NOVELTY - Generating an algal biomass, comprises: (a) forming an algal culture by combining (i) a population of algal cells that are capable for proliferating in a culture medium comprising carpet industry wastewater, and (ii) a culture medium comprising carpet industry wastewater and a sewage system effluent; and (b) maintaining the algal culture under conditions suitable for the proliferation of the population of algal cells to form the algal biomass.    USE - The method is useful for generating an algal biomass, which is converted into biofuel (claimed) i.e. biodiesel.    ADVANTAGE - The method is capable of converting about 65% of the algal oil obtained from the algal consortium cultured on carpet industry wastewater into the biodiesel. The wastewater generated by the carpet industry, when combined with a typical city sewage, can act as a cheap source of algal culture medium while simultaneously treated to reduce or remove the industry by-products that are undesired in the environment, thus the method ensures economical production of algal biomass and biodiesel.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) producing a biofuel from carpet industry wastewater comprising the steps (a) and (b) as above per se, (c) isolating the algal biomass from the medium, and (d) obtaining a biofuel or a source of a biofuel from the isolated algal biomass, where the step of obtaining the biofuel from the isolated biomass comprises isolating a lipid material from the biomass or converting the biomass to a biofuel, and the isolated lipid material is converted to a biofuel; (2) a system for generating the algal biomass comprising an algal culture container including a raceway, a vertical tower reactor or a polybag, where the container(s) is/are optionally provided with an air supply supplemented with carbon dioxide, an algal culture medium comprising carpet industry wastewater and optionally a sewage system effluent and a population of algal cells in the algal culture medium, where the algal cells include Chlamydomonas, Chlorella vulgaris, Chlorococcaceae sp., Chlorococcum humicola, Coelastrum microporum, Gloeocystis vesiculosa, Monoraphidium mirabile, Oedogonium sp., Oocystis lacustris, Scenedesmus abundans, Scenedesmus acuminatus, Scenedesmus acutus, Scenedesmus acutus alternans, Scenedesmus bicaudatus, Scenedesmus bijuga, Scenedesmus bijuga alternans, Scenedesmus denticulatus, Scenedesmus dimorphus, Scenedesmus incrassatulus, Scenedesmus obliquus, Scenedesmus quadricauda, Scenedesmus quadrispina, Scenedesmus serratus, Stigeoclonium sp., Ulothrix variabilis, Uroglena sp., Anabaena sp., Aphanocapsa delicatissima, Aphanocapsa hyalina, Aphanothece sp., Calothrix braunii, Chroococcaceae sp., Chroococcus minutus, Cylindrospermopsis sp., Leibleinia kryloviana, Limnothrix sp., Limnothrix redekei, Lyngbya sp., Nostoc sp., Oscillatoria sp., Oscillatoria tenuis, Planktolyngbya limnetica, Raphidiopsis curvata, Synechococcus elongatus, Synechococcus sp., Synechocystis sp., Eunotia sp., Navicula pelliculosa, Navicula sp., Nitzschia palea, Nitzschia amphibia, Nitzschia pura, Gomphonema parvulum, Gomphonema gracile or Rhodomonas sp.; and (3) an isolated population of algal cells comprising at least one algal strain isolated from a source in contact with the waste water effluent of the carpet industry and capable of proliferating on a medium comprising the carpet industry wastewater.