scholarly journals Study on the Removal of Odorous Gases from Composting Process using Local Bio-Media of Vietnam

2020 ◽  
Vol 20 (2) ◽  
pp. 130
Author(s):  
Nguyen Nhat Huy ◽  
Nguyen Thi Thuy ◽  
Lam Pham Thanh Hien ◽  
Nguyen Thi Thanh Hang ◽  
Vuong Bao Khuong ◽  
...  

Odor pollution is an increasing problem in Vietnam as a tropical country during the urbanization and industrialization. The odor from sewage systems, farms of poultry, pig, and beef, food processing companies, composting factory, and landfills is a severe problem in many nearby residential areas. In this study, two lab-scale biofiltration systems where pristine local bio-media and cultured bio-media with specially formulated microorganisms were employed in biofilters and bio-trickling filter for controls of odor (i.e., hydrogen sulfide and ammonia) from composting process were fabricated and operated. The odorous gas flow was created by composting solid waste collected from an agricultural market (i.e., mainly vegetable), containing low concentrations of 1.32 ± 0.32 mgNH3 m-3 and 5.20 ± 0.28 mgH2S m-3 under stable condition. For the biofilter model, commercial compost and cow manure were used as substrates and packed into the models. For the bio-trickling filter model, K3 bio-media with biofilm developed by contacting activated sludge was used as packing material. The results showed that adding specially formulated microorganisms could reduce adaption time and lead to slightly better odor control performance. Among the substrates, cow manure provided the highest odorous gas removal efficiency of ≥ 90% during the stable phase with the elimination capacity of 0.0492 gNH3 m-3 h-1 and 0.225 gH2S m-3 h-1. The study results show a high potential of cow manure biofilter for control of H2S and NH3 gases in the practical application under Vietnam’s condition.

2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Kelvin Reyes Pinto ◽  
Víctor Meza-Contreras ◽  
Julio César Alegre-Orihuela ◽  
Warren Réategui-Romero

Objectives. To characterize the total content of heavy metals (Cd, Cr, Cu, Hg, Mo, Ni, Pb, and Zn) and trace elements (As and Se) of interest, their bioavailability and solubility during the composting of cow manure and tree litter in piles inoculated with beneficial microorganism (IBM), or not inoculated (NBM), on the university campus of the Universidad Nacional Agraria La Molina (UNALM). Methods. The investigation evaluated composting in six piles, three IBM piles and three NBM piles, for 120 days. Every 30 days, a composite sample was taken from each pile. The raw materials used were cattle manure and tree litter. The variables analyzed were the total concentrations (content) of metals and trace elements of interest, extracted with diethylenetriaminepentaacetic acid/pentatetic acid (DTPA) (for the bioavailability study) and extracted with deionized water (for the solubility study). Results. The average values (n = 3) of the total content (mg·kg−1) on day 120 in IBM were in the following order: Zn (404.33) > Cu (86.33) > Pb (71.2) > Cr (34.33) > As (28.0) > Ni (13.83) > Mo (2.86) > Se (1.38) > Cd (1.32) > Hg (0.39) and in NBM: Zn (466.0) > Cu (112.23) > Pb (73.23) > Cr (35.33) > As (29.67) > Ni (14.37) > Mo (3.23) > Se (1.55) > Cd (1.38) > Hg (0.38). The values complied with the Austrian Compost Standard for Landscaping and Land Rehabilitation and the Peruvian Standard for Nonorganic Agriculture. Significant differences were observed in some elements ( p  < 0.05) between 0 and 120 days in both types of pile (IBM and NBM). Conclusions. For nonorganic agriculture in Peru, urban compost is recommended, whereby raw organic materials are inoculated with beneficial microorganisms during the composting process to reduce the bioavailability of Cu and Zn, as these elements showed less bioavailability than noninoculated piles. The composting process for both piles (IBM and NBM) reduced the solubility in Cu, Pb, and Zn.


Data in Brief ◽  
2021 ◽  
pp. 106966
Author(s):  
Shuai Luo ◽  
Ruizhi Wei ◽  
Zicheng Qi ◽  
Qichao Zhang ◽  
Kaifen Wang

2000 ◽  
Vol 612 ◽  
Author(s):  
Sang-Soo Han ◽  
Byeong-Soo Bae

AbstractFluorinated amorphous carbon (a-C:F) thin films were deposited by inductively coupled plasma enhanced chemical vapor deposition (ICP-CVD) with increasing CF4:CH4 gas flow rate ratio, and then annealed with increasing annealing temperature (100, 200, 300, and 400.). We have found the reduction mechanism of the dielectric constant and the thermally stable condition for the a-C:F films. On the basis of the results, the optimal condition to satisfy both the low dielectric constant and the thermal stability is followed as; the a-C:F films have to have the compatible F content to make a compromise between the two properties; the C-Fx bonding configuration has to exist as a form of C-F2 & C-F3 instead of C-F; The films should be somewhat cross-linked structure.


Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2320 ◽  
Author(s):  
You Jin Kwon ◽  
Dong Kun Lee ◽  
Kiseung Lee

Urban heat island effects (UHIE) are becoming increasingly widespread, thus, there is an urgent need to address thermal comfort, which significantly influences the daily lives of people. In this study, a means of improving the thermal environment by spatial analysis of heat was implemented to ensure basic thermal comfort in future smart cities. Using Seoul as the study site, the relationship between sensible heat and land cover type was used to identify heat islands in this city. Thereafter, k-means clustering was employed to extract unfavourable and favourable thermal areas. High sensible heat indicates locations where environmental heat needs to be mitigated. Sensible heat distribution data were used for spatial typification to formulate an effective land cover factor to mitigate the UHIE. In-situ net radiation data measured at six sites were utilised to confirm the spatial typification of the thermal environment. It was found that expanding the green space by 1% reduces the sensible heat by 4.9 W/m2. Further, the building coverage ratio and green coverage influence the sensible heat in compact residential areas. The study results can be used to establish spatial planning standards to improve the thermal environments of sustainable cities.


2012 ◽  
Vol 610-613 ◽  
pp. 1824-1828
Author(s):  
Zhi Fei Liu ◽  
De Hong Pang

Activated carbon and wood chips were applied respectively as packing material of bio-trickling filter and bio-filter which composed the compound bio-filter and the effect of different operating parameters on NOx removal efficiency were studied. The results show that the best operating conditions of the compound bio-filter are: NO inlet concentration 604.5 mg/m3, spray volume 1.2 L/h, gas flow 0.6 m3/h(empty bed residence time 103.7 s).In such cases,NOx removal efficiency is over 96% and NOx removal load of the packing material is 29.66 g/(m3•h) . The remove of NOx is mainly completed by the packing layer of 0~50 cm height both in the bio-trickling filter and in the bio-filter, that is to say ,when the total packing layer height of the compound bio-filter is 100 cm, the purification effect is ideal and economical; The system can return to normal in about 7 hr when the dynamic load changes largely and suddenly, showing that it has strong anti shock load capacity.


2018 ◽  
Vol 9 (2) ◽  
pp. 61-66 ◽  
Author(s):  
Thanh Phong Nguyen ◽  
Thi Ngoc Quynh Nguyen

The aim of this study was to assess the effect of composting process of cow manure and rice straw with application of cow urine and to evaluate the quality of composting products. There were two treatment piles, in which one pile was applied with cow urine every week and another pile without urine application. Each pile was set up by one tone cow manure and 500kg rice straw. The piles were half-covered by plastic foil to protect from rain and turned one a week. The composting duration lasted 8 weeks. The parameters such as temperature, pH, DM, density and nitrogen were monitored and observed during the 8-week period. The results showed that there was a significant difference in temperature, compost quality and duration between two piles with and without cow urine application. The application of cow urine increased significant nitrogen and phosphorous content and shortened the composting process. This study recommends that cow urine should be applied for composting process of cow manure and rice straw in order to increase the quality of compost. The final product was in the range of matured compost level and can be used directly for agriculture crop. Mục tiêu của nghiên cứu nhằm đánh giá ảnh hưởng đến chất lượng phân compost của việc bổ sung nước tiểu vào trong quá trình ủ phân từ nguyên liệu phân bò và rơm rạ. Thí nghiệm được thực hiện trên hai đống ủ phân, một đống ủ được bổ sung nước tiểu bò hàng tuần và một đống ủ không bổ sung nước tiểu bò như là một nghiệm thức đối chứng. Mỗi đống ủ được trộn 1 tấn phân bò và 500kg rơm. Đống ủ phân được đậy kín một nửa phía trên nhằm ngăn cản ảnh hưởng của mưa và được đảo trộn một lần mỗi tuần. Quá trình thí nghiệm được tiến hành trong 8 tuần. Các chỉ tiêu như nhiệt độ, pH, DM, mật độ và chất dinh dưỡng Nitơ và Phốt Pho được quan trắc trong thời gian ủ. Kết quả cho thấy có sự khác biệt đáng kể giữa hai đống phân ủ đối với các chỉ tiêu như nhiệt độ, chất lượng phân compost và thời gian ủ. Đống ủ phân có bổ sung nước tiểu có hàm lượng Nitơ và Phốt pho cao hơn và thời gian ủ ngắn hơn. Kết quả nghiên cứu khuyến cáo nên bổ sung nước tiểu bò cho quá trình ủ phân compost nhằm tăng hàm lượng chất dinh dưỡng cho sản phẩm phân compost. Sản phẩm sau quá trình ủ đạt mức độ phân hữu cơ và có thể sử dụng cho cây trồng.


Author(s):  
Nguyen Thoai Tam ◽  
Ho Quoc Bang ◽  
Vu Hoang Ngoc Khue ◽  
Nguyen Thi Thu Thuy

Ho Chi Minh City (HCMC) is the largest city in Vietnam, with the highest economic growth rate and the most populous density in the country. By the year 2019, HCMC currently has 8.99 million people with 24 districts. Ho Chi Minh city has robust industrial and service development; therefore, HCMC focuses on developing large-scale livestock facilities with a large number of pigs and limiting small livestock facilities. According to statistic data, HCMC has a total of 290.152 pigs in 2018. These livestock facilities are mainly built in Cu Chi, Hoc Mon, Binh Chanh, Can Gio, and Nha Be districts. These livestock facilities in HCMC have inefficient waste treatment systems located interleaved with residential areas. So that, environmental issues are also a big challenge for the city's government because of the great influence of odor on the surrounding environment causing by the wind direction. The main purposes of this study are (i) calculation of odor emissions from livestock facilities, (ii) simulation of the odor from livestock facilities , and (iii) development of the safe distance of odor for livestock facilities in HCMC. The study results show that, the concertrations from livestock facilitties with capacity from from 50 to 200 pigs and 200 to 500 pigs are lower than QCVN 06:2009/BTNMT. The minimum distance for the livestock facility with capacity from over 500 to 1,000 pigs and over 1,000 pigs to the residential area are 230m and 650m, respectively. The procedure for calculating the odor isolation distance developing in this study could apply for other livestock facilities in other provinces, cities.


2021 ◽  
Vol 5 (1) ◽  
pp. p65
Author(s):  
R. Vardanjans ◽  
L. Cirule

Preterm neonates often have to spend a long time in incubator which simulates necessary enviromental conditions to maintain patients in stable condition. Authors have found neglected problem with Carbon Dioxide (CO2) concentration in newborn inhaled gas when using “oxygen hood” into infant incubator that has not been studied very closely. Methods in this experiement were carried out as condition monitoring while changing some parameters and positions. Results have shown that CO2 level is letally high in some aspects. Situation is alarming as CO2 level in incubator is not limited by current regulation, as IEC60601-2-19: 2009 +A1:2016. Currently the Incubator manufacturers declare that CO2 maximal concentration should be periodically checked by users, which are hospitals. Some commercially available incubators have the maximum allowed CO2 level 8000 ppm, which is much higher than recommended 2000 ppm CO2 level in indoor working place. There is no limitation of maximal level of CO2 using “oxygen hood”, which are specified in incubator operation manual. This paper goal is to show the correlation of CO2 level versus gas flow into oxygen hood.


2021 ◽  
Author(s):  
HEMANT PUROHIT ◽  
Parneet Kaur ◽  
Shilpa Choudhary

Abstract The COVID – 19 lockdown has led all the citizens (mobile subscribers) of India to stay at home and rather work from home. The people have started consuming more channel utilization (in mobile communication) through a continuous long duration conversations and more internet data through more streaming content as well as logging on to work from home. It was also reflected in how data demand from residential areas rose as compared to commercial areas. Consequently the bandwidth and channel saturation has evolved out to be a severe problem thereby affecting the work performance of all online offices and multi-national companies. This research paper proposes the simulation based experimental study of DITMC technique for mitigating this effect with a special concern in North Western Rajasthan part of India. The simulation results show that significant enhancement of 60.52% in channel utilization and bandwidth optimization is possible with negligible overhead of 0.23%. This technique also enables the telecom operators to ponder research in this field that will promisingly lead to manage augmented number of mobile subscribers (independent of any lockdown period) in limited bandwidth thereby using the spectrum efficiently.


2021 ◽  
Vol 3 (2) ◽  
pp. 50-58
Author(s):  
Muhammad Faiz Andeaz Fawwaz ◽  
Juliana Juliana ◽  
Aneu Cakhyaneu ◽  
Mumuh Muhammad ◽  
Ropi Marlina

The productive Waqf can be utilized for developing infrastructure in Indonesia as this country has incredible waqf potential. However, the utilization of waqf assets has not been specified for infrastructure development, which has many benefits (maslahah) for Indonesia. This study aims to determine the main problem in utilizing Waqf for infrastructure development in Indonesia from regulatory dimension, management dimension, program dimension, and literacy dimension. The data analysis technique used in this study is Analytical Hierarchy Process (AHP). This study has five experts to deliver their perspective regarding problems and solutions for infrastructure development using productive Waqf in Indonesia. The study results indicate that the severe problem in utilizing productive Waqf for infrastructure in Indonesia based on experts' agreement is the Lack of professional waqf (nazhir) management in managing waqf assets. With increasing the professionalism of nazhir in the management of productive Waqf, the waqf assets are expected to grow gradually that can be used to develop and improve infrastructure in Indonesia. Lastly, the excellent management of Waqf will be able to attract the Muslim community's intention to donate.


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