Black liquor management for small and medium mills based on agri-residues is still a problem, though several technologies are developed. One of the non conventional technologies being practiced by many of the mills is Modified Copeland Process.
Links:
[1] http://admin.indiaenvironmentportal.org.in/feature-article/anaerobic-treatment-wheat-straw-wash-water
[2] http://admin.indiaenvironmentportal.org.in/category/author/k-n-tiwary
[3] http://admin.indiaenvironmentportal.org.in/category/author/s-k-sharma
[4] http://admin.indiaenvironmentportal.org.in/category/author/anil-kumar
[5] http://admin.indiaenvironmentportal.org.in/category/journal/ippta
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/paper-and-pulp-industry
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/industrial-waste-treatment
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/wastewater-recycling
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/crop-residues
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/india