scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Improvement of anaerobic co-digestion of plant waste and excess sludge using calcium peroxide.

24 Apr 2021-Environmental Science and Pollution Research (Springer Berlin Heidelberg)-Vol. 28, Iss: 34, pp 47540-47549
TL;DR: In this paper, the mixed proportion of plant waste and excess sludge co-digestion was optimized at mesophilic temperature, and then the anaerobic co digestion of PW and ES was enhanced with strong oxidant calcium peroxide (CP).
Abstract: Plant waste (PW) and excess sludge (ES) are two main organic matters of municipal solid waste. However, there are few reports on their anaerobic co-digestion. In this work, the mixed proportion of PW and ES anaerobic co-digestion was first optimized at mesophilic temperature, and then the anaerobic co-digestion of PW and ES was enhanced with strong oxidant calcium peroxide (CP). The results showed that the optimal mixing ratio of PW and ES was 1/1 (in terms of volatile solids), the C/N of mixed digestion substrate was 23.5/1, and the maximum methane production was 172.6 mL/g (in terms of volatile solids). CP could enhance methane production from anaerobic co-digestion of PW and ES. When the content of CP was 0.2 g/g (in terms of total suspended solids), the maximum methane production was 234.8 mL/g, about 1.4 times of the blank. The mechanism investigation showed that CP promoted the release of organic matter during the co-digestion, and the higher the content of CP, the greater the release of soluble chemical oxygen demand. The presence of appropriate amount of CP promoted the activities of key enzymes in anaerobic fermentation process, and then increased the efficiency of methane production. The results of this work provide an alternative strategy for the resource utilization of PW and ES.
Citations
More filters
Journal ArticleDOI
TL;DR: In this article , anaerobic co-digestion of excess sludge and different varieties of rice straw including indica rice straw (IRS), japonica rice straw and glutinous rice straw was investigated in batch and semi-continuous experiments.

5 citations

Journal ArticleDOI
TL;DR: The results showed that the optimal dosage of RL was 50 g/kg total suspended solids, and the maximum yield of methane was 198.5 mL/g volatile suspension solids (VSS), which was 2.3 times of that in the control.

2 citations

Journal ArticleDOI
TL;DR: In this paper , a series of batch assays, Napier grass (NG) was mixed with chicken manure (CM) at various proportions (100:0, 80:20, 60:40, 50:50, 40:60, 20:80 and 0:100) to identify co-substrate synergism, followed by physiochemical conditioning (size reduction and ultrasonication) of NG before co-digestion.
Journal ArticleDOI
TL;DR: In this paper , the use of CaO2 in the oxidation of Reactive Black 5 (RB5) was investigated without any activator, and the effects of various independent parameters on the oxidation process were investigated.
Abstract: Discharge of dye-containing textile wastewater can have significant adverse effects on environmental health. Advanced oxidation processes (AOPs) are effective in removing dyes from wastewater as they can mineralize the dyes into harmless substances. However, AOPs have some disadvantages, including sludge formation, metal toxicity, and high cost. Calcium Peroxide (CaO2) is an eco-friendly and strong oxidant that can be used as an alternative to AOPs for the removal of dyes from textile wastewater. The direct use of CaO2 for the oxidation of dyes does not result in any sludge formation, unlike some AOPs that generate sludge as a byproduct. In this study, the use of CaO2 in the oxidation of Reactive Black 5 (RB5) was investigated without any activator. The effects of various independent parameters on the oxidation process were investigated. These were pH, CaO2 dosage, temperature, and some anions. The weights of the independent parameters on the dye oxidation were evaluated with the Multiple Linear Regression Method (MLR). It was determined that the most effective parameter on RB5 oxidation was CaO2 dosage. The optimum pH for the oxidation of RB5 by CaO2 was determined as 10. It was found that 0.5 g CaO2 was sufficient for the oxidation of 100 mg/L RB5 with approximately 99% efficiency. The study also reveals that the oxidation process is endothermic in nature, and the activation energy (Ea) and the standard enthalpy (ΔH°) for the oxidation of RB5 by CaO2 are determined as 31.135 kJ mol-1 and 110.4 kJ mol-1, respectively. The presence of anions was found to decrease RB5 oxidation, with the order of decreasing effectiveness being PO43->SO42->HCO3->Cl->CO32->NO3-. Overall, the study demonstrates that CaO2 is an effective, easily applicable, eco-friendly, and cost-effective method for RB5 removal from textile wastewater.
References
More filters
Journal Article
TL;DR: Procedures are described for measuring protein in solution or after precipitation with acids or other agents, and for the determination of as little as 0.2 gamma of protein.

289,852 citations

Book
01 Jan 1992
TL;DR: The most widely read reference in the water industry, Water Industry Reference as discussed by the authors, is a comprehensive reference tool for water analysis methods that covers all aspects of USEPA-approved water analysis.
Abstract: Set your standards with these standard methods. This is it: the most widely read publication in the water industry, your all-inclusive reference tool. This comprehensive reference covers all aspects of USEPA-approved water analysis methods. More than 400 methods - all detailed step-by-step; 8 vibrant, full-color pages of aquatic algae illustrations; Never-before-seen figures that will help users with toxicity testing and the identification of apparatus used in the methods; Over 300 superbly illustrated figures; A new analytical tool for a number of inorganic nonmetals; Improved coverage of data evaluation, sample preservation, and reagant water; And much more!

78,324 citations

Journal ArticleDOI
M Dubois1, K. A. Gilles1, J K Hamilton1, P. A. Rebers1, F. Smith1 
28 Jul 1951-Nature
TL;DR: Preliminary experiments showed that the anthrone and the α-naphthol sulphonate reagents give good results with pure sugar solutions, but the presence of only traces of solvents such as butanol, phenol and propionic acid used in the chromatographic separation of the sugars rendered them useless.
Abstract: VOLUMETRIC procedures have been used for the quantitative determination of sugars after separation by partition chromatography1,2. It has been our experience that these methods not only require considerable skill, but also they are lengthy and sensitive to slight variation of the conditions. We have therefore attempted to develop a simple quantitative colorimetric procedure. Preliminary experiments showed that the anthrone3 and the α-naphthol sulphonate4 reagents give good results with pure sugar solutions, but the presence of only traces of solvents such as butanol, phenol and propionic acid used in the chromatographic separation of the sugars rendered them useless.

1,770 citations

Journal ArticleDOI
TL;DR: The principles and applications of the solid-state anaerobic digestion (SS-AD) process are reviewed in this article, and the variation in biogas production yields of different feedstocks is discussed as well as the need for pretreatment of lignocellulosic biomass such as crop residues and energy crops.
Abstract: Solid-state anaerobic digestion (SS-AD) generally occurs at solid concentrations higher than 15%. In contrast, liquid anaerobic digestion (AD) handles feedstocks with solid concentrations between 0.5% and 15%. Animal manure, sewage sludge, and food waste are generally treated by liquid AD, while organic fractions of municipal solid waste (OFMSW) and lignocellulosic biomass such as crop residues and energy crops can be processed through SS-AD. Some advantages of SS-AD include smaller reactor capacity requirements, less energy used for heating, and no processing energy needed for stirring. Due to its lower water content, the digestate of SS-AD is much easier to handle than the effluent of liquid AD. However, SS-AD systems also have disadvantages such as larger amounts of required inocula and much longer retention time. The principles and applications of the SS-AD process are reviewed in this paper. The variation in biogas production yields of different feedstocks is discussed as well as the need for pretreatment of lignocellulosic biomass to enhance biogas production. The effects of major operational parameters, including C/N ratio, solids content, temperature, and inoculation on the performance of SS-AD are summarized. While an increase in operating temperature can improve both the biogas yield and the production efficiency, other practices such as using AD digestate or leachate as an inoculant or decreasing the solid content, may increase the biogas yield but have negative impact on production efficiency. Different reactor configurations used in current commercial scale SS-AD systems and the impact of economics on system selection are also discussed.

882 citations

Journal ArticleDOI
TL;DR: In this paper, a literature review of anaerobic digestion of municipal wastewater sludges is presented, focusing on the fundamentals of the process and setting forth a checklist for review of key process factors including retention time, mixing, pH, temperature, nutrients, toxic materials and feed characteristics.
Abstract: This paper presents a literature review of anaerobic digestion of munidpal wastewater sludges. The paper focuses on the fundamentals of anaerobic digestion, setting forth a checklist for review of key process factors including: retention time, mixing, pH, temperature, nutrients, toxic materials, and feed characteristics. Major areas discussed are the microbiology and biochemistry of digestion, kinetics of digestion, environmental factors of concern, process performance indices, product stability, and laboratory and pilot studies on digestion. Although the text is aimed at digestion of municipal sludges, the fundamentals are sufficiently general to permit extrapolation to decomposition of other organics.

753 citations