scholarly journals Surfactant rhamnolipid promotes anaerobic codigestion of excess sludge and plant waste

Author(s):  
Yongliang Wang ◽  
Xiaohui Zhou ◽  
Bin Dai ◽  
Xiaoqiang Zhu

Abstract In order to solve the bottleneck of low methane production in anaerobic co digestion of excess sludge (ES) and plant waste (PW), a new strategy of enhancing hydrolysis and acidification by rhamnolipid (RL) was proposed under thermophilic condition . 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 suspended solid (VSS), which was 2.3 times of that in the control. RL promoted the dissolution of organic matter in the codigestion process of ES and PW, and the higher the dosage of RL, the higher the concentration of soluble chemical oxygen demand (SCOD) in the fermentation broth. When RL was 100 g/Kg, the maximum content of SCOD in fermentation broth was 2,451 mg/L, and the contents of soluble protein and polysaccharide were 593 mg/L and 419 mg/L on 10 d, respectively, which were significantly higher than other groups. In addition, the yield of VFA in RL group was also significantly increased, and acetate and propionate were the main components of VFAs. This research work provides data support for the resource utilization of ES and PW, and expands the application field of RL.

2021 ◽  
Author(s):  
Yongliang Wang ◽  
Xiaohui Zhou ◽  
Bin Dai ◽  
Xiaoqiang Zhu

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), and the C/N of mixed digestion substrate was 23.5/1, 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.


2020 ◽  
Vol 16 (3) ◽  
pp. 303-311
Author(s):  
Qi Huang ◽  
Chunsong Cheng ◽  
Lili Li ◽  
Daiyin Peng ◽  
Cun Zhang

Background: Scutellariae Radix (Huangqin) is commonly processed into 3 products for different clinical applications. However, a simple analytical method for quality control has rarely been reported to quickly estimate the degree of processing Huangqin or distinguish differently processed products or unqualified Huangqin products. Objective: To study a new strategy for quality control in the processing practice of Huangqin. Methods: Seven kinds of flavonoids that mainly exist in Huangqin were determined by HPLC-DAD. Chromatographic fingerprints were established to study the variation and discipline of the 3 processed products of Huangqin. PCA and OPLS-DA were used to classify differently processed products of Huangqin. Results: The results showed that baicalin and wogonoside were the main components in the crude and the alcohol Huangqin herb while baicalein and wogonin mainly existed in carbonized Huangqin. The results of mathematical statistics revealed that the processing techniques can make the quality of medicinal materials more uniform. Conclusion: This multivariate monitoring strategy is suitable for quality control in the processing of Huangqin.


2020 ◽  
Vol 15 (3) ◽  
pp. 70-77
Author(s):  
J.D Bala ◽  
F. A Kuta ◽  
N.U Adabara ◽  
O.P Abioye ◽  
H.S Auta ◽  
...  

Water used for washing carcasses of slaughtered animals and slaughter house is referred to as abattoir wastewater. This study was designed to investigate the microorganisms associated with abattoir wastewater and to establish the biodegradation potential of abattoir wastewater microbiota. Isolation of the microbes was carried out using pour plate technique. The total viable count for the microbes’ ranges from 2.5×104 - 4.6×105 cfu/mL. Results revealed that all the physicochemical parameters exceeded the permissible limits (total dissolved solid (TDS) 1748mg/L, total suspended solid (TSS) 176mg/L, biochemical oxygen demand (BOD5) 91 mg/L and chemical oxygen demand (COD) 227 mg/L). Microorganisms isolated include Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, Bacillus anthracis, Aspergillus niger, A. flavus, Mucor sp, Trichophyton quickeanum and Penicillium sp. Some of the microbes were observed to have biodegradation potential by their ability to grow on mineral salt media (MSM) incorporated with starch, cellulose, crude oil, kerosene and diesel as the sole source of carbon and energy. This study suggests that abattoir wastewater harbors microorganisms that could be hazardous to public health when discharged into the environment untreated hence the need for strict monitoring. These microbes isolated could be employed as agent of bioremediation of wastewaters. Key words: Abattoir; Biodegredation; Isolation; Microbiota; Wastewater


2012 ◽  
Vol 518-523 ◽  
pp. 2431-2438
Author(s):  
Ying Zhang Wang ◽  
Shang Hua Zhang ◽  
Chang Qing Pang ◽  
Jie Li

Luffa cylindrical sponge and plastic sponge were used as carriers in sequencing batch biofilm reactor (SBBR) for sewage treatment in this paper. The removals of suspended solid (SS), chemical oxygen demand (COD) and NH3-N in sewage were studied. The average removal efficiencies of SS, COD and NH3-N with luffa cylindrical sponge were 96%, 89% and 90%, respectively, while these with plastic sponge were 94%, 83% and 80%, respectively. As a natural, cheap and environment friendly biocarrier, luffa cylindrical sponge was easy to get a biofilm with enriched microbes during the first few days of sewage treatment. It was much more suitable as a carrier than the plastic sponge for SBBR.


Jurnal Ecolab ◽  
2021 ◽  
Vol 15 (2) ◽  
pp. 101-109
Author(s):  
Dewi Ratnaningsih ◽  
◽  
Retno Puji Lestari ◽  
Ernawita Nazir

Kualitas air di suatu wilayah yang merupakan salah satu indikator lingkungan dapat dievaluasi menggunakan parameter fisika, kimia, dan biologi. Indeks Kualitas Air Indonesia (IKA-INA) dapat digunakan untuk menilai kondisi kualitas air secara menyeluruh pada lokasi dan waktu tertentu. IKA-INA dihitung dengan menggunakan sepuluh (10) parameter yaitu pH, Total Dissolved Solid (TDS), Total Suspended Solid (TSS), Dissolved Oxygen (DO), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), NO3, NH3, Total Phosphate (TP) dan fecal coliform. IKA-INA tersebut merupakan indeks kualitas air yang dapat memberikan informasi secara sederhana. Dalam pemanfaatannya, tidak semua data parameter dalam IKA-INA tersebut dapat terpenuhi karena adanya data tidak valid atau data yang hilang. Kajian ini bertujuan untuk memberi alternatif rumusan IKA-INA dengan parameter yang tidak lengkap atau jika tidak semua data dalam parameters tersebut tersedia. Metode yang digunakan dalam menyusun rumusan adalah dengan melakukan koreksi faktor bobot parameter IKA-INA terhadap parameter yang hilang dan nilai Q (nilai sub-indeks). Setelah itu dilakukan uji coba pada nilai baku mutu air dalam Peraturan Pemerintah No. 22/2021 Lampiran VI serta pada data kualitas air sungai yang mewakili kualitas baik dan buruk. Hasil uji coba menunjukkan bahwa bobot parameter terkoreksi dapat digunakan untuk penanganan parameter yang hilang dalam penilaian kualitas air dengan metode IKA-INA. Hasil IKA-INA dengan parameter hilang yang menggunakan bobot terkoreksi dan hasil IKA-INA dengan parameter lengkap mayoritas memberikan status IKA yang tidak berbeda, kecuali untuk parameter fecal coli dan parameter yang mempunyai kadar jauh berbeda terhadap kondisi air secara keseluruhan.


2017 ◽  
Vol 77 (1) ◽  
pp. 204-210 ◽  
Author(s):  
Hongying Yuan ◽  
Yuping Yang ◽  
Jian Yuan ◽  
Yanning Wang ◽  
Yameng Song ◽  
...  

Abstract The dewaterability of excess sludge significantly improved upon pretreatment with Fenton's reagent in this study. After 0.9 g/L of Fe2+ and 5.0 g/L of H2O2 were added to the sludge, and reacted for 2 h at pH = 4, the specific resistance to filtration (SRF) of the excess sludge decreased from an initial value of 29.74 × 1012 m/kg to 6.49 × 1012 m/kg. The factors that affected this improvement in sludge dewaterability as evaluated by SRF reduction showed the following order: H2O2 > pH > Fe2+ > reaction time. Furthermore, the hydrolysis performance of the sludge under the optimal reaction conditions was investigated. The results indicated that the concentration of soluble chemical oxygen demand in the supernatant increased almost 14 times compared to raw sludge, and the contents of soluble protein and soluble polysaccharide were more than 8 and 17 times higher, respectively, than for the untreated situation. However, the amounts of ammonia nitrogen (NH4+-N) and phosphate (PO43−-P) released from the sludge showed different trends: NH4+-N increased by 200%, while PO43−-P decreased by 82%. The production of volatile fatty acids (VFAs) from the treated sludge showed that total VFAs increased by 66%, and iso-butylacetic acid was the dominant product among the total VFAs.


2020 ◽  
Vol 44 (01) ◽  
pp. 1-7
Author(s):  
P Vithu ◽  
Sanjaya K. Dash ◽  
Kalpana Rayaguru ◽  
Uma Sankar Pal

The aim of this research work was to optimize the machine parameters of a commercially available tuber peeler for peeling of sweet potato to get maximum yield with minimum loss. The process was proposed for different parameters such as peeling efficiency, material loss and peeling effectiveness at different speeds of rotating disc (300, 400 and 500 rev/min or 5.4, 7.2 and 9 m/s), peeling durations (20, 40 and 60 s) and batch loads of 1 and 2 kg. The study revealed that the peeling parameters were greatly influenced by the speed of rotating disc, peeling duration and batch loads. The optimal conditions for peeling sweet potato were a peeling duration of 40 s and speed of rotating disc of 500 rev/min 2 kg batch loads. The corresponding peeling efficiency, peeling effectiveness and material loss were 83.8±2.0%, 74.2±1.3% and 11.45±0.71%, respectively. Further, the study showed that a batch load of 2 kg was suitable for commercial processing of sweet potato than 1 kg because of the better performance indices of peeling.


2018 ◽  
Vol 67 ◽  
pp. 04006 ◽  
Author(s):  
Irfan Aditya ◽  
Sutrasno Kartohardjono

Wastewater generated from the tofu industry usually still contains high organic pollutants that can contaminate the surface water. Therefore, it should be treated properly before it can be disposed to the environment. This study aims to evaluate the combination of coagulationflocculation and ultrafiltration methods in treating the wastewater from tofu industry. Based on the preliminary tests, the wastewater from tofu industry have pH, total dissolved solid (TDS), total suspended solid (TSS), turbidity and chemical oxygen demand (COD) of 3.4, 870 - 1080 mg/L, 370 mg/L, 446 FAU and 7954 mg/L, respectively. The coagulant and membrane used in this study were Poly aluminum chloride (PAC) and the ceramic membrane, respectively. Experimental results showed that the best pH for coagulation-flocculation process is at pH of 7.0, and this pH was then used for ultrafiltration process. The flux of the ultrafiltration membrane increased with increasing the trans membrane pressure due to increasing driving force. The observed parameters such as TSS and turbidity of wastewater decreased drastically after experiencing ultrafiltration process and met the National Environmental Quality Standard. However, the COD of water produced in the ultrafiltration process was still high and did not meet the National Environmental Quality Standard.


2020 ◽  
Vol 32 (4) ◽  
pp. 827-834
Author(s):  
Muhammad Towhid Moula ◽  
Ranjit K. Nath ◽  
Mh. Mosfeka Chowdhury ◽  
Md. Abu Bakar Siddique

Halda is an important river of Bangladesh, is now polluted in different ways through industrial, agricultural, domestic and sewage disposal. Increased anthropogenic activities have increased the potential pollution of the river and excessive pollutants may be toxic to humans and aquatic fauna. Presence of heavy metals in the river water causes perilous impact on the aquatic organisms. Hence, regular monitoring of pollution levels in the river is indispensable. In this study, we discuss about physico-chemical assessments of water quality parameters viz. pH, dissolve oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total solid (TS), total suspended solid (TSS), total dissolved substance (TDS), total alkalinity, turbidity, salinity, electrical conductivity (EC), hardness, chloride and heavy metals in the water of Halda river during rainy and winter seasons, at different points; sources of pollutants in water and their effects given starting from the early research until the current research.


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