the lowered pH for the Fenton reaction, and recover the pH for final effluent discharge. This study demonstrated that the overall efficiency of this sustainable PE-Fenton process was improved by rapidly recycling the iron substance. Nanosized iron oxide was prepared and employed to ensure such rapid recycling. SEM and XRD results showed that the as-prepared iron oxide wasα-FeOOH with 20 nm in size. The experimental results of dimethyl phthalate (DMP) degradation showed that diatomite-supportedα-FeOOH (N-α-FeOOH/diatomite) could efficiently reduce the DMP concentration and total organic carbon. Furthermore, compared with Fe3+, the N-α-FeOOH/diatomite saved 160 min for iron settlement at 20 mg L−1DMP concentration. Also, with the increment in the initial DMP concentration, extra energy consumed by the individual step of PE-Fenton reaction using the N-α-FeOOH/diatomite became negligible compared with that using free iron ions with the increment in the initial DMP concentration. This development is expected to be a major step of the PE-Fenton process with RCpA towards actual water treatment.

Effect of Initial pH Adjustment on Hydrolysis and Acidification of Sludge by Ultrasonic Pretreatment

2011 ◽  
Vol 50 (22) ◽  
pp. 12372-12378 ◽  
Author(s):  
Xiao-Rong Kang ◽  
Guang-Ming Zhang ◽  
Lin Chen ◽  
Wen-Yi Dong ◽  
Wen-De Tian
Keyword(s):  
Ultrasonic Pretreatment ◽  
Ph Adjustment ◽  
Initial Ph

scholarly journals Ozone-based advanced oxidation process as pre-treatment of wastewater from the wood-based industry

2017 ◽  
Author(s):  
Alexandre Amaro ◽  
Henrik Hanson ◽  
Fabio Kaczala ◽  
Marcia Marques ◽  
William Hogland
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Advanced Oxidation ◽  
Municipal Wastewater Treatment ◽  
Ph Adjustment ◽  
Municipal Wastewater Treatment Plant ◽  
Initial Ph

Three ozone-based advanced oxidation treatments (O3; O3 with initial pH adjustment and; O3/UV with initial pH adjustment) were compared for the treatment of a recalcitrant wastewater generated during washing/cleaning of surfaces and equipment used in filling and gluing processes (urea-formaldehyde and phenol-formaldehyde resins) in a wood-floor industry in Sweden. The wastewater (initial COD 3,400-4,000 mg/L) was obtained at the outlet of a sedimentation tank, which receive an inflow with an average COD of 45,000 mg/L. The experiments were performed in a semi-batch microbubble column reactor connected to a UV reactor, where 2.5 L samples of wastewater were submitted to the maximum dose of 2 g of O3 per gram of initial COD. For the full-factorial design, the independent variables were O3 concentration (g O3/Nm3); recirculation flow (L/min); and initial pH (pHi). The evaluation of the treatment performance was based on COD and TOC reductions (in %), and the effluent obtained was used in respirometric assays with activated sludge obtained at a municipal wastewater treatment plant to assess biodegradability/inhibitory effects. The results showed that ozonation at the original low pH promoted a reduction of 65% and 31% of COD and TOC respectively, but made the effluent less biodegradable. The highest COD and TOC reductions were achieved when O3 /UV treatment with pHi = 9.3 were applied (93% e 56% reductions for COD and TOC respectively). The results with the respirometry tests suggest that application of O3 only at higher pH values promoted biodegradability enhancement of the effluent, making it treatable by microbiota obtained with activated sludge from a municipal wastewater treatment plant.

Converting digested residue eluted from dry anaerobic digestion of distilled grain waste into value-added fertilizer by aerobic composting

2017 ◽  
Vol 166 ◽  
pp. 530-536 ◽  
Author(s):  
Ting-Ting Wang ◽  
Shi-Peng Wang ◽  
Xiao-Zhong Zhong ◽  
Zhao-Yong Sun ◽  
Yu-Lian Huang ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Value Added ◽  
Aerobic Composting ◽  
Distilled Grain Waste ◽  
Dry Anaerobic Digestion

Effect of pH control strategies and substrate concentration on the hydrogen yield from fermentative hydrogen production in large laboratory-scale

2012 ◽  
Vol 65 (2) ◽  
pp. 262-269 ◽  
Author(s):  
I. Mariakakis ◽  
J. Krampe ◽  
H. Steinmetz
Keyword(s):  
Hydrogen Production ◽  
Control Strategies ◽  
Sucrose Concentration ◽  
Ph Control ◽  
Laboratory Scale ◽  
Hydrogen Yield ◽  
Batch Experiments ◽  
Ph Adjustment ◽  
Fermentative Hydrogen Production ◽  
Initial Ph

A series of batch experiments investigating two different pH control strategies, initial pH adjustment and continuous pH control, have been carried out in large laboratory-scale reactors with working volumes of 30 L. In both cases, pH was varied between 5 and 7.5. Sucrose concentrations were also varied starting from 0 up to 30 g/L. Higher hydrogen production yields can be achieved by batch experiments through continuous pH control than by simple initial pH adjustment. In the case of continuous pH control, maximization of hydrogen yield was acquired for slightly acidic pH of 6.5. Continuous pH control in the neutral pH range of 7.0 and in pH lower than 6.5, induced a reduction in the hydrogen production yield. Sucrose can be completely degraded only for a pH higher than 6. Lower pH values seem to inhibit the hydrogen-producing bacteria. Under the conditions of continuous pH adjustment at pH 6.5 and a sucrose concentration of 25 g/L the maximum hydrogen yield of 1.79 mol H2/mol hexose was obtained. These conditions could be applied for the batch start-up of large fermentors.

scholarly journals Effective removal of lead (II) ions by dead calcareous skeletons: sorption performance and influencing factors

2016 ◽  
Vol 74 (7) ◽  
pp. 1577-1584 ◽  
Author(s):  
Ai Phing Lim ◽  
Zufarzaana Zulkeflee ◽  
Ahmad Zaharin Aris
Keyword(s):  
Removal Efficiency ◽  
Contact Time ◽  
Low Cost ◽  
High Concentration ◽  
Initial Concentration ◽  
Ph Adjustment ◽  
Equilibrium Time ◽  
Factors Influencing ◽  
Effective Removal ◽  
Initial Ph

Dead calcareous skeletons (CSs) as low-cost adsorbents were studied to remove lead ions (Pb (II)) in an aqueous solution. Factors influencing the efficiency of CSs were evaluated by adsorbent size, contact time, initial concentration, dosage concentration and pH. The optimum CS size for removal of Pb (II) was 710 μm at an equilibrium time of 720 min. The best dosage of CS was 10 g/L for a 99% removal efficiency without pH adjustment. Pb (II) ions were effectively removed in the initial pH of the metal solution. CS was able to remove a high concentration (100 mg/L) of Pb (II) at a removal efficiency of 99.92% and at an adsorption capacity of 13.06 mg/g. Our results demonstrated the potential of CS as a metal adsorbent in the aqueous phase with a high-removal efficiency and distinct physical characteristics.

pH-adjustment strategy for volatile fatty acid production from high-strength wastewater for biological nutrient removal

2014 ◽  
Vol 69 (10) ◽  
pp. 2043-2051 ◽  
Author(s):  
Li Xie ◽  
Hui Liu ◽  
Yin-guang Chen ◽  
Qi Zhou
Keyword(s):  
Fatty Acid ◽  
Chemical Oxygen Demand ◽  
Sodium Acetate ◽  
Volatile Fatty Acid ◽  
Oxygen Demand ◽  
High Strength ◽  
Thin Stillage ◽  
Ph Adjustment ◽  
Adjustment Strategy ◽  
Initial Ph

Volatile fatty acid (VFA) production from three types of high-strength organic wastewater (cassava thin stillage, starch wastewater and yellow-wine processing wastewater) were compared. The results showed that cassava thin stillage was the most suitable substrate, based on its high specific VFA production (0.68 g chemical oxygen demand (COD)/g initial soluble chemical oxygen demand (SCOD)) and yield (0.72 g COD/g SCOD) as well as low nutrient content in the substrate and fermented liquid. The acid fermented cassava thin stillage was evaluated and compared with sodium acetate in a sequencing batch reactor system. Total nitrogen removal efficiency was higher with fermented cassava thin stillage than with the sodium acetate. The effects of pH and a pH-adjustment strategy on VFA production and composition were determined using cassava thin stillage. At an initial pH range of 7–11, a relatively high VFA concentration of about 9 g COD/L was obtained. The specific VFA production (g COD/g initial SCOD) increased from 0.27 to 0.47 to 0.67 at pH 8 and from 0.26 to 0.68 to 0.81 at pH 9 (initial pH, interval pH, and constant pH adjustment, respectively). The dominant VFA species changed significantly with the increasing frequency of the pH adjustment. Further studies will examine the metabolic pathways responsible for VFA composition.

Instant 99mTc Compounds

1971 ◽  
Vol 10 (03) ◽  
pp. 245-251 ◽  
Author(s):  
P. Richards ◽  
W. C. Eckelman
Keyword(s):  
Physical Properties ◽  
High Purity ◽  
Analytical Techniques ◽  
Full Potential ◽  
Labeled Compounds ◽  
Ph Adjustment ◽  
One Step ◽  
Stannous Ion ◽  
99Mtc Radiopharmaceuticals ◽  
Potential Use

SummaryThe full potential use of technetium has not been achieved despite its ideal physical properties, dosimetry and availability because of the complex preparations required for 99mTc radiopharmaceuticals. One of the goals of our work is to develop techniques for the preparation of high-purity 99mTc compounds which can be easily prepared, ideally by adding pertechnetate to a prepared solution.The use of stannous ion as reducing agent for technetium makes it possible to obtain such one-step, high-purity products. All non-radioactive components can be premixed in a single vial before addition of the radioactive pertechnetate. No final pH adjustment, further chemical manipulation or purification is required.Procedures for two instantly labeled compounds have been developed to date: 99mTc DTPA and 99mTc HSA. The 99mTc DTPA is prepared by adding pertechnetate to a previously prepared solution of stannous ion and CaNa3 DTPA which has been stored at pH 4. The 99mTc HSA is prepared by adding pertechnetate to a solution of stannous ion and HSA. The parametric variations and analytical techniques involved in formulating these procedures are described. It appears that development of kits for other biologically interesting compounds may be possible using similar procedures.

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