Paper and pulp mill wastewater: characterization, microbial-mediated degradation, and challenges

Paper industry uses huge amount of freshwater during different steps of the papermaking process, and discharge highly contaminated toxic effluent in the environment. The paper and pulp industry effluent characteristics are alkaline pH, high biological oxygen demand, chemical oxygen demand, total dissolved solids, suspended solids, chloride, phenols, phosphate, sulfate, nitrate, lignin, and several toxic mutagenic pollutants along with various heavy metals. Moreover, paper and pulp industry effluent toxicity assessment on Phaseolus aureus seed germination and tubifex tubifex aquatic worms was done. While several studies have been conducted to eliminate the problems associated with paper and pulp industry effluent, but the problem still persists. Physical and chemical treatments are reliable, but they lack the cost effectiveness and residual effects of biological treatments. The biological treatment of paper industry effluent is thought to be effective in reducing organic load and toxic effects. The chemicals found in paper industry effluent have been degraded by several microorganisms such as bacteria and fungi with the help of various ligninolytic enzymes. This chapter described the paper industry effluent characteristics, toxicity, and treatment using native dominant bacterial and fungal isolates.