Sugarcane cultivation and sugar industry plays a very important role in the socio-economics of rural areas of Maharashtra. Untreated discharge of sugar mill effluent can affect surface and/or ground water, soil as well as crops/plants. The objective of the present research was to explore a simple, easy to operate and lesser energy consuming sugar effluent treatment technology that could be operated even by unskilled manpower. Treatment of sugar effluent using Spirulina platensis was explored. The treatment achieved significant reduction in chemical oxygen demand of the effluent i.e. [50 % in 96 h and 80-89 %s after 144-216 h. Further, 81-85 % removal of nitrogen, 45-65 % removal of phosphorous and 90-91 % removal in potassium was achieved. These observations claimed significant development in sugar effluent treatment technology.Keywords Sugar mill effluent Á Chemical oxygen demand (COD) Á Biochemical oxygen demand (BOD) Á Phyco-remediation Á Effluent treatment, Spirulina species Effluent generated in sugar mills and its treatment/disposal attains a high significance due to its potential to cause pollution of surface and/or ground water as well as soil (Upadhyay et al. 2009). Effluent from sugar industry, if directly released for irrigation, affects the soil fertility, plant growth and seed germination (Ramkrishan et al. 2001). Sugar mill effluent also affects the soil micro flora.Activated sludge (AS) process based effluent treatment plant (ETP) operation requires significant energy, skilled manpower, skilled supervision and regular maintenance. These factors are responsible for poor performance of ETP in sugar industry and as a result the untreated or partially treated effluent is discharged. The rising costs of energy, both environmental and financial, was a driving force for this research to explore, low-cost and effective means of wastewater treatment to comply the norms of regulatory authorities.Spirulina has a potential to reduce biochemical oxygen demand (BOD) of high carbon containing wastewater (Olguín et al. 1995). Therefore, an option of phyco-remediation was explored, using Spirulina platensis. The observations were compared with other reported effluent treatment methods for sugar mill effluent as well as effluent/wastewater treatment experiment carried out using S. platensis.Sugar mill effluent was collected from sugar factories, located near to the laboratory. Freshly collected effluent was used for each batch of experiment. The initial pH of the effluent was in the range of 3.6-4.0 however it was adjusted to 7.2 (±0.1) by adding lime (Ca(OH) 2 --0.1 g/L of effluent) because algal culture requires pH between 7 and 9 (Vonshak and Guy 1992). As a part of pre-treatment, alum dosing also carried out (10 g for 35 L of effluent) to settle suspended solids and reduce their potential interference in photosynthetic activity. The settled solids were

A 'fixed film algal photobioreactor (FFAPBR)' was tested forsugar mill effluent (SME) treatment. This reactor was developed in-house using Chlorellavulgaris, an alga, that allowedto grow on weathered rooftop sheet made of Fiber-reinforced plastic (FRP).Experiments carried out in open sun light, in which SME of 80 L, pumped slowly @12 L -1 minuteatone end of thereactor, collected at another and re-circulated.To check the effectiveness of the treatment parameters pH, COD and BOD were studied. Reduction in chemical (COD) and biological oxygen demand (BOD) was >80% in just 12h of treatment.Treated water was diluted in a ratio of 1:1with tap water and tested for fish survival. All fishes survived 96 hours of observation period and beyond.

No abstract

Water security may be regarded as a first step toward achieving food and energy security. Efficient use of fresh water resources and recycling of wastewater after proper treatment are viewed as tools to achieve water sustainability. Sugar industry can have good potential to treat and reuse its effluents. This potential is not realized by prevailing effluent treatment technologies because of high capital and operation cost of treatment process. More upon, these technologies require substantial amount of energy (electricity) as well as chemicals and labors. We have therefore focused on the development of a technology that would help to overcome these limitations. The algaSpirulina-was our choice to (1) treat the effluent and (2) use the sugar mill effluent as its growth medium. Experiments using Spirulina at secondary treatment stage showed 91 % reduction in chemical oxygen demand in 108-h treatment time. Further, biochemical analysis of Spirulina harvested from the sugar mill effluent treatment tanks revealed that the harvested biomass has high protein levels. Spirulina is well known for its usage as a protein supplement and therefore can be used as an additional source of revenue generation.