scholarly journals Reducing Pollution of Stabilized Landfill Leachate by Mixing of Coagulants and Flocculants: A Comparative Study

2021 ◽  
Author(s):  
Mlika Kastali ◽  
Latifa Mouhir ◽  
Abdelaziz Madinzi ◽  
Abdeslam Taleb ◽  
Abdelkader Anouzla ◽  
...  
Keyword(s):  
Ferric Chloride ◽  
Aluminum Sulfate ◽  
Nitrogen Concentration ◽  
Iron Hydroxides ◽  
Leachate Treatment ◽  
Time Treatment ◽  
Physico Chemical ◽  
The Cost ◽  
The City ◽  
Kjeldahl Nitrogen

The physico-chemical process of coagulation-flocculation is very efficient and economical for the treatment of leachate. The latter can have considerable impacts on the environment. The leachate from the landfill of the city of Mohammedia is characterized by a high COD content which varies between 2200 and 2700 mg/l, a total Kjeldahl nitrogen concentration varying from 1080 to 1405 mg/l while the ammonium content has a concentration varying between 587 and 1410 mg/l. Organic matter is not readily biodegradable (BOD5/COD: 0.2 to 0.13). Metal concentrations ranged from 0.1 to 4.2 mg/l for Cr, 40 to 5 mg/l for Cd, and 0.3 to 0.8 mg/l for lead. For monitoring the leachate treatment, several coagulants and flocculants were used (FeCl3, Al2(SO4)3, Alginate, cationic flocculants, anionic flocculants). In parallel with the monitoring of the physicochemical parameters we followed the production of the volume of the settled sludge over time. Treatment with all coagulants and flocculants used is pH dependent. Ferric Chloride has been shown to be effective at a pH of 6.5 while for Aluminum Sulfate the optimum pH is 5.3. The results showed that coagulation-flocculation by Ferric Chloride and Aluminum Sulfate is very effective in reducing turbidity. This reduction reaches 95 and 98% respectively for FeCl3 and Al2(SO4)3, while the reduction in COD for the two coagulants is around 60%. Organic flocculants alone do not lead to a significant reduction in turbidity and COD, while their combination with coagulants marks a good reduction in pollution. Hydrated iron hydroxides precipitate more easily than flocs formed by aluminum, resulting in more efficient removal of pollutants than that obtained at lower pH values. The order of introduction strongly influences the coagulation flocculation. The optimal doses of the various coagulants and flocculants chosen for the study vary from one reagent to another. FeCl3 remains the most suitable coagulant to further eliminate organic and metal pollution. The cost associated with the treatment using flocculants remains much higher when the flocculant is used in admixture with a coagulant.

This Is an Abridged Account of Delhi Which Is an Old City and One of the Chosen Ones amongst the Cities

2018 ◽  
Author(s):  
Mirza Sangin Beg
Keyword(s):  
Popular Culture ◽  
East India Company ◽  
Ordinary People ◽  
Work Spaces ◽  
History Of ◽  
English East India Company ◽  
Local Traditions ◽  
The Cost ◽  
The City ◽  
Cost Of Construction

The second part of the translation has three segments. The first is dedicated to the history of Delhi from the time of the Mahabharat to the periods of Anangpal Tomar to the Mughal Emperor Humayun as also Sher Shah, the Afghan ruler. In the second and third segments Mirza Sangin Beg adroitly navigates between twin centres of power in the city. He writes about Qila Mubarak, or the Red Fort, and gives an account of the several buildings inside it and the cost of construction of the same. He ambles into the precincts and mentions the buildings constructed by Shahjahan and other rulers, associating them with some specific inmates of the fort and the functions performed within them. When the author takes a walk in the city of Shahjahanabad, he writes of numerous residents, habitations of rich, poor, and ordinary people, their mansions and localities, general and specialized bazars, the in different skills practised areas, places of worship and revelry, processions exemplifying popular culture and local traditions, and institutions that had a resonance in other cultures. The Berlin manuscript gives generous details of the officials of the English East India Company, both native and foreign, their professions, and work spaces. Mirza Sangin Beg addresses the issue of qaum most unselfconsciously and amorphously.

Bulking and Foaming Organism Control at Phoenix, AZ WWTP

1992 ◽  
Vol 26 (3-4) ◽  
pp. 461-472 ◽  
Author(s):  
O. E. Albertson ◽  
P. Hendricks
Keyword(s):  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Retention Time ◽  
Oxygen Transfer ◽  
Average Rate ◽  
Oxygen Transfer Efficiency ◽  
Solids Retention ◽  
Total Nitrogen Removal ◽  
The Cost ◽  
The City

A 1630 L/s activated sludge plant at Phoenix was limited to an average rate of 1050 L/s and operated, at 400-600 mg/L MLSS and 0.8-1.3 day solids retention time (SRT) due to bulking sludge and limited clarification capacity. Higher SRTs also produced uncontrolled Nocardia foaming and low dissolved oxygen due to partial nitrification. The City retained the services of a team of consultants to resolve these problems as well as to upgrade the plant to provide nitrification and total nitrogen removal. An anoxic selector design was implemented within the existing basin and the clarifiers were modified to improve inlet design and sludge transport. The modified advanced wastewater treatment (AWT) plant operating at 1450 L/s has averaged an effluent of 7.6 mg/L BOD5, 8.2 mg/L TSS, 1.3 mg/L NH4N, 4.1 mg/L NO3N and 2.9 mg/L TP. Oxygen transfer efficiency has increased about 80% in the nitrification-denitrification (NdeN) mode. The cost of modification/upgrading to AWT was approximately $730,000 and a 400 L/s increase in hydraulic capacity was realized. Upgrading costs were $5.63/m3 ($0.02/gal.)

A new index to measure cost of living for expatriates in cities

2018 ◽  
Vol 28 (3) ◽  
pp. 295-317
Author(s):  
Khee Giap Tan ◽  
Nguyen Trieu Duong Luu ◽  
Le Phuong Anh Nguyen
Keyword(s):  
New York ◽  
Hong Kong ◽  
Quality Data ◽  
Cost Of Living ◽  
Content Type ◽  
Goods And Services ◽  
Commercial Research ◽  
The Cost ◽  
Cost Of Living Index ◽  
The City

Purpose Cost of living is an important consideration for the decision-making of expatriates and investment decisions of businesses. As competition between cities for talent and capital becomes global instead of national, the need for timely and internationally comparable information on global cities’ cost of living increases. While commercial research houses frequently publish cost of living surveys, these reports can be lacking in terms of scientific rigour. In this context, this paper aims to contribute to the literature by formulating a comprehensive and rigorous methodology to compare the cost of living for expatriates in 103 world’s major cities. Design/methodology/approach A cost of living index for expatriates composed of the ten consumption categories is constructed. The results from the study covers a study period from 2005 to 2014 in 103 cities. More than 280 individual prices of 165 goods and services have been compiled for each city in the calculation of the cost of living index for expatriates. New York has been chosen as the base city for the study, with other cities being benchmarked against it. A larger cost of living index for expatriates implies that the city is more expensive for expatriates to live in and vice versa. Findings While the authors generate the cost of living rankings for expatriates for 103 cities worldwide, in this paper, the authors focus on five key cities, namely, London, Hong Kong, Singapore, Tokyo and Zurich, as they are global financial centres. In 2013, the latest year for which data are available, Zurich was the most expensive for expatriates among the five cities, followed by Singapore, Tokyo, London and Hong Kong. These results pertain to the cost of living for expatriates, and cities compare very differently in terms of cost of living for ordinary residents, as ordinary residents follow different consumption patterns from expatriates. Originality/value Cost of living in the destination city is a major consideration for professionals who look to relocate, and organisations factor such calculations in their decisions to post employees overseas and design commensurate compensation packages. This paper develops a comprehensive and rigorous methodology for measuring and comparing cost of living for expatriates around the world. The value-addition lies in the fact that the authors are able to differentiate between expatriates and ordinary residents, which has not been done in the existing literature. They use higher quality data and generate an index that is not sensitive to the choice of base city.

Wartime activities of the Vavilov Institute

2021 ◽  
Vol 182 (2) ◽  
pp. 151-162
Author(s):  
I. G. Loskutov
Keyword(s):  
Plant Genetic Resources ◽  
Cultivated Plants ◽  
Left Behind ◽  
Long Time ◽  
Potato Collection ◽  
The Government ◽  
The Cost ◽  
The City ◽  
Harsh Reality ◽  
Difficult Part

Among the chronicles relating the heroism of the besieged Leningrad, there are pages dedicated to the deeds performed by the staff the world-famous All-Union Research Institute of Plant Industry (VIR, now the N.I. Vavilov All-Russian Institute of Plant Genetic Resources). With the beginning of the war, even before the city was surrounded by the Nazi troops, the government decided to evacuate a number of factories and institutes from Leningrad, including VIR, but the plan failed. Only in winter did the Institute start partial evacuation, although preparations had been going on for a long time. The largest and most important part of the collection was left behind in the besieged city. The remaining employees were forced to work under the hardest conditions of the siege, in unheated premises. In the harsh reality of the winter in 1941–1942, the daily bread rationing was cut down, and hunger raged in the city, killing tens of thousands of city residents, including VIR employees who kept the stored seeds and tubers untouched. The most difficult part was preserving the potato collection. In the spring of 1942, preparations were made for sowing to restore the viability of seeds and tubers in the fields of Leningrad’s suburban area under the fire from the enemy artillery. Only the heroic efforts of VIR’s staff helped to save the collection from destruction and loss of germination. This heroism cost more than 20 experts and scientists their lives. So, the most dangerous period for the Institute was overcome at such price. Immediately after the siege was lifted, a group of experts was sent to Leningrad from Krasnoufimsk to help with selecting seed accessions for urgent reproduction. Working under extreme physical exhaustion in frozen premises, without water or electricity, under continuous shelling, they saved, many at the cost of their own lives, the collection of cultivated plants and their wild relatives, the herbarium, and the scientific library for future generations. 

Pre-Ozonation-Coagulant Interactions in Direct Filtration

2010 ◽  
Vol 45 (3) ◽  
pp. 317-326 ◽  
Author(s):  
Murat Eyvaz ◽  
Hatice Deniz ◽  
Tuğrul S. Aktaş ◽  
Ebubekir Yüksel ◽  
Ahmet M. Saatçi
Keyword(s):  
Ferric Chloride ◽  
Aluminum Sulfate ◽  
Pilot Scale ◽  
The Other ◽  
Design Parameters ◽  
Dimensionless Number ◽  
Raw Water ◽  
Direct Filtration ◽  
Effluent Quality ◽  
Sulfate Application

Abstract Pre-ozonation–coagulant interactions effects in relation to the coagulant type and dosage in direct filtration of surface waters were investigated. The performance of the process was evaluated by monitoring the effluent quality and head loss development through the filter bed. Two identical pilot scale filter columns filtering the same raw water were operated in parallel. The raw water was brought from Ömerli Reservoir in Istanbul. Before filtering, the raw water flow was split into two equal flows. One of the streams was pre-ozonated and the other was aerated using contact chambers with equal volumes equipped with same number and type of diffusers. In coagulation experiments, one of the filters was operated using aluminum sulfate as a coagulant while the other one was run with ferric chloride. For similar filter run times, the effluent quality was always better with pre-ozonation compared to aeration. It was also observed that, aluminum sulfate application gave more favorable results for both particle and turbidity removal compared to ferric chloride. Ives’ filterability index which incorporates the important filtration design parameters such as: effluent quality, the headloss and the velocity of filtration into a dimensionless number was used for the comparison of the experimental results.

scholarly journals A Multilayer Path Planning Method for High Voltage Distribution Network Based on the Floyd-Warshall Algorithm

2021 ◽  
Vol 2121 (1) ◽  
pp. 012006
Author(s):  
Zhaolong Quan ◽  
Jie Xing ◽  
Ruilin Cao
Keyword(s):  
Path Planning ◽  
Life Cycle Cost ◽  
Cost Model ◽  
Distribution Networks ◽  
Load Flow ◽  
Planning Method ◽  
Cost Matrix ◽  
Planning Scheme ◽  
The Cost ◽  
The City

Abstract With the development of the city, a huge number of distribution networks are waiting for planning. A reasonable planning scheme can meet the power demand and reduce the investment cost. In this paper, a life cycle cost model including the investments of substation and wiring is established with the constraints about load flow calculation and maxi-mum load of wiring. Additionally, a multilayer planning method based on the Floyd-Warshall algorithm has been proposed to solve the model. The area of the city containing substations is divided based on the position of load through the hybrid clusters algorithm in the method. Then, using the divided result of power supply area, the cost matrix for the multilayer path planning method can be constructed through the principle of the method. Lastly, with the cost matrix, the planning scheme in each area will be provided by the Floyd-Warshall algorithm. The result on the actual planning area between the two algorithms shows the total cost of the investment is decreased through using the planning method in this paper.

scholarly journals PENENTUAN BIAYA KECELAKAAN LALU LINTAS: STUDI KASUS LOMBOK TIMUR

2018 ◽  
Vol 1 (3) ◽  
pp. 128
Author(s):  
Andyka Kusuma ◽  
Tri Tjahjono ◽  
Nuzul Achjar
Keyword(s):  
Traffic Safety ◽  
Human Development Index ◽  
Traffic Accident ◽  
Analytical Approach ◽  
Traffic Accidents ◽  
Price Index ◽  
Consumer Price Index ◽  
Potential Losses ◽  
The Cost ◽  
The City

Traffic accident cost analysis is needed to predict potential losses of nation due to the emergence of traffic accident victims. The cost of traffic accidents in Indonesia is based on the characteristics of the City of Bandung in 2003, and it is shown that the cost of traffic accidents can vary according to regional characteristics. This study tries to compare the analytical approach in Bandung in 2003 with the Consumer Price Index and Human Development Index approaches for an area with medium accessibility, namely East Lombok, West Nusa Tenggara Province. The location of traffic accidents greatly influences the cost of traffic accidents, because the costs on inter-city roads are relatively higher compared to those on roads in the city. This study shows that the cost of traffic accidents is related to accessibility of health facilities. This analysis can be developed for all regions in Indonesia, so that it can be used as a reference for traffic stakeholders in assessing the performance of the traffic safety programs implemented. Analisis biaya kecelakaan lalu lintas diperlukan untuk memprediksi potensi kerugian negara akibat timbulnya korban kecelakaan lalu lintas. Biaya kecelakaan lalu lintas di Indonesia dibangun berdasarkan karakteristik kota Bandung tahun 2003, dan diperlihatkan bahwa biaya kecelakaan lalu lintas dapat bervariasi sesuai dengan karakteristik wilayah. Penelitian ini mencoba membandingkan pendekatan analisis di Bandung tahun 2003 dengan pendekatan Indeks Harga Konsumen dan Indeks Pembangunan Manusia untuk suatu wilayah dengan aksesibilitas menengah, yakni Lombok Timur, Provinsi Nusa Tenggara Barat. Lokasi kecelakaan lalu lintas sangat mempengaruhi biaya kecelakaan lalu lintas, karena biaya di jalan antar kota relatif lebih tinggi dibandingkan dengan biaya di jalan dalam kota. Penelitian ini meperlihatkan bahwa biaya kecelakaan lalu lintas terkait dengan aksesibilitas fasilitas kesehatan. Analisis ini dapat dikembangkan untuk semua wilayah di Indonesia, sehingga dapat dijadikan acuan bagi pemangku kepentingan lalu lintas dalam menilai kinerja program keselamatan lalu lintas yang dijalankan.

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