Optimization of the humic acid separation and coagulation with natural starch by RSM for the removal of COD and colour from stabilized leachate

2021 ◽  
pp. 0734242X2110127
Author(s):  
Zaber Ahmed ◽  
Mohd Suffian Yusoff ◽  
Nurul Hana Mokhtar Kamal ◽  
Hamidi Abdul Aziz

The removal of concentrated colour (around 5039 Pt–Co) and chemical oxygen demand (COD; around 4142 mg L−1) from matured landfill leachate through a novel combination of humic acid extraction and coagulation with natural oil palm trunk starch (OPTS) was investigated in this study. Central composite design from response surface methodology of Design Expert-10 software executed the experimental design to correlate experimental factors with desired responses. Analysis of variance developed the quadratic model for four factors (e.g. coagulant dosage, slow mixing speed and time and centrifugation duration) and two responses (% removal of colour, COD). The model confirmed the highest colour (84.96%) and COD (48.84%) removal with a desirability function of 0.836 at the optimum condition of 1.68 g L−1 coagulant dose, 19.11 rpm slow mixing speed, 16.43 minutes for mixing time and 35.75 minutes for centrifugation duration. Better results of correlation coefficient ( R2 = 0.98 and 0.96) and predicted R2 (0.94 and 0.84) indicates the model significance. Electron microscopic images display the amalgamation of flocs through bridging. Fourier transforms infrared spectra confirmed the existence of selected organic groups in OPTS, which eventually signifies the applied method.

2015 ◽  
Vol 1088 ◽  
pp. 353-357 ◽  
Author(s):  
Zhen Zhen Jiang ◽  
Yang Chen ◽  
Jun Ren Zhu

In the paper, the optimization of the coagulation process for Kaolin and humic acid removal using polymeric aluminum ferric sulfate (PAFS) was studied. In order to obtain the maximum turbidity and humic acid removal efficiency of Kaolin and humic acid simulated wastewater, the optimum coagulation conditions was investigated with the factors of mixing speed and time. Furthermore, mixing speed and time including parameters affecting the coagulation performance such as rapid mixing speed, rapid mixing time, slow mixing speed and slow mixing time using single factor and orthogonal array L9 (34) analysis were examined. The results showed that the optimum single factor of mixing speed and time indicated rapid mixing speed of 350 rpm, rapid mixing time of 1.0 min, slow mixing speed of 60 rpm and slow mixing time of 20 min. Then the orthogonal optimization experiment of mixing speed and time indicated maximum HA removal efficiency was 97.5% at rapid mixing speed of 350 rpm, rapid mixing time of 1.25 min, slow mixing speed of 60 rpm, and slow mixing time of 20 min.


Author(s):  
A.O. Smirnova ◽  
◽  
O.V. Rybachuk ◽  

In this paper, we consider two ways for obtaining hymatomelanic acid extraction into conventional Soxhlet extractions: directly from the peat and from the dry product of humic acid. The results of the study of the elemental composition of humic and hymatomelanic acids are presented, their similarities and differences are analyzed. In order to study the effect of humic and hymatomelanic acid preparations on the growth processes of spring wheat, a vegetation experiment was conducted. Peculiarities of biological action of the solutions and hymatomelanic and humic acids of different concentrations in spring wheat varieties “IREN” were investigated. The paper presents a method for determining the ash content of the studied peat, as well as, calculations of the economic feasibility of using preparations based on the hymatomelanic acids.


2011 ◽  
Vol 11 (3) ◽  
pp. 253-257 ◽  
Author(s):  
Winarti Andayani ◽  
Agustin N M Bagyo

Degradation of humic acid in aqueous solution containing TiO2 coated on ceramics beads under irradiation of 254 nm UV light has been conducted in batch reactor. The aim of this experiment was to study photocatalytic degradation of humic acid in peat water. The irradiation of the humic acid in aqueous solution was conducted in various conditions i.e solely uv, in the presence of TiO2-slurry and TiO2 beads. The color intensity, humic acid residue, conductivity and COD (chemical oxygen demand) of the solution were analyzed before and after irradiation.  The compounds produced during photodegradation were identified using HPLC. The results showed that after photocatalytic degradation, the color intensity and the COD value of the solution decreased, while the conductivity of water increased indicating mineralization of the peat water occurred. In addition, oxalic acid as the product of degradation was observed.


2013 ◽  
Vol 652-654 ◽  
pp. 159-166 ◽  
Author(s):  
Muneer Al-Qadhi ◽  
Nesar Merah ◽  
Khaled Mezghani ◽  
Zafarullah Khan ◽  
Zuhair Gasem ◽  
...  

Epoxy-clay nanocomposites were prepared by high shear mixing method using Nanomer I.30E nanoclay as nano-reinforcement in diglycidyl ether of bisphenol A (DGEBA). The effect of mixing speed and time on the nature and degree of clay dispersion were investigated by varying the mixing speed in the range of 500-8000 RPM and mixing time in the range of 15-90 minutes. The effect of degassing temperature on the morphology of the resultant nanocomposites was also studied. Scanning and transmission microscopy (SEM & TEM) along with x-ray diffraction (XRD) have been used to characterize the effect of shear mixing speed, mixing time and degassing temperature on the structure of the resultant nanocomposites. The SEM, TEM and XRD examinations demonstrated that the degree of clay dispersion was improved with increasing the high shear mixing speed and mixing time. The results showed that the optimum high shear mixing speed and mixing time were 6000 rpm and 60 min, respectively. It was observed that the structure of the nanocomposites that have been degassed at 65oC was dominated by ordered intercalated morphology while disordered intercalated with some exfoliated morphology was found for the sample degassed at 100oC for the first 2 hours of the degassing process.


2015 ◽  
Vol 75 (1) ◽  
Author(s):  
Choo Wei Chun ◽  
Nina Farhana Mohd Jamaludin ◽  
Norazwina Zainol

A research was conducted on anaerobic digestion from poultry manure wastewater to produce biogas. This research was considered as a triumph to the concept of waste-to-wealth. The poultry manure collected was characterized and pre-treated to remove excessive ammonia-N which caused inhibition to the biogas production. Central Composite Design (CCD) with five replicates at centre points was used to investigate the simultaneous effect of the variables: agitation (110-130 rpm) and reaction time (2-4 days) on the biogas production. Then, the experiment was designed and analyzed using Design Expert V7.0 software by applying response surface methodology (RSM) concept.The biogas production performance was evaluated on the basis of biogas yield from initial Chemical Oxygen Demand (COD) and was found ranged from 0.49 to 4.37 mL/g COD. Quadratic model was well fitted (R-squared>0.80) with a confidence level higher than 95 %. The optimum biogas production condition was at agitation: 120 rpm and reaction time: 3.3 days. Under this condition, 4.45 mL/g COD of biogas yield was obtained. This counted for 5.82% error from predicted values.


2020 ◽  
Vol 27 (2) ◽  
pp. 47-56
Author(s):  
A.O. Okewale ◽  
O.A. Adesina ◽  
B.H. Akpeji

Effect of Terminalia catappa leaves (TCL) extract in inhibiting corrosion of mild steel was investigated. In order to obtain the maximum inhibition efficiency, optimization of the process variables affecting corrosion of mild steel was carried out using the Box – Behnken Design plan and desirability function of Response Surface Methodology (RSM). The three parameters - varied include; TCL concentration (inhibitor), immersion time, and temperature and there effects in corrosion inhibition were established. The optimum conditions predicted from the quadratic model were inhibitor’s concentratrion (0.39 g/l), exposure time (8.68 hours), and temperature (36.06 oC) with the inhibition efficiency of 91.95 %. The data fitted well to the quadratic model which was validated. Adsorption of the extract’s component on the mild steel was responsible for the inhibitory effect of the TCL extract.The results showed that 97.92% of the total variation in the inhibition efficiency of TCL can be connected to the variables studied. Keywords: Mild steel, acid, Terminalia catappa, Corrosion, Response surface methodology (RSM).


2013 ◽  
Vol 67 (8) ◽  
pp. 1816-1821 ◽  
Author(s):  
E. Hosseini Koupaie ◽  
M. R. Alavi Moghaddam ◽  
S. H. Hashemi

The application of a granular activated carbon-sequencing batch biofilm reactor (GAC-SBBR) for treatment of wastewater containing 1,000 mg/L Acid Red 18 (AR18) was investigated in this research. The treatment system consisted of a sequencing batch reactor equipped with moving GAC as biofilm support. Each treatment cycle consisted of two successive anaerobic (14 h) and aerobic (8 h) reaction phases. Removal of more than 91% chemical oxygen demand (COD) and 97% AR18 was achieved in this study. Investigation of dye decolorization kinetics showed that the dye removal was stimulated by the adsorption capacity of the GAC at the beginning of the anaerobic phase and then progressed following a first-order reaction. Based on COD analysis results, at least 77.8% of the dye total metabolites were mineralized during the applied treatment system. High-performance liquid chromatography analysis revealed that more than 97% of 1-naphthyalamine-4-sulfonate as one of the main sulfonated aromatic constituents of AR18 was removed during the aerobic reaction phase. According to the scanning electron microscopic analysis, the microbial biofilms grew in most cavities and pores of the GAC, but not on the external surfaces of the GAC.


Radiocarbon ◽  
2006 ◽  
Vol 48 (3) ◽  
pp. 337-353 ◽  
Author(s):  
Femke H Tonneijck ◽  
Johannes van der Plicht ◽  
Boris Jansen ◽  
Jacobus M Verstraten ◽  
Henry Hooghiemstra

Volcanic ash soils (Andosols) may offer great opportunities for paleoecological studies, as suggested by their characteristic accumulation of organic matter (OM). However, understanding of the chronostratigraphy of soil organic matter (SOM) is required. Therefore, radiocarbon dating of SOM is necessary, but unfortunately not straightforward. Dating of fractions of SOM obtained by alkali-acid extraction is promising, but which fraction (humic acid or humin) renders the most accurate 14C dates is still subject to debate. To determine which fraction should be used for 14C dating of Andosols and to evaluate if the chronostratigraphy of SOM is suitable for paleoecological research, we measured 14C ages of both fractions and related calibrated ages to soil depth for Andosols in northern Ecuador. We compared the time frames covered by the Andosols with those of peat sequences nearby to provide independent evidence. Humic acid (HA) was significantly older than humin, except for the mineral soil samples just beneath a forest floor (organic horizons), where the opposite was true. In peat sections, 14C ages of HA and humin were equally accurate. In the soils, calibrated ages increased significantly with increasing depth. Age inversions and homogenization were not observed at the applied sampling distances. We conclude that in Andosols lacking a thick organic horizon, dating of HA renders the most accurate results, since humin was contaminated by roots. On the other hand, in mineral soil samples just beneath a forest floor, humin ages were more accurate because HA was then contaminated by younger HA illuviated from the organic horizons. Overall, the chronostratigraphy of SOM in the studied Andosols appears to be suitable for paleoecological research.


2012 ◽  
Vol 550-553 ◽  
pp. 2932-2935
Author(s):  
Hong Juan Zheng ◽  
Yan Rong Wang ◽  
Zhi Wei Zhao ◽  
Lin Qi Zhang

PLA has excellent processing property and good thermal stability, which are closely related to the processing technology, and the general processing temperature can be controlled in 170~230°C. Effects of different processing conditions (internal mixing temperature, internal mixing time and internal mixing speed) on the properties of PLA were discussed. The results show that the mechanical properties and other performance of PLA can be obviously enhanced by internal mixing. Internal mixing time and internal mixing speed have little effects on the performance of PLA, but the internal mixing temperature has obvious effect on the properties of PLA. PLA has the optimum properties when the internal mixing time is 5min, internal mixing speed is 20r/min and internal mixing temperature is 190°C. The spherocrystal size and spherocrystal rate of PLA are influenced strongly by the mixing conditions.


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