污泥余热干化技术及其经济性分析

我国污水处理厂每年都会产生大量的污泥,其复杂的成分及高含水率制约污泥的有效利用,如何降低污泥的含水率是其资源化利用的关键.首先调研了污泥产生及成分,从污泥干化的典型工艺及设备、干化过程的环境污染与控制、污泥干化过程的尾气处理和污泥干化经济性分析4个方面对污泥干化技术进行阐述,指出污泥余热干化是污泥实现节能、经济及环保的有效处置方式.     

脱硫石膏气流烘干工艺的改进

介绍了脱硫石膏气流烘干改进工艺，该工艺可以解决烘干筒内水分聚集影响烘干效果和浪费燃料的问题。     

Possibilities for enhanced nitrogen recovery from digestate through thermal drying

Journal of Material Cycles and Waste Management - Ammonia release during thermal drying of digestate originating from a thermophilic anaerobic digestion process was continuously measured using...     

Transformation of phosphorus during drying and roasting of sewage sludge

Sewage sludge (SS), a by-product of wastewater treatment, consists of highly concentrated organic and inorganic pollutants, including phosphorus (P). In this study, P with different chemical fractions in SS under different drying and roasting temperatures was investigated with the use of appropriate standards, measurements, and testing protocol. The drying and roasting treatment of SS was conducted in a laboratory-scale furnace. Two types of SS samples under different treatment temperatures were analyzed by ³¹P NMR spectroscopy. These samples were dried by a vacuum freeze dryer at ?50 °C and a thermoelectric thermostat drying box at 105 °C. Results show that the inorganic P (IP) content increased as the organic P content decreased, and the bio-availability of P increased because IP is a form of phosphorous that can be directly absorbed by plants. ³¹P NMR analysis results indicate the change in P fractions at different temperatures. Non-apatite P was the dominant form of P under low-temperature drying and roasting, whereas apatite P was the major one under high-temperature drying and roasting. Results indicate that temperature affects the transformation of P.     

浅谈氨法脱硫中硫酸铵的干燥工艺

介绍了氨法烟气脱硫产品硫酸铵的各种干燥工艺,并对各工艺的特点进行了比较,认为选择振动流化床工艺进行硫酸铵干燥比较适宜。     

Effect of drying on leaching testing of treated municipal solid waste incineration APC-residues

Air-pollution-control (APC) residues from waste incinerators are hazardous waste according to European legislation and must be treated prior to landfilling. Batch and column leaching data determine which type of landfill can receive the treated APC-residues. CEN standards are prescribed for the batch and column leaching test; however, these standards do not specify whether or not the residue samples should be dried prior to the leaching testing. Laboratory tests were performed in parallel (dried/non-dried) on treated APC-residue samples and evaluated with respect to Cr, Cd, Cu, Pb and Zn leaching. The effect of drying of the wet APC-residue samples was particularly dramatic regarding the leaching of Cr. Drying resulted in 10-100 times more Cr leaching in both batch and columns test. Drying also affected the leaching of Cd, Cu and Pb. Initial Cd leaching was up to 100 times higher in column tests with dried APC-residue than in tests with wet residues. The effect of drying appeared to be a combination of decreasing the reduction capacity of the sample (Cr), decreasing pH (Cd, Cu) and in column tests also a wash-out of salts (probably affecting Cd and Pb). If the leaching tests are intended to mimic landfill conditions, the results of this paper suggest that the tests should be done on wet, non-dried residue samples, although this may be less practical than testing dried samples.     

Sewage sludge drying by energy recovery from OFMSW composting: Preliminary feasibility evaluation

In this paper an original energy recovery method from composting is analyzed. The integrated system exploits the heat available from the aerobic biochemical process in order to support the drying of sewage sludge, using a specific solar greenhouse. The aim is to tackle the problem of organic waste treatment, with specific regard to food waste. This is done by optimizing the energy consumption of the aerobic process of composting, using the heat produced to solve a second important waste management problem such as the sewage waste treatment. Energy and mass balances are presented in a preliminary feasibility study. Referring to a composting plant with a capacity of 15,000 t/y of food waste, the estimation of the power from recovered heat for the entire plant resulted about 42 kW. The results demonstrated that the energy recoverable can cover part of the heat necessary for the treatment of sludge generated by the population served by the composting plant (in terms of food waste and green waste collection). The addition of a renewable source such as solar energy could cover the residual energy demand. The approach is presented in detail in order for it to be replicated in other case studies or at full scale applications.     

Quality improvement of mixed MSW drying using a pilot-scale solar greenhouse biodrying system

Journal of Material Cycles and Waste Management - This paper addresses on improving the drying performance of high-moisture content (57.76%) municipal solid waste (MSW) using novel-design solar...     

智能全水快速分析仪加热干燥系统试验研究

对智能全水快速分析仪的加热干燥系统进行了优化对比试验，最终选用远红外加热干燥技术。该仪器成本低、使用寿命长、操作方便，对人体无危害，其测定准确度和精密度符合GB／T211－1996要求。     

Release characteristics and control of hydrogen sulfide during thermal drying of municipal wastewater sludge

Journal of Material Cycles and Waste Management - Hydrogen sulfide (H2S) is the most predominant malodorous gas released during the thermal drying of municipal wastewater sludge. Experiment using a...     

Study of drying systems for the utilization of biodegradable municipal solid wastes as animal feed

The effectiveness of different drying systems used for the dehydration of certain fractions of biodegradable municipal solid wastes with a high moisture content (fruit and vegetable remains) was analyzed. Some tests using small amounts of the material were carried out in natural and forced convection ovens. For larger quantities of wastes, a discontinuous cabinet dryer and a continuous rotary dryer were used. With these dryers, the moisture content was reduced from 800 to 100 g kg(-1). It was verified that the continuous rotary dryer was the most efficient type of equipment studied, since it allowed a dried waste to be obtained with better nutritional and microbiological qualities and in accordance to the specifications of the products for animal feeding.     

Integrated drying and incineration of wet sewage sludge in combined bubbling and circulating fluidized bed units

An original integrated drying and incineration technique is proposed to dispose of sewage sludge with moisture content of about 80% in a circulating fluidized bed. This system combines a bubbling fluidized bed dryer with a circulating fluidized bed incinerator. After drying, sewage sludge with moisture less than 20% is transported directly and continuously from the fluidized bed dryer into a circulating fluidized bed incinerator. Pilot plant results showed that integrated drying and incineration is feasible in a unique single system. A 100 t/d Sewage Sludge Incineration Demonstration Project was constructed at the Qige sewage treatment plant in Hangzhou City in China. The operational performance showed that the main operation results conformed to the design values, from which it can be concluded that the scale-up of this technique is deemed both feasible and successful.     

Hazardous emission from thermal drying of municipal sludge and industrial sludge as well as associated odor pollution

Journal of Material Cycles and Waste Management - Disposal of sewage sludge, a by-product of wastewater treatment, is one of the most intractable problems for environmental protection industry. The...