Preprint Article Version 1 This version not peer reviewed

Effects of Medium-Term Amendment with Sewage Sludge on Soil Organic Fertility and on Heavy Metal Bioavailability

Version 1 : Received: 6 December 2017 / Approved: 7 December 2017 / Online: 7 December 2017 (05:41:57 CET)

How to cite: Rossi, G.; Beni, C. Effects of Medium-Term Amendment with Sewage Sludge on Soil Organic Fertility and on Heavy Metal Bioavailability. Preprints 2017, 2017120038 (doi: 10.20944/preprints201712.0038.v1). Rossi, G.; Beni, C. Effects of Medium-Term Amendment with Sewage Sludge on Soil Organic Fertility and on Heavy Metal Bioavailability. Preprints 2017, 2017120038 (doi: 10.20944/preprints201712.0038.v1).

Abstract

The biomass fraction of processed municipal and industrial wastes added to soil can maintain, and in some case improve, the soil’s organic fertility. One of the main constraints in the agricultural use of the sewage sludge is its content of heavy metals. In the long term, soil administration of sewage sludge in agriculture could result in a risk of environmental impact. The aim of this research was to evaluate the effects of medium-term fertilization with sewage sludge diversely processed on the soil’s organic carbon content and humification – mineralization soil’s processes and on the physical and mechanical properties of soil. Furthermore, the heavy metals accumulation in soil, in their total and available form, has been investigated. After eight years of administration to soil, the use of sewage sludge as an agricultural soil amendment has contributed to maintaining the soil’s organic fertility. An increase in concentrations of total Ni and Zn was detected in soil. For bioavailable form (DTPA-extractable) this trend was evidenced for all heavy metals analysed. However, the concentrations of total and available heavy metals in the soil did not exceed the legal threshold established by Italian law for unpolluted soils.

Subject Areas

sewage sludge recycling; soil organic fertility; heavy metals bioavailability

Readers' Comments and Ratings (1)

Comment 1
Received: 7 December 2017
Commenter: Craig Monk
The commenter has declared there is no conflict of interests.
Comment: Subject: "One of the main constraints in the agricultural use of the sewage sludge is its content of heavy metals. In the long term, soil administration of sewage sludge in agriculture could result in a risk of environmental impact." and the additional unstudied impact of the following:
Biosolids are derived from industrial, medical, storm and household sewage.
  • US EPA 40 CFR 261.30(d) and 261.33 (4): (Every US industry connected to a sewer can discharge any amount of hazardous and acute hazardous waste into sewage treatment plants.) There are over 80,000 chemicals in commerce and growing even today. It ends up in biosolids which is broadcasted over forest, farms and even bags taken to the consumers home
    • **US EPA Office Inspector General (OIG) puts out Report # 14-P-0363 in 09/2014
    • Google and read it for yourself. To sum up, industrial pre-treatment is not
    working and has never worked and nothing has been done about it. It ends up in
    biosolids and sewage plant effluent.
    • So when you hear anyone from the multi-billion dollar sewage industry or anyone with monetary ties to any part of the sewage industry says the chemicals in biosolids are minimal and inconsequential or that they support composting with biosolids, ask them for any test showing the degree of hazard and concentrations of 80,000 chemicals that are found in biosolids or a composted biosolids.
    • Chemicals that are persistent in the environment, bio-accumulate in people and/or wildlife, and are toxic are called PBTs and neurotoxins such as microcystin (a hemotoxin), phycotoxins, domoic acid, brevetoxin. Because of these features, as long as they remain in commerce and may therefore be released into the environment, they will threaten the health of humans, wildlife including aquatic life.
    • Did I mention sewage sludge or biosolids spread on farms is loaded with unregulated phosphates. The main ingredient in proliferating algae.
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