Recent Approaches for the Production of High Value-Added Biofuels from Gelatinous Wastewater
Ahmed Tawfik,
Shou-Qing Ni,
Hanem. M. Awad,
Sherif Ismail,
Vinay Kumar Tyagi,
Mohd Shariq Khan,
Muhammad Abdul Qyyum,
Moonyong Lee
Affiliations
Ahmed Tawfik
Water Pollution Research Department, National Research Centre, Giza 12622, Egypt
Shou-Qing Ni
Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
Hanem. M. Awad
Department Tanning Materials and Leather Technology & Regulatory Toxicology Lab, National Research Centre, Centre of Excellence, Giza 12622, Egypt
Sherif Ismail
Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
Vinay Kumar Tyagi
Environmental Biotechnology Group (EBiTG), Department of Civil Engineering, Indian Institute of Technology, Roorkee 247667, India
Mohd Shariq Khan
Department of Chemical Engineering, Dhofar University, Salalah 211, Oman
Muhammad Abdul Qyyum
School of Chemical Engineering, Yeungnam University, Gyeongsan 712-749, Korea
Moonyong Lee
School of Chemical Engineering, Yeungnam University, Gyeongsan 712-749, Korea
Gelatin production is the most industry polluting process where huge amounts of raw organic materials and chemicals (HCl, NaOH, Ca2+) are utilized in the manufacturing accompanied by voluminous quantities of end-pipe effluent. The gelatinous wastewater (GWW) contains a large fraction of protein and lipids with biodegradability (BOD/COD ratio) exceeding 0.6. Thus, it represents a promising low-cost substrate for the generation of biofuels, i.e., H2 and CH4, by the anaerobic digestion process. This review comprehensively describes the anaerobic technologies employed for simultaneous treatment and energy recovery from GWW. The emphasis was afforded on factors affecting the biofuels productivity from anaerobic digestion of GWW, i.e., protein concentration, organic loading rate (OLR), hydraulic retention time (HRT), the substrate to inoculum (S0/X0) ratio, type of mixed culture anaerobes, carbohydrates concentration, volatile fatty acids (VFAs), ammonia and alkalinity/VFA ratio, and reactor configurations. Economic values and future perspectives that require more attention are also outlined to facilitate further advancement and achieve practicality in this domain.
