We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Long-term agricultural reuse of treated wastewater and sewage sludge: developing a Time to Critical Content Index for metal species
Summary
Researchers reviewed long-term effects of treated wastewater and sewage sludge reuse in agriculture, developing a framework to assess microplastic and contaminant accumulation in soils and crops over repeated application cycles.
This study evaluates the sustainability of spreading wastewater or sewage sludge on agricultural land, balancing benefits with contamination risks. Conventional ecological risk indices often fail to address the long-term accumulation of metals in soils. We investigate the feasibility of spreading based on current knowledge of potentially contaminating metals and their behavior in soil. We analyzed the speciation of metals (Ag, Cd, Co, Cr, Cu, Ni, Pb, Ti, Zn) through sequential extraction in sludge, treated wastewater, and soils after 14 years of application of sewage sludge and treated wastewater issued from an Algerian wastewater treatment plant. We introduce a Time to Critical Content Index (TCCI) that calculates the time required to reach critical levels of potentially mobile metals, considering total metal content and speciation. The TCCI takes into account product knowledge, soil characteristics, metal behavior, ecological/toxicological thresholds, and regulations. Applied to our case study, the TCCI indicates that spreading sewage sludge can continue despite metal contents exceeding regulatory ceiling values. The index serves as a precautionary measure, adaptable to evolving knowledge, providing a comprehensive framework for sustainable agricultural practices.
Sign in to start a discussion.
More Papers Like This
Impact of sewage sludge application on soil microplastic accumulation and nutrient levels: Analysis of 22 years of data from central UK farmland
Researchers analyzed a 22-year dataset from 5,323 fields in central UK to examine the relationship between repeated sewage sludge application and microplastic accumulation in agricultural soils, alongside changes in nutrient levels such as nitrogen and phosphorus. They found that microplastic concentrations increased with cumulative sludge applications while nutrients were taken up by crops, raising concerns about long-term plastic accumulation in farmland receiving sludge-derived fertilizers.
Impact of sewage sludge application on soil microplastic accumulation and nutrient levels: Analysis of 22 years of data from central UK farmland
Researchers analyzed 22 years of data from central UK farmland to assess how repeated sewage sludge application accumulates microplastics in agricultural soil while nutrients are absorbed by crops, finding that microplastic buildup disrupts geochemical cycling of carbon, nitrogen, and phosphorus.
Assessing metal contamination and speciation in sewage sludge: implications for soil application and environmental risk
This systematic review estimated that global sewage sludge production could triple to 160 million tons if all wastewater were treated to EU standards, and found that metals in sludge applied to farmland are predominantly in less bioavailable forms. The research is relevant to microplastics because sewage sludge is a major pathway for microplastic contamination of agricultural soils, carrying both metal and plastic pollutants to farmland.
Microplastics in an agricultural soil following repeated application of three types of sewage sludge: A field study
Researchers investigated microplastics in agricultural soil after repeated sewage sludge application, finding that sludge-amended soils contained significantly more small microplastic particles than unamended soils, with particle accumulation varying by sludge type.
Evidence of microplastic accumulation in agricultural soils from sewage sludge disposal
Agricultural soils from 31 fields with different sludge application histories were analyzed for microplastics, finding significant accumulation in fields with repeated sludge applications and a positive correlation between application frequency and plastic particle counts. The study provides direct field evidence that sewage sludge fertilization is a major pathway for microplastic accumulation in agricultural soil.