Alkalinity is a reliable indicator of process stability in anaerobic digestion system.Total alkalinity(TA)and partial alkalinity(PA)are usually monitored offline as indicators for the status of anaerobic digestion pro...Alkalinity is a reliable indicator of process stability in anaerobic digestion system.Total alkalinity(TA)and partial alkalinity(PA)are usually monitored offline as indicators for the status of anaerobic digestion process.In order to online monitor TA and PA,the linear regression method was used as estimator to predict alkalinity via software sensor method.Parameters,namely,pH,oxidation and reduction potential(ORP),and electrical conductivity(EC),were used as input variables.EC was the most significant parameter with TA and PA.Multiple linear regression(MLR)models and simple linear regression models with EC were constructed to predict TA and PA in anaerobic co-digestion system.On the basis of the evaluation of prediction accuracy,the applications of linear regression models were better for monitoring PA than TA.MLR models provided higher accuracy for alkalinity prediction than simple linear regression models.The two MLR models based on single-phase anaerobic digestion system were also feasible to predict TA in anaerobic co-digestion systems.However,the accuracy of these models should be improved by calibrating for broad applications of linear regression method in online alkalinity measurement.展开更多
Siloxanes in biogas are detrimental to engine,turbine,fuel cell,etc.,thus it is necessary to remove siloxanes from biogas before biogas high-value utilization.At present,there are few domestic researches and related r...Siloxanes in biogas are detrimental to engine,turbine,fuel cell,etc.,thus it is necessary to remove siloxanes from biogas before biogas high-value utilization.At present,there are few domestic researches and related reports in view of siloxanes removal from biogas.This paper introduces the property of siloxanes as well as sampling and analysis method,and then presents the research progress of siloxanes removal from biogas.Three commercial technologies overseas are adsorption,absorption and cryogenic condensation.Among them,adsorption on activated carbon is the most widely used method.Other technologies,such as biological removal,catalytic processes,membranes,source controlling,etc.are under exploration and development.At last,this paper summarizes the advantages and disadvantages of siloxanes removal technologies as well as the applicability and analyzes the future research trend and emphasis.This paper could provide a reference in the field of biogas high-value utilization.展开更多
Every day,human beings produce excreta all over the world,and the sludge that accumulates in waste disposal systems is referred to as the‘faecal sludge(FS)’.FS can cause serious environmental pollution in urban area...Every day,human beings produce excreta all over the world,and the sludge that accumulates in waste disposal systems is referred to as the‘faecal sludge(FS)’.FS can cause serious environmental pollution in urban areas if it cannot be disposed of properly.A complete FS management system must include onsite sanitation technologies,FS collection and transport,a treatment plant,and resource recovery or disposal of the treatment end-products.Focusing on the treatment and reuse/disposal step of a FS complete service chain,this research presents two cases of FS treatment in Beijing.In Case 1,FS biogas plant adopts anaerobic digestion(AD)to treat FS,and the digestate can be used as biofertilizer in the surrounding greenhouse.In Case 2,several technologies including solid-liquid separation,dewatering,pyrolysis,AD and co-composting are integrated to find innovative solutions for FS treatment.A comprehensive assessment including the aspects of technology,economy and environment is conducted for further SWOT(Strengths,Weaknesses,Opportunities and Threats)analysis.Then,critical strategies are developed,which include(1)selecting project site for optimized transportation,maximum waste reuse,minimum environmental impact and convenient final effluent disposal;(2)planning technical options at a feasible study stage,considering resource recovery,secondary pollution prevention and fire protection;(3)exploring market channels for by-products sale to increase profitability;(4)guaranteeing engineering quality and service life for the purpose of sustainable operation;(5)minimizing health risks to persons exposed to the untreated FS;and(6)providing necessary training for hygiene protection.The cases in Beijing can provide valuable lessons for urban areas in developing countries and the strategies can provide a reference for stakeholders and decision-makers who intend to develop FS treatment projects.展开更多
基金the International Scientific and Technological Cooperation and Exchange Projects(2013DFG92620)the Beijing Science and Technology Program(D141100001214003)+1 种基金the National Key Research and Development Plan(2016YFE0115600)Fundamental Research Funds for the Central Universities(FRF-TP-15-045A1).
文摘Alkalinity is a reliable indicator of process stability in anaerobic digestion system.Total alkalinity(TA)and partial alkalinity(PA)are usually monitored offline as indicators for the status of anaerobic digestion process.In order to online monitor TA and PA,the linear regression method was used as estimator to predict alkalinity via software sensor method.Parameters,namely,pH,oxidation and reduction potential(ORP),and electrical conductivity(EC),were used as input variables.EC was the most significant parameter with TA and PA.Multiple linear regression(MLR)models and simple linear regression models with EC were constructed to predict TA and PA in anaerobic co-digestion system.On the basis of the evaluation of prediction accuracy,the applications of linear regression models were better for monitoring PA than TA.MLR models provided higher accuracy for alkalinity prediction than simple linear regression models.The two MLR models based on single-phase anaerobic digestion system were also feasible to predict TA in anaerobic co-digestion systems.However,the accuracy of these models should be improved by calibrating for broad applications of linear regression method in online alkalinity measurement.
基金the Beijing Science and Technology Program(D141100001214003)Fundamental Research Funds for the Central Universities(No.FRF-TP-15-045A1)National Key Research and Development Plan(No.2016YFE0115600).
文摘Siloxanes in biogas are detrimental to engine,turbine,fuel cell,etc.,thus it is necessary to remove siloxanes from biogas before biogas high-value utilization.At present,there are few domestic researches and related reports in view of siloxanes removal from biogas.This paper introduces the property of siloxanes as well as sampling and analysis method,and then presents the research progress of siloxanes removal from biogas.Three commercial technologies overseas are adsorption,absorption and cryogenic condensation.Among them,adsorption on activated carbon is the most widely used method.Other technologies,such as biological removal,catalytic processes,membranes,source controlling,etc.are under exploration and development.At last,this paper summarizes the advantages and disadvantages of siloxanes removal technologies as well as the applicability and analyzes the future research trend and emphasis.This paper could provide a reference in the field of biogas high-value utilization.
基金National Key Research and Development Plan(2016YFE0115600)Fundamental Research Funds for the Central Universities(TW201704)The authors would like to take this opportunity to express our sincere appreciation for the support of National Environment and Energy International Science and Technology Cooperation Base and Reinvent the Toilet Challenge-China Regional Program(Global Development Grant Number OPP1051913).
文摘Every day,human beings produce excreta all over the world,and the sludge that accumulates in waste disposal systems is referred to as the‘faecal sludge(FS)’.FS can cause serious environmental pollution in urban areas if it cannot be disposed of properly.A complete FS management system must include onsite sanitation technologies,FS collection and transport,a treatment plant,and resource recovery or disposal of the treatment end-products.Focusing on the treatment and reuse/disposal step of a FS complete service chain,this research presents two cases of FS treatment in Beijing.In Case 1,FS biogas plant adopts anaerobic digestion(AD)to treat FS,and the digestate can be used as biofertilizer in the surrounding greenhouse.In Case 2,several technologies including solid-liquid separation,dewatering,pyrolysis,AD and co-composting are integrated to find innovative solutions for FS treatment.A comprehensive assessment including the aspects of technology,economy and environment is conducted for further SWOT(Strengths,Weaknesses,Opportunities and Threats)analysis.Then,critical strategies are developed,which include(1)selecting project site for optimized transportation,maximum waste reuse,minimum environmental impact and convenient final effluent disposal;(2)planning technical options at a feasible study stage,considering resource recovery,secondary pollution prevention and fire protection;(3)exploring market channels for by-products sale to increase profitability;(4)guaranteeing engineering quality and service life for the purpose of sustainable operation;(5)minimizing health risks to persons exposed to the untreated FS;and(6)providing necessary training for hygiene protection.The cases in Beijing can provide valuable lessons for urban areas in developing countries and the strategies can provide a reference for stakeholders and decision-makers who intend to develop FS treatment projects.
