highly significantp < 0.001
The coefficient is negative and highly significant (β = −0.220, p < 0.001).
The coefficient is negative and highly significant (β = −0.220, p < 0.001).
The positive effect of wastewater treatment remained significant (β = 0.158, p < 0.05), whereas the coefficient of ammonia nitrogen emissions became weaker and marginally significant (β = −0.132, p < 0.10).