Algae are important bioremediation agents and are already being used in wastewater treatment. An attempt has been made to study the feasibility of laboratories (WI) and production (WII) pharmaceutical wastewaters treatment using free and immobilized cyanobacterium Phormidium fragile. Laboratories waste showed high toxicity, only 0.5% conc. was effective while production waste was used at high conc. of 40%. Role of Phormidium fragile in bioremediation of pharmaceutical wastewaters was effective where as maximum percentage removal in tested parameters were 51.56% and 58.89% for ammonia, 66.67% and 61.23% for phosphorus, 51.74 and 54.55 for COD and 37.05% and 59.85% for BOD in WI and WII respectively. N-starvation prior to cultivation caused increase in percentage removal of ammonia, phosphorus and COD with increase in algal dose than unstarved cells, 100%, 100% and 72.56% for WI and 87.28%, 100% and 71.98% for WII, respectively with 40 ml algal dose. It was found that 2500 lux and 25 ºC were the best for nutrients removal. Chlorophyll a, dry weight, protein and total carbohydrates contents were also estimated. During this study, pH levels increased and remained in the range 7.3 to 9.1. Significant removal of ammonia, phosphorus and COD were observed in algal alginate beads treatments than blank beads. Starvation before immobilization recorded the highest removal percentage when compared to unstarved beads or free cells in both wastes types and their mixture (1:1). When starved and unstarved Phormidium beads were incubated in WI, WII and a mixture of both in a semi-continuous system for five consecutive cycles (10 days each), there was increase in nutrients percentage removal up to the third cycle which gives a promise to upgrading immobilization technique for wastewater treatment with low cost.
Cyanobacteria, Phormidium, Pharmaceutical wastewater treatment, starvation, immobilization, alginate beads.