Remediation of Soil Containing Sludge Generated by Printed Circuit Board Production and Electroplating

Abstract

This paper examines the environmental conditions at the premises of printed circuit boards (PCBs) manufacturers, which have electroplating plants. It provides a brief overview of the key aspects of adverse environmental impacts of wastes generated by PCB manufacture and electroplating plants. The aim of this research was to improve the test method for evaluation of wastewater effect on the soil salinity at the premises of PCBs manufacturers. The object of research was the process of extraction and use of copper from wastewater generated by PCBs manufacture and electroplating. As an example, the process of sludge formation during PCBs etching has been reviewed. With the etching line capacity of 14 m2/h, one-shift manufacturing process will result in the production of up to 2,500 kg of sludge monthly. For enterprises with capacities of 2,000–4,000 m2 circuits, this means annual accumulation at their premises of up to 70 tons of wastes in the form of sludge. Estimates suggest that the upper half-meter layer of the aeration zone will be qualified as slightly saline in one year after accumulation of the sludge. In subsequent years, the salt content will increase and saline soil can be found at the depths of 1.5–2 m over ten years of storage. The authors of this paper propose to treat spent etching solutions applying regeneration technology in order to reduce the amount of sludge. With this technology, it is possible to use the extracted metal as a secondary raw material for copper production and re-use the regenerated solution in PCBs etching. This paper provides estimated hazard indices calculated for the storage of sludge at the manufacturer’s premises before and after the implementation of the proposed technology. With regards to findings of the study, it has been proposed to reuse copper recovered from wastes as a raw material for the industry.

Method for predicting the dissemination of hazardous substances in the soil during long-term storage of galvanic waste

“…The research methodology is based on the use of the theory of physical-chemical hydrodynamics of porous media. The process of motion of metal salts can be described by the differential equation of motion and conservation of mass of matter for vertical mass transfer of matter [21]. The presence of sludge on the soil surface corresponds to the boundary condition of the first kind:…”

Regenerating Etching Solutions for Circuit Boards while Extracting Copper

“…It is noteworthy to highlight specific studies that explore metal extraction alongside solution regeneration (Trokhymenko et al, 2020;Nester et al, 2020).…”