Effect of ultrasonication on anaerobic degradability of solid waste digestate

2016 ◽  
Vol 48 ◽  
pp. 209-217 ◽  
Author(s):  
M.R. Boni ◽  
E. D’Amato ◽  
A. Polettini ◽  
R. Pomi ◽  
A. Rossi
2001 ◽  
Vol 44 (4) ◽  
pp. 103-108 ◽  
Author(s):  
B. Fernández ◽  
P. Porrier ◽  
R. Chamy

The anaerobic systems start-up for solid waste treatment is a fundamental step, especially for those with two phases. It is necessary to know both the waste characteristics and the inoculum conditions. The objective of this work was to study the inoculum-substrate ratio (ISR) influence as a previous step of the start-up of an anaerobic system for the solid waste digestion. During this research spent grain was chosen as residue, working at three different concentrations (7; 13 and 20% w/v), studying the ISR effect in terms of anaerobic degradability (AD) and specific methane productivity (SMP). The initial acetoclastic activities (A0) were calculated based on the equation which describes the methane accumulation during each test. The model constants were also calculated and were adjusted to the experimental data. The results showed that in general the ISR variation has less impact on AD than on SMP. While maximum AD were reached in those tests with high ISR, the greatest values of SMP were with the lowest values of ISR ratio. A low ISR caused a slow hydrolysis, although the methane production was fast. So, during the start-up of a two-phase anaerobic system an elevated ISR would not be necessary in order to reach a good AD and a good intermediate products production, because the hydrolysis and the VFA production must be optimised in the first phase of these systems. While in conventional systems, where phases are together, it is much better to optimise the methane production. The ISR and the SMP indicated which inoculum percentage would be interesting based on the objective of the whole system: methane or intermediate compounds (VFA) production. All this information is important during the conventional anaerobic reactors operation because these tests would show which ISRs avoid inhibition.


2008 ◽  
Vol 58 (8) ◽  
pp. 1615-1622 ◽  
Author(s):  
D. Scaglione ◽  
S. Caffaz ◽  
E. Ficara ◽  
F. Malpei ◽  
C. Lubello

The present study was aimed at setting and applying a procedure to measure the anaerobic degradability of different organic substrates by short-term tests (2–7 days) carried out at lab-scale with a low food to biomass (F/M) ratio. All tests were carried out using an acclimated sludge taken from a pilot-plant anaerobic digester (200 L). Trials were performed with a manometric system. The experimental reliability of the device in measuring the anaerobic degradability was assessed by several preliminary tests carried out using acetate and glucose as reference substrates. The average conversion to methane was 99% for acetate and of 83% for glucose. The results of tests in triplicate showed the high repeatability of the method with an average coefficient of variation lower than 2%. Then, the lab-scale procedure was applied to study the short-term anaerobic degradability of complex organic substrates: thickened waste activated sludge, two kinds of organic fraction of municipal solid waste (a kitchen waste and a fruit and vegetable waste collected at the wholesale market of Florence), olive mill wastewater and freshly harvested grass. Results indicated that organic fraction of municipal solid waste, olive mill wastewater and grass were characterized by a much higher anaerobic degradability if compared to the thickened activated sludge, well in agreement with literature data.


Author(s):  
Kriti Jain ◽  
Chirag Shah

The increasing volume and complexity of waste associated with the modern economy as due to the ranging population, is posing a serious risk to ecosystems and human health. Every year, an estimated 11.2 billion tonnes of solid waste is collected worldwide and decay of the organic proportion of solid waste is contributing about 5 per cent of global greenhouse gas emissions (UNEP). Poor waste management - ranging from non-existing collection systems to ineffective disposal causes air pollution, water and soil contamination. Open and unsanitary landfills contribute to contamination of drinking water and can cause infection and transmit diseases. The dispersal of debris pollutes ecosystems and dangerous substances from waste or garbage puts a strain on the health of urban dwellers and the environment. India, being second most populated country of the world that too with the lesser land area comparatively, faces major environmental challenges associated with waste generation and inadequate waste collection, transport, treatment and disposal. Population explosion, coupled with improved life style of people, results in increased generation of solid wastes in urban as well as rural areas of the country. The challenges and barriers are significant, but so are the opportunities. A priority is to move from reliance on waste dumps that offer no environmental protection, to waste management systems that retain useful resources within the economy [2]. Waste segregation at source and use of specialized waste processing facilities to separate recyclable materials has a key role. Disposal of residual waste after extraction of material resources needs engineered landfill sites and/or investment in waste-to-energy facilities. This study focusses on the minimization of the waste and gives the brief about the various initiations for proper waste management system. Hence moving towards the alternatives is the way to deal with these basic problems. This paper outlines various advances in the area of waste management. It focuses on current practices related to waste management initiatives taken by India. The purpose of this article put a light on various initiatives in the country and locates the scope for improvement in the management of waste which will also clean up the unemployment.


2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Salma Savira Siddik ◽  
Eka Wardhani

<p>Hospital X was class b private hospitals that are located in Batam with 297 unit beds. The waste that can be categorized as solid waste medical in the hospital which is infectious, pharmacy, hazardous and toxic waste, cytotoxic, sharp object.  The purpose of this research is to identify, a source of , the characteristics, solid waste medical produced by hospital X in Batam and also conduct an evaluation of solid waste medical management hospital in accordance with the minister of environment and forestry 56 2015 on procedures and technical requirements of hazardous and toxic waste management than health service facilities. This research used primary and secondary data collection method. The research results show solid waste medical management at the hospital X in Batam most of them are in according to rule. But there are some things that must be improved are blinding trash bag, efficiency and minimal temparature the combustion chamber incinerator. Management efforts must to do are briefing to officer of the waste collection about the way to blinding trash bag in according to the regulation and the incinerator that can serve confirming to standard of burning hazardous and toxic waste. <strong></strong></p>


TAPPI Journal ◽  
2017 ◽  
Vol 16 (7) ◽  
pp. 383-391
Author(s):  
CARLA CÉLIA ROSA MEDEIROS ◽  
FLÁVIA AZEVEDO SILVA ◽  
SAULO GODOY PIGNATON ◽  
ESTANISLAU VICTOR ZUTAUTAS ◽  
KLEVERSON FIGUEIREDO

There are many points in a kraft mill where the alkaline compounds are purged from the process. Several effluents, solid waste, and air emissions contain alkali, which leads to the necessity of chemical makeups to maintain the liquor balance. The main loss of alkali at the Veracel mill is present in the wastewater from the recovery boiler; more precisely, it is from the ash leaching system, which represents 80% of the total losses. To minimize the alkaline losses while keeping the chloride level in the recovery cycle under control, a project was developed at Veracel. Key actions were taken by adjusting the control loops of the ash leaching system, mainly on the slurry density and purge control. These adjustments led to a decrease in alkali losses and to an increase of treated ash, and kept the chloride level of the recovery boiler dust at 2.6%.


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