Soil Quality after Six Years of Paper Mill Industrial Wastewater Application

Abstract

ABSTRACT:The application of wastewater to irrigate soils may be an attractive option for paper mills, especially when the effluents can also provide nutrients to plants. Since there could be negative environmental effects, such activity must be preceded by a thorough evaluation of the consequences. The changes in soil quality of a Neossolo Flúvico Distrófico (Typic Udifluvent) were evaluated over a period of six years of irrigation with treated effluent from a wood pulp company. Although effluent application for six years did not affect soil resistance to penetration and soil hydraulic conductivity, it promoted a decrease in the mean size of aggregates and an increase in clay dispersion. Effluent application increased soil pH but did not change exchangeable Ca and Mg contents and organic carbon. After a full rotation of eucalyptus cultivation common in Brazil (six years), no negative effects in tree growth were found due to effluent irrigation. However, effluent addition caused higher values of Na adsorption ratio and intermediate electrical conductivity in the soil, which indicates a possible negative effect on soil quality if the application continues over a longer period. Therefore, a monitoring program should be carried out during subsequent crop rotations, and alternatives must be studied to obtain better effluent quality, such as adding Ca and Mg to the wastewater and using gypsum in the soil.

A Review of Environmental Contamination and Health Risk Assessment of Wastewater Use for Crop Irrigation with a Focus on Low and High-Income Countries

“…The application of wastewater will increase the OM contents in the soil which is considered a beneficial effect for soil [ 3 ]. The addition of organic matter into the soil through wastewater application improves the soil structure and the moisture content’s increased cation exchange capacity and helps to retain the metals and reduce their bioavailability and mobility and adds nutrients into the soils [ 108 , 109 , 110 ].…”

Impact of Paper Board Industry Effluent Irrigation to Agroforestry System on Changes in Soil Quality

“…). The lowest saturated hydraulic conductivity of treated effluent soil was due to higher bulk density and lowest total porosity of the soil [25]. Infiltration rate was ranged from 6.6 to 52.5 cm h -1 with the mean value of 23.0 cm h -1 (Fig.…”

“…The bulk density increased with distance from paper mill in the northeren, the western and eastern directions of nagaon pulp and paper mill of Assam, India [24]. The lowest total porosity in treated effluent mainly due to presents of higher micropore and lowest macropore within the soil [25].…”

Characteristics and treatment of Brazilian pulp and paper mill effluents: a review

“…For irrigation purposes, Rezende et al ( 2010 ) reported that treated effluent can be used to irrigate eucalyptus plantations, which is the main raw material used in Brazilian pulp and paper mills. In turn, Almeida et al ( 2017 ) applied treated effluent on soil for 6 years, a period of a complete rotation of eucalyptus cultivation. It was noted that irrigation did not affect soil strength, hydraulic conductivity, and Ca, Mg, and organic carbon contents, while reducing mean aggregate size and increasing clay dispersion and pH.…”