Tanning industry in Pakistan has shown rapid growth in last few decades. However, environmental regulations are not strictly followed regarding the processing as well as discharge of effluents. Tannery wastewater and sludge have become a major source of water and soil pollution. This research study was designed to appraise the harmful impacts of untreated tannery wastewater along with proper management of sludge by utilizing green technologies. In this study, management of tannery sludge was done by utilizing environment friendly practices in four experimental phases. In first phase, the impacts of tannery wastewater on soil and selected plants were studied in comparison with a control group. Characterization of tannery wastewater showed that values of parameters like pH, biological oxygen demand, chemical oxygen demand, sulphate and chloride were higher as compared to National environmental quality standard. The concentration of Cr, Zn, Mn, Fe, Cu, Na, and K were higher in soil and plants (D. sanguinalis, S. cumini and E. camaldulensis) samples irrigated with tannery wastewater as compared to fresh water samples. It is concluded that the untreated tannery wastewater is not suitable for irrigation purpose. Hence, proper treatment of tannery wastewater is required before its usage for irrigation purpose. Biogas production through anaerobic co-digestion of waste activated tannery sludge (WATS) with biomasses (rice husk, cow dung and sewerage sludge) as co-substrates was investigated in second phase. The initial results of waste activated tannery sludge were best as compared to primary lagoon sludge, secondary lagoon sludge and tannery solid waste collected from Kasur tannery treatment plant. The waste activated tannery sludge was used in biogas experiments as co-substrate. Different proportions of waste activated tannery sludge and cow dung were used for biogas production. The cumulative biogas production in WATS (waste activated tannery sludge 100 %) was found 80 mL (0.10 mL/g TVS), WATSCD-1 (WATS 70 % and cow dung 30 %) that is 158 mL (0.20 mL/g TVS) and WATSCD-2 (WATS 50 % and cow dung 50 %) sample 195 mL (0.24 mL/g TVS). The overall results of WATSCD-2 combination were best. To optimize biogas production ultrasonic and chemical pre-treatment were applied through series of experiments on different combination of WATSCD-2. Seven combinations of WATSCD-2 with sewerage sludge and rice husk were ii prepared and designated as CDCT-1 to CDCT-7, treated chemically. Similarly, seven proportions CDUT-1 to CDUT-7 were treated ultrasonically. Biogas production results of ultrasonically treated sludge combinations (CDUT-1 to CDUT-7) were better as compared to chemically treated sludge combinations (CDCT-1 to CDCT-7). The optimum results were obtained in ultrasonically treated combination CDUT-7 (202 mL, 9.25 mL/g TVS) as it contains maximum biomass concentration as compared to CDUT-1 to CDUT-6. In third phase, series of experiments were conducted to optimize the parameters like sulfur, ash and gross heating value (GHV) by preparing different sludge combinations with biomasses. These combinations were prepared by using primary sludge, secondary sludge and WATSCD-2 with coal and rice husk on weight percent basis. The higher GHV results were found in WATSCD-2 combinations as compared to both primary and secondary sludge combinations. The WATSC-2 combination (WATSCD-2 50 % and coal 50 %) have lower sulfur and ash contents along with high GHV as compared to primary and secondary sludge combinations. So, this combination has better potential to use as refuse derived fuel for energy recovery. The statistical analysis (one-way ANOVA) was found significant for ash, sulfur and GHV for different sludge combinations with p < 0.05. It is concluded that sludge is a very valuable fuel like traditional biomass. However, efforts should be exercised to overcome the problem of drying and emissions from sludge. In last phase, compost was prepared from different combinations of WATSCD-2 with different co-substrates. These combinations were designated as WATSCD-SR (mixture of WATSCD-2, sewerage sludge and rice husk), WATSCD-RL (mixture of WATSCD-2, rice husk and leaves), WATSCD-SL (mixture of WATSCD-2, sewerage sludge and leaves) at laboratory scale by using 1:1:1 ratio of each component. The WATS-RL combination showed better results of nitrogen (2.9 ± 0.38 %), phosphorous (0.038 ± 0.01 %), potassium (0.07 ± 0.01 %), organic matter (57.55 ± 6.35 %) and C/N ratio (18.05 ± 1.93) as compared to WATS-SR and WATS-SL. Environmental regulations are getting more restricted related to landfilling of biodegradable waste. The solution of these problems is to use of biodegradable portion for biogas production and residual tannery sludge as bio-solid (composting) or thermal utilization for energy recovery.