Sugar Cane Industry as a Source of Water Pollution – Case Study on the Situation in Ipojuca River, Pernambuco, Brazil

Abstract

The Ipojuca river, a river in Northeast Brazil extending from west to east, is situated in the semiarid interior and rainy coastal zone of Pernambuco state. The river basin covers an area of 3,514 km 2 , with a total river length of 215 km. The water flow regime is characterized by the annual change from dry to rainy season as well as periodically occurring dry cycles. Mean flow rates vary between 2 and 35 m 3 s −1 . The dominant impacts on water quality of the river are domestic sewage input in the upper catchment and sugar cane cultivation and processing in the lower catchment. Long-term monitoring data used to demonstrate the impact of sewage discharge on the river's self-purification capacity indicated a severe change to the worse in the lower course. One reason is the use of stillage (wastewater from cane processing) for fertilization and irrigation (fertigation). Pathways of contamination have been identified by evaluating cultivation and processing techniques of a bio-alcohol factory with annexed sugar cane cultivation. The river's main ecological problems are water heating, acidification, increased turbidity, oxygen imbalance, and increased coliform bacteria levels. Precipitation-related wash-off and wash-out causes significant contamination within one to two days after rainfall. The increase in coliform bacteria is a consequence of secondary contamination.To determine the impact of the sugar cane industry on the river, the Brazilian bio-alcohol program must be subject to a critical evaluation. Environmentally friendly sugar cane cultivation methods need to be developed, and sugar cane factories must use wastereducing technologies and water cycling processes in order to protect the region's water resources.

Plants in constructed wetlands help to treat agricultural processing wastewater

“…These differ greatly from domestic wastewater because of their high organic-matter concentrations, variable flow rates, relatively low levels of nutrients, low pH and lack of pathogens. Gunkel et al (2006) monitored sugarcane fertigation and wash-down waters (used to clean equipment) in Brazil and noted their very low pH (3.8) and high sodium (1,320 milligrams per liter), salinity and organic loads. Kumar et al (2007) obtained similar results in India and also noted high sulfates.…”

“…described the negative impacts of winery wastewater downstream, which led to requirements for its control and on-site treatment. Similarly, downstream degradation from sugarcane process waters has been documented in the Ipojuca River of northeast Brazil (Gunkel et al 2006) and in coastal lagoons of northwest Mexico (González-Farias et al 2006). Wastewater from molasses processing follows a seasonal variation similar to that of wineries, with high flows and loadings from November through May, followed by harvesting and grape crush in late summer and early fall.…”

Physicochemical Properties of Sugar Industry and Molasses Based Distillery Effluent and its Effect on Water Quality of River Musamya in Uganda

“…According to Salequzzaman, et al [4], the main associated environmental impact of discharge of sugar and distillery wastewater on an open water body is the alteration of its chemistry. This causes fish mortality, serious health hazards to the rural and semi-urban populations [5,6], reduces soil alkalinity and inhibits seed germination [6]. Studies [7] have shown that sugar and distillery wastewater effluent contain higher amount of suspended solids, dissolved solids, Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), chloride sulphate, nitrates, calcium and magnesium, and cause odor nuisance during decomposition.…”

Vinasse application to sugar cane fields. Effect on the unsaturated zone and groundwater at Valle del Cauca (Colombia)

“…In laboratory experiments, Miyamoto et al (2012) indicated a decrease in saturated and unsaturated hydraulic conductivity by physical clogging and nitrate leaching (Eykelbosh et al, 2015) after sugar cane vinasse applications. A high contamination potential of surface waters, which caused water temperature and acidification to rise, and turbidity and oxygen depletion to increase, has been observed in the Ipojuca River (Brazil) by Gunkel et al (2007).…”